The URL can be used to link to this page

Home My WebLink About1.00 General Application Materials_Part 9AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 54 Please see the following pages for the Determination of No Hazard to Air Navigation from the Federal Aviation Administration for AES Eagle Springs Organic Solar, LLC published in September 2022. FAA - DETERMINATION OF NO HAZARD TO AIR NAVIGATION Appendix C5 Mail Processing Center Federal Aviation Administration Southwest Regional Office Obstruction Evaluation Group 10101 Hillwood Parkway Fort Worth, TX 76177 Aeronautical Study No. 2022-ANM-5856-OE Page 1 of 4 Issued Date: 09/22/2022 Kat Kelly AES Clean Energy 282 Century pl #2000 Louisville, CO 80027 ** DETERMINATION OF NO HAZARD TO AIR NAVIGATION ** The Federal Aviation Administration has conducted an aeronautical study under the provisions of 49 U.S.C., Section 44718 and if applicable Title 14 of the Code of Federal Regulations, part 77, concerning: Structure: Solar Panel PV System Location: Silt, CO Latitude: 39-31-43.35N NAD 83 Longitude: 107-41-43.25W Heights:5610 feet site elevation (SE) 15 feet above ground level (AGL) 5625 feet above mean sea level (AMSL) This aeronautical study revealed that the structure does not exceed obstruction standards and would not be a hazard to air navigation provided the following condition(s), if any, is(are) met: It is required that FAA Form 7460-2, Notice of Actual Construction or Alteration, be e-filed any time the project is abandoned or: _____ At least 10 days prior to start of construction (7460-2, Part 1) __X__ Within 5 days after the construction reaches its greatest height (7460-2, Part 2) Based on this evaluation, marking and lighting are not necessary for aviation safety. However, if marking/ lighting are accomplished on a voluntary basis, we recommend it be installed in accordance with FAA Advisory circular 70/7460-1 M. This determination expires on 03/22/2024 unless: (a) the construction is started (not necessarily completed) and FAA Form 7460-2, Notice of Actual Construction or Alteration, is received by this office. (b) extended, revised, or terminated by the issuing office. (c) the construction is subject to the licensing authority of the Federal Communications Commission (FCC) and an application for a construction permit has been filed, as required by the FCC, within Page 2 of 4 6 months of the date of this determination. In such case, the determination expires on the date prescribed by the FCC for completion of construction, or the date the FCC denies the application. NOTE: REQUEST FOR EXTENSION OF THE EFFECTIVE PERIOD OF THIS DETERMINATION MUST BE E-FILED AT LEAST 15 DAYS PRIOR TO THE EXPIRATION DATE. AFTER RE-EVALUATION OF CURRENT OPERATIONS IN THE AREA OF THE STRUCTURE TO DETERMINE THAT NO SIGNIFICANT AERONAUTICAL CHANGES HAVE OCCURRED, YOUR DETERMINATION MAY BE ELIGIBLE FOR ONE EXTENSION OF THE EFFECTIVE PERIOD. This determination is based, in part, on the foregoing description which includes specific coordinates, heights, frequency(ies) and power. Any changes in coordinates, heights, and frequencies or use of greater power, except those frequencies specified in the Colo Void Clause Coalition; Antenna System Co-Location; Voluntary Best Practices, effective 21 Nov 2007, will void this determination. Any future construction or alteration, including increase to heights, power, or the addition of other transmitters, requires separate notice to the FAA.This determination includes all previously filed frequencies and power for this structure. If construction or alteration is dismantled or destroyed, you must submit notice to the FAA within 5 days after the construction or alteration is dismantled or destroyed. This determination does include temporary construction equipment such as cranes, derricks, etc., which may be used during actual construction of the structure. However, this equipment shall not exceed the overall heights as indicated above. Equipment which has a height greater than the studied structure requires separate notice to the FAA. This determination concerns the effect of this structure on the safe and efficient use of navigable airspace by aircraft and does not relieve the sponsor of compliance responsibilities relating to any law, ordinance, or regulation of any Federal, State, or local government body. If we can be of further assistance, please contact our office at (206) 231-2990, or paul.holmquist@faa.gov. On any future correspondence concerning this matter, please refer to Aeronautical Study Number 2022- ANM-5856-OE. Signature Control No: 544150339-554213186 ( DNE ) Paul Holmquist Specialist Attachment(s) Map(s) Page 3 of 4 TOPO Map for ASN 2022-ANM-5856-OE Page 4 of 4 Sectional Map for ASN 2022-ANM-5856-OE Mail Processing Center Federal Aviation Administration Southwest Regional Office Obstruction Evaluation Group 10101 Hillwood Parkway Fort Worth, TX 76177 Aeronautical Study No. 2022-ANM-5853-OE Page 1 of 4 Issued Date: 09/22/2022 Kat Kelly AES Clean Energy 282 Century pl #2000 Louisville, CO 80027 ** DETERMINATION OF NO HAZARD TO AIR NAVIGATION ** The Federal Aviation Administration has conducted an aeronautical study under the provisions of 49 U.S.C., Section 44718 and if applicable Title 14 of the Code of Federal Regulations, part 77, concerning: Structure: Solar Panel PV System Location: Silt, CO Latitude: 39-31-38.49N NAD 83 Longitude: 107-42-14.04W Heights:5560 feet site elevation (SE) 15 feet above ground level (AGL) 5575 feet above mean sea level (AMSL) This aeronautical study revealed that the structure does not exceed obstruction standards and would not be a hazard to air navigation provided the following condition(s), if any, is(are) met: It is required that FAA Form 7460-2, Notice of Actual Construction or Alteration, be e-filed any time the project is abandoned or: _____ At least 10 days prior to start of construction (7460-2, Part 1) __X__ Within 5 days after the construction reaches its greatest height (7460-2, Part 2) Based on this evaluation, marking and lighting are not necessary for aviation safety. However, if marking/ lighting are accomplished on a voluntary basis, we recommend it be installed in accordance with FAA Advisory circular 70/7460-1 M. This determination expires on 03/22/2024 unless: (a) the construction is started (not necessarily completed) and FAA Form 7460-2, Notice of Actual Construction or Alteration, is received by this office. (b) extended, revised, or terminated by the issuing office. (c) the construction is subject to the licensing authority of the Federal Communications Commission (FCC) and an application for a construction permit has been filed, as required by the FCC, within Page 2 of 4 6 months of the date of this determination. In such case, the determination expires on the date prescribed by the FCC for completion of construction, or the date the FCC denies the application. NOTE: REQUEST FOR EXTENSION OF THE EFFECTIVE PERIOD OF THIS DETERMINATION MUST BE E-FILED AT LEAST 15 DAYS PRIOR TO THE EXPIRATION DATE. AFTER RE-EVALUATION OF CURRENT OPERATIONS IN THE AREA OF THE STRUCTURE TO DETERMINE THAT NO SIGNIFICANT AERONAUTICAL CHANGES HAVE OCCURRED, YOUR DETERMINATION MAY BE ELIGIBLE FOR ONE EXTENSION OF THE EFFECTIVE PERIOD. This determination is based, in part, on the foregoing description which includes specific coordinates, heights, frequency(ies) and power. Any changes in coordinates, heights, and frequencies or use of greater power, except those frequencies specified in the Colo Void Clause Coalition; Antenna System Co-Location; Voluntary Best Practices, effective 21 Nov 2007, will void this determination. Any future construction or alteration, including increase to heights, power, or the addition of other transmitters, requires separate notice to the FAA.This determination includes all previously filed frequencies and power for this structure. If construction or alteration is dismantled or destroyed, you must submit notice to the FAA within 5 days after the construction or alteration is dismantled or destroyed. This determination does include temporary construction equipment such as cranes, derricks, etc., which may be used during actual construction of the structure. However, this equipment shall not exceed the overall heights as indicated above. Equipment which has a height greater than the studied structure requires separate notice to the FAA. This determination concerns the effect of this structure on the safe and efficient use of navigable airspace by aircraft and does not relieve the sponsor of compliance responsibilities relating to any law, ordinance, or regulation of any Federal, State, or local government body. If we can be of further assistance, please contact our office at (206) 231-2990, or paul.holmquist@faa.gov. On any future correspondence concerning this matter, please refer to Aeronautical Study Number 2022- ANM-5853-OE. Signature Control No: 544150336-554213187 ( DNE ) Paul Holmquist Specialist Attachment(s) Map(s) Page 3 of 4 TOPO Map for ASN 2022-ANM-5853-OE Page 4 of 4 Sectional Map for ASN 2022-ANM-5853-OE Mail Processing Center Federal Aviation Administration Southwest Regional Office Obstruction Evaluation Group 10101 Hillwood Parkway Fort Worth, TX 76177 Aeronautical Study No. 2022-ANM-5855-OE Page 1 of 4 Issued Date: 09/22/2022 Kat Kelly AES Clean Energy 282 Century pl #2000 Louisville, CO 80027 ** DETERMINATION OF NO HAZARD TO AIR NAVIGATION ** The Federal Aviation Administration has conducted an aeronautical study under the provisions of 49 U.S.C., Section 44718 and if applicable Title 14 of the Code of Federal Regulations, part 77, concerning: Structure: Solar Panel PV System Location: Silt, CO Latitude: 39-31-17.21N NAD 83 Longitude: 107-41-42.60W Heights:5660 feet site elevation (SE) 15 feet above ground level (AGL) 5675 feet above mean sea level (AMSL) This aeronautical study revealed that the structure does not exceed obstruction standards and would not be a hazard to air navigation provided the following condition(s), if any, is(are) met: It is required that FAA Form 7460-2, Notice of Actual Construction or Alteration, be e-filed any time the project is abandoned or: _____ At least 10 days prior to start of construction (7460-2, Part 1) __X__ Within 5 days after the construction reaches its greatest height (7460-2, Part 2) Based on this evaluation, marking and lighting are not necessary for aviation safety. However, if marking/ lighting are accomplished on a voluntary basis, we recommend it be installed in accordance with FAA Advisory circular 70/7460-1 M. This determination expires on 03/22/2024 unless: (a) the construction is started (not necessarily completed) and FAA Form 7460-2, Notice of Actual Construction or Alteration, is received by this office. (b) extended, revised, or terminated by the issuing office. (c) the construction is subject to the licensing authority of the Federal Communications Commission (FCC) and an application for a construction permit has been filed, as required by the FCC, within Page 2 of 4 6 months of the date of this determination. In such case, the determination expires on the date prescribed by the FCC for completion of construction, or the date the FCC denies the application. NOTE: REQUEST FOR EXTENSION OF THE EFFECTIVE PERIOD OF THIS DETERMINATION MUST BE E-FILED AT LEAST 15 DAYS PRIOR TO THE EXPIRATION DATE. AFTER RE-EVALUATION OF CURRENT OPERATIONS IN THE AREA OF THE STRUCTURE TO DETERMINE THAT NO SIGNIFICANT AERONAUTICAL CHANGES HAVE OCCURRED, YOUR DETERMINATION MAY BE ELIGIBLE FOR ONE EXTENSION OF THE EFFECTIVE PERIOD. This determination is based, in part, on the foregoing description which includes specific coordinates, heights, frequency(ies) and power. Any changes in coordinates, heights, and frequencies or use of greater power, except those frequencies specified in the Colo Void Clause Coalition; Antenna System Co-Location; Voluntary Best Practices, effective 21 Nov 2007, will void this determination. Any future construction or alteration, including increase to heights, power, or the addition of other transmitters, requires separate notice to the FAA.This determination includes all previously filed frequencies and power for this structure. If construction or alteration is dismantled or destroyed, you must submit notice to the FAA within 5 days after the construction or alteration is dismantled or destroyed. This determination does include temporary construction equipment such as cranes, derricks, etc., which may be used during actual construction of the structure. However, this equipment shall not exceed the overall heights as indicated above. Equipment which has a height greater than the studied structure requires separate notice to the FAA. This determination concerns the effect of this structure on the safe and efficient use of navigable airspace by aircraft and does not relieve the sponsor of compliance responsibilities relating to any law, ordinance, or regulation of any Federal, State, or local government body. If we can be of further assistance, please contact our office at (206) 231-2990, or paul.holmquist@faa.gov. On any future correspondence concerning this matter, please refer to Aeronautical Study Number 2022- ANM-5855-OE. Signature Control No: 544150338-554213188 ( DNE ) Paul Holmquist Specialist Attachment(s) Map(s) Page 3 of 4 TOPO Map for ASN 2022-ANM-5855-OE Page 4 of 4 Sectional Map for ASN 2022-ANM-5855-OE Mail Processing Center Federal Aviation Administration Southwest Regional Office Obstruction Evaluation Group 10101 Hillwood Parkway Fort Worth, TX 76177 Aeronautical Study No. 2022-ANM-5854-OE Page 1 of 4 Issued Date: 09/22/2022 Kat Kelly AES Clean Energy 282 Century pl #2000 Louisville, CO 80027 ** DETERMINATION OF NO HAZARD TO AIR NAVIGATION ** The Federal Aviation Administration has conducted an aeronautical study under the provisions of 49 U.S.C., Section 44718 and if applicable Title 14 of the Code of Federal Regulations, part 77, concerning: Structure: Solar Panel PV System Location: Silt, CO Latitude: 39-31-47.47N NAD 83 Longitude: 107-42-18.81W Heights:5540 feet site elevation (SE) 15 feet above ground level (AGL) 5555 feet above mean sea level (AMSL) This aeronautical study revealed that the structure does not exceed obstruction standards and would not be a hazard to air navigation provided the following condition(s), if any, is(are) met: It is required that FAA Form 7460-2, Notice of Actual Construction or Alteration, be e-filed any time the project is abandoned or: _____ At least 10 days prior to start of construction (7460-2, Part 1) __X__ Within 5 days after the construction reaches its greatest height (7460-2, Part 2) Based on this evaluation, marking and lighting are not necessary for aviation safety. However, if marking/ lighting are accomplished on a voluntary basis, we recommend it be installed in accordance with FAA Advisory circular 70/7460-1 M. This determination expires on 03/22/2024 unless: (a) the construction is started (not necessarily completed) and FAA Form 7460-2, Notice of Actual Construction or Alteration, is received by this office. (b) extended, revised, or terminated by the issuing office. (c) the construction is subject to the licensing authority of the Federal Communications Commission (FCC) and an application for a construction permit has been filed, as required by the FCC, within Page 2 of 4 6 months of the date of this determination. In such case, the determination expires on the date prescribed by the FCC for completion of construction, or the date the FCC denies the application. NOTE: REQUEST FOR EXTENSION OF THE EFFECTIVE PERIOD OF THIS DETERMINATION MUST BE E-FILED AT LEAST 15 DAYS PRIOR TO THE EXPIRATION DATE. AFTER RE-EVALUATION OF CURRENT OPERATIONS IN THE AREA OF THE STRUCTURE TO DETERMINE THAT NO SIGNIFICANT AERONAUTICAL CHANGES HAVE OCCURRED, YOUR DETERMINATION MAY BE ELIGIBLE FOR ONE EXTENSION OF THE EFFECTIVE PERIOD. This determination is based, in part, on the foregoing description which includes specific coordinates, heights, frequency(ies) and power. Any changes in coordinates, heights, and frequencies or use of greater power, except those frequencies specified in the Colo Void Clause Coalition; Antenna System Co-Location; Voluntary Best Practices, effective 21 Nov 2007, will void this determination. Any future construction or alteration, including increase to heights, power, or the addition of other transmitters, requires separate notice to the FAA.This determination includes all previously filed frequencies and power for this structure. If construction or alteration is dismantled or destroyed, you must submit notice to the FAA within 5 days after the construction or alteration is dismantled or destroyed. This determination does include temporary construction equipment such as cranes, derricks, etc., which may be used during actual construction of the structure. However, this equipment shall not exceed the overall heights as indicated above. Equipment which has a height greater than the studied structure requires separate notice to the FAA. This determination concerns the effect of this structure on the safe and efficient use of navigable airspace by aircraft and does not relieve the sponsor of compliance responsibilities relating to any law, ordinance, or regulation of any Federal, State, or local government body. If we can be of further assistance, please contact our office at (206) 231-2990, or paul.holmquist@faa.gov. On any future correspondence concerning this matter, please refer to Aeronautical Study Number 2022- ANM-5854-OE. Signature Control No: 544150337-554213189 ( DNE ) Paul Holmquist Specialist Attachment(s) Map(s) Page 3 of 4 TOPO Map for ASN 2022-ANM-5854-OE Page 4 of 4 Sectional Map for ASN 2022-ANM-5854-OE Mail Processing Center Federal Aviation Administration Southwest Regional Office Obstruction Evaluation Group 10101 Hillwood Parkway Fort Worth, TX 76177 Aeronautical Study No. 2022-ANM-5852-OE Page 1 of 4 Issued Date: 09/22/2022 Kat Kelly AES Clean Energy 282 Century pl #2000 Louisville, CO 80027 ** DETERMINATION OF NO HAZARD TO AIR NAVIGATION ** The Federal Aviation Administration has conducted an aeronautical study under the provisions of 49 U.S.C., Section 44718 and if applicable Title 14 of the Code of Federal Regulations, part 77, concerning: Structure: Solar Panel PV System Location: Silt, CO Latitude: 39-31-44.89N NAD 83 Longitude: 107-42-22.82W Heights:5540 feet site elevation (SE) 15 feet above ground level (AGL) 5555 feet above mean sea level (AMSL) This aeronautical study revealed that the structure does not exceed obstruction standards and would not be a hazard to air navigation provided the following condition(s), if any, is(are) met: It is required that FAA Form 7460-2, Notice of Actual Construction or Alteration, be e-filed any time the project is abandoned or: _____ At least 10 days prior to start of construction (7460-2, Part 1) __X__ Within 5 days after the construction reaches its greatest height (7460-2, Part 2) Based on this evaluation, marking and lighting are not necessary for aviation safety. However, if marking/ lighting are accomplished on a voluntary basis, we recommend it be installed in accordance with FAA Advisory circular 70/7460-1 M. This determination expires on 03/22/2024 unless: (a) the construction is started (not necessarily completed) and FAA Form 7460-2, Notice of Actual Construction or Alteration, is received by this office. (b) extended, revised, or terminated by the issuing office. (c) the construction is subject to the licensing authority of the Federal Communications Commission (FCC) and an application for a construction permit has been filed, as required by the FCC, within Page 2 of 4 6 months of the date of this determination. In such case, the determination expires on the date prescribed by the FCC for completion of construction, or the date the FCC denies the application. NOTE: REQUEST FOR EXTENSION OF THE EFFECTIVE PERIOD OF THIS DETERMINATION MUST BE E-FILED AT LEAST 15 DAYS PRIOR TO THE EXPIRATION DATE. AFTER RE-EVALUATION OF CURRENT OPERATIONS IN THE AREA OF THE STRUCTURE TO DETERMINE THAT NO SIGNIFICANT AERONAUTICAL CHANGES HAVE OCCURRED, YOUR DETERMINATION MAY BE ELIGIBLE FOR ONE EXTENSION OF THE EFFECTIVE PERIOD. This determination is based, in part, on the foregoing description which includes specific coordinates, heights, frequency(ies) and power. Any changes in coordinates, heights, and frequencies or use of greater power, except those frequencies specified in the Colo Void Clause Coalition; Antenna System Co-Location; Voluntary Best Practices, effective 21 Nov 2007, will void this determination. Any future construction or alteration, including increase to heights, power, or the addition of other transmitters, requires separate notice to the FAA.This determination includes all previously filed frequencies and power for this structure. If construction or alteration is dismantled or destroyed, you must submit notice to the FAA within 5 days after the construction or alteration is dismantled or destroyed. This determination does include temporary construction equipment such as cranes, derricks, etc., which may be used during actual construction of the structure. However, this equipment shall not exceed the overall heights as indicated above. Equipment which has a height greater than the studied structure requires separate notice to the FAA. This determination concerns the effect of this structure on the safe and efficient use of navigable airspace by aircraft and does not relieve the sponsor of compliance responsibilities relating to any law, ordinance, or regulation of any Federal, State, or local government body. If we can be of further assistance, please contact our office at (206) 231-2990, or paul.holmquist@faa.gov. On any future correspondence concerning this matter, please refer to Aeronautical Study Number 2022- ANM-5852-OE. Signature Control No: 544150335-554213190 ( DNE ) Paul Holmquist Specialist Attachment(s) Map(s) Page 3 of 4 TOPO Map for ASN 2022-ANM-5852-OE Page 4 of 4 Sectional Map for ASN 2022-ANM-5852-OE Mail Processing Center Federal Aviation Administration Southwest Regional Office Obstruction Evaluation Group 10101 Hillwood Parkway Fort Worth, TX 76177 Aeronautical Study No. 2022-ANM-5851-OE Page 1 of 4 Issued Date: 09/22/2022 Kat Kelly AES Clean Energy 282 Century pl #2000 Louisville, CO 80027 ** DETERMINATION OF NO HAZARD TO AIR NAVIGATION ** The Federal Aviation Administration has conducted an aeronautical study under the provisions of 49 U.S.C., Section 44718 and if applicable Title 14 of the Code of Federal Regulations, part 77, concerning: Structure: Solar Panel PV System Location: Silt, CO Latitude: 39-31-35.35N NAD 83 Longitude: 107-41-57.30W Heights:5595 feet site elevation (SE) 15 feet above ground level (AGL) 5610 feet above mean sea level (AMSL) This aeronautical study revealed that the structure does not exceed obstruction standards and would not be a hazard to air navigation provided the following condition(s), if any, is(are) met: It is required that FAA Form 7460-2, Notice of Actual Construction or Alteration, be e-filed any time the project is abandoned or: _____ At least 10 days prior to start of construction (7460-2, Part 1) __X__ Within 5 days after the construction reaches its greatest height (7460-2, Part 2) Based on this evaluation, marking and lighting are not necessary for aviation safety. However, if marking/ lighting are accomplished on a voluntary basis, we recommend it be installed in accordance with FAA Advisory circular 70/7460-1 M. This determination expires on 03/22/2024 unless: (a) the construction is started (not necessarily completed) and FAA Form 7460-2, Notice of Actual Construction or Alteration, is received by this office. (b) extended, revised, or terminated by the issuing office. (c) the construction is subject to the licensing authority of the Federal Communications Commission (FCC) and an application for a construction permit has been filed, as required by the FCC, within Page 2 of 4 6 months of the date of this determination. In such case, the determination expires on the date prescribed by the FCC for completion of construction, or the date the FCC denies the application. NOTE: REQUEST FOR EXTENSION OF THE EFFECTIVE PERIOD OF THIS DETERMINATION MUST BE E-FILED AT LEAST 15 DAYS PRIOR TO THE EXPIRATION DATE. AFTER RE-EVALUATION OF CURRENT OPERATIONS IN THE AREA OF THE STRUCTURE TO DETERMINE THAT NO SIGNIFICANT AERONAUTICAL CHANGES HAVE OCCURRED, YOUR DETERMINATION MAY BE ELIGIBLE FOR ONE EXTENSION OF THE EFFECTIVE PERIOD. This determination is based, in part, on the foregoing description which includes specific coordinates, heights, frequency(ies) and power. Any changes in coordinates, heights, and frequencies or use of greater power, except those frequencies specified in the Colo Void Clause Coalition; Antenna System Co-Location; Voluntary Best Practices, effective 21 Nov 2007, will void this determination. Any future construction or alteration, including increase to heights, power, or the addition of other transmitters, requires separate notice to the FAA.This determination includes all previously filed frequencies and power for this structure. If construction or alteration is dismantled or destroyed, you must submit notice to the FAA within 5 days after the construction or alteration is dismantled or destroyed. This determination does include temporary construction equipment such as cranes, derricks, etc., which may be used during actual construction of the structure. However, this equipment shall not exceed the overall heights as indicated above. Equipment which has a height greater than the studied structure requires separate notice to the FAA. This determination concerns the effect of this structure on the safe and efficient use of navigable airspace by aircraft and does not relieve the sponsor of compliance responsibilities relating to any law, ordinance, or regulation of any Federal, State, or local government body. If we can be of further assistance, please contact our office at (206) 231-2990, or paul.holmquist@faa.gov. On any future correspondence concerning this matter, please refer to Aeronautical Study Number 2022- ANM-5851-OE. Signature Control No: 544150334-554213191 ( DNE ) Paul Holmquist Specialist Attachment(s) Map(s) Page 3 of 4 TOPO Map for ASN 2022-ANM-5851-OE Page 4 of 4 Sectional Map for ASN 2022-ANM-5851-OE AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 55 Please see the following pages for the Stormwater Memo prepared by NEI Engineering for AES Eagle Springs Organic Solar published in March 2023. STORMWATER MEMO Appendix C6 neiengineering.com + 303-431-7895 12600 W Colfax Avenue, Suite C500, Lakewood, CO 80215 To: Joshua Mayer AES Clean Energy The AES Corporation 282 Century Place, Suite 2000 Louisville, CO 80027 From: NEI Electric Power Engineering, Inc. 12600 W Colfax Avenue, Suite C500 Lakewood, CO 80215 Date: March 22, 2023 Project Name: Eagle Springs Solar Project No.: 4084.001 Subject: Stormwater Memo (30% Review) Eagle Springs Solar is a proposed solar facility located near County Road 315 and 346, Garfield County, approximately 1 mile east of the Rifle Garfield County Airport. Disturbed area of this project will be limited to approximately 78.5 acres of the 301-acre lot. The project is expected to change approximately 58,583 sq-ft (1.34 ac; 1.71% lot coverage) of pervious area into impervious area. The impervious area will consist of four (4) concrete equipment pads, two (2) gravel access roads, and foundations for solar arrays. Onsite drainage patterns will be maintained with exception to minor grading related to proposed gravel roads; there a Drainage Report is not required per county standards. This memo is intended to provide Garfield County with drainage and land disturbance information with respect to this project. Existing Conditions The project site is mostly developed agricultural fields throughout the property. The undeveloped land cover consists of agriculture fallow, native vegetation, sparse weeds and grasses. The topography consists of rolling hills, plains and mesas. The existing soils on site are primarily type C. The site generally drains from southeast to northwest atop a mesa with approximately 160 ft of topographic relief. Stormwater runoff sheet flows northwest and AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. ii collects in dispersed ephemeral ditches. These ditches convey flow northwest into an approximately 1.8 ac. detention basin. This basin discharges to the Last Chance Ditch, thence into Mamm Creek, thence into the Colorado River approximately 1.0 mile northwest of the project site. Proposed Conditions Construction activities associated with the proposed solar facility will affect approximately 78.5 acres onsite. However, much of the disturbed area will involve construction of support structures for solar panel arrays, leaving the surface beneath the panels undeveloped and pervious. These solar arrays are not expected to result in a significant creation of impervious area. The project also proposes four (4) concrete equipment pads, an integrated switch gear pad, and gravel access roads. In total, the project will result in the generation of approximately 58,583 sf of impervious area which covers 1.71% of the project site. Grading activities will be localized around the gravel access road and existing drainage patterns will be maintained. Impervious Area Calculations Quantity Area (ft2) Impervious Factor Impervious Area (ft2) Equipment Pads 3 7,920 1.0 23,760 Equipment Pad with Switchgear 1 11,991 1.0 11,991 Array Piles 3,705 ~0.037 1.0 139 Gravel Access Road 1 56,733 0.4 22,693 Total Area (ft2) 58,583 Total LOD (ft2) 3,417,895 Coverage Ratio 1.71% A gravel access road will cross existing stormwater conveyances; therefore, the project also proposes one (1) culvert, which will be discussed below. Stormwater Management Strategy Stormwater Management (treatment & detention) are not required because the proposed impervious area is not expected to significantly alter stormwater quality and quantity and existing drainage patterns are maintained. Using a grass seed mix to restore all areas of disturbance, stormwater quality will be improved through a native seed mix. The mix will also decrease the quantity of stormwater runoff previously experienced on site. Flood Zone The project site would be reported on Flood Insurance Rate Map (FIRM) community panel 0802051360B. Currently the panel is not printed, and flood hazard areas are unidentified. However, the project site is approximately 160 and 130 ft above the intermittent creeks to the north and west, respectively. Therefore, this project is not expected to be negatively impacted, nor negatively impact these creeks. AES Clean Energy Eagle Springs Solar STORMWATER MANAGEMENT PLAN p. iii Culvert Design This project proposes an access road which intersects an existing drainage ditch. This crossing requires a culvert to maintain drainage through the site. The culverts are designed to convey the 25-yr peak flow from their contributing drainage basin. The 25-yr storm event (4% annual exceedance probability) is the typical design storm for stormwater conveyances per the County’s Land Use & Development Code (2013). The UDFCD’s modified rational method, an allowable reference per CDOT’s Drainage Design Manual (DDM, 2019), was used to quantify the 25-yr peak flow for each culvert’s contributing drainage basin. The following equation is referenced: Q25 =C25 ∙ I25 ∙ A Where Q25 is the 25-yr peak flow (cfs), A is the contributing drainage area (acres), I25 is the rainfall intensity in inches per hour for a duration equal to the time of concentration, and C25 is the runoff coefficient from equations based on NRCS soil groups and storm return period. For soil groups C/D, the runoff coefficient was determined from the equation: CC/D = 0.56i + 0.319 (i = % Imperviousness expressed as a decimal) The runoff coefficient, C, used was 0.33 and the rainfall intensity, I, used was 0.502 inches per Hour with a basin Tc of 2 hours. Rainfall depth was derived from “NOAA ATLAS 14 POINT PRECIPITATION FREQUENCY ESTIMATES”. Existing culverts are constructed of CMP, proposed culverts are to be RCP, which both have a roughness coefficient (n) of 0.012 per the DDM. The results of the hydraulics calculations are shown in Table 1 below. Table 1 – Culvert Sizing Results Summary The project proposes 1.34 ac of impervious area, which consists of concrete equipment pads, gravel access roads, and foundations for solar arrays. This impervious area constitutes 1.71% of the solar development area. The project will not alter existing drainage patterns, thus does not require a drainage report. The proposed access roads will require the installation of one (1) culvert. Initial sizing has been provided and will be refined as the site design develops. Attachments • Hydrology Basin Exhibit WWWWWWWWWWWWW WWWWWW W W WWW DRAINAGEBASIN 1(33.08 AC.)DRAINAGEBASIN 2(0.69 AC.)DATEPROJECT TITLE:DESCRIPTIONAPV:PROJECT LOCATION:NO.KEY PLAN:PE STAMP:REVISIONS:SHEET NO:REV:SCALE AT 24" x 36":CHK:DWN:DES:DATE:PROJNUM:SHEET TITLE & DESCRIPTION:2180 South 1300 East, Suite 600Salt Lake City, UT 84106-2749(801) 679 - 3500ELECTRIC POWER ENGINEERING, INC.12600 W. COLFAX AVE, STE. C500LAKEWOOD, CO 80215(303) 431-7895 www.neieng.com0 100' 200' 300' 400'1" = 200'A 3/29/23 HYDROLOGY_BASIN_EXHIBIT- - -- - -- - --PLOTTED: 3/29/2023 12:53 PMH:\Project\4000\4084.001 Eagle Springs PV_BESS_30 PCT PV_BESS_AES\4_DWGs\2_NEI\Solar\PV CIV\Stormwater Memo Exhibit\DRAINAGE MEMO EXHIBIT.dwg - -- - -- - -- - -JPD03/16/2023EX-1.0 A4084.001JJSJJSJPDAES Titleblock 24X36 v210209PRELIMINARYNOT FOR CONSTRUCTIONFOR REVIEW & APPROVAL ONLY200' 100' 0200' 400' 600'1"=200'NLEGEND:MODULE BUILDABLE AREAPARCEL BOUNDARYFENCE SETBACK LINELoDLIMIT OF DISTURBANCEIRRIGATION LINESFENCE SETBACK LINEWOVERHEAD POWER LINESOHEDRAINAGE BASINHYDROLOGY BASINEXHIBITSILT, COHYDROLOGY BASINEXHIBITCIVIL AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 56 Please see the following pages for proof of receipt from the Colorado Department of Health and Environment a Stormwater Management Plan prepared by NEI Engineering for AES Eagle Springs Organic Solar, LLC and submitted to CDPHE on April 6th, 2023. The full stormwater management plan will be provided as separate addenda to this application given its size. STORMWATER MANAGEMENT PLAN – RECEIPT OF SUBMISSION TO CDPHE Appendix C6a A. PERMIT INFORMATION Reason for Application þ NEW CERT ¨RENEW CERT ¨MODIFICATION ¨TRANSFER ¨CHANGE OF CONTACT ¨TERMINATION Existing Cert # B. PERMITTED PROJECT/FACILITY INFORMATION Facility Name:Eagle Springs Organic Solar, LLC Original ID: Property Address 1:315 Country Road Property Address 2:County:Garfield City:silt State:CO Zip Code:81652 Latitude :39.5225 Longitude :-107.6953 SIC Code Description 1542 Nonresidential construction, nec C. CONTACT INFORMATION 1) *OPERATOR – RESPONSIBLE OFFICIAL - the party that has operation control over day to day activities – may be the same as the Owner Receiving Water Name Receiving Water Type Last Chance Ditch Immediate Colorado River Ultimate ASSIGNED PERMIT NUMBER Date Received 04/06/2023 08:06:19 MM DD YYYY HH:MM:SS Revised: 3-2016 STORMWATER DISCHARGE ASSOCIATED WITH CONSTRUCTION ACTIVITIES APPLICATION COLORADO DISCHARGE PERMIT SYSTEM (CDPS) PHOTO COPIES, FAXED COPIES, PDF COPIES OR EMAILS WILL NOT BE ACCEPTED. Any additional information that you would like the Division to consider in developing the permit should be provided with the application. Examples include effluent data and/or modeling and planned pollutant removal strategies. Beginning July 1, 2016, invoices will be based on acres disturbed. DO NOT PAY THE FEES NOW – Invoices will be sent after the receipt of the application. Disturbed Acreage for this application (see page 4) ¨Less than 1 acre ($83 initial fee, $165 annual fee) ¨1-30 acres ($175 initial fee, $350 annual fee) ¨Greater than 30 acres ($270 initial fee, $540 annual fee) 1 OF 4 Responsible Person (Title): Authorized Representative First Name:David Last Name:Gomez Telephone No:720-951-3517 Email Address:david.gomez@aes.com Organization: AES Clean Energy Mailing Address:282 Century Pl Ste 2000 City:Louisville State:CO Zip Code:80027 2) *PROPERTY OWNER (CO-PERMITTEE) RESPONSIBLE OFFICIAL Responsible Person (Title): Authorized Representative First Name:David Last Name:Gomez Telephone No:720-951-3517 Email Address:david.gomez@aes.com Organization: AES Clean Energy Mailing Address:282 Century Pl Ste 2000 City:Louisville State:CO Zip Code:80027 3) *SITE CONTACT (local contact for questions relating to the facility & discharge authorized by this permit) Responsible Person (Title): AES Project Manager First Name:Elliot Last Name:Muse Telephone No:720-610-5231 Email Address:jay.muse@aes.com Organization: AES Clean Energy Mailing Address:282 Century Place, Suite 2000 City:Louisville State:CO Zip Code:80027 4) *BILLING CONTACT Responsible Person (Title): First Name:Last Name: Telephone No:Email Address:Organization: Mailing Address: City:State:CO Zip Code: 5) OTHER CONTACT TYPES Title First Name Last Name Phone Email Address City State Zip Contact Type Other 6) Former Permittee (transfer) Responsible Person (Title): First Name:Last Name: Email Address:Company: D. LEGAL DESCRIPTION Legal description: if subdivided, provide the legal description below, or indicate that it is not applicatable. Do not supply Township/Range/Section or metes and bounds description of the site. Subdivision(s): Lot(s):Block(s): OR ¨Not applicable (site has not been subdivided) ¨Facility additional description info E. AREA OF CONSTRUCTION SITE Total area of construction site 98.6 acres 2 OF 4 F. NATURE OF CONSTRUCTION ACTIVITY Check the appropriate box(s) or provide a brief description that indicates the general nature of the construction activities. (The full description of activities must be included in the Stormwater Management Plan.) ¨Commercial Development ¨Residential Development ¨Highway and Transportation Development ¨Pipeline and Utilities (including natural gas, electricity, water, and communications) ¨Oil and Gas Exploration and Well Pad Development ¨Non-structural and other development (i.e. parks, trails, stream realignment, bank stabilization, demolition, etc.) þ Other Solar Generation Facility G. ANTICIPATED CONSTRUCTION SCHEDULE Construction Start Date:10/16/2023 Final Stabilization Date:7/10/2025 • Construction Start Date - This is the day you expect to begin ground disturbing activities, including grubbing, stockpiling, excavating, demolition, and grading activities. • Final Stabilization Date - in terms of permit coverage, this is when he site is finally stabilized. This means that all ground surface disturbing activities at the site have been completed and all disturbed areas have either been built on, paved, or a uniform vegetative cover has been established with an individual plant density of at least 70 percent of pre-disturbance levels. • Permit coverage must be maintained until the site is finally stabilized. Even if you are only doing one part of the project, the estimated final stabilization date must be for the overall project. If permit coverage is still required once your part is completed, the permit certification may be transferred to a new responsible operator. SIGNATURE REQUIREMENTS: TERMINATION CERTIFICATION ¨By checking this box I understand that by submitting this notice of termination, I am no longer authorized to discharge stormwater associated with construction activity by the general permit. I understand that discharging pollutants in stormwater associated with construction activities to the waters of the State of Colorado, where such discharges are not authorized by a CDPS permit, is unlawful under the Colorado Water Quality Control Act and the Clean Water Act. þ STORMWATER MANAGEMENT PLAN CERTIFICATION (on new and renewals) By checking this box “I certify under penalty of law that a complete Stormwater Management Plan, has been/or will be completed, prior to the commencement of any construction activity. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the Stormwater Management Plan is/or will be, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for falsely certifying the completion of said SWMP, including the possibility of fine and imprisonment for knowing violations.” THIS PORTION OF THE SIGNATURE LANGUAGE IS REQUIRED ON ALL SUBMITTALS "I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is to the best of my knowledge and belief, true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations." “I understand that submittal of this application is for coverage under the State of Colorado General Permit for Stormwater Discharges Associated with Construction Activity for the entirety of the construction site/project described and applied for, until such time as the application is amended or the certification is transferred, inactivated, or expired.” Signature of Operator Date Signed Name (printed)Title Signature of Owner Date Signed Name (printed)Title Total area of project disturbance 78.4 acres 3 OF 4 Signature: The applicant must be either the owner and operator of the construction site. Refer to Part B of the instructions for additional information. The application must be signed by the applicant to be considered complete. In all cases, it shall be signed as follows: (Regulation 61.4 (1ei) a) In the case of corporations, by the responsible corporate officer is responsible for the overall operation of the facility from which the discharge described in the form originates b) In the case of a partnership, by a general partner. c) In the case of a sole proprietorship, by the proprietor. d) In the case of a municipal, state, or other public facility, by either a principal executive officer, ranking elected official, (a principal executive officer has responsibility for the overall operation of the facility from which the discharge originates). FORMER PERMITTEE used for transfers Signature (Legally Responsible Party)Date Name (printed)Title 4 OF 4 AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 57 Please see the following pages for the Forge Solar Glare Analysis for AES Eagle Springs Organic Solar, LLC conducted in February 2023. FORGESOLAR GLARE ANALYSIS Appendix C7 2/19/23, 9:16 PM 10MWac Site Config | ForgeSolar https://www.forgesolar.com/projects/14968/configs/84753/1/10 Misc. Analysis Settings Summary of Results No glare predicted! PV Name Tilt Orientation "Green" Glare "Yellow" Glare Energy Produced deg deg min min kWh PV array 1 SA tracking SA tracking 0 0 - PV array 2 SA tracking SA tracking 0 0 - PV array 3 SA tracking SA tracking 0 0 - Eagle Springs Organic 10MWac Created Feb. 19, 2023 Updated Feb. 19, 2023 Time-step 1 minute Timezone offset UTC-7 Site ID 84753.14968 Project type Advanced Project status: active Category 5 MW to 10 MW DNI: varies (1,000.0 W/m^2 peak) Ocular transmission coefficient: 0.5 Pupil diameter: 0.002 m Eye focal length: 0.017 m Sun subtended angle: 9.3 mrad PV Analysis Methodology: Version 2 Enhanced subtended angle calculation: On ForgeSolar 2/19/23, 9:16 PM 10MWac Site Config | ForgeSolar https://www.forgesolar.com/projects/14968/configs/84753/2/10 Component Data 2/19/23, 9:16 PM 10MWac Site Config | ForgeSolar https://www.forgesolar.com/projects/14968/configs/84753/3/10 PV Array(s) Total PV footprint area: 48.5 acres Name: PV array 1 Footprint area: 26.9 acres Axis tracking: Single-axis rotation Backtracking: Shade-slope Tracking axis orientation: 180.0 deg Maximum tracking angle: 55.0 deg Resting angle: 5.0 deg Ground Coverage Ratio: 0.45 Rated power: - Panel material: Smooth glass with AR coating Vary reflectivity with sun position? Yes Correlate slope error with surface type? Yes Slope error: 8.43 mrad Vertex Latitude Longitude Ground elevation Height above ground Total elevation deg deg ft ft ft 1 39.525202 -107.695418 5627.14 5.00 5632.14 2 39.522281 -107.695246 5646.67 5.00 5651.67 3 39.522306 -107.697971 5628.65 5.00 5633.65 4 39.523249 -107.699806 5606.31 5.00 5611.31 5 39.524499 -107.699817 5601.50 5.00 5606.50 6 39.524731 -107.699634 5601.78 5.00 5606.78 7 39.524788 -107.698368 5612.97 5.00 5617.97 8 39.525153 -107.698390 5613.82 5.00 5618.82 Name: PV array 2 Footprint area: 3.6 acres Axis tracking: Single-axis rotation Backtracking: Shade-slope Tracking axis orientation: 180.0 deg Maximum tracking angle: 55.0 deg Resting angle: 5.0 deg Ground Coverage Ratio: 0.45 Rated power: - Panel material: Smooth glass with AR coating Vary reflectivity with sun position? Yes Correlate slope error with surface type? Yes Slope error: 8.43 mrad Vertex Latitude Longitude Ground elevation Height above ground Total elevation deg deg ft ft ft 1 39.526502 -107.699634 5589.87 5.00 5594.87 2 39.526526 -107.697199 5613.88 5.00 5618.88 3 39.526046 -107.697199 5615.25 5.00 5620.25 4 39.526063 -107.697499 5615.03 5.00 5620.03 5 39.525641 -107.697499 5616.38 5.00 5621.38 6 39.525649 -107.698561 5611.66 5.00 5616.66 7 39.526046 -107.698572 5605.29 5.00 5610.29 8 39.526063 -107.699613 5591.14 5.00 5596.14 2/19/23, 9:16 PM 10MWac Site Config | ForgeSolar https://www.forgesolar.com/projects/14968/configs/84753/4/10 2-Mile Flight Path Receptor(s) Name: PV array 3 Footprint area: 18.0 acres Axis tracking: Single-axis rotation Backtracking: Shade-slope Tracking axis orientation: 180.0 deg Maximum tracking angle: 55.0 deg Resting angle: 5.0 deg Ground Coverage Ratio: 0.45 Rated power: - Panel material: Smooth glass with AR coating Vary reflectivity with sun position? Yes Correlate slope error with surface type? Yes Slope error: 8.43 mrad Vertex Latitude Longitude Ground elevation Height above ground Total elevation deg deg ft ft ft 1 39.528759 -107.695999 5600.46 5.00 5605.46 2 39.528461 -107.695517 5610.92 5.00 5615.92 3 39.526996 -107.695506 5614.76 5.00 5619.76 4 39.526980 -107.696536 5610.15 5.00 5615.15 5 39.527344 -107.696568 5607.55 5.00 5612.55 6 39.527319 -107.696954 5604.60 5.00 5609.60 7 39.527021 -107.696944 5608.51 5.00 5613.51 8 39.526963 -107.699336 5588.31 5.00 5593.31 9 39.527394 -107.699347 5586.74 5.00 5591.74 10 39.527385 -107.699873 5582.84 5.00 5587.84 11 39.527013 -107.699894 5585.80 5.00 5590.80 12 39.526980 -107.701203 5570.93 5.00 5575.93 13 39.527981 -107.701235 5572.74 5.00 5577.74 14 39.528602 -107.700967 5573.48 5.00 5578.48 15 39.528610 -107.700549 5574.59 5.00 5579.59 16 39.527865 -107.700527 5577.78 5.00 5582.78 17 39.527725 -107.700248 5580.03 5.00 5585.03 18 39.527758 -107.698971 5587.39 5.00 5592.39 19 39.528585 -107.698703 5583.47 5.00 5588.47 20 39.528718 -107.698242 5585.17 5.00 5590.17 Name: FP 1 Description: Threshold height : 50 ft Direction: 268.0 deg Glide slope: 3.0 deg Pilot view restricted? Yes Vertical view restriction: 30.0 deg Azimuthal view restriction: 50.0 deg Point Latitude Longitude Ground elevation Height above ground Total elevation deg deg ft ft ft Threshold 39.526335 -107.741129 5462.58 50.00 5512.58 2-mile point 39.527369 -107.703625 5554.33 511.68 6066.01 2/19/23, 9:16 PM 10MWac Site Config | ForgeSolar https://www.forgesolar.com/projects/14968/configs/84753/5/10 Route Receptor(s) Name: 346 Route type Two-way View angle: 50.0 deg Vertex Latitude Longitude Ground elevation Height above ground Total elevation deg deg ft ft ft 1 39.530219 -107.687230 5440.63 5.00 5445.63 2 39.530240 -107.686678 5441.90 5.00 5446.90 3 39.530286 -107.686329 5440.39 5.00 5445.39 4 39.530906 -107.683153 5417.17 5.00 5422.17 5 39.531229 -107.681437 5418.57 5.00 5423.57 6 39.531308 -107.681329 5416.82 5.00 5421.82 7 39.531440 -107.681294 5414.13 5.00 5419.13 8 39.532133 -107.681302 5408.01 5.00 5413.01 Name: 346 Route type Two-way View angle: 50.0 deg Vertex Latitude Longitude Ground elevation Height above ground Total elevation deg deg ft ft ft 1 39.531070 -107.709608 5383.90 5.00 5388.90 2 39.531144 -107.708776 5382.20 5.00 5387.20 3 39.531463 -107.707124 5380.06 5.00 5385.06 4 39.531504 -107.706630 5379.84 5.00 5384.84 5 39.531347 -107.705804 5383.38 5.00 5388.38 6 39.530904 -107.704780 5382.06 5.00 5387.06 7 39.530594 -107.703937 5382.67 5.00 5387.67 8 39.530325 -107.703455 5382.40 5.00 5387.40 9 39.530276 -107.703117 5384.78 5.00 5389.78 10 39.530296 -107.702725 5386.89 5.00 5391.89 11 39.530229 -107.701930 5395.65 5.00 5400.65 12 39.530241 -107.701463 5395.10 5.00 5400.10 13 39.530312 -107.700745 5395.72 5.00 5400.72 14 39.530295 -107.699918 5395.49 5.00 5400.49 15 39.530332 -107.699157 5398.90 5.00 5403.90 16 39.530481 -107.697043 5402.71 5.00 5407.71 17 39.530523 -107.695986 5410.63 5.00 5415.63 18 39.530473 -107.695482 5413.41 5.00 5418.41 19 39.530241 -107.694044 5417.09 5.00 5422.09 20 39.530183 -107.693660 5419.24 5.00 5424.24 21 39.530158 -107.693127 5417.33 5.00 5422.33 22 39.530208 -107.688937 5428.84 5.00 5433.84 23 39.530221 -107.687226 5440.63 5.00 5445.63 2/19/23, 9:16 PM 10MWac Site Config | ForgeSolar https://www.forgesolar.com/projects/14968/configs/84753/6/10 Name: 346 Route type Two-way View angle: 50.0 deg Vertex Latitude Longitude Ground elevation Height above ground Total elevation deg deg ft ft ft 1 39.531082 -107.709611 5383.76 5.00 5388.76 2 39.531140 -107.710137 5385.88 5.00 5390.88 3 39.531132 -107.710571 5388.52 5.00 5393.52 4 39.531008 -107.711220 5385.92 5.00 5390.92 5 39.530983 -107.711564 5387.47 5.00 5392.47 6 39.530999 -107.712283 5392.31 5.00 5397.31 7 39.530932 -107.712559 5395.74 5.00 5400.74 8 39.530672 -107.712978 5397.32 5.00 5402.32 9 39.530339 -107.712977 5393.88 5.00 5398.88 10 39.529950 -107.712824 5393.91 5.00 5398.91 11 39.529454 -107.712266 5397.37 5.00 5402.37 12 39.528891 -107.711505 5403.44 5.00 5408.44 13 39.527972 -107.709928 5413.80 5.00 5418.80 14 39.527757 -107.709670 5412.29 5.00 5417.29 Name: Mamm Creek Rd Route type Two-way View angle: 50.0 deg Vertex Latitude Longitude Ground elevation Height above ground Total elevation deg deg ft ft ft 1 39.527757 -107.709664 5412.42 5.00 5417.42 2 39.526094 -107.707701 5421.80 5.00 5426.80 3 39.525713 -107.706929 5428.56 5.00 5433.56 4 39.525341 -107.706070 5434.65 5.00 5439.65 5 39.524999 -107.705637 5433.36 5.00 5438.36 6 39.523833 -107.704779 5448.09 5.00 5453.09 7 39.523439 -107.704489 5451.94 5.00 5456.94 8 39.523146 -107.704044 5457.88 5.00 5462.88 9 39.522935 -107.703438 5459.31 5.00 5464.31 10 39.522761 -107.702805 5462.89 5.00 5467.89 11 39.522422 -107.701935 5468.36 5.00 5473.36 12 39.521402 -107.699859 5472.67 5.00 5477.67 13 39.520847 -107.699017 5474.49 5.00 5479.49 14 39.520603 -107.698528 5474.58 5.00 5479.58 15 39.520058 -107.696407 5496.65 5.00 5501.65 16 39.519260 -107.694342 5503.30 5.00 5508.30 17 39.518324 -107.691981 5507.08 5.00 5512.08 18 39.517952 -107.691439 5509.31 5.00 5514.31 Name: Mamm Creek Rd Route type Two-way View angle: 50.0 deg Vertex Latitude Longitude Ground elevation Height above ground Total elevation deg deg ft ft ft 1 39.517955 -107.691445 5509.21 5.00 5514.21 2 39.517545 -107.691177 5511.34 5.00 5516.34 3 39.515526 -107.690244 5516.01 5.00 5521.01 4 39.514192 -107.689590 5524.01 5.00 5529.01 5 39.513579 -107.689505 5524.69 5.00 5529.69 6 39.512859 -107.689687 5521.01 5.00 5526.01 7 39.512379 -107.689869 5522.34 5.00 5527.34 8 39.511618 -107.689805 5531.90 5.00 5536.90 9 39.510914 -107.689505 5540.39 5.00 5545.39 2/19/23, 9:16 PM 10MWac Site Config | ForgeSolar https://www.forgesolar.com/projects/14968/configs/84753/7/10 Discrete Observation Receptors Number Latitude Longitude Ground elevation Height above ground Total Elevation deg deg ft ft ft OP 1 39.527062 -107.704011 5565.20 5.00 5570.20 OP 2 39.530620 -107.701717 5385.72 5.00 5390.72 OP 3 39.530618 -107.694772 5405.68 5.00 5410.68 OP 4 39.530762 -107.695651 5402.95 5.00 5407.95 OP 5 39.530452 -107.693759 5412.29 5.00 5417.29 2/19/23, 9:16 PM 10MWac Site Config | ForgeSolar https://www.forgesolar.com/projects/14968/configs/84753/8/10 Summary of PV Glare Analysis PV configuration and total predicted glare PV Name Tilt Orientation "Green" Glare "Yellow" Glare Energy Produced Data File deg deg min min kWh PV array 1 SA tracking SA tracking 0 0 - PV array 2 SA tracking SA tracking 0 0 - PV array 3 SA tracking SA tracking 0 0 - PV & Receptor Analysis Results Results for each PV array and receptor PV array 1 no glare found PV array 2 no glare found Component Green glare (min)Yellow glare (min) FP: FP 1 0 0 OP: OP 1 0 0 OP: OP 2 0 0 OP: OP 3 0 0 OP: OP 4 0 0 OP: OP 5 0 0 Route: 346 0 0 Route: 346 0 0 Route: 346 0 0 Route: Mamm Creek Rd 0 0 Route: Mamm Creek Rd 0 0 No glare found 2/19/23, 9:16 PM 10MWac Site Config | ForgeSolar https://www.forgesolar.com/projects/14968/configs/84753/9/10 PV array 3 no glare found Assumptions Component Green glare (min)Yellow glare (min) FP: FP 1 0 0 OP: OP 1 0 0 OP: OP 2 0 0 OP: OP 3 0 0 OP: OP 4 0 0 OP: OP 5 0 0 Route: 346 0 0 Route: 346 0 0 Route: 346 0 0 Route: Mamm Creek Rd 0 0 Route: Mamm Creek Rd 0 0 No glare found Component Green glare (min)Yellow glare (min) FP: FP 1 0 0 OP: OP 1 0 0 OP: OP 2 0 0 OP: OP 3 0 0 OP: OP 4 0 0 OP: OP 5 0 0 Route: 346 0 0 Route: 346 0 0 Route: 346 0 0 Route: Mamm Creek Rd 0 0 Route: Mamm Creek Rd 0 0 No glare found Times associated with glare are denoted in Standard time. For Daylight Savings, add one hour. Glare analyses do not automatically account for physical obstructions between reflectors and receptors. This includes buildings, tree cover and geographi obstructions. Detailed system geometry is not rigorously simulated. The glare hazard determination relies on several approximations including observer eye characteristics, angle of view, and typical blink response time. Actual values and results may vary. The system output calculation is a DNI-based approximation that assumes clear, sunny skies year-round. It should not be used in place of more rigorous modeling methods. Several V1 calculations utilize the PV array centroid, rather than the actual glare spot location, due to algorithm limitations. This may affect results for larg PV footprints. Additional analyses of array sub-sections can provide additional information on expected glare. The subtended source angle (glare spot size) is constrained by the PV array footprint size. Partitioning large arrays into smaller sections will reduce the maximum potential subtended angle, potentially impacting results if actual glare spots are larger than the sub-array size. Additional analyses of the combined area of adjacent sub-arrays can provide more information on potential glare hazards. (See previous point on related limitations.) Hazard zone boundaries shown in the Glare Hazard plot are an approximation and visual aid. Actual ocular impact outcomes encompass a continuous, no discrete, spectrum. 2/19/23, 9:16 PM 10MWac Site Config | ForgeSolar https://www.forgesolar.com/projects/14968/configs/84753/10/10 Glare locations displayed on receptor plots are approximate. Actual glare-spot locations may differ. Refer to the Help page for detailed assumptions and limitations not listed here. AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 58 Please see the following pages for a Letter of Attestation from Holy Cross Energy in support for AES Eagle Springs Organic Solar, LLC provided in March 2023. HOLY CROSS ENERGY LETTER OF ATTESTATION Appendix C8 March 7, 2023 AES Clean Energy 282 Century Place, Suite 2000 Louisville, CO 80027 RE: Letter of Support Dear Mr. Mayer, Please let this letter serve as an attestation that Holy Cross Energy (HCE) is supportive of AES’s Eagle Springs Organic solar and battery storage project that is in development in Garfield County. HCE confirms there is a Power Purchase Agreement in place between HCE and AES for a previous site location that was less favorable, and HCE and AES are working together to amend the agreement and timing to reflect the current site location. While this letter serves to support AES’s permit efforts with Garfield County, it does not constitute permission to operate in parallel with HCE’s electric distribution system, which is being handled by a separate generator interconnection process and is contingent on network upgrades completed by HCE and Public Service Company of Colorado. Please contact me with any questions and concerns. Sincerely, Phil Armstrong Manager, Power Supply parmstrong@holycross.com AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 59 Please see the following pages for AES’ Fire Risk Assessment of Battery Storage Systems similar to those designed and specified for AES Eagle Springs Organic Solar. AES BATTERTY STORAGE SYSTEM FIRE RISK ASSESSMENT Appendix C9 - AES Clean Energy Confidential - AES Clean Energy 40’ CEN Battery Energy Storage System Project Battery Energy Storage System (BESS) Level Fire Risk Assessment 20221215-CEN-AW0423-BESS-FRA-R0 Issued: 5 January 2023 Prepared for: AES Clean Energy 4300 Wilson Blvd, , Arlington, VA 24639 Issued by: Hiller 2120 Capital Drive Wilmington NC 28405 - AES Clean Energy Confidential - - AES Clean Energy Confidential - 2 Table of Contents Revision History ............................................................................................................................................... 3 Executive Summary ......................................................................................................................................... 4 Scope ............................................................................................................................................................... 6 Purpose and Objectives .................................................................................................................................. 6 Assessment Methodology ............................................................................................................................... 8 Definition of the Project Scope ....................................................................................................................... 9 Analysis Enabling Assumptions ........................................................................................................ 10 Construction of the Samsung SDI NMC Battery Cell ....................................................................... 10 NMC Battery Failure Mechanisms and Risks .................................................................................... 11 Lithium Ion Battery Hazards: Thermal Runaway – Causes and Results .......................................... 12 Risk Acceptability Thresholds and Failure Initiation ..................................................................................... 15 Identification of the Hazards......................................................................................................................... 16 Exothermic and Thermal Runaway Hazard Evaluation ................................................................................. 17 Quantification of Heat Flux of a ESS Fire ......................................................................................... 17 1. Effective Heat Release Rate (HRR) ...................................................................... 17 2. Mass Flow Rate within the emitting (on fire) BESS ............................................ 18 3. Quantification of Peak Heat Release Rate of ESS Fire Event .............................. 19 4. Temperature of the Hot Gas Layer over time .................................................... 22 5. Internal Wall Temperature of the BESS Fire Source .......................................... 23 6. Heat Transfer Coefficient .................................................................................... 24 7. Fire/Smoke Plume Centerline Temperature ...................................................... 25 8. Configuration/View Factors ................................................................................ 25 9. Total Radiant and Convective Heat Flux ............................................................. 27 10. Total Convection Heat Flux ................................................................................. 28 Wind Driven Convection Heat Transfer and Surface Level Analysis ............................................... 31 Internal Temperature of Adjacent Target ESS ................................................................................. 34 Theoretical Toxic Composition of Smoke Plume ............................................................................. 35 Lithium Ion ESS Fire Smoke Plume Research Conclusion ................................................................ 38 Recommended Minimum Approach Distance ................................................................................ 39 Scenarios ....................................................................................................................................................... 40 Data Sources ................................................................................................................................................. 40 3 - AES Clean Energy Confidential - - AES Clean Energy Confidential - Revision History Revision Date Description 0 5 January 2023 Issued for Client Dissemination - AES Clean Energy Confidential - - AES Clean Energy Confidential - 4 Executive Summary This containerized battery energy storage system (BESS) Fire Risk Assessment (FRA) evaluates the 40’ CEN BESS in a bounding design basis fire event per the requirements of NFPA 855, Section 4.1.4.2 to evaluate the fire risk associated with the thermal runaway of a single unit. While global energy storage market sector BESS does not readily demonstrate container-to-container fire propagation, this FRA establishes the maximum theoretical design basis accident heat flux that could be realized by an adjacent BESS separated by a 6.5’ passageway. This FRA is intended to demonstrate the maximum theoretical heat flux for a typical installation to demonstrate how the 40’CEN BESS may perform in a design basis fire accident. The methodologies used in this AES Clean Energy Fire Risk Assessment are based on internationally recognized Process Safety Management principles for the reliance on recognized and generally accepted good engineering practices. These engineering practices utilizes numerous international consensus standards and market sector testing data to ensure the efficacy of the quantitative analysis. Specifically, the Society of Fire Protection Engineers (SFPE) Engineering Guide, Fire Risk Assessments was utilized to frame the Fire Risk Assessment format to be compliant with the requirements of the National Fire Protection Association (NFPA) Standard 551, Guide for the Evaluation of Fire Risk Assessments. Where necessary to compute the radiant heat at the adjacent Energy Storage Units and structure adjacencies, the SFPE Handbook of Fire Protection Engineering and NFPA Fire Protection Handbook as well as other peer- reviewed research and publications were relied upon to establish the technical basis for the applicable computations. The application of each standard and peer reviewed document is referenced throughout this report. This Fire Risk Assessment is a fundamental element that defines a bounding theoretical fire scenario to be integrated into the NFPA 855 required Hazard Mitigation Analysis. This FRA is a fundamental element of the integrated documents necessary for submittal in accordance with NFPA 855 and the International Fire Code (IFC) Section 1207. A Fire risk assessment is a common engineering decision making tool for the estimation and evaluation of fire risk for credited fire scenarios and their probabilities and consequences. This Fire Risk Assessment is used to establish the documented technical basis supporting risk and engineering management decisions. The enabling scenario is an unmitigated fire where all non-certified Safety Integrity Level (SIL) components fail to operate. While today’s energy storage safety codes and standards acknowledge cascading thermal runaway as a risk, they stop short of prohibiting it, and fail to address the risk of non-flaming heat transfer to adjacent structures or equipment [1]. Therefore, to address the associated risk, the magnitude of the fire risk is quantified and presented herein. Based on our continued research, and the completed numerical analysis, there remains approximately less than a 1% likelihood across the global battery energy storage system market sector that an event resulting in an exothermic reaction and thermal runaway could occur. In the event the theoretical bounding design basis accident scenario of a complete fire engagement of the CEN Solutions 40’ Battery Energy Storage System (BESS) is realized, there is an estimated Peak Heat Release Rate of approximately 107 MW. The corresponding temperature of the compartmental gases after 3000 seconds will be approximately 1635 oK (1362 oC). Using classical heat transfer calculations the uninsulated (worst case) internal wall temperature will be 1514 oK (1241 oC). The external wall temperature due to heat lost to the surrounding environment will - AES Clean Energy Confidential - - AES Clean Energy Confidential - 5 be approximately 1514 oK (1241oC). The centerline temperature of the plume will be approximately 926 oK (629 oC). The total radiant heat flux, considering geometric focus factors, from the radiated heat emanating from the fully engage container (754 kW/m2) and released fire plume (1.2 kW/m2) will be approximately 755.6 kW/m2. Assuming a design basis wind of 4.16 m/s, the calculated surface temperature of a first responder at a distance of 6.5 feet (3.048 m) passageway could intermittently reach as high as 1383 K (1110 oC). While very unlikely based on the global ESS market sector of cascading fires between adjacent containerized battery energy storage systems, if a design basis fire event is realized and is unnoticed and unmitigated, the an adjacent 4-‘ CEN BESS Thermal Management System should be able to control the internal environment but could eventually shutdown when internal temperatures exceed pre-established setpoints (typically 90oF/32 oC). Once the internal thermal management is no longer in operation, the heat transfer from the adjacent fully developed container fire could, as a function of the fire lifecycle and thermal insulation degradation, will could exceed the thermal stability thresholds of the adjacent racks. It is recommended that additional mitigation measures (evaporative cooling) be considered within the required Hazard Mitigation Analysis to control adjacent BESS surface temperatures to lessen the probability of cascading container fire propagation. - AES Clean Energy Confidential - - AES Clean Energy Confidential - 6 Scope This product level Fire Risk Assessment (FRA) identifies and quantifies the potential fire and heat flux hazards associated with AES Clean Energy 40’ Battery Energy Storage Container Energy Storage Project (BESS) within the 40’ CEN BESS. The 40’ CEN BESS utilizes the Samsung SDI 112 Ah E4L NMC battery technology [2-5]. This product level FRA is based on an assumed installation adjacent within Sun City Arizona to characterize the performance of the BESS. No adjacencies were evaluated as project level design documentation was not provided. This FRA is based on a theoretical installation. A final FRA will be required for actual installations that considers all the project level and environmental variables. The results of this FRA are intended to establish the technical basis for fire risk management decisions. This Fire Risk Assessment was conducted in accordance with the requirements and guidelines of the: • NFPA 551, Guide for the Evaluation of Fire Risk Assessments [6] • SFPE G.04:2006 – Engineering Guide: Fire Risk Assessment; [7] • NFPA No.: HFPE-01 - SFPE Handbook of Fire Protection Engineering [8] • ISO 16732-1: 2012 – Fire Safety Engineering – Fire Risk Assessment, Part 1: General[9] • ISO 16732-3: 2012 – Fire Safety Engineering – Fire Risk Assessment, Part 3: Example of an Industrial Property [10] This FRA is intended to be used to support engineering decisions when estimating the likelihood of an asset fire and to address the questions of: (1) Identifying potentially important accident scenarios (“what can go wrong”), (2) Determining their consequences (“what can happen when something goes wrong”), and (3) Assessing their likelihood (“how likely is it that something will go wrong”) Purpose and Objectives The use of Lithium-ion (Li-ion) battery-based energy storage systems (ESS) has grown significantly over the past few years. In the United States alone, Li-ion battery (LIB) use has gone from 1 MW to almost 700 MW in the last decade (refer to Figure 2) [11]. Many of these systems are smaller installations located in commercial occupancies, such as office buildings or manufacturing facilities. Yet, there has been relatively little research conducted on large commercial or industrial systems that can be used to ensure that effective fire protection strategies are in place. - AES Clean Energy Confidential - - AES Clean Energy Confidential - 7 Figure 1: AES Clean Energy Utility-Energy Storage Concept Figure 2: US Large Scale Battery Storage Installations by Region (2021)[11] Many studies have addressed how failure of a single cell battery is affected by characteristics such as chemistry, electrolyte composition, state-of-charge (SOC), or format [12-22]. The subsequent propagation of thermal runaway to adjacent cells in a multiple cell battery module have also be studied and characterized. From a fire protection and fire risk perspective, the overall fire hazard of any ESS is a combination of all the combustible system components, including battery chemistry, battery form factors (e.g., cylindrical, prismatic, polymer pouch), battery capacity and energy density, state of change (SoC), materials of construction, and component design (e.g., battery, module). To ensure confidence in the resulting fire protection guidance, the ESS was assumed to be operating under normal electrical operation where - AES Clean Energy Confidential - - AES Clean Energy Confidential - 8 electrical abuse may occur, such that any proprietary electronic protection systems, e.g., battery management system (BMS), were limited in mitigative response. Any benefit from these proprietary systems would further reduce the overall hazard, (e.g., the likelihood of ignition), but is not necessary or sufficient to ensure the adequacy of the fire protection or response measures [23, 24]. The Samsung SDI UL9540A Module Level Test demonstrated cell-to-cell propagation with ignition of the flammable gases[3]. While the 40’ CEN Solutions BESS includes the Samsung SDI Thermal Management System that directly injects Novec 1230 into a module experiencing thermal runaway, the direct injection system has not been certified to be compliant with ASME B31.3 as required by UL9540, the system is not assumed to be operational to establish the bounding design basis fire event. As part of this Fire Risk Assessment, the body of knowledge was researched, collected, reviewed, and summarized related to LIB ESSs to establish the technical basis for performance and any potential mitigation measures. The sources used includes the Department of Energy (DOE) Safety Roadmap, relevant international consensus codes and standards, incident reports, related test plans, peer-reviewed research, and previous fire testing/research with the objective of identifying the inherent risks associated with the deployment of the LIB ESS technology to life (occupants or fire fighters) and for property (asset) protection. Continuity of Operations is specifically excluded from this assessment as no administrative controls are assumed to limit the resultant hazard. The literature review conducted as part of this Assessment is intended to identify potential knowledge or technology gaps in the information currently available. Assessment Methodology This Fire Risk Assessment and the format of this report employs both qualitative and quantitative methods to determine the inherent risks of the lithium-ion battery (LIB) energy storage system (ESS) technology and follows the guidance outlined in the SFPE Engineering Guide to Application of Risk Assessment in Fire Protection Design and the National Fire Protection Association (NFPA) Standard 551 Guide for the Evaluation of Fire Risk Assessments [6, 7]. The SFPE Guide to Fire Risk Assessments recommends the use of risk assessment methodologies in the design and assessment of building and/or process fire safety. This guide is a recognized and generally accepted and good engineering approach to fire risk assessments. The SFPE guide provides direction to practitioners in the selection and use of fire risk assessment methodologies used to determine adequacy of design for fire safety. It also provides guidance to project stakeholders in addressing fire risk acceptability. Furthermore, the SFPE guide establishes recommended processes to be considered for the use of risk assessment methodologies and provides references to available detailed sources of information on risk assessment methodologies, procedures, and data sources. However, the SFPE Guide to Fire Risk Assessments does not provide specific fire risk assessment methodologies or tools; nor does this guide provide specific data or acceptance criteria for use in the risk assessment process. Therefore, in the absence of specific quantification methodologies, the SFPE Handbook of Fire Protection Engineering [8] and the Fire Protection Handbook [25] as well as other peer-reviewed publications were used to identify the characteristic equations for calculating compartmental fires, heat release rates (HRRs), flammable gas temperatures, and surface temperatures. The following figure outlines the process outlined in the SFPE Guide. The format of this report closely follows - AES Clean Energy Confidential - - AES Clean Energy Confidential - 9 the recommendations of the SFPE Fire Risk Assessment Guide. Figure 3: SFPE Fire Risk Assessment Process Flow Chart Definition of the Project Scope This BESS Level FRA was developed in support of the AES Clean Energy to characterize the fire performance of the 40’ CEN BESS installed in a theoretical installation. As a conservative measure, due to the environmental considerations (elevation, humidity, wind directions and velocities) the theoretical installation is located in in Sun City Arizona. This project focuses on the inherent fire hazards and risks associated with the Samsung SDI lithium-ion battery (LIB) technology and limits the fire generated from the flammable gas emitted from one-Stack Level and determines the potential impacts to the surrounding adjacent structures [26]. This steady-state FRA leverages the qualitative information gained through an exhaustive literature review of the failure rates (the total number of failures within an item population, divided by the total time expended by that population, during a particular measurement interval under stated conditions) and consequences of LIB within the global ESS market sector, as well as calculates the heat flux generated from a fully engaged stack fire within a given ESS. In the absence of specific failure data of a manufacturer’s part number, comparable and approximate reliability data presented in the Electronic Parts Reliability Database (EPRD), Non- electrical Parts Reliability Database (NPRD) or Failure Modes/Mechanisms Database (FMD). - AES Clean Energy Confidential - - AES Clean Energy Confidential - 10 Analysis Enabling Assumptions The following enabling assumptions were used to facilitate this Fire Risk Assessment to characterize a worst case scenario: • Designed engineering controls for BMS or supplemental controls are assumed to be operable, but in a degraded condition to mitigate exothermic reaction. • Ambient conditions are assumed to be standard pressure temperature (STP). • External environmental air conditions assume a design basis wind velocity of 1.5 m/s. Ambient temperature is 295 oK (22 oC/72 oF). • UL 9540A testing of the comparable Modules Level Test for the Samsung SDI E4L Unit, and the associated measured temperatures are the best available data of heat release rates and associated target wall temperatures are assumed to be representative of containerized/compartmentalized BESS gas layer temperatures. • Numerical/analytical methodologies employed are based on SFPE,NFPA Handbooks, or other peer-reviewed publications and are assumed to be adequate for characterizing the critical calculation variables, and are cited herein. Construction of the Samsung SDI NMC Battery Cell This BESS Level Fire Risk Assessment uses the best available information to characterize the associated risks with the LIB technologies. The Samsung SDI BESS design has an integrated solution containing the Samsung SDI Power Battery Cell, Model Number CS1120RT001A, 3.63VDC, 112Ah technology as shown in Table 1. Table 1: SAMSUNG E4L Cell Under Test Cell Manufacturer Samsung SDI Model Number CS1120RT001A Chemistry NMC (Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2)) Nominal Electrical Ratings 3.63VDC, 112Ah Dimensions 174*46.2*133mm Weight 2100 g Construction Description Prismatic, Cell with UL approval Tested to UL 1642 Yes Tested to UL 1973 Yes - AES Clean Energy Confidential - - AES Clean Energy Confidential - 11 NMC Battery Failure Mechanisms and Risks As it pertains to the design and construction of the Samsung SDI battery modules, research of the failure modes and mechanisms of NMC cells was conducted as part of this analysis. It is assumed the published research on typical NMC failure mechanisms are comparable to the Samsung SDI Model CS1120RT001A cells. Therefore, the following discussion is based on comparable NMC battery chemistry and form factors to establish a technical basis upon which failure mechanics and performance characteristics could be extrapolated to support this analysis. Figure 4: Samsung SDI MS1304E101A Module Lithium-ion batteries have many advantages but the reactive, volatile and flammable materials present in the battery are a concern and may be a threat to auto-induced thermal runaway temperature and voltage [14]. Although not demonstrated within the BESS market sector by the Samsung SDI MS1304E101A battery modules, as shown in the UL9540A tests overheating may start exothermal reactions that release even more heat which in turn can lead to an accelerated thermal runaway and propagation between cells [2-5]. Research and industry experience indicates thermal runaway could be initiated due to overcharge, over-discharge, mechanical deformation, external heating or an external or internal short circuit. The heat generated by any of these events may start exothermal reactions in the battery that in turn could lead to cell venting, fire or explosion [20, 27-30]. These risks are well known and are not only associated with the heat and high temperatures that may develop, the emission of harmful or poisonous gases also pose a danger that has been emphasized in literature but also other gases which can be flammable may be emitted. The reactions during overheating are typically due to the decomposition of the solid electrolyte interphase (SEI) layer, anode and cathode as well as electrolyte decomposition and combustion. In general, when Li-ion battery failure is induced by thermal or electrical abuse, the failure eventually evolves into a thermal runaway [31]. The failures may be induced by external forces (i.e., severe mechanical shock or damage or internal/external thermal transients leading to damage), internal shorting (i.e., manufacturing induced defects, dendrite formation, metal particles, poison), or the poor thermal stability of Li-ion cells during uncontrolled overcharging or discharging [31]. Research has shown that when a number of lithium-ion cells are used in a battery pack, there is always a disproportional capacity distribution band due to the individual battery state of charge, thermal performance, and “variation of capacity” between different cells [32]. This capacity band will continue to broaden throughout the battery pack as a function of the number of charging cycles, and eventually, the capacity of a battery pack will be limited by the cell with the lowest capacity . Thus, the lowest capacity cell may experience overcharge and over-discharge through the charging/discharging - AES Clean Energy Confidential - - AES Clean Energy Confidential - 12 cycles. This has been proven to be the case, even if the whole pack is experiencing normal charge/discharge cycles, inducing electrical abuse and potentially leading to thermal runaway. Without a battery management system, the capacity band of a cylindrical lithium-ion battery cannot be eliminated. Although not specific to the Samsung SDI E4L NMC cells due to the limitation of published information, research demonstrates NMC cells within a battery pack or module are shown to degrade during testing demonstrating performance during excessive abuse. Testing objectively demonstrates that when cells fail, there is the formation of irregularities and dendrites create micro-shorting pathways during overcharge cycling conditions due to degraded cell capacity in the distribution band. Simultaneous formation of dendrites within the anode during charging eventually creates an micro-shorting pathways and increase internal heating. Research indicates an increased rate of dendrite formation occurs in overcharge conditions than in the normal charging conditions [16-20, 30]. Research of NMC Cells indicates that as temperature increases above 60 oC, the Li-ion deintercalates from anode and the solid electrolyte interface film (SEI) layer of the lithium intercalated carbon anode undergoes an exothermic decomposition reaction. As the temperature continues to increase to about 105 oC, the SEI layer further decomposes where the cathode material generally loses its protection thereby exposing the electrolyte. Sustained exposures to temperatures above 100oC facilitates system breakdown resulting in the initiation of exothermic reactions between the cathode active material and electrolyte resulting in rapidly increasing temperatures. As the temperature increases, the separator of the lithium-ion battery degrades and thins. As the exothermic reaction continues, at temperatures above 180oC the separator (polypropylene) degrades, thus reducing the protective properties between the positive and negative electrodes of the cell. This results in the flow of short circuit currents and the cell enters into the thermal runaway. As the internal temperatures increase to the range of 180–250oC, an exothermic reaction heat occurs between the lithium-ion positive electrode and the electrolyte. At sustained temperatures above 200oC, the electrolyte decomposes, resulting in the release of significant heat from the exothermic reaction. Generally, thermal runaway occurs when an uncontrolled exothermic reaction occurs. The exothermic reaction exponentially increases due to a surge in environmental temperature causing a further increase in internal cell temperature, that could without mitigation result in an explosion/deflagration. It is proposed when temperatures are sustained above 200 ◦C, thermal runaway can occur spontaneously as a result of fire or explosion. The state of charge (SOC) is a significant contributing variable to the onset of thermal runaway of NMC Cells. Other noted research indicates conditions where partially or fully discharged NMC cells, under adiabatic-like constant power heating similar to the UL9540A Module Level Test did not experience induced thermal runaway below 100°C. Therefore, it is reasonable to assume when the Samsung SDI E4L NMC cells are partially discharged and incipient battery failure occurs, thermal runaway is unlikely. Lithium Ion Battery Hazards: Thermal Runaway – Causes and Results Fire challenges associated with the bulk storage of Li-ion batteries are unique given the presence of a flammable organic electrolyte within the Li-ion battery as compared to the aqueous electrolytes typically found in other widely used battery types. As presented, when exposed to an external heat source (fire), Li- ion batteries can experience thermal runaway reactions resulting in the release of flammable organics and the potential rupture of the battery [33, 34]. - AES Clean Energy Confidential - - AES Clean Energy Confidential - 13 The different stages and reactions contributing to the general thermal runaway process of a lithium ion cell have been examined and are well documented within the energy storage industry. When a lithium-ion cell experiences thermal runaway, the noted degradation occurs resulting in elevated cell surface temperatures causing cascading impacts that have been demonstrated to propagate to the surrounding environment and adjacent cells. Observations from previous tests have shown these effects are very similar for all cell types (cylindrical hard case, prismatic hard case, pouch cell). Depending on the battery system design, adjacent cells may likewise be thermally damaged enter thermal runaway. It is well documented that cell component breakdown due to thermal runaway results in the production of hot flammable gases due to the chemical reactions mentioned above [15, 18, 19, 35-40]. The flammable gas generation occurs during cell decomposition resulting in increased internal pressure, leading to cell expansion, including the application of compressive force to adjacent parts in the system. Depending on the magnitude of the expansive forces the cells have been known to rupture encapsulation. Upon rupture, the cell begins to vent and together with the produced gas and a chaotic mixture of hot and glowing particles are ejected from the cell. Expelled particles typically contain pieces of active material from the cell’s anode and cathode. Temperature measurement of released gases for the Samsung SDI E4L NMC cells averages 150 oC. Analysis of the ejected gas showed high proportions of hydrogen, hydrocarbon, and carbon monoxide. Therefore, flammability and the risk of deflagration or explosion, based upon industry performance is given at a fuel concentration of approximately 9.21% at ambient temperatures[2-5]. The mentioned effects usually have their impact on the battery and its environment as a function of time. The Samsung SDI E4L cells time to thermal runaway ranges from 24:26 min to 27:15 min [4]. The heat release rate of a single cell thermally interacts with adjacent cells increasing the internal temperatures and challenges the integrity of the cell. This combination of effects creates the environment where subsequent cell failure will occur resulting in cascading degradation of the battery modules. Unmitigated, the entire module assembly will be damaged due to cell thermal runaway [3]. The cascading degradations process will exponentially accelerate and usually within several minutes, the battery housing may lose integrity due to the amount of thermal energy. During degradation, the prismatic cells swell and bulge during pressurization. To be compliant with UL 1642, all lithium=ion cells include safety vents that are designed to release the internal pressure of the cell when a specified pressure is reached [41]. Upon cell rupture, the gas accumulating inside the cell will be released and will react with atmospheric air (with fresh oxygen and moisture). The air exchange with the battery will react with the freshly plated lithium metal and electrolyte and may cause explosion and ignition. The research associated with this FRA indicates the cell State of Charge (SoC) significantly and adversely impacts the reactivity of the cell during an external fire scenario. In particular, a fully charged battery has an increased propensity to undergo a thermal runaway reaction, increased initial fire growth rate and interestingly, decreased total energy release. This suggests that, to reduce the hazard potential in bulk storage, LIB should be well managed to avoid under/over-charging or being maintained at a reduced SOC [26]. Overcharge There are a few ways in which overcharge can occur. The most obvious overcharge mode is charging a cell to too high of a voltage (over voltage, overcharge). For example, charging a 3.2 V rated cell above 5 V will likely lead to energetic failure. Charging at excessive currents, but not excessive voltages, can also cause an overcharge failure; in this case, localized regions of high current density within a cell will become - AES Clean Energy Confidential - - AES Clean Energy Confidential - 14 overcharged, while other regions within the cell will remain within appropriate voltage limits [13, 42]. Although controlled through the Battery Management System (BMS), severe overcharge failures are not uncommon[31]. Unless the BMS is designed to meet Safety Integrity Level (SIL) Ratings, there is the potential a design or manufacturing defect can cause bypassing of protection mechanisms and result in severe overcharge failures. As noted in the report for the ESS used globally, these types of failures also occur as a result of human error with systems that either lack hardwired protection (e.g., prototype systems that are being tested) or in charging schemes with manual voltage and current settings [31]. Although severe overcharge will lead to cell thermal runaway, repeated slight overcharge of a cell may not cause a failure for an extended timeframe, but can eventually result in thermal runaway [14, 18]. Industry response to this known problem prompted requirements in IEEE 1725 and IEEE 1625 for cell manufacturers to communicate specific high voltage limits appropriate for secondary protection settings specific to each cell design to pack and device designers who purchase their cells. IEEE 1625 adopted the concept of a safe charging current and charging voltage envelope relative to temperature [13, 33, 43]. External Short Circuit High rate discharging (or charging) can cause resistive heating within cells at points of high impedance as indicated in the findings associated with the ESS fires within the market sector [12, 31]. Such internal heating could cause cells to exceed thermal stability limits. Points of high impedance could include weld points within a cell (internal tab attachment) or electrode surfaces. As cell size and capacity increases, the likelihood of internal impedance heating leading to thermal runaway also increases. Larger cells exhibit slower heat transfer to their exteriors, and they usually have higher capacities. Thus, they have the potential to convert more electrical energy to internal heat. UN and UL testing requirements provide a minimum requirement for cell external short circuit resistance: discharge through a resistance of less than 0.1 ohm in a 55°C (131°F) environment. International and domestic shipping regulations (as found in the US CFR, as well as IATA and ICAO publications) require that cells or batteries be protected from short-circuiting. Investigation of a number of thermal runaway failures that have occurred during transport has revealed that improper packaging, particularly a failure to prevent short circuits is a common cause of these incidents. Over‐Discharge Research demonstrates over-discharging a lithium-ion cell to 0 V will not cause a thermal runaway reaction [27]. However, such over-discharge can cause internal damage to electrodes and current collectors, can lead to lithium plating if the cell is recharged (particularly, if the cell is repeatedly over-discharged), and can ultimately lead to thermal runaway [18]. Most BMS will allow the recharge of over-discharged cells, despite the potential for the negative electrode to become damaged [14]. Therefore, over-discharge does periodically cause thermal runaway of lithium-ion cells. Forcing a cell into “reversal” (charging to a negative voltage, “forced over-discharge”) may also cause thermal runaway. UL 1973 and UN tests provide a minimum requirement for resistance to forced over- discharge for cells used in multi-cell packs [44]. These tests are designed to simulate the most likely mechanism of forced discharge, which occurs when a cell with lower capacity than its neighboring series elements is present in a multi-series battery pack that is externally short circuited. A lower capacity cell of this type can occur due to aging of the battery pack. In this scenario, current flow from the higher capacity series elements in the pack will drive the discharged series element into reversal. The UN and UL testing - AES Clean Energy Confidential - - AES Clean Energy Confidential - 15 does not include repeated forced discharge. Thus, if a system does not include protection electronics that will detect and disable charging of a damaged cell, it is possible a cell could be repeatedly force over- discharged and ultimately undergo a thermal runaway reaction. Thermal Abuse The most direct way to exceed the thermal stability limits of a lithium-ion cell is to subject it to excessive external heating. Industry testing relies upon the use of an external heat source that is applied to the exterior of target cells to induce localized reactions and to determine if the failure propagates to the entire module [3]. This literature review of the failure mechanisms of LIB indicates energetic field failures of LIB devices have been attributed to long-term operation of cells at temperatures just above the self-heating point of 70 to 90°C (158 to 194°F). Such failures require not only elevated temperature, but an adiabatic (highly insulated) environment, and extended times to reach a self-sustaining thermal runaway condition. If a ESS was exposed to long-term operation without environmental thermal management, significant damage could occur. Acute exposure of a cell to high temperatures will readily induce thermal runaway in that cell. As demonstrated in the UL9540A Module Level Test of the Samsung SDI E4L Series battery module, if an internal cell fault is sufficient to cause thermal runaway in a single cell of a multi-cell battery pack, heat transfer from the faulting cell can cause thermal runaway in neighboring cells of the battery pack[45]. Thus, the thermal runaway reaction will propagate through a battery rack if there is a performance issue with the Thermal Management System. Propagation of cell thermal runaway has significant implications for fire suppression and fire protection. LIB in exothermic reactions self-generate oxygen to sustain the fire. A fire suppressant or low oxygen environment may extinguish flames from a battery pack, but the thermal runaway reaction will propagate if heat is not sufficiently removed from the adjacent cells[24]. Responders to fires involving lithium-ion battery packs have often described a series of re-ignition events. Typically, responders report they used a fire extinguisher on a battery pack fire, thought they had extinguished the fire, and then observed the fire re-ignite as an additional cell vented [42]. Risk Acceptability Thresholds and Failure Initiation Since May 2019, there have over 30 documented stationary energy storage system fires within the global market sector. Research has shown there are four main causes that have been attributed to ESS failures that include: • Insufficient Battery Protection Systems against electric shock [28, 31] . • Inadequate management of operating environment • Faulty Installations • Insufficient ESS BMS and EMS System Integration [31]. Based on the number of recent recorded industry failures, energy storage system Battery Management Systems (when designed as non- SIL) do not have a proven track record of fire mitigation/prevention due to thermal or electrical abuse. Research has objectively demonstrated that once the critical sustainment point of an exothermic reaction is reached, a Battery Management System cannot stop or mitigate the cascading failures of adjacent cells within modules [14, 17, 20, 27, 29, 30, 33, 46]. The National Fire Protection Association (NFPA) has conducted a series of tests to determine preferable suppression systems for ESS [47, 48] and determined that water based automatic sprinkler systems was - AES Clean Energy Confidential - - AES Clean Energy Confidential - 16 chosen as a viable option for evaluating fire protection strategies for Li-ion batteries for lowering the exothermic reaction temperature. At present, there is no industry or standard that designates a fire protection suppression strategy for bulk packaged Li-ion cells, larger format Li-ion cells, or Li-ion cells contained in or packed with other equipment. NFPA 13 does not provide a specific recommendation for the protection of Li-ion cells or complete batteries, and it is not known if water is the most appropriate extinguishing medium for Li-ion batteries. There is limited real-scale data available to support a fire hazard assessment of Li-ion based ESS and there is no experimental data available to support sprinkler protection guidance[23, 24, 29]. Therefore, to determine the worst case scenario it is assumed the ESS that is experiencing a potential exothermic reaction and is suppressed results in a loss. Identification of the Hazards The major hazards for large-scale ESS systems can be categorized as electrical, mechanical and other hazards. Electrical hazards occur when there is a live contact between a person and an ESS system exposing the person to severe electric shocks. Mechanical hazards occur when there is a (unforeseen) physical collision between a person and an ESS system. Potential other hazards (mainly related to electric and electrochemical systems) include: • Explosion hazards, caused by a rapid expansion of gases due to exothermic reaction and subsequent failure of LIB cells, modules, Stacks, and containers. • Fire hazards, arising from combustible materials used in the storage system • Thermal hazards, due to the thermal properties of a system or its components • Thermal runaway hazard, causing propagation of increasing temperatures, pressures, and fire towards neighboring cells. • Chemical hazards, caused by (unforeseen) contact between a person and toxic, acidic, corrosive • Components leaking from the ESS system [49]. The risk of electrical shock at the system level should be mitigated by applying design rules regarding electrical insulation (e.g. containment), by wearing adequate personnel protective equipment and by imposing operational instructions. The risk of mechanical shock at the system level should be mitigated by applying design rules regarding containment. The risk of other hazards at the system level should be mitigated by applying design rules regarding containment. To ensure safe handling in general, the following recommendations should be considered to prevent exposure to abusive environmental conditions: • The ESS system or its components should not be opened or punctured, including during emergency operations • The ESS system or its components should not be left in places of high temperature • The ESS system or its components should not be exposed to condensation and high humidity and contact with water should be avoided • The ESS system or its components should not be submitted to excessive electrical stress [49]. Therefore, this Fire Risk Assessment bounds the aforementioned risks with the most conservative hazard that is a direct result of thermal defects within LIB resulting in the cascading impacts of exothermic reactions resulting in thermal runaway. Assuming conservative quazi-linearity of the published failure - AES Clean Energy Confidential - - AES Clean Energy Confidential - 17 rates resulting in fire, the ESS may experience up to approximately 1% of failures depending on the level of electrical and thermal abuse [12, 32]. However, while there is no readily identifiable industry research on failure of large-scale NMC systems, recent UL9540A testing of the Samsung SDI cells objectively demonstrates a lower propensity of thermal runaway propagation [50]. Exothermic and Thermal Runaway Hazard Evaluation Quantification of Heat Flux of a ESS Fire Characterizing the fire hazards associated with the Samsung SDI containerized battery energy storage systems requires an understanding of the amount of energy released during the exothermic reaction of a lithium-ion battery (LIB) failure. The potential cascading impacts associated with a fire in a lithium-ion battery ESS is significant based on the quantities of energy contained. Although the Samsung SDI modules are utilized in the 40’ BESS systems has been certified and tested in accordance with UL 1973, the aforementioned fire safety features of the design is to prevent a catastrophic event in a lithium-ion ESS. The quantification of the radiant heat flux within BESS presents several challenges due to the unavailability of proprietary information. When available, specific manufacturer data was applied. In absence of specific data, the “best available” information was used with an integrated standards-based approach with recognized and generally accepted good engineering practice. The conservative approach to radiant heat flux quantification is used to present a bounding scenario. Understandably, proximity and adjacencies of siting and spacing of ESS containers contributes a significant role in fire safety. Therefore, a radiation heat transfer analysis was used to assess separation distances between adjacent ESS containers. The overall approach to the radiation heat transfer analysis of an ESS container fire on an exposed ESS container is based on the cited works of the SPFE Handbook of Fire Protection Engineering for compartmental fires [8] and those of Quintiere’s works in Fundamentals of Fire Phenomena [51] to calculate the following: 1. Effective Heat Release Rate (HRR) 2. Mass Flow Rate within the emitting (on fire) BESS 3. Quantification of Peak Heat Release Rate of ESS Fire Event 4. Temperature of the Hot Gas Layer over time 5. Wall Temperature of the BESS Fire Source 6. Heat Transfer Coefficient 7. Smoke Plume Centerline Temperature 8. View Factors 9. Radiant and Convective Heat Flux 10. Convective and Radiative Heat Flux at the Fence Line 1. Effective Heat Release Rate (HRR) The energy release rate (heat release rate, HRR) of the compartmental fire is based on UL 9540A testing and assumes sustained peak based on the UL9540A Cell level test data and is extrapolated to numerically characterize a worst-case scenario. The heat release rate is the recognized single most important variable in a fire hazard[8]. The heat release - AES Clean Energy Confidential - - AES Clean Energy Confidential - 18 rate of a burning item is measured in kilowatts (kW). It is the rate at which the combustion reactions produce heat. The relationship of these two quantities can be expressed as 𝐻𝐻𝐻𝐻𝐻𝐻=∆ℎ𝑐𝑐∗𝑀𝑀𝑀𝑀𝐻𝐻 Where ∆hc is the effective heat of combustion and MLR is the Mass Loss Rate of the LIB. The mass loss rate (burning rate) of the battery is an essential element in quantifying the heat release rate; however, in comparison to the volumetric flow rates within the compartment, the mass loss rate plays a somewhat insignificant role in the total heat release rate. Therefore, the mass flow rate of air and the heat of combustion of lithium-ion batteries combusting in air is used to approximate the peak heat release rate. A prismatic LIB has an average mass of the Samsung SDI E3L is 2.1 kg [4] . NMC Cells have an energy density of 90 to 250 W/kg [52, 53]. A mass loss rate (MLR) of 0.0015 kg/s is assumed [14]. The effective heat of combustion (∆hc) for a LIB is the heat of combustion which would be expected in a fire where incomplete combustion takes place. The effective heat of combustion is often also described as a fraction of the theoretical heat of combustion [2]. The effective heat of combustion assumed for this analysis is based on the Thermal runaway and safety of large lithium‐ion battery systems and the Underwriters Laboratory UL 9540A testing of the Samsung SDI cells. The range of values used for this analysis is based on the interpolated data presented in the UL 9540A Cell Level Test for the Samsung SDI 112 Ah NMC cells and is assumed to be 24.2 kJ/kg for the fully engaged Stack as well as the upper range of identified effective heat of combustion [2-5, 42]. 2. Mass Flow Rate within the emitting (on fire) BESS Compartment fires with forced ventilation can significantly impact the fire growth, temperature within the compartment, spread of gases from the fire, and the decent of the smoke layer within the compartment [8]. This Fire Risk Assessment assumes normal HVAC operation throughout the event to establish a bounding scenario. It is generally understood the HVAC control will be established by the Fire Alarm Control Panel (FACP) at some interval based on internal temperature and will be de-energized. However, to establish the maximum design basis fire event, the non-SIL certified HVAC control system is assumed to fail to respond to shutdown commands and remain energized. This scenario applies the analyzes a compartmental fire under natural convection thermal management conditions, the growth of the fire will be significantly impacted by the volumetric air flow rate within the ESS container by providing an adequate oxygen supply for the large quantity of fuel. However, it also serves as a limiting factor for the peak heat release rate of a fire in a compartment with uniform air flow. Therefore, a compartment fire with forced-ventilation is assumed and behaves significantly different than a naturally ventilated space. A forced ventilation compartment may have an unstable gas layer due to the mixing of the combustion products and the air flow which spreads the hot gases throughout the compartment [8]. A compartmentalized forced ventilation scenario also limits the formation of the smoke layer. As in any compartment fire, the depth of the smoke layer increases over time. However, the smoke layer in forced ventilation scenarios descends until it reaches equilibrium; this phenomenon allows for additional fuel to be consumed. Once the fire reaches its peak heat release rate, the fire growth is limited - AES Clean Energy Confidential - - AES Clean Energy Confidential - 19 to the ventilation rate throughout the compartment. Since the ventilation rate is constant, the amount of fuel that can be consumed per second becomes constant, allowing the fire to reach a steady-state condition until all fuel within the container is consumed [8]. The mass flow of the burning fuel is given as the ratio of the fire energy release rate and the effective heat of combustion and is quantified by 𝑚𝑚′=𝑄𝑄′Δℎ𝑐𝑐+𝑚𝑚𝑎𝑎𝑎𝑎𝑎𝑎′ Where, Q’ is the fire energy release rate ∆hc is the effective heat of combustion m’air is the mass flow of the forced ventilation 3. Quantification of Peak Heat Release Rate of ESS Fire Event The heat release rate (HRR) of a fully involved ESS fire is the factor that quantifies the fire source within an ESS. The HRR is defined as “the rate at which energy is generated by the burning of a fuel and oxygen mixture. As the heat release rate increases, the heat, smoke production and pressure within the area will increase and spread along available flow paths toward low pressure areas” [51]. The peak heat release rate quantifies the heat released for complete combustion of the fuel – peak burning rate [8, 25]. The most common method of quantifying the heat release rate is through Oxygen Consumption Calorimetry (OC), which assumes that the HRR is proportional to the oxygen consumed during the combustion of common organic fuels [42]. However, quantifying the heat release rate through OC methods is challenging for lithium-ion batteries due to their ability to release oxygen during failure. LIB’s produce sufficient oxygen during the exothermic reaction to sustain a flame [8, 25, 51]. The heat release rate of a LIB ESS fire is interdependent on the initiating event, status of the LIB charging/discharging the quantity of fuel, environmental conditions, and the status of the ventilation conditions [13, 42, 47, 48]. To bound the conditions for determining the peak heat release rate, is assumed to be limited to the forced-ventilation air flow within the compartment [8]. Industry research on the failure mechanics of thermal runaway in large lithium-ion battery systems, the effective heat of combustion of a lithium-ion battery in air was determined to be approximately 28 to 40 kJ/kg [14, 27, 29, 30, 33, 54]. It is well published the mass flow rate of the gas layer within the compartment is dependent on the mass loss rate of the fuel (kg/s), density of air (1.2 kg/m3) and the range of volumetric airflow rates (m3/s). Although, it is generally understood that it is uncommon for LIBs to reach full combustion, for the purposes of bounding a quantifiable fire risk, it is assumed the combustion efficiency for oxygen containing products can be between 90 and 100%. Therefore, the mass flow rate of the flammable gas compartmentalized fires is dependent on the temperature dependent density of the air and the volumetric flow rate of the natural convection cooling ventilation system in addition to the mass loss rate of the fuel (rate of volatile release from LIB failure) which is mechanically combined to form the mixed flammable gas layer. It is also assumed the fire engagement is the initiating source for volatile gases. The failure of any other system, structure, or component concurrent with a LIB fire event is assumed to be beyond extremely unlikely. - AES Clean Energy Confidential - - AES Clean Energy Confidential - 20 Various small scale tests of various types of lithium-ion batteries have indicated that between 16% and 27% of the battery mass is lost over a time period of 40 to 60 seconds [14, 18, 20]. Since different battery formats vary in mass, a few different types of commonly used lithium-ion batteries were analyzed to obtain a range of mass loss rates for various battery types. The entire mass was lost during UL9540A Module Level Test [3]. Conservatively, 25% is assumed to be consumed during a thermal runaway (TRA) event. As part of the quantification of the peak energy released during a LIB exothermic reaction, it has been determined the mass loss rate of the battery although important, in comparison to the volumetric flow rates within the compartment, the mass loss rate is nearly negligible. Both are quantified in this analysis for consistency. Therefore, the mass flow rate of air and the heat of combustion of lithium-ion batteries combusting in air is used to approximate the peak heat release rate where 𝑄𝑄̇=Δ𝐻𝐻𝑒𝑒𝑒𝑒𝑒𝑒∗ 𝑚𝑚̇ Where, 𝑚𝑚̇= 𝑚𝑚𝑎𝑎𝑎𝑎𝑎𝑎̇+𝑚𝑚̇𝐿𝐿𝐿𝐿𝐿𝐿= �𝜌𝜌𝑎𝑎𝑎𝑎𝑎𝑎∗ 𝑉𝑉̇�+𝑀𝑀𝑀𝑀𝑀𝑀𝑒𝑒𝑓𝑓𝑒𝑒𝑓𝑓 ρair is the density of air 𝑉𝑉̇ is the volumetric flow rate MLRfuel is the Mass Loss Rate of the LIB Once the peak heat release is reached, the ESS compartment assumed to be fully-developed/engaged. A normalized time 3000 seconds (50 minutes) is assumed based on LIB failure tests [14, 20, 27, 29, 33, 54- 57]. At this time an exothermic reaction is determined to be steady rate and will be sustained until a large percentage of the fuel is consumed. The components of a LIB fire and the associated release of volatile gasses and sustainment of the exothermic reaction included in the thermal breakdown of the module and battery includes the separators, packaging, and electrolyte of LIBs. The gases potentially vented during a thermal runaway reaction may include: The following list of emitted gases are based on an independent third party Nationally Recognized Testing Laboratory (NRTL) cell, module, and unit testing in accordance with UL 9540a, Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems [57, 58]. The volume of gas measured during the test is provided in Figure 8. The gases vented during a thermal runaway reaction include: • Acetylene • Ethylene • Methane • Methanol • Propane • Formaldehyde [37, 38, 59-61] - AES Clean Energy Confidential - - AES Clean Energy Confidential - 21 Figure 5: Results of Flammable Gas Monitoring during NRTL Testing of UL 9540A emitted from the Samsung SDI Module [3] With the large quantity of batteries and corresponding energy stored within these systems, a large amount of fuel and flammable gases will be generated during exothermic reaction leading to a potential deflagration. For the purposes of establishing bounding conditions for this Fire Risk Assessment, it is reasonable to assume that flammable volatiles will continued to be released from failing cells even after the peak heat release rate has been reached. As the temperature continues to rise in the containerized BESS, excess unburnt fuel vapors will continue to be released contributing to the temperature increase of the gaseous mass within the container. The Samsung SDI E4L cell released 212 liters during the UL9540A Cell Level Test and 5911 liters of flammable gas during the UL9540A Module Level Test [3, 4]. The Samsung SDI MS1304E101A module result in TRA propagation between cells and fire. The Samsung SDI MS1304E101A module weight was not obtainable as the module was completely consumed as shown in Figure 6 [3]. It is recognized the Novec Direct Injection System was able to cool the thermal runaway event documented in the Samsung SDI Unit Level Test. However, the design of the Direct Injection System cannot respond and cool subsequent thermal runaway events. Therefore, while not likely subsequent TRA and module to module propagation is assumed [62-64]. . - AES Clean Energy Confidential - - AES Clean Energy Confidential - 22 Figure 6: Samsung SDI Module MS1304E101A UL9540A Module Level Test Result. The resultant calculated Peak Heat Release Rate for the 40’ CEN Solutions BESS is 107.2MW. 4. Temperature of the Hot Gas Layer over time Research conducted for this FRA has identified recommendations from the SFPE Fire Protection Engineering Handbook [25] a suitable method for calculating the temperature rise of the upper gas layer in a compartmentalized fire is through the method of McCaffrey, Quintiere, and Harkleroad (MQH) [25]. The MQH method applies the conservation of energy principle to the hot gas layer, which gives the following Δ𝑇𝑇𝑔𝑔𝑇𝑇∞=𝑄𝑄̇𝑚𝑚̇𝑔𝑔𝑐𝑐𝑝𝑝𝑇𝑇∞1 + 𝐴𝐴ℎ𝑔𝑔𝑚𝑚̇𝑔𝑔𝑐𝑐𝑝𝑝 Where ∆𝑇𝑇𝑔𝑔𝑇𝑇∞ is the Change in Temperature above ambient overtime 𝑄𝑄̇ is the Heat Release Rate (kW) 𝑚𝑚̇𝑔𝑔 is the Mass Flow Rate of gas layer (kg/s) Cp is the Specific Heat of Air (kJ/kg-K) 𝑇𝑇∞ is the Ambient Air Temperature (oK) ℎ𝑔𝑔is the Heat Transfer Coefficient (kW/m2K) A is the Surface Area of Compartment Boundaries The MQH methodology facilitates the analyzation of the compartment temperature with respect to the energy generated by the fire, the flow rate of the gas out an opening under natural ventilation (𝑚𝑚̇𝑔𝑔), the specific heat of the air (cp), and the heat lost from the hot gas layer to the surrounding surfaces (ℎ𝑔𝑔). The MQH method identifies the compartmentalized hot gas layer temperature under naturally ventilated conditions [40]. For the purposes of this FRA, it is assumed the 40’ CEN container release smoke and flames through openings around the enclosure access doors to naturally ventilate to atmosphere. Lithium-ion batteries challenge this ventilation-limited premise as sufficient oxygen is generated through the exothermic reaction for sustainability [13, 14, 20, 47, 48, 65]. Testing has shown that lithium-ion - AES Clean Energy Confidential - - AES Clean Energy Confidential - 23 batteries are capable of producing sparks of flaming combustion in an inert environment along with a release of significant quantities of flammable gases. Therefore, it is assumed that a substantial amount of oxygen can release during each battery failure, as a result of the decomposition of the battery’s metal oxide (cathode). It is also assumed a limited oxygen concentration within the container will not stop the progression of thermal runaway within the ESS. Recent studies of LIB failures have indicated that one the ambient temperature reaches the battery thermal stability limits (typically 180 oC) thermal runaway chain- reactions may occur more readily. Although the oxygen released from the individual batteries may not be sufficient to sustain steady combustion within a ventilation-limited compartment, masses of flammable gases from the thermal runaway reactions of LIB’s will continue to be released. If the container is breached, sufficient oxygen may enter the container resulting in a deflagration of flammable gases [8, 25]. The likely scenario poses over-pressurization and explosion hazards due to the mass of unburnt fuel in a closed unventilated compartment; this presents additional hazards that are outside the scope of this report. Therefore, based on the assumption that forced ventilation will be used to mitigate hazards posed by lithium-ion batteries during failure, a forced ventilation scenario can be used to characterize a fully developed fire within an ESS. The continuous air flow into the ESS container will allow the fire to be limited to the quantity of fuel within the compartment – representing a fully-involved ESS fire event. The hot gas layer temperature is largely impacted by the ventilation conditions within the compartment. Therefore, with the understanding of the MQH methodology constraints, it is refined by the application of the work of Foote, Pagni, and Alvares [8]. Foote, Pagni, and Alvares conducted a series of 64 fire tests with varying forced ventilation conditions [8]. From these tests, empirical constants that represent the change in the hot gas layer temperature in forced ventilation conditions were derived. Applying the MQH method, Foote, Pagni, and Alvares added data for forced ventilation fires – now referred to as the FPA method was applied to calculate the temperature of the gas layer through Δ𝑇𝑇𝑔𝑔𝑇𝑇∞= 0.63 �𝑄𝑄̇𝑚𝑚̇𝑔𝑔𝑐𝑐𝑝𝑝𝑇𝑇∞�0.72 �𝐴𝐴ℎ𝑔𝑔𝑚𝑚̇𝑔𝑔𝑐𝑐𝑝𝑝�−0.36 The calculated temperature of the heated gas mixture is 1635 oK (1362 oC) after 3000 seconds. 5. Internal Wall Temperature of the BESS Fire Source The approach to calculating the wall temperature follows the SFPE Fire Protection Engineering Handbook [25] for compartmentalized fires for the application of the Peatross and Beyler method for highly conductive materials. Peatross and Beyler refined the MQH method based on the assumption normal insulating materials will have negligible impact on the total heat released during a fully engaged fire with highly conductive walls. Therefore, Peatross and Beyler ignores insulation of the container walls. This FRA follows the precedence and recognizes the existence of insulating materials but bounds the total risk through the application of Peatross and Beyler. Therefore, the rise of the wall temperature of the container is a function of the heat transfer between the hot gas layer and the steel panel. The temperature of the panel is a function of the heat stored within the panel with respect to the steel’s material properties (density, specific heat, thickness, surface area). The rise in the wall temperature is dependent on the enthalpy flow through the wall – heat into the wall from - AES Clean Energy Confidential - - AES Clean Energy Confidential - 24 the developed compartment fire and the outflow of heat from the wall to the external ambient environment. The gas layer throughout a mechanically ventilated compartment is assumed to be uniform, which heats the boundary layers (walls) at a constant rate. 𝑚𝑚𝑤𝑤"𝑐𝑐𝑑𝑑𝑇𝑇𝑤𝑤𝑑𝑑𝑑𝑑=ℎ𝑔𝑔�𝑇𝑇𝑔𝑔− 𝑇𝑇𝑤𝑤� − ℎ∞𝑇𝑇𝑤𝑤 This analyzes the heat flow into the wall from the radiant and convective heat from the hot gas layer and the heat outflow of the convective losses from the wall to the outside. According to Quintiere’s Fundamentals of Fire Phenomena [51], the temperature rise of the wall of the ESS fire source is calculated through the application of 𝑑𝑑𝑇𝑇𝑤𝑤𝑑𝑑𝑑𝑑=1𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠𝐴𝐴𝑤𝑤Δ𝑥𝑥�𝜀𝜀𝜀𝜀�𝑇𝑇𝑔𝑔4 +𝑇𝑇𝑊𝑊4 �+ℎℎ𝑜𝑜𝑜𝑜𝐴𝐴𝑊𝑊�𝑇𝑇𝑔𝑔− 𝑇𝑇𝑤𝑤� − ℎ∞𝐴𝐴𝑤𝑤(𝑇𝑇𝑤𝑤− 𝑇𝑇∞)� Where, 𝑑𝑑𝑇𝑇𝑤𝑤𝑑𝑑𝑜𝑜 is the change in wall temperature above ambient over time 𝜌𝜌𝑠𝑠 is the density of the container wall steel plate 𝒄𝒄𝒔𝒔 is the specific heat of steel Δ𝑥𝑥 is the thickness of the steel plate 𝐴𝐴𝑤𝑤 is the area of the containerized BESS exposed to the hot gas layer 𝜀𝜀 is emissivity 𝜀𝜀 is the Boltzman’s Constant 𝑇𝑇𝑔𝑔 is the temperature of the gas layer 𝑇𝑇∞ is the ambient temperature Tw is the temperature of the wall hhot is the heat transfer coefficient (hot) ℎ∞ is the heat transfer coefficient (ambient) The calculated internal wall temperature of the heated gas mixture is 1514 oK (1241 oC) after 3000 seconds. 6. Heat Transfer Coefficient To quantify the convective heat transfer at the boundary layer between the hot gas layer and the compartment walls, an effective heat transfer coefficient must be calculated. A heat transfer coefficient quantifies that rate at which heat is transferred from the hot gas layer of the fire through the solid wall [66]. The heat transfer coefficient used to represent the energy exchange at the hot side of the walls was based on the following equation 𝑇𝑇𝑤𝑤𝑎𝑎𝑓𝑓𝑓𝑓.𝑒𝑒𝑒𝑒𝑜𝑜=�𝑘𝑘𝑘𝑘𝑐𝑐𝑑𝑑 Where, k = thermal conductivity (kW/m-K) 𝑘𝑘 = density of steel (kg/m3) c = specific heat (kJ/kg-K) - AES Clean Energy Confidential - - AES Clean Energy Confidential - 25 t = time (s) This equation represents a heat transfer coefficient that is a function of the temperature dependent thermal conductivity of the steel panel, density, and specific heat of the steel with respect to time. Under ambient conditions, the heat transfer coefficient is a stagnant value, which is used to represent the convective losses to the outside of the container. This heat transfer coefficient is a function of the thermal conductivity of the steel at ambient condition and the thickness of the steel. Understanding the thermal resistivity limitations of (assumed) Polyurethane insulation of a maximum published value of 150oC and fails above the temperature limits, it is assumed the external surface temperature is 1514 oK (1241 oC) [67]. 7. Fire/Smoke Plume Centerline Temperature A characteristic accompanying the phenomenon of a BESS fire, especially in compartments in the phase of its development, is Fire Plume. For various reasons, the subject of concern may be the determination of an incipient smoke temperature. From the point of view of the used methods and extent of details, the temperature analysis of smoke and Fire Plume may be quite variable and challenging to determine. However, publications evaluated for this Fire Risk Assessment has identified the following methodology for calculating the centerline temperature for a smoke/fire plume as follows [68, 69]: ∆𝑇𝑇𝑜𝑜𝑠𝑠𝑎𝑎= 0.0964 �𝑇𝑇∞𝑔𝑔 𝑐𝑐𝑝𝑝2 𝜌𝜌𝑜𝑜2 �13 𝑄𝑄′𝑘𝑘23 (𝑧𝑧 − 𝑧𝑧0 )−53 Where, ∆𝑇𝑇𝑜𝑜𝑠𝑠𝑎𝑎is the smoke plume centerline temperature 𝑇𝑇∞ is the ambient temperature g is the gravitational constant cp gas specific heat capacity ρo ambient air density Q’k heat flux shared by convection z height above the inflammable material surface zo Fire Plume virtual start Understanding the plume centerline temperature is an important characteristic that contributes thermal radiation heat transfer to the adjacent containers and to the calculation of the ground level surface temperatures. Adjacent container and surface level temperatures are a function of the Configuration/View factors. 8. Configuration/View Factors A configuration factor is a purely geometrical relation between two surfaces, and is defined as the fraction of radiation leaving one surface which is intercepted by the other surface [8]. This factor is the variable that determines the fraction of radiation received by the target, with respect to the total radiation emitted from the source. The view factor accounts for the shape, orientation, and size of both the emitter and the target as well as the separation distance between them. Since this model accounts for the radiation coming from the heated ESS container and the externally vented flames, two view factors are calculated. Therefore, the incident radiant flux from a BESS fully engaged fire (source) to an adjacent BESS (target) separated by a given distance x, is given by - AES Clean Energy Confidential - - AES Clean Energy Confidential - 26 𝑞𝑞̈=𝐸𝐸𝐹𝐹12 Where E is the emissivity of the transmitting medium, and F is the no-wind view factor between the source and the Target. In this case, the view factor will be the integration of the emitting side of the target and the energy emitted from escaping hot gas. It is assumed the hot gases will escape around the doors of the source and will form a pseudo-cylindrical shape. Secondly, the side of the source that radiates the thermal energy to the adjacent BESS as indicated in Figure 9. Figure 7 The view factor from the BESS radiant source to adjacent containers is a critical component of this radiation heat transfer analysis. It is within this factor that the various separation distances are accounted for. Intuitively, the radiated heat is inversely proportional to distance: a fire’s intensity reduces with distance. The view factors account for the angle, separation distance, area of radiating surface/flame and the area of the target surface. The view factors for the radiating panel and cylindrical vented flames are calculated through the methods shown as follows: Determining the geometry for the identical, parallel, directly opposing BESS containers is taken from the SFPE Fire Protection Engineering Handbook [25] where 𝐹𝐹𝑝𝑝𝑓𝑓𝑎𝑎𝑜𝑜𝑒𝑒𝑠𝑠=�2𝜋𝜋𝜋𝜋𝜋𝜋��𝑙𝑙𝑙𝑙�𝜋𝜋1 𝜋𝜋11 +𝜋𝜋2 𝜋𝜋2 +𝜋𝜋�1 +𝜋𝜋2 ∗𝑑𝑑𝑡𝑡𝑙𝑙−1 �𝜋𝜋√1 +𝜋𝜋2 �−𝜋𝜋tan−1 (𝜋𝜋)−𝜋𝜋tan−1 (𝜋𝜋)� Where 𝜋𝜋1 = 1 +𝜋𝜋2 And 𝜋𝜋1 = 1 +𝜋𝜋2 X is the ratio of width to length of the BESS Y is the ratio of height to length of the BESS The view factor from the escaping hot gases is determined its vertical and horizontal components by - AES Clean Energy Confidential - - AES Clean Energy Confidential - 27 𝐹𝐹𝑐𝑐𝑐𝑐𝑐𝑐𝑓𝑓.𝑒𝑒𝑓𝑓𝑎𝑎𝑓𝑓𝑒𝑒.𝑣𝑣𝑒𝑒𝑎𝑎𝑜𝑜=1𝜋𝜋𝜋𝜋∗tan−1 �ℎ√𝜋𝜋2 + 1 �−ℎ𝜋𝜋𝜋𝜋∗tan−1 ��𝜋𝜋−1𝜋𝜋+ 1 �+𝐴𝐴ℎ𝜋𝜋𝜋𝜋√𝐴𝐴2 −1∗tan−1 ��(𝐴𝐴+ 1 )(𝜋𝜋−1)(𝐴𝐴 −1)(𝜋𝜋+ 1 )� And 𝐹𝐹𝑐𝑐𝑐𝑐𝑐𝑐𝑓𝑓.𝑒𝑒𝑓𝑓𝑎𝑎𝑓𝑓𝑒𝑒.ℎ𝑜𝑜𝑎𝑎𝑎𝑎𝑜𝑜=�𝐵𝐵 −1𝑠𝑠�𝜋𝜋√𝐵𝐵2 −1 ∗tan−1 ��(𝐵𝐵+ 1 )(𝜋𝜋−1)(𝐴𝐴 −1)(𝜋𝜋+ 1 )�−𝐴𝐴 −1𝜋𝜋𝜋𝜋√𝐴𝐴2 −1∗tan−1 ��(𝐴𝐴+ 1 )(𝜋𝜋−1)(𝐴𝐴 −1)(𝜋𝜋+ 1 )� Where the separation distance between the cylindrical radiant body (L), and the size of the flame (diameter (D) and flame height (H)) and, 𝜋𝜋=2𝑀𝑀𝐷𝐷 ℎ=2𝐻𝐻𝐷𝐷 𝐴𝐴=ℎ2 +𝜋𝜋2 + 12𝜋𝜋 𝐵𝐵=1 +𝜋𝜋22𝜋𝜋 9. Total Radiant and Convective Heat Flux As noted, the radiant heat flux between containers is determined by the derivation of 𝑞𝑞̈=𝐸𝐸𝐹𝐹12 , therefore determining the total incident radiative heat flux emitted from the ESS fire source is a summation of the heat flux from the flame and the heat radiated from the steel panel. The radiant heat flux emitted by the heated panel of the ESS fire source is quantified by the correlation shown in the equation below. 𝑞𝑞̇𝑝𝑝𝑎𝑎𝑝𝑝𝑒𝑒𝑓𝑓.𝑎𝑎𝑎𝑎𝑑𝑑=𝜀𝜀𝜀𝜀𝐹𝐹1𝑝𝑝,2𝑝𝑝(𝑇𝑇𝑤𝑤4 − 𝑇𝑇∞4 ) And 𝑞𝑞̇𝑐𝑐𝑐𝑐𝑓𝑓.𝑎𝑎𝑎𝑎𝑑𝑑=𝜀𝜀𝜀𝜀𝐹𝐹1𝑐𝑐,2𝑐𝑐�𝑇𝑇𝑒𝑒𝑓𝑓4 − 𝑇𝑇∞4 � Where, ε= emissivity of surface σ = Stefen-Boltzman Constant - AES Clean Energy Confidential - - AES Clean Energy Confidential - 28 F1p,2p = View factor from parallel BESS steel panels F1c,2c = View factor from cylindrical flame exiting ESS to exposed ESS steel panel Tw = Wall temperature of flames exiting the fire source ESS Tfl = Flame temperature of flames exiting the fire source ESS 𝑇𝑇∞ is the ambient temperature The calculated radiant heat flux and the external wall temperature of the fully engaged BESS is 782 kWm2 with a surface temperature of 1514 oK (1241 oC), respectively. 10. Total Convection Heat Flux An assumed 4.16 m/s Wind Driven Event ground level (surface) temperature due to thermal radiation heat transfer was calculated assuming the ESS container could be compromised due to the internal heat and fire during an exothermic reaction. If there was a breach in the container integrity resulting in a release of a smoke/fire plume, the centerline temperature of the fire/smoke plume would be calculated using the following numerical analysis outlined in SPFE Handbook of Fire Protection Engineering for compartmental fires [2] and those of Quintiere’s works in Fundamentals of Fire Phenomena [51]: The centerline temperature of the fire/smoke plume was determined by: ∆𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜= 0.0964 �𝑇𝑇∞𝑔𝑔 𝑐𝑐𝑝𝑝2 𝜌𝜌𝑜𝑜2 �13 𝑄𝑄′𝑘𝑘23 (𝑧𝑧 − 𝑧𝑧0 )−53 Where, ∆𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜is the smoke plume centerline temperature 𝑇𝑇∞ is the ambient temperature g is the gravitational constant cp gas specific heat capacity ρo ambient air density Q’k heat flux shared by convection z height above the inflammable material surface zo Fire Plume virtual start Understanding the BESS acts as a radiation shield from the plume centerline point source, the magnitude of the incident thermal radiation exposure on the surface, the quantity of radiation absorbed into the ground (assumed black body) was calculated using the Mudan Method [8]as follows: 𝑞𝑞′𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝=𝐸𝐸𝐸𝐸𝐸𝐸 Where E is the average emissive power of the plume at the flame surface F is the view factor to the target 𝐸𝐸 is the atmospheric transmissivity. The thermal power of the flame is given by - AES Clean Energy Confidential - - AES Clean Energy Confidential - 29 𝐸𝐸=𝐸𝐸𝑝𝑝𝑜𝑜𝑚𝑚𝑒𝑒−𝑜𝑜𝑠𝑠+𝐸𝐸𝑜𝑜[1 − 𝑒𝑒 −𝑜𝑜𝑠𝑠] Where, 𝐸𝐸𝑝𝑝𝑜𝑜𝑚𝑚 is equivalent blackbody emissive power, 140 kW/m2 s is the extinction coefficient, 0.12 m–1 D is the diameter of the fire 𝐸𝐸𝑜𝑜is the emissive power of smoke, 20kW/m2 The view factor of the wind driven fire/smoke plume is determined by 𝐸𝐸=�𝜋𝜋𝐸𝐸𝑣𝑣2 +𝜋𝜋𝐸𝐸𝐻𝐻2 Where, 𝜋𝜋𝐸𝐸𝑣𝑣=𝑎𝑎cos 𝜃𝜃𝑏𝑏 − 𝑎𝑎 𝑠𝑠𝑠𝑠𝑠𝑠𝜃𝜃 𝑎𝑎2 +(𝑏𝑏+ 1 )2 −2𝑏𝑏(1 +𝑠𝑠𝑠𝑠𝑠𝑠𝜃𝜃)√𝐴𝐴𝐴𝐴𝑡𝑡𝑎𝑎𝑠𝑠−1 ��𝐴𝐴𝐴𝐴�𝑏𝑏 −1𝑏𝑏+ 1 �12 � +𝑐𝑐𝑐𝑐𝑠𝑠𝜃𝜃√𝐶𝐶 𝑥𝑥�𝑡𝑡𝑎𝑎𝑠𝑠−1 �𝑎𝑎𝑏𝑏−(𝑏𝑏2 −1)𝑠𝑠𝑠𝑠𝑠𝑠𝜃𝜃√𝑏𝑏2 −1√𝐶𝐶�+𝑡𝑡𝑎𝑎𝑠𝑠−1 �(𝑏𝑏2 −1)𝑠𝑠𝑠𝑠𝑠𝑠𝜃𝜃√𝑏𝑏2 −1√𝐶𝐶�� −𝑎𝑎cos 𝜃𝜃(𝑏𝑏 − 𝑎𝑎 𝑠𝑠𝑠𝑠𝑠𝑠𝜃𝜃)𝑡𝑡𝑎𝑎𝑠𝑠−1 ��𝑏𝑏 −1𝑏𝑏+ 1 � And 𝜋𝜋𝐸𝐸𝐻𝐻=𝑡𝑡𝑎𝑎𝑠𝑠−1 ��𝑏𝑏 −1𝑏𝑏+ 1 �− 𝑎𝑎2 +(𝑏𝑏+ 1 )2 −2(𝑏𝑏+ 1 +𝑎𝑎𝑏𝑏𝑠𝑠𝑠𝑠𝑠𝑠𝜃𝜃)√𝐴𝐴𝐴𝐴𝑡𝑡𝑎𝑎𝑠𝑠−1 ��𝐴𝐴𝐴𝐴�𝑏𝑏 −1𝑏𝑏+ 1 �12 � +𝑠𝑠𝑠𝑠𝑠𝑠𝜃𝜃√𝐶𝐶 𝑥𝑥�𝑡𝑡𝑎𝑎𝑠𝑠−1 �𝑎𝑎𝑏𝑏−(𝑏𝑏2 −1)𝑠𝑠𝑠𝑠𝑠𝑠𝜃𝜃√𝑏𝑏2 −1√𝐶𝐶�+𝑡𝑡𝑎𝑎𝑠𝑠−1 �(𝑏𝑏2 −1)12 𝑠𝑠𝑠𝑠𝑠𝑠𝜃𝜃√𝐶𝐶�� Where, a is the ratio of the Flame Height to Flame Radius (H/R) b is the ratio of the distance between the center of the flame cylinder to the target to the flame radius A is given by the equation 𝐴𝐴=𝑎𝑎2 +(𝑏𝑏+ 1 )2 −2𝑎𝑎(𝑏𝑏+ 1 )𝑠𝑠𝑠𝑠𝑠𝑠𝜃𝜃 B is given by the equation 𝐴𝐴=𝑎𝑎2 +(𝑏𝑏+ 1 )2 −2𝑎𝑎(𝑏𝑏 −1)𝑠𝑠𝑠𝑠𝑠𝑠𝜃𝜃 C is given by the equation 𝐶𝐶= 1 + (𝑏𝑏2 + 1 )𝑐𝑐𝑐𝑐𝑠𝑠𝜃𝜃 Atmospheric absorption The radiation from the fire to surrounding objects will be partially attenuated by absorption and scattering along the intervening path. The principal constituents of the atmosphere that absorb thermal radiation are water vapor (H2O) and carbon dioxide (CO2) [8]. The atmospheric transmissivity is given by - AES Clean Energy Confidential - - AES Clean Energy Confidential - 30 𝐸𝐸= 1 − 𝛼𝛼𝑤𝑤− 𝛼𝛼𝑐𝑐 Where the carbon dioxide vapor absorption coefficient is, 𝛼𝛼𝑐𝑐=𝜀𝜀𝑐𝑐�𝑇𝑇𝑜𝑜𝑇𝑇𝑜𝑜�0.65 The partial pressure of CO2 remains relatively constant at about 3x10–4 atm. The emissivity of the carbon dioxide band is shown in Figure 10 [8]. Figure 8Total emissivity of carbon dioxide in a mixture of total pressure of 1 atm [2] And the water vapor absorption coefficient is 𝛼𝛼𝑤𝑤=𝜀𝜀𝑤𝑤�𝑇𝑇𝑜𝑜𝑇𝑇𝑜𝑜�0.45 Where 𝜀𝜀𝑤𝑤 is determined by the partial pressure of water vapor, 𝑝𝑝′𝑤𝑤=𝑅𝑅𝑅𝑅100 𝑒𝑒�14.4114− 5328𝑇𝑇𝑎𝑎� And the pathlength from the flame surface to the target is 𝑝𝑝𝑤𝑤𝐿𝐿=𝑝𝑝′𝑤𝑤𝐿𝐿�𝑇𝑇𝑜𝑜𝑇𝑇𝑜𝑜� - AES Clean Energy Confidential - - AES Clean Energy Confidential - 31 The source temperature, and 𝑝𝑝𝑤𝑤𝐿𝐿, determine the water vapor emissivity, 𝜀𝜀𝑤𝑤, using emissivity plots given in Figure 11. Where the centerline temperature was determined to be approximately 913oK. The atmospheric transmissivity is approximately 0.95. Figure 9:Total emissivity of water-vapor in a mixture of total pressure of 1 atm [8] Wind Driven Convection Heat Transfer and Surface Level Analysis Calculating the wind driven forced convection and the resultant contribution to the heat transfer of the surface of the adjacent ESS is subject to numerous assumptions. For the purposes of establishing bounding conditions where heat transfer is bounded and follows the work of Cengel [70]. - AES Clean Energy Confidential - - AES Clean Energy Confidential - 32 Figure 10: Luke AFB Windrose Data Example It is assumed a 4.16m/s wind event over the top of an engaged ESS will follow the principles in the transition from laminar to turbulent flow depends on the surface geometry, flow velocity, surface temperature, and type of fluid. For the purposes of this analysis, surface roughness is assumed to be negligible. Figure 11:Analyzed Forced Convection over the top of the Engaged ESS Assuming the top of the ESS to be a flat plate for maximum heat transfer, the Reynolds Number, the transition point where the air flow transitions from laminar to turbulent over a flat plate is governed by 𝑅𝑅𝑒𝑒𝐿𝐿=𝐿𝐿 𝑉𝑉𝐿𝐿𝑣𝑣 Where 𝐿𝐿 is the length of the headed surface (2.232 m, top of ESS) VL is the velocity of the wind event (4.165m/s) 𝑣𝑣 is the kenetic viscosity of air (1.338x10-5 m/s at 20oC) [71] Given the Reynolds number is less than the ideal (5x105), it is determined there is both turbulent and - AES Clean Energy Confidential - - AES Clean Energy Confidential - 33 laminar flow over the ESS. Given the thermal conductivity of air (k = 0.02514) and the Prandt number (Pr, 0.977 at 20oC for Sun City AZ), the Nusselt Number (Nu) numbers for laminar assuming uniform heat flux from the surface of the ESS is 𝑁𝑁𝑁𝑁𝐿𝐿=(0.664 𝑅𝑅𝑒𝑒𝑚𝑚0.8 )𝑃𝑃𝑃𝑃13 The net heat flux from the top of the container assuming a heat transfer coefficient of 62.5 kW/hr (ℎ=𝑘𝑘𝐿𝐿�𝑁𝑁𝑁𝑁) and applying the classical forced convection heat transfer equation [70] below 𝑄𝑄𝑐𝑐𝑜𝑜𝑐𝑐𝑣𝑣=ℎ 𝐴𝐴𝑜𝑜(𝑇𝑇1 − 𝑇𝑇2 ) and given the naturally occurring upward lift and wall shear of the heated air, assuming a bounding condition where 50% of the heat transfer due to convection is pulled into the wake region between ESSs, the total heat flux to the surface of the adjacent ESS is 𝑞𝑞𝑇𝑇𝑜𝑜𝑇𝑇𝑜𝑜𝑝𝑝′=𝑞𝑞𝐶𝐶𝑜𝑜𝑐𝑐′+𝑞𝑞𝑅𝑅𝑜𝑜𝑅𝑅′ The wind driven surface temperature of the adjacent ESS due to normal heat propagation, wind velocity, and direction will have an additional intermittent contribution of 365 kW/m2 to the first responders approximately 6.5’ away as shown in Figure 13. Figure 12: Maximum Theoretical Radiated Heat Flux at 10' (3.04m) - AES Clean Energy Confidential - - AES Clean Energy Confidential - 34 Table 2: Theoretical Momentary Heat Flux as a Function of Distance Distance Momentary Maximum Theoretical Heat Flux (kW/m2) 10’ 939 20’ 589 30’ 348 40’ 235 50’ 170 60’ 127 70’ 98 80’ 77 90’ 62 100’ 51 Internal Temperature of Adjacent Target ESS The rate of heat conduction through the adjacent container wall and internal container surface temperature would be determined by manipulation of [51] 𝑞𝑞𝑟𝑟𝑝𝑝𝑐𝑐.𝑜𝑜𝑅𝑅𝑎𝑎.𝐸𝐸𝐸𝐸𝐸𝐸"=𝐴𝐴�𝜋𝜋4 𝑘𝑘𝜌𝜌𝑐𝑐𝑡𝑡(𝑇𝑇𝑜𝑜𝑅𝑅𝑎𝑎.𝐸𝐸𝐸𝐸𝐸𝐸.𝑜𝑜𝑝𝑝𝑟𝑟𝑠𝑠𝑜𝑜𝑐𝑐𝑝𝑝− 𝑇𝑇𝑜𝑜𝑅𝑅𝑎𝑎.𝑜𝑜𝑜𝑜.𝑖𝑖𝑐𝑐𝑇𝑇) Assuming the application of a typical Polyurethane insulation product with a Thermal Conductance of 0.22, the temperature on the internal surface is determined through manipulation of 𝑞𝑞𝑟𝑟𝑝𝑝𝑐𝑐.𝑜𝑜𝑅𝑅𝑎𝑎.𝐸𝐸𝐸𝐸𝐸𝐸"=𝑘𝑘𝐿𝐿�𝑇𝑇𝑜𝑜𝑅𝑅𝑎𝑎.𝑜𝑜𝑜𝑜.𝑖𝑖𝑐𝑐𝑇𝑇− 𝑇𝑇𝑜𝑜𝑅𝑅𝑎𝑎.𝑖𝑖𝑐𝑐𝑇𝑇� Polyurethane performance above 130 oC is not published, therefore the Thermal Conductance is assumed to be degraded to approximately 0.05. Considering the geometric focus factors of a CEN 40’ CEN across an 6.5’ passageway, the atmospheric attenuation factors, assuming black-body radiated heat emanating from the painted iron fully engage BESS to an adjacent ESS, and radiation and convection heat transfer from the EnerC and the released fire plume could reach a momentary 1148 kW/m2. The calculated steady-state interior temperature of the CEN 40’ BESS across the 6.5’ passageway may experience approximately a 420K (147 oC) increase. Once the internal thermal management is no longer in operation, the heat transfer from the adjacent fully developed container fire could, as a function of the fire lifecycle and thermal insulation degradation, likely exceed the thermal stability thresholds of the adjacent BESS requiring additional mitigation strategies (i.e., use of fire water for evaporative cooling). - AES Clean Energy Confidential - - AES Clean Energy Confidential - 35 Theoretical Toxic Composition of Smoke Plume It is well documented that Lithium-ion battery fires generate intense heat and considerable amounts of gas and smoke [21, 34, 55, 61, 72-78]. Although the emission of toxic gases can be a larger threat than the heat, the knowledge of such emissions is limited for large grid-connected energy storage systems. Therefore, the following discussion outlines the findings of research into peer-reviewed publications and government sources to identify the potential toxic gas constituents in a ESS fire. New York State Energy Research & Development Authority (NYSERDA) and Consolidated Edison, the New York City Fire Department (FDNY) and the New York City Department of Buildings (NY DOB), DNV-GL was commissioned to address code and training updates required to accommodate deployment of energy storage in New York City. The research by NYSERDA concluded “that all batteries tested emitted toxic fumes, the toxicity is similar to a plastics fire and therefore a precedent exists”[55]. Several different manufacturer battery cells were tested and the typical gases emitted included: • Carbon monoxide (CO) • Hydrochloride (HCI) • Hydrogen Fluoride (HF) • Hydrogen Cyanide (HCN) Figure 13: Representative emissions histogram from a Li-ion battery DNV-GL concluded the “average emissions rate of a battery during a fire condition is lower per kilogram of material than a plastics fire”….”However, the peak emissions rate (during thermal runaway of a Li-ion battery, for example) is higher per kilogram of material than a plastics fire. This illustrates that a smoldering Li-ion battery on a per kilogram basis can be treated with the same precautions as something like a sofa, mattress, or office fire in terms of toxicity, but during the most intense moments of the fire (during the 2- 3 minutes that cells are igniting exothermically) precautions for toxicity and ventilation should be taken. It should be noted that if Li-ion battery modules are equipped with cascading protections, the cell failure rate may be randomized and staggered. The randomized failure rate limits the toxicity and heat release rate of the fire”[55]. However, few studies have been published that report measurements of released HF amounts from commercial Li-ion battery cells during abuse and HF release during electrolyte fire tests [59, 61, 75]. - AES Clean Energy Confidential - - AES Clean Energy Confidential - 36 Larsson et al. studied a broad range of commercial Li-ion battery cells with different chemistry, cell design and size and included large-sized automotive-classed cells, undergoing fire tests. Their objective was to evaluate fluoride gas emissions for a large variety of battery types and for various test setups. Based on their specialized results, they determined as a function of LIB design, a wide range of amounts of HF, ranging between 20 and 200 mg/Wh of nominal battery energy capacity, were detected from the burning Li-ion batteries [37, 59, 75]. Larsson determined the vented gases can contain evaporated solvents and decomposition products, e.g. CO, CO2, H2, CH4. Beside CO, a large number of different toxic compounds can be released including fluoride gases and most concerningly Hydrogen fluoride (HF). The fluorine in the cells comes from the Li- salt, e.g. LiPF6, but also from electrode binders, e.g. PVdF, electrode materials and coatings, e.g. fluorophosphates and AlF3-coated cathodes, as well as from fluorine containing additives, e.g. flame retardants [59]. PF5, POF3 and HF are of greatest concern but consideration should also be given to the fluorinated phosphoric acids since they will give HF and phosphoric acid when completely reacted with water [61]. Figure 14: Peak ppm per kg (in a 0.44 m3 volume) for all batteries tested as compared to plastics [55] The National Institute for Occupational Safety and Health (NIOSH) states that HF has a Immediately Dangerous to Life and health (IDLH) value of 30 ppm as shown in Table 3 [79]. No exposure limits are given for Phosphorus pentafluoride (PF5) and Phosphoryl fluoride (POF3), however their chlorine analogues, Phosphorus pentachloride (PCl5) and Phosphoryl chloride (POCl3) have recommended exposure limits (REL) values of 0.1 ppm [79]. - AES Clean Energy Confidential - - AES Clean Energy Confidential - 37 As it pertains to the Samsung SDI NMC cells, the work performed by the SP Technical Research Institute of Sweden when testing NMC, lithium ion phosphate cells, determined the measured concentrations of HF were “generally quite low but well above the detection limits” [61]. The SP Technical Research Institute of Sweden concluded based on their research “POF3 was detected in all the small scale tests using pure electrolyte. However, no POF3 was detected in the tests on cells. The detection limit for POF3 was 6 ppm. Extrapolating from the small scale tests to the cells tests one ends up at concentrations below 6 ppm, which probably explains why no POF3 was detected in these tests” [61]. “It is an important finding that POF3 is emitted from a battery fire as this will increase the toxicity of the fire effluents. The amount of POF3 is shown to be significant, 5-40 % of the HF emissions on a weight basis. No PF5 could be detected in any of the tests” [61]. Table 3: NIOSH Chemical Listing for Hydrogen Fluoride (HF) - AES Clean Energy Confidential - - AES Clean Energy Confidential - 38 Figure 15: HF release both as the measured concentrations[75] Lithium Ion ESS Fire Smoke Plume Research Conclusion Research has shown the complex mixture of flammable and toxic gases are emitted from the thermal decomposition of LIB is manufacturer and chemistry dependent. The composite breakdown of particles is a function of the size of the energy source and the inherent design chemistry that can only be estimated based on the research of others. To date, there is no readily identifiable performance data for the Samsung E4L batteries used in the Samsung SDI applications. Therefore, the following list of potentially flammable and toxic gases is theoretical based on the cited works of [21, 34, 55, 61, 72-78]: Table 4: List of Potential Emitted Gases during Thermal Runaway. Gases Measured Chemical Formula Gas Type Acetylene C2H2 Hydrocarbons Ethylene C2H4 Hydrocarbons Ethane C2H6 Hydrocarbons Methane CH4 Hydrocarbons Methanol CH3OH Hydrocarbons Formaldehyde CH2O Hydrocarbons (Aldehydes) Hydrogen Bromide HBr Hydrogen Halides Hydrogen Chloride HCl Hydrogen Halides Hydrogen Fluoride HF Hydrogen Halides Hydrogen Sulfide H2S Sulfur Containing Carbon Dioxide CO2 Carbon Containing Carbon Monoxide CO Carbon Containing Ammonia NH3 Nitrogen Containing Hydrogen Cyanide HCN Nitrogen Containing Hydrogen H2 - Sulfur Dioxide SO2 Sulfur Containing It is noted, that while the DNV-GL/NYSERDA report lists only 4 emitted gases, CSA testing of the Samsung - AES Clean Energy Confidential - - AES Clean Energy Confidential - 39 SDI 112 Ah batteries measured the following emitted gases: • “Carbon dioxide (CO2) • Carbon monoxide (CO) • Methane (CH4) • Ethylene (C2H4) • Ethane (C2H6) • Propene (C3H6) • Propane (C3H8) • Hydrogen (H2)”[80] Recommended Minimum Approach Distance The Occupational Safety and Health Administration requires employers to establish minimum approach distance (MAD) as “the closest distance a qualified employee may approach an energized conductor or object” [81]. While directly applicable to energized circuits, the requirement of notifying employees of occupational hazards and risks and establishing both engineering and administrative controls is presented in 29CFR 1910. For the purposes of this analysis, the Minimum Approach Distance is defined as the closet distance a qualified employee may approach a known hazard. While there are several different organizations (ACGIH, AIHA, OSHA, ISO, and NIOSH) that establish controls for hazard exposure, all require a job hazard analysis (JHA) be conducted to identify the hazard controls. It is assumed the appropriate JHA will be performed for each scheduled task when operating and maintaining the Samsung SDI energy storage systems. Table 2 presents the radiated heat flux as a function of distance from a fully engaged energy storage system. Table 5 presents the physiological effects of thermal radiation and the time of exposure to extreme pain and 2nd degree burns. Table 5: Physiological Effects of Thermal Radiation [82] Time for Physiological Effects (on bare skin) to Occur Following Exposure to Specific Thermal Radiation Levels the Radiation Intensity (kW/m2) Time for Severe Pain (seconds) Time for 2nd Degree Burn (seconds) 1 115 663 2 45 187 3 27 92 4 18 57 5 13 40 6 11 30 8 7 20 10 5 14 12 4 11 Therefore, it is recommended the Minimum Approach Distances for First Responders be set at a - AES Clean Energy Confidential - - AES Clean Energy Confidential - 40 conservative distance of 50 ft. when responding to a fire due to the potential radiated heat and HF exposure. Scenarios From a fire protection standpoint, the overall fire hazard of any ESS is a combination of all the combustible system components, including battery chemistry, battery format (e.g., cylindrical, prismatic, polymer pouch), battery capacity and energy density, materials of construction, and component design (e.g., battery, module). To ensure confidence in the conservative approach for this FRA, the ESS are assumed to be operating under a normal operating condition, such that proprietary electronic protection systems, e.g., battery management system (BMS), are active. It is recognized any benefit from these proprietary systems would further reduce the overall hazard, e.g., the likelihood of ignition, but is not necessary to ensure the adequacy of the protection. The enabling assumption of the fire scenario is based on the numerous published energy storage system fires with a probability of occurrence of less than 1 % across the global ESS market sector. Based on the UL9540A Cell, Module, and Unit Level Testing, and understanding the lack of propagation when heated to thermal runaway temperatures, the likelihood of a sustained fire within the Samsung SDI is reasonably less than 1%. Data Sources [1] D. Hill, "Technical Support for APS Related to Mcmicken Thermal Runaway and Explosion: McMicken Battery Energy Storage System Event Technical Analysis and Recommendations," DNV GL Energy Insights USA, Inc., Chalfont, PA, 18 July 2020 2020. [2] UL, "Unit Test Report - UL 9540A Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems (AACD)," Underwriters Laboratory, Northbrook IL, 20 January 2022. [3] UL, "Module Test Report - UL 9540A Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems (AACD)," Underwriters Laboratory, Northbrook IL, 20 January 2022. [4] UL, "Cell Test Report - UL 9540A Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems (AACD)," Underwriters Laboratory, Northbrook IL, 14 October 2020. [5] UL, "Installation Test Report - UL 9540A Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems (AACD)," Underwriters Laboratory, Northbrook IL, 17 May 2022. [6] NFPA, "NFPA 551: guide for the evaluation of fire risk assessments," National Fire Protection Association, Quincy, USA, 2016. [7] Engineering Guide: Fire Risk Assessment, SFPE, Gaithersburg, MD, 2006. [8] M. J. Hurley et al., SFPE Handbook of Fire Protection Engineering. Quincy, Massachusetts: National Fire Protection Association, 2015. [9] ISO 16732-1: Fire Safety Engineering - Fire RIsk Assessment, Part 1 - General, ISO, Geneva, Switzerland, 15 February 2012 2012. [10] ISO 16732-1: Fire Safety Engineering - Fire RIsk Assessment, Part 3: Example of an Industrial Property, ISO, Geneva, Switzerland, 15 February 2012 2012. [11] DOE, "U.S. Battery Storage Market Trends," ed. Washington DC: US Department of Energy, US Energy Information Administration 2018. [12] DNV-GL, "McMicken Battery Energy Storage System Event Technical Analysis and - AES Clean Energy Confidential - - AES Clean Energy Confidential - 41 Recommendations," Chalfont, PA, 18 July 2020 2020. [13] D. Belov and M.-H. Yang, "Failure mechanism of Li-ion battery at overcharge conditions," Journal of Solid State Electrochemistry, vol. 12, no. 7-8, pp. 885-894, 2008. [Online]. Available: https://www.researchgate.net/profile/Dmitry_Belov6/publication/226507209_Failure_me chanism_of_Li- ion_battery_at_overcharge_conditions/links/56fb42cb08ae8239f6dadb98.pdf. [14] N. Ponchaut, K. Marr, F. Colella, V. Somandepalli, and Q. Horn, "Thermal runaway and safety of large lithium-ion battery systems," Proceedings of the The Battcon, pp. 17.1-17.10, 2015. [15] F. Xu et al., "Failure investigation of LiFePO4 cells under overcharge conditions," Journal of The Electrochemical Society, vol. 159, no. 5, p. A678, 2012. [16] Z. Wang, K. Zhu, J. Hu, and J. Wang, "Study on the fire risk associated with a failure of large- scale commercial LiFePO4/graphite and LiNixCoyMn1-x-yO2/graphite batteries," Energy Science & Engineering, vol. 7, no. 2, pp. 411-419, 2019. [17] S. Wang, Z. Du, Z. Han, Z. Zhang, L. Liu, and J. Hao, "Study of the Temperature and Flame Characteristics of Two Capacity LiFePO4 Batteries in Thermal Runaway," Journal of The Electrochemical Society, vol. 165, no. 16, pp. A3828-A3836, 2018, doi: 10.1149/2.0531816jes. [18] Q. Wang, P. Ping, X. Zhao, G. Chu, J. Sun, and C. Chen, "Thermal runaway caused fire and explosion of lithium ion battery," Journal of power sources, vol. 208, pp. 210-224, 2012. [19] Q. Wang, B. Mao, S. I. Stoliarov, and J. Sun, "A review of lithium ion battery failure mechanisms and fire prevention strategies," Progress in Energy and Combustion Science, vol. 73, pp. 95-131, 2019. [20] P. Ping et al., "Study of the fire behavior of high-energy lithium-ion batteries with full-scale burning test," Journal of Power Sources, vol. 285, pp. 80-89, 2015. [21] D. Ouyang, M. Chen, Q. Huang, J. Weng, Z. Wang, and J. Wang, "A review on the thermal hazards of the lithium-ion battery and the corresponding countermeasures," Applied Sciences, vol. 9, no. 12, p. 2483, 2019. [22] X. Li and Z. Wang, "A novel fault diagnosis method for lithium-Ion battery packs of electric vehicles," Measurement, vol. 116, pp. 402-411, 2018. [23] B. Ditch and D. Zeng, "Research Technical Report: Development of Sprinkler Protection Guidance for Lithium Ion Based Energy Storage Systems," FM Global, Norwood, MA, June 2019 2019. [24] NFPA, "Sprinkler Protection Guidance for Lithium-Ion Based Energy Storage Systems," National Fire Protection Association, Quincy, MA USA, June 2019 2019. [Online]. Available: https://www.nfpa.org//-/media/Files/News-and-Research/Fire-statistics-and- reports/Suppression/RFESSSprinklerProtection.pdf [25] A. E. Cote, NFPA No.: FPH2008 - Fire Protection Handbook, Twentieth Edition ed. Quincy, MA: National Fire Protection Assoc, 2008. [26] CSA, "Project 80040846: CSA Group hereby confirms that it has completed an evaluation of: Li-ion Battery Cell, models 001CB310, CB310 and CB2W0," CSA Group, Ningde City, China, Project 80040846, 22 July 2020. [27] S. Koch, K. Birke, and R. Kuhn, "Fast thermal runaway detection for lithium-ion cells in large scale traction batteries," Batteries, vol. 4, no. 2, p. 16, 27 March 2018 2018. [Online]. Available: www.mdpi.com/journal/batteries. [28] M. Ghiji et al., "A Review of Lithium-Ion Battery Fire Suppression," Energies, vol. 13, no. 19, p. 5117, 2020. [29] R. T. L. Jr., J. A. Sutula, and M. J. Kahn, "Lithium Ion Batteries Hazard and Use Assessment - AES Clean Energy Confidential - - AES Clean Energy Confidential - 42 Phase IIB, Flammability Characterization of Li-ion Batteries for Storage Protection," The Fire Protection Research Foundation, Quincy MA, April 29, 2013 2013. [30] L. Kong, C. Li, J. Jiang, and M. Pecht, "Li-ion battery fire hazards and safety strategies," Energies, vol. 11, no. 9, p. 2191, 2018. [31] S. Cummings. "South Korea Identifies Top 4 Causes that Led to ESS Fires." Li-ion Tamer. https://liiontamer.com/south-korea-identifies-top-4-causes-that-led-to-ess-fires/ (accessed 26 July 2019, 2019). [32] S. J. Harris, D. J. Harris, and C. Li, "Failure statistics for commercial lithium ion batteries: A study of 24 pouch cells," Journal of Power Sources, vol. 342, pp. 589-597, 2017. [33] J. Lamb, C. J. Orendorff, L. A. M. Steele, and S. W. Spangler, "Failure propagation in multi- cell lithium ion batteries," Journal of Power Sources, vol. 283, pp. 517-523, 2015. [34] J. Lamb, C. J. Orendorff, E. P. Roth, and J. Langendorf, "Studies on the thermal breakdown of common Li-ion battery electrolyte components," Journal of The Electrochemical Society, vol. 162, no. 10, pp. A2131-A2135, 2015. [35] W. Tang, W. C. Tam, L. Yuan, T. Dubaniewicz, R. Thomas, and J. Soles, "Estimation of the critical external heat leading to the failure of lithium-ion batteries," Applied thermal engineering, vol. 179, p. 115665, 2020. [36] A. Sarkar, I. C. Nlebedim, and P. Shrotriya, "Performance degradation due to anodic failure mechanisms in lithium-ion batteries," Journal of Power Sources, vol. 502, p. 229145, 2021. [37] F. Larsson, P. Andersson, P. Blomqvist, A. Lorén, and B.-E. Mellander, "Characteristics of lithium-ion batteries during fire tests," Journal of Power Sources, vol. 271, pp. 414-420, 2014. [38] F. Larsson, P. Andersson, P. Blomqvist, and B.-E. Mellander, "Toxic fluoride gas emissions from lithium-ion battery fires," Scientific reports, vol. 7, no. 1, pp. 1-13, 2017. [39] N. Williard, W. He, C. Hendricks, and M. Pecht, "Lessons learned from the 787 Dreamliner issue on lithium-ion battery reliability," Energies, vol. 6, no. 9, pp. 4682-4695, 2013. [40] J. Vetter et al., "Ageing mechanisms in lithium-ion batteries," Journal of power sources, vol. 147, no. 1-2, pp. 269-281, 2005. [41] UL 1642 UL Standard for Safety Lithium Batteries, UL, Nrothbrook, IL, 29 September 2020 2020. [42] Celina Mikolajczak, Michael Kahn, Kevin White, and Richard Thomas Long, "Lithium-Ion Batteries Hazard and Use Assessment - Final Report," The Fire Protection Research Foundation, Quincy MA, July 2011 2011. [43] "IEEE Standard for Rechargeable Batteries for Multi-Cell Mobile Computing Devices," IEEE Std 1625-2008 (Revision of IEEE Std 1625-2004), pp. c1-79, 2008, doi: 10.1109/IEEESTD.2008.4657368. [44] ANSI/CAN/UL-1973:2018, Batteries for Use in Stationary, Vehicle Auxiliary Power and Light Electric Rail (LER) Applications, UL, Northbrook, IL, February 7, 2018 2018. [45] UL, "Module Test Report UL 9540A Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems (AACD) [Samsung SDI MS8943E101A]," Underwriters Laboratory, GYEONGGI-DO, Republic of Korea, 4789768841, 25 May 2022. [46] NHTSA, "Lithium-ion Battery Safety Issues for Electric and Plug-in Hybrid Vehicles," US Department of Transportation, National Highway Traffic Safety Administration, Washington D.C., October 2017 2017. [Online]. Available: https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/12848- lithiumionsafetyhybrids_101217-v3-tag.pdf [47] A. Blum and R. Long Jr, "Lithiu m Ion Batteries Hazard and Use Assessment - Phase III," in "Fire Protection Research Foundation," Fire Protection Research Foundation, Quincy, MA, - AES Clean Energy Confidential - - AES Clean Energy Confidential - 43 November 2016 2016. [48] A. F. Blum and R. T. Long Jr, Fire Hazard Assessment of Lithium Ion Battery Energy Storage Systems. Springer Nature, 2016. [49] DNV-GL, "Safety, Operation and Performance of Grid Connected Energy Storage Systems," vol. DNVGL-RP-0043, ed. Oslo, Norway: Det Norske Veritas Holding AS, 2017. [50] UL, "Cell Test Report: UL 9540A Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems (AACD)," Underwriters Laboratory, LLC, Fujian, CN, 27 December 2019. [51] J. Quintiere, Fundamentals of fire phenomena. Wiley, 2006. [52] M. Greenwood, M. Wentker, and J. Leker, "A bottom-up performance and cost assessment of lithium-ion battery pouch cells utilizing nickel-rich cathode active materials and silicon- graphite composite anodes," Journal of Power Sources Advances, vol. 9, p. 100055, 2021. [53] G. Mulder et al., "Comparison of commercial battery cells in relation to material properties," Electrochimica Acta, vol. 87, pp. 473-488, 2013. [54] T. Ohsaki et al., "Overcharge reaction of lithium-ion batteries," Journal of Power Sources, vol. 146, no. 1-2, pp. 97-100, 2005. [55] DNV-GL, "Considerations for ESS Fire Safety," 3rd ed. Dublin, OH: Det Norske Veritas (U.S.A.), Inc. (DNV GL), 2017. [56] C. Edison, "Considerations for ESS Fire Safety," DET NORSKE VERITAS (U.S.A.),, Dublin, OH, OAPUS301WIKO(PP151894), Rev. 3, January 18th, 2017 2017. [Online]. Available: https://nysolarmap.com/media/1718/dg-hubbess-con-edison-nyserda-final-report- 11817.pdf [57] UL, "UL 9540A Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems: Module Level Test Report - Model EM048290P5B1," UL Research and Development, Energy & Power Technologies, Washington D.C., 2019. [58] UL, "UL 9540a Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems," UL Research and Development, Energy & Power Technologies, Washington D.C., 2018-06-15 2018. [59] F. Larsson, S. Bertilsson, M. Furlani, I. Albinsson, and B.-E. Mellander, "Gas explosions and thermal runaways during external heating abuse of commercial lithium-ion graphite-LiCoO2 cells at different levels of ageing," Journal of power sources, vol. 373, pp. 220-231, 2018. [60] F. Larsson and B.-E. Mellander, "Abuse by external heating, overcharge and short circuiting of commercial lithium-ion battery cells," Journal of The Electrochemical Society, vol. 161, no. 10, p. A1611, 2014. [61] P. Andersson, P. Blomqvist, A. Loren, and F. Larsson, Investigation of fire emissions from Li- ion batteries. 2013. [62] M. Held et al., "Thermal runaway and fire of electric vehicle lithium-ion battery and contamination of infrastructure facility," Renewable and Sustainable Energy Reviews, vol. 165, p. 112474, 2022. [63] Z. Wang, H. Yang, Y. Li, G. Wang, and J. Wang, "Thermal runaway and fire behaviors of large- scale lithium ion batteries with different heating methods," Journal of hazardous materials, vol. 379, p. 120730, 2019. [64] X. Tian et al., "Design strategies of safe electrolytes for preventing thermal runaway in lithium ion batteries," Chemistry of Materials, vol. 32, no. 23, pp. 9821-9848, 2020. [65] A. Blum and R. Long Jr, "Hazard assessment of lithium ion battery energy storage systems," in "Fire Protection Research Foundation," Fire Protection Research Foundation, Bowie, MD, February 2016 2016. [66] D. Pitts and L. Sissom, Schaum's Outline of Theory and Problems of Heat Transfer 2ed. - AES Clean Energy Confidential - - AES Clean Energy Confidential - 44 (Schaum's Outline Series). New York, NY: McGraw Hill, 1988. [67] C. Choy and D. Greig, "The low temperature thermal conductivity of isotropic and oriented polymers," Journal of Physics C: Solid State Physics, vol. 10, no. 2, p. 169, 1977. [68] J. Pokorný, "Determination of centreline temperature of Fire Plume with respect to a gas hot layer," presented at the Fire Engineernig, 3nd International Scientific Conference, Technical university in Zvolen, Slovak republic, January 2010, 2010. [Online]. Available: https://www.researchgate.net/publication/269990367_Determination_of_centreline_tem perature_of_Fire_Plume_with_respect_to_a_gas_hot_layer. [69] Z. Xing, J. Mao, Y. Huang, J. Zhou, W. Mao, and F. Deng, "Scaled experimental study on maximum smoke temperature along corridors subject to room fires," Sustainability, vol. 7, no. 8, pp. 11190-11212, 2015. [70] Y. Cengel, Heat and mass transfer: fundamentals and applications. McGraw-Hill Higher Education, 2014. [71] "Viscosity of Air, Dynamic and Kinematic." Engineers Edge, LLC. https://www.engineersedge.com/physics/viscosity_of_air_dynamic_and_kinematic_1448 3.htm (accessed 17 February 2020. [72] A. Nedjalkov et al., "Toxic gas emissions from damaged lithium ion batteries—analysis and safety enhancement solution," Batteries, vol. 2, no. 1, p. 5, 2016. [73] DNV-GL, "Testing of Aerosol Fire Extinguishing Agent for Li-ion Battery Fires," vol. 10030271 – HOU – R -01, ed. Rochester, NY: Det Norske Veritas (DNV) GL - Energy Advisory Americas, 2017. [74] UL, "UL 9540A Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems Cell Level Test Report Model Model 6LH3L8," Underwriters Laboratory, Washington DC, Project Number 4788679452, 31 May 2019 2019. [75] F. Larsson, P. Andersson, P. Blomqvist, and B.-E. Mellander, "Toxic fluoride gas emissions from lithium-ion battery fires," Scientific reports, vol. 7, no. 1, p. 10018, 2017. [76] P. Ribière, S. Grugeon, M. Morcrette, S. Boyanov, S. Laruelle, and G. Marlair, "Investigation on the fire-induced hazards of Li-ion battery cells by fire calorimetry," Energy & Environmental Science, vol. 5, no. 1, pp. 5271-5280, 2012. [77] A. Lecocq, G. G. Eshetu, S. Grugeon, N. Martin, S. Laruelle, and G. Marlair, "Scenario-based prediction of Li-ion batteries fire-induced toxicity," Journal of Power Sources, vol. 316, pp. 197-206, 2016. [78] N. S. Spinner et al., "Physical and chemical analysis of lithium-ion battery cell-to-cell failure events inside custom fire chamber," Journal of Power Sources, vol. 279, pp. 713-721, 2015. [79] M. E. Barsan, "NIOSH pocket guide to chemical hazards," 2007. [80] CSA, "UL 9540A - Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems, 3rd edition for Li-ion Battery Cell, models 001CB310, CB310 and CB2W0, nominal voltage 3.2V, 280Ah," CCIC-CSA International Certification Co., Ltd. Kunshan Branch, Kunshan, China, 22 July 2020. [81] (2021). 1926.968 - Definitions. [Online] Available: https://www.osha.gov/laws- regs/regulations/standardnumber/1926/1926.968 [82] F. E. M. Agency, "Handbook of Chemical Hazard Analysis Procedures," ed: US EPAU. S. DOT, 1993. AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 60 Please see the following pages for the Garfield County Wildfire Susceptibility Map in the area of the AES Eagle Springs Organic Solar project. GARFIELD COUNTY WILDFIRE SUSCEPTIBILITY MAP Appendix C10 Battlement MesaRulisonCarbonateN/CDE BEQUE FPDRIFLE FPDLOWER VALLEY N/CN/CGRAND VALLEY FPDBURNING MOUNTAINS FPDN/CN/CGYPSUM FPDGLENWOOD SPRINGS FDCARBONDALE AND RURAL FPDN/CN/CN/CN/CRifleSiltGlenwood SpringsNew CastleCarbondaleParachute§¨¦70§¨¦70§¨¦70UV13UV139UV82UV6UV325UV133£¤6£¤6£¤6T2NT5ST1NT2ST1ST5ST4ST6ST7SR93WR91WR99WR96WR89WR97WR90WR92WR88WR98WR101WR102WR95WR103WR104WR94WR100WR105W107°5'W107°5'W107°10'W107°10'W107°15'W107°15'W107°20'W107°20'W107°25'W107°25'W107°30'W107°30'W107°35'W107°35'W107°40'W107°40'W107°45'W107°45'W107°50'W107°50'W107°55'W107°55'W108°0'W108°0'W108°5'W108°5'W108°10'W108°10'W108°15'W108°15'W108°20'W108°20'W108°25'W108°25'W108°30'W108°30'W108°35'W108°35'W108°40'W108°40'W108°45'W108°45'W108°50'W108°50'W108°55'W108°55'W109°0'W109°0'W40°10'N40°10'N40°5'N40°5'N40°0'N40°0'N39°55'N39°55'N39°50'N39°50'N39°45'N39°45'N39°40'N39°40'N39°35'N39°35'N39°30'N39°30'N39°25'N39°25'N39°20'N39°20'N39°15'N39°15'N$WeldMoffatMesaBacaParkRouttYumaLas AnimasGarfieldLincolnLarimerPuebloGunnisonBentElbertSaguacheGrandRio BlancoLoganEagleKiowaEl PasoMontroseOteroDeltaWashingtonLa PlataKit CarsonProwersJacksonFremontPitkinMontezumaCheyenneHuerfanoMorganAdamsCostillaConejosArchuletaDoloresChaffeeHinsdaleMineralSan MiguelCusterTellerDouglasCrowleyPhillipsBoulderOurayAlamosaArapahoeSummitRio GrandeLakeSedgwickJeffersonSan JuanClear CreekGilpinDenverBroomfieldUta hUta hKansasK a ns asWyomingWyomingNew MexicoNew MexicoNebraskaNebraskaOklahomaOklahomaGarfield County Community Wildfire Protection PlanMap 7: Wildland Fire Susceptibility IndexGarfield County, CONAD83 UTM Zone 13NU:\Projects\901162_0001_010_GarfieldCWPP\map_mxd\GarfieldCWPP_WildfireSusceptibility_ANSID.mxd 9/25/2012010MilesUtility LinesRailroadsCounty Roads - GarfieldLocal Roads - GarfieldInterstate-ExpresswayHighwayStreamsTownshipsCity LimitsFire Districts (N/C = Not Covered)Wildland Urban InterfaceLakes-ReservoirsWildland Fire Susceptibility IndexNR240,661 AcresLow1,194,700 AcresModerate246,396 AcresHigh145,838 AcresVery High65,790 AcresSource: CSFS AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 61 Please see the following pages for the Geotechnical Engineering Report performed for AES Eagle Springs Organic Solar, LLC in February 2023. GEOTECHNICAL ENGINEERING REPORT Appendix C11 Report Cover Page Eagle Springs Organic Solar Revised Design-Level Geotechnical Engineering Report February 17, 2023 |Terracon Project No. 61225141 Prepared for: ACE DevCo NC, LLC 282 Century Place Suite 2000 Louisville, CO 80027 6949 South High Tech Drive Midvale, Utah 84047 P (801) 545-8500 Terracon.com Facilities | Environmental |Geotechnical |Materials Report Cover L etter to SignFebruary 17, 2023 ACE DevCo NC, LLC 282 Century Place Suite 2000 Louisville, CO 80027 Attn: Mr. Michael Jenkinson P:(720) 431-8599 E:michael.jenkinson@aes.com Re: Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar near County Road 315 and 346 Garfield County, Colorado Terracon Project No. 61225141 Dear Mr. Michael Jenkinson: We have completed the scope of Revised Design-Level Geotechnical Engineering services for the above-referenced project in general accordance with Terracon Proposal No. P61225141 dated June 28, 2022. This report presents the findings of the subsurface exploration and provides geotechnical recommendations concerning earthwork as well as the design and construction of foundations and access roads for the proposed project. We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report or if we may be of further service, please contact us. Sincerely, Terracon Charles V. Molthen, P.E. (UT)Scott Myers, P.E. Senior Associate/Geotechnical Department Manager Principal/Senior Engineer SME Review –Matthew R.Kleinholz, P.E. (AZ) Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials i Table of Contents Introduction .................................................................................................... 1 Project Description .......................................................................................... 1 Site Conditions ................................................................................................ 2 Geotechnical Characterization ......................................................................... 3 Site Geology ............................................................................................ 3 Subsurface Profile ..................................................................................... 3 Groundwater Conditions ............................................................................. 4 Seismic Site Class ............................................................................................ 4 Thermal Resistivity and Soil Chemistry ............................................................ 5 Thermal Resistivity ................................................................................... 5 Soil Corrosivity ......................................................................................... 6 Contributory Risk Components ......................................................................... 7 Pile Load Testing ............................................................................................. 9 Pile Driving .............................................................................................. 9 Pile Load Test Procedures and Equipment ..................................................... 9 Summary of Pile Load Test Results ............................................................. 10 Solar Panel Pile Design Recommendations ..................................................... 11 Adfreeze Considerations for Driven Pile Foundations ...................................... 12 Geotechnical Axial Capacity ....................................................................... 12 Geotechnical Lateral Capacity .................................................................... 14 Construction Considerations ...................................................................... 15 Pile Design Recommendations for Other Structures ....................................... 16 Deep Foundation Recommendations for Other Structures ............................... 16 Earthwork ..................................................................................................... 19 Site Preparation....................................................................................... 19 Soil Stabilization ...................................................................................... 19 Fill Material Types .................................................................................... 20 Fill Placement and Compaction Requirements ............................................... 21 Utility Trench Backfill................................................................................ 22 Grading and Drainage ............................................................................... 23 Earthwork Construction Considerations ....................................................... 23 Construction Observation and Testing ......................................................... 23 Mat/Slab Foundations ................................................................................... 24 Mat Foundations for Support of Inverters ..................................................... 24 Frost Susceptible Soils .............................................................................. 24 Mat Foundation Design Recommendations ................................................... 25 Mat Foundation Construction Considerations ................................................ 26 Access Roadways .......................................................................................... 26 General Comments ........................................................................................ 28 Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials ii Attachments Exploration and Testing Procedures Site Location and Exploration Plans Exploration and Laboratory Results Pile Load Testing Results Refer to each individual Attachment for a listing of contents. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 1 Introduction This report presents the results of our subsurface exploration and Revised Design-Level Geotechnical Engineering services performed for the proposed Eagle Springs Organic Solar Facility to be located near County Road 315 and 346 in Garfield County, Colorado. The purpose of these services was to provide information and geotechnical engineering recommendations relative to: ■subsurface soil conditions ■pile load test results ■electrical resistivity for grounding design ■thermal resistivity ■seismic site classification per IBC ■site preparation and earthwork ■foundation design and construction ■unpaved access roads ■frost considerations ■groundwater considerations The geotechnical engineering Scope of Services for this project consists of field exploration, laboratory testing, engineering analysis, and preparation of this report. Drawings showing the site and boring locations are shown on the Site Location and Exploration Plan, respectively. The results of the laboratory testing performed on soil samples obtained from the site during our field exploration are included on the boring logs and as separate graphs in the Exploration and Laboratory Results section. Project Description Our initial understanding of the project was provided in our proposal and was discussed during project planning. A period of collaboration has transpired since the project was initiated, and our final understanding of the project conditions is as follows: Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 2 Item Description Information Provided Project information was provided by AES via emails received on May 31, 2022. The information included: ■Google Earth KMZ file outlining the project parcel ■“Solar and Energy Storage Project, Geotechnical Scope Minimum Technical Requirements, Version R001” dated February 2022 Project Description The project consists of providing site and subsurface conditions for a proposed solar facility project. The power capacity of the project is on the order of about 10 MW AC with 20 MWh battery storage. Due to the presence of existing transmission lines and substation infrastructure immediately adjacent to the project parcels, we have assumed no substation scope is needed for the development. Proposed Structure Photovoltaic modules aligned in arrays and affixed to a single-axis tracking system to be supported on driven steel piles. Electrical equipment and substation elements will be supported on concrete slabs-on-grade and or shallow spread footings. Maximum Loads (assumed) ■PV Module Downward: 1 to 7 kips ■PV Module Uplift: 0.5 to 3 kips ■PV Module Lateral: 1 to 2 kips ■PV Module Moment: 0.1 to 30 kip-ft Grading/Slopes Grading and/or site plans were not provided at this stage of the project. However, it is our assumption that proposed grades will follow existing site grades with minimal earthwork. Access Roads We understand that access road cross sections used for construction of the project will be the responsibility of the engineering, procurement, and construction (EPC) contractor, and that only postconstruction traffic with an allowable rut depth of 2 inches is what we are to design for this project. We anticipate low-volume, aggregate-surfaced, and native subgrade soil access roads will have a maximum vehicle load of 30,000 lbs and will travel over the access roads only once per week. Estimated Start of Construction 2023 Terracon should be notified if any of the above information is inconsistent with the planned construction, especially the grading limits, as modifications to our recommendations may be necessary. Site Conditions The following description of site conditions is derived from our site visit in association with the field exploration and our review of publicly available geologic and topographic maps. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 3 Item Description Parcel Information The proposed solar facility is to be constructed on up to 95 acres of land located near County Road 315 and 346 in Garfield County, Colorado. Coordinates near the center of the site are: Latitude: 39.5276°, Longitude: -107.6976° See Site Location Existing Improvements The project site is currently an undeveloped parcel consisting of ranch and farmland. Current Ground Cover Soil and native vegetation Existing Topography A valley borders the site to the southwest. Moderate slopes line the northeast side of the valley. The remaining portion of the site appears to be relatively level with 20 feet of elevation difference. Geotechnical Characterization Site Geology Eagle Springs Organic Solar project is located in Garfield County, Colorado within the Silt Quadrangle 1:24,000. The Silt Quadrangle extends from Grand Hogback to the southeast portion of Piceance Basin. The mapped units within the boundaries of the project site generally consist of terrace alluvial deposits overlain by loess. The terrace alluvial deposits range from middle to late Pleistocene in age mostly consisting of pebbly gravel in a silty sand matrix. The loess, also Pleistocene in age, is generally wind-deposited, nonstratified, calcareous clayey sandy silts. Due to the loess’s low dry density, grain size, sorting, and weakly developed vertical desiccation cracks, it is prone to sheet erosion, gullying, piping, and hydrocompaction. Other geologic hazards in the area include landslides, debris flows, and rock falls in steeper areas. Subsurface Profile Based on the field exploration, subsurface soil conditions vary across the site. Stiff to hard fine-grained soils underlain by medium dense to very dense granular soils were encountered in a majority of the explorations. Fine-grained soils consisted of clay with varying amounts of silt and sands. Granular soils consisted of gravels and sand mixtures with varying amounts of silt and clay. Occasional evaporative mineralization occurred throughout the site. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 4 Difficult drilling conditions were encountered in multiple borings and at various depths throughout the project site. Auger refusal occurred in Boring No. B-2 at a depth of about 13 1/2 feet below surface grade. Specific conditions encountered at each boring location are indicated on the individual boring logs presented in the Exploration and Laboratory Results section. Stratification boundaries on the boring logs represent the approximate location of changes in soil types; in situ, the transition between materials may be gradual. We have developed a general characterization of the subsurface conditions based on our review of the subsurface exploration, laboratory data, geologic setting, and our understanding of the project. This characterization, termed GeoModel, forms the basis of our geotechnical calculations and evaluation of the site. Conditions observed at each exploration point are indicated on the individual logs. The GeoModel can be found in the Figures attachment of this report. As part of our analyses, we identified the following model layers within the subsurface profile. For a more detailed view of the model layer depths at each boring location, refer to the GeoModel. Model Layer Layer Name General Description 1 Native Clay and Silt1 Clays and silts with varying amounts of sand and gravel 2 Native Sand and Gravel Sands and gravels with varying amounts of clays and silts 1.Average topsoil depth is 6 inches. Groundwater Conditions Groundwater was not encountered in any test boring at the time of our field exploration, nor when checked upon completion of drilling to the maximum depths explored of about 13½ and 16½ feet. These observations represent groundwater conditions at the time of the field exploration and may not be indicative of conditions at other times or at other locations. Groundwater conditions can change with varying seasonal and weather conditions, and other factors. Well logs in the area indicate groundwater depth ranges from 30 to 50 feet. Seismic Site Class The seismic design requirements for buildings and other structures are based on Seismic Design Category. Site Classification is required to determine the Seismic Design Category for a structure. The Site Classification is based on the upper 100 feet of the Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 5 site profile defined by a weighted average value of either shear wave velocity, standard penetration resistance, or undrained shear strength in accordance with Section 20.4 of ASCE 7-16. Additional deeper borings or geophysical testing may be performed to confirm the conditions below the current boring depth. Description Value Seismic Risk Category II 2018 International Building Code Site Classification (IBC)1 D 2 Site Latitude 39.56010° Site Longitude 110.67923°W SS MCER ground motion (for 0.2 second period)3 0.345g S1 MCER ground motion (for 0.1 second period)3 0.078g SDs 0.35g SD1 0.124g SMs 0.525 SM1 0.186 PGAM Site modified peak ground acceleration 3 0.292g 1.Seismic site classification in general accordance with the 2018 International Building Code, which refers to ASCE 7-16. 2.The 2021 International Building Code (IBC) uses a site profile extending to a depth of 100 feet for seismic site classification. Borings at this site were extended to a maximum depth of 16.5 feet. The site properties below the boring depth to 100 feet were estimated based on our experience and knowledge of geologic conditions of the general area. Additional deeper borings or geophysical testing may be performed to confirm the conditions below the current boring depth. 3.These values were obtained using online seismic design maps and tools provided by the USGS (http://earthquake.usgs.gov/hazards/designmaps/). Thermal Resistivity and Soil Chemistry Thermal Resistivity A total of eight thermal resistivity laboratory tests were performed for this project. During this exploration performed, we obtained four bulk samples at approximately 0 to 4 feet below grades. Each of these bulk samples had a Standard Proctor test performed, and each bulk sample was tested for thermal resistivity on samples remolded to approximately in-situ, 85 and 90 percent of the material’s maximum dry density as determined by test method ASTM D698 (Standard Proctor). Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 6 Soil Corrosivity The table below lists the results of laboratory soluble sulfate, soluble chloride, sulfides, redox potential, total salts, electrical resistivity, and pH testing. The values may be used to estimate potential corrosive characteristics of the on-site soils with respect to contact with the various underground materials which will be used for project construction. Exploration No. Sample Depth (feet bgs) pH Sulfate (mg/kg) Sulfides (mg/kg) Chlorides (mg/kg) Red- Ox (mV) Total Salts (mg/kg) Electrical Resistivity (Ω-cm) B-02 1 to 5 8.3 27 Nil 100 +425 589 2,375 B-03 1 to 5 8.4 47 Nil 113 +433 902 2,994 As discussed in Section 10.7.5 of the AASHTO LRFD Bridge Manual, 8th Edition, 2017, the following soil or site conditions should be considered as indicative of potential deterioration or corrosion situation for steel piles: ■soil electrical resistivity less than 2,000 ohm-cm ■pH less than 5.5 ■pH between 5.5 and 8.5 with high organic content ■sulfate concentration greater than 1,000 ppm (mg/kg) Publications indicate soils with resistivity values less than 2,000 ohm-cm can be highly corrosive to ferrous materials, and soil resistivity values between 2,000 and 5,000 ohm- cm can be mildly to moderately corrosive to ferrous materials. Resistivity values above 5,000 ohm-cm are considered to be mildly corrosive to noncorrosive. Based on the resistivity test results, the samples would be considered mild to moderately corrosive to ferrous materials. The Portland Cement Association states that sulfate attack from soils containing less than 1,000 ppm water-soluble sulfate is negligible, and Type I Portland cement would be suitable. Based on the soluble sulfate test results of the soil samples, it appears that no cement type restriction is required due to soluble sulfate concentrations in the soils tested. The pH, sulfates, sulfides, total dissolved salts, oxidation-reduction potential, and chlorides can affect the aggressiveness of corrosion to buried metal structures. These test results are provided to assist in determining the type and degree of corrosion protection that may be required. We recommend that a certified corrosion engineer be employed to determine the need for corrosion protection and to design appropriate protective measures. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 7 Contributory Risk Components Item Description Soil Conditions The project site subsurface consists of primarily lean clay, silt, and sand. Average topsoil depth is estimated at 6 inches. Access Wet and soft surface conditions due to precipitation and runoff can pose access issues for vehicles. The previous use as agricultural fields will generally be more accessible in the summer and early fall due to the improved drying conditions or possibly in winter if limited snow cover and snow drifts are present. The fields have limited entrances to cross roadside ditches. Surface drainage areas have limited crossings, likely designed to facilitate access with agricultural equipment. Grading We anticipate very little grading will be required. We expect localized areas of unsuitable conditions will be encountered prior to placing fill and within the subgrade for roadways and shallow foundations that are planned. Stabilization measures, such as undercutting/replacement and surface compaction should be expected. Anticipated Pile Drivability We do not anticipate difficulties during excavation and pile driving, and we do not anticipate pre-drilling will be required across the majority of the site for piles driven up to depths of 10 feet or less. If piles extend into dense sand and gravel layers, pile refusal may be encountered. Groundwater Groundwater was not encountered in the soil borings and or the test pits performed for this exploration. Site Drainage Portions of the subject site have possibly been irrigated using flooding techniques. Lower-strength subgrade soils and generally undesirable subsurface conditions could be encountered in areas where flood irrigation has been performed. Corrosion Hazard1 The Miller box resistivity tests indicated electrical resistivity values of about 2,300 to 3,000 ohm-cm. Publications indicate soils with resistivity values less than 2,000 ohm- cm can be corrosive to severely corrosive to ferrous materials, and soils with resistivity values between 2,000 and 5,000 ohm-cm can be mildly to moderately corrosive to ferrous materials. The soils have a ‘negligible’ classification for sulfate exposure according to the ACI Design Manual. The results of our laboratory soil testing and in-situ electrical resistivity testing are expected to assist a qualified corrosion engineer to design corrosion protection for the production piles and other project elements. Excavation Hazards Based on the results of our soil borings and our experience with the geology of the project site, we do not expect difficult excavation Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 8 Item Description conditions will be encountered during construction across the majority of the site. Additionally, we expect general instability in the form of caving, sloughing, and raveling to be encountered in excavations. Excavations could require bracing, sloping, and/or other means to create safe and stable working conditions. General Construction Considerations The near-surface soils could become unstable with typical earthwork and construction traffic, especially after precipitation events. Effective drainage should be implemented early in the construction sequence and maintained after construction to reduce potential issues. If possible, the grading should be performed during the warmer and drier times of the year. If grading is performed during the wetter months, an increased risk for possible undercutting and replacement of unstable subgrade will exist. Heavy equipment traffic directly on bearing surfaces should be avoided. The use of track-mounted or remotely operated equipment, such as a backhoe or dozer, would be beneficial to perform excavations and reduce subgrade disturbance. If unstable subgrade conditions develop, stabilization measures will need to be employed to improve subgrade support. Slope Hazards The project site grades are relatively flat to gently rolling/sloping with individual parcel areas sloping down toward the east and other surface drainage areas. Sloughing could occur in cut areas, particularly where side slopes are subject to seepage from water- bearing layers. Sloughing could occur on slopes steeper than 2:1 (horizontal:vertical). Structures and other improvements near slopes steeper than 2:1 should be setback from slope crest a distance equal to slope height. Liquefaction Sands located below groundwater levels can be subject to liquefaction, a phenomenon characterized by sudden loss of strength and collapse under seismic loading. Based on the subsurface profile encountered at the project site, our preliminary assessment is that liquefaction should not be expected under an earthquake of the magnitude predicted for the site. Problematic Soils Soils exhibiting Hydro-collapse potential were observed on site. 1.The soil properties that can significantly affect the aggressiveness of corrosion to buried metal structures include pH, oxidation-reduction potential, sulfates, sulfides, total dissolved salts, chlorides, resistivity, and water content. These properties were measured, and the results are attached in Exploration and Laboratory Results. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 9 Pile Load Testing Pile load tests were performed at four locations across the site. The test piles consisted of wide flange W6x9 steel piles. These test piles were installed to embedment depths of 5, 7 and 8 feet below current ground surfaces. The piles are identified in this report as text “PLT” followed by test number followed by letter “A”, “B”, and “C”. Pile load tests with letters “A” and “B” were tested for axial tension first and lateral load next and pile load tests with the letter “C” were tested for axial compression only. Pile Driving The pile driving operation was performed by Terracon on September 7, 2022 with a rubber track-mounted Vermeer PD10 pile diver. None of the piles encountered refusal during installation. The criteria for refusal is when the pile takes longer than 120 seconds to advance 1 foot. A summary of the time required to advance each pile to its specified embedment depth is summarized in the following table, and the installation times per foot along with the plots can be found in Pile Load Testing Results. Pile Location Embedment Depth (feet)Drive Time (sec)Average Drive Time (sec/foot) PLT-1A 7 304 43.4 PLT-1B 5 142.3 28.5 PLT-1C 8 ---1 ---1 PLT-2A 8 257.3 32.2 PLT-2B 5 55.2 11.0 PLT-2C 5 70.9 14.2 PLT-3A 8 56.2 7.0 PLT-3B 5 29.6 5.9 PLT-3C 5 37.5 7.5 PLT-4A 8 109.2 13.7 PLT-4B 5 49.0 9.8 PLT-4C 5 47.6 9.5 1.Drive time data was deleted prior to data being recorded. Pile Load Test Procedures and Equipment Axial tension, lateral load, and axial compression pile load tests were performed on September 12 and 13, 2022. These tests were performed three or more days after the piles were installed. The following types of load tests were performed: Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 10 ■Axial Tension Load Tests for each pile (8 total) for skin friction evaluation. ■Axial Compression Load Tests for 4 piles for end bearing evaluation. ■Lateral Load Tests for each pile (8 total) for LPILE and P-multiplier evaluation. The following are procedures for each test type performed: ■The axial tension tests were performed on Piles A and B at each location by connecting to the pile using a locking 5-ton plate clamp (vertical) designed for connection to W-sections. Axial loads were applied to the test pile using an Enerpac hydraulic pump and a 10-kip pull cylinder. The loads were recorded with an electronic load cell and deflections were measured with two calibrated Humboldt 2- inch digital gauges. The arm of a tracked excavator was used to provide the reaction frame. The axial tension load was applied in load increments of 500 lbs to a maximum of 10,000 lbs or until the pile reached about ¾ of an inch of vertical displacement. ■The lateral tests were performed after testing under axial tension on Piles A and B. Each pile was individually connected to the excavator to provide a reaction for the pile, and each pile was tested individually. For lateral testing, the piles were pulled toward the excavator and deflections of the pile were measured. The load for the lateral tests was applied at about 4 feet above the ground surface. The loads were applied in 500 lbs increments in a maximum 5 cycles from 0 lbs to a maximum lateral load of 7,000 lbs. The limit of soil capacity during the lateral test is defined as movement in excess of approximately 2 inches measured at 6 inches above the ground surface. Each load increment was held for at least 30 seconds and the stabilized deflection reading of both indicator gauges was recorded. ■The axial compression tests were performed using a ½-inch plate that was placed on the top of the pile followed by the compression load cell, which was used to record the loads. The deflection was measured using two calibrated Humboldt 2- inch digital gauges. An Enerpac 5-ton cylinder jack was then placed on top of the load cell. The counterweight of the tracked backhoe was used to provide the reaction load. The axial compression load was applied in load increments of 500 lbs to a maximum of 13,000 lbs or until the pile reached about ¾ of an inch of vertical displacement. Summary of Pile Load Test Results The following table provides a summary of each test pile location, embedment depth, uplift load at ¼ of an inch of vertical displacement, compression load at ¼ of an inch vertical displacement, and the lateral load at ½ an inch of lateral displacement. The individual pile load test results can be found in Pile Load Testing Results. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 11 Pile Location Actual Embedment Depth (feet) Installation Drive Time (seconds)3 Uplift Load at ¼” Displacement (lbs) Lateral Load at ½” Displacement (lbs)2 Compressive Load at ¼” Displacement (lbs) PLT-1A 5 304.0 10,000+1,871 ---1 PLT-1B 7 142.3 10,000+1,677 ---1 PLT-1C 5 ------1 ---1 13,000+1 PLT-2A 5 257.3 10,000+5,867 ---1 PLT-2B 8 55.2 10,000+5,310 ---1 PLT-2C 5 70.9 ---1 ---1 13,000+ PLT-3A 5 56.2 10,000+5,185 ---1 PLT-3B 8 29.6 10,000+4,123 ---1 PLT-3C 5 37.5 ---1 ---1 13,000+ PLT-4A 5 109.2 10,000+5,313 ---1 PLT-4B 8 49.0 10,000+5,398 ---1 PLT-4C 5 47.6 ---1 ---1 13,000+ 1.Test not performed. 2.Lateral displacement measured at 6 inches above the ground surface. 3.Pile drive refusal criteria is 120+ seconds/foot. Solar Panel Pile Design Recommendations Based on the pile load test results, the project site consists of one zone for axial capacity (Zone 1) and two zones for lateral capacity (Zones A and B). When combined, the site can be separated into two different zones, Zone A1 and Zone B1 as outlined in the table below and illustrated in the attached Zoning Plan included in the Site Location and Exploration Plans section. Lateral Groups Axial Zones Zone 1 A PLT-2, 3, and 4 B PLT- 1 Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 12 Final pile design is to be completed by an engineer licensed in the State of Colorado. The structural engineer should evaluate the moment capacity of the pile as part of their structural evaluation. Piles should have a minimum center-to-center spacing of at least five times their largest cross-sectional dimension to prevent impacts from group effects. If piles will be spaced closer than five times their largest cross-sectional dimension, we should be notified to provide supplemental recommendations regarding resistance to lateral loads. Adfreeze Considerations for Driven Pile Foundations Near-surface clays are present across the site. These materials are frost susceptible, and water at the surface or within the near-surface soils can affect the performance of slabs- on-grade and roadways. Exterior slabs should be anticipated to heave during freezing temperatures. If the anchorage/embedment of the foundations and the deadweight of the structure is not enough to resist these forces, it can cause uplift of the structures. In colder climates, the design to resist frost heave forces exerted on foundations is a critical factor in the foundation design, especially for lightly loaded structures such as solar panel arrays. Pile lengths will need to be long enough to counteract potential “adfreeze” heave forces in a portion of the seasonal frost penetration zone. Groundwater was not encountered within any of the borings at the time of the field exploration. After review of nearby well data, shallow seasonal groundwater is not expected at the site, therefore, the risk of developing adfreeze forces on this site is considered to be low. Geotechnical Axial Capacity The axial uplift capacity of driven piles may be estimated based on skin friction developed along the perimeter of the pile, while the compression capacity may be estimated using the skin friction and end bearing. When determining embedment depths, the perimeter of a wide flange beam should be taken as twice the sum of the flange width and section depth. The upper 12 inches of soil for each pile should be neglected in the axial capacity analyses due to considerations of strength losses that can occur due to freeze/thaw action, soil moisture variations and shrinkage, and other potential surface disturbances. Based on the results of the axial pile load testing program, we recommend the site be broken into one zone as follows: Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 13 Axial Capacity Design Parameters Axial Zone Embedment Depth (ft) Ultimate Uplift and Compression Skin Friction qs (psf)1, 2, 3 Ultimate End Bearing (lbs)2, 4 Zone 1 (PLT-1, -2, -3, and - 4) 1 to 5 1,000 None 5 to 8 1,000 3,000 1.The upper 1.0 feet should be neglected in pile design for axial loading conditions due to loss of soil strength or contact with pile due to freeze- thaw action, seasonal water content variations, and other potential surface disturbances. 2.For Allowable Strength Design (ASD), we recommend the allowable capacity be determined by applying a minimum factor of safety of at least 1.5 to the ultimate values. 3.Skin friction values of 5–8 feet can be used for pile embedment depths greater than 8 feet. We recommend using a FOS of at least 2.0 for piles deeper than 8 feet. 4.Values applicable to piles embedded a minimum of 5 feet bgs. For Allowable Stress Design (ASD), we recommend the allowable skin friction values and allowable end bearing be determined by applying a factor of safety (FOS) of at least 1.5 to the ultimate values provided in the table above. The above values are to be used in the following equations to obtain the ultimate uplift or compression load capacity of a pile: 𝑷𝒍𝒍𝒍 (𝒂𝒍𝒍𝒍𝒍𝒂𝒍𝒍𝒊𝒍𝒂)=𝑷𝒍𝒍𝒍 (𝒂𝒍𝒂)+𝑯×𝑷×𝒍𝒍 𝑷𝒍𝒍𝒍 (𝒍𝒍𝒍𝒊𝒂𝒍)=𝑯×𝑷×𝒍𝒍 𝑃𝑟𝑙𝑟 (𝑐𝑙𝑙𝑙𝑟𝑐𝑟𝑟𝑖𝑟𝑐) = 𝑈𝑘𝑘𝑖𝑘𝑎𝑘𝑎 𝑎𝑘𝑘𝑘𝑘𝑎𝑘𝑘𝑖𝑘𝑘 𝑎𝑎𝑘𝑎𝑎𝑖𝑘𝑦 𝑘𝑎 𝑘𝑘𝑘𝑘 (𝑘𝑎𝑘) 𝑃𝑟𝑙𝑟 (𝑟𝑙𝑙𝑖𝑐𝑟) = 𝑈𝑘𝑘𝑖𝑘𝑎𝑘𝑎 𝑘𝑘𝑘𝑖𝑎𝑘 𝑎𝑎𝑘𝑎𝑎𝑖𝑘𝑦 𝑘𝑎 𝑘𝑘𝑘𝑘 (𝑘𝑎𝑘) 𝑃𝑟𝑙𝑟 (𝑐𝑙𝑐)= 𝑈𝑘𝑘𝑖𝑘𝑎𝑘𝑎 𝑎𝑘𝑎 𝑎𝑎𝑎𝑘𝑖𝑘𝑎 𝑎𝑎𝑘𝑎𝑎𝑖𝑘𝑦 𝑘𝑎𝑘 𝑘ℎ𝑎 𝑘𝑎𝑎𝑘𝑎 𝑎𝑎𝑘𝑘𝑎 (𝑘𝑎𝑘) 𝐻 = 𝐷𝑎𝑘𝑘ℎ 𝑘𝑎 𝑘𝑖𝑘𝑎 𝑎𝑘𝑎𝑎𝑎𝑘𝑎𝑘𝑘 (𝑎𝑘) 𝑃 = 𝑃𝑎𝑘𝑖𝑘𝑎𝑘𝑎𝑘 𝑎𝑘𝑎𝑎 𝑘𝑎 𝑘𝑖𝑘𝑎 (𝑖.𝑎.𝑊6 × 9 = 1.64 𝑘𝑘𝑎𝑘/𝑎𝑘) 𝑘𝑟= 𝑆𝑘𝑖𝑘 𝑎𝑘𝑖𝑎𝑘𝑖𝑘𝑘 𝑘𝑎𝑘 𝑎𝑎𝑘𝑘ℎ 𝑘𝑎𝑘 𝑘ℎ𝑎 𝑘𝑎𝑎𝑘𝑎 𝑎𝑎𝑘𝑘𝑎 Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 14 An example calculation to determine the allowable capacity for a W6x9 pile in tension and founded at a depth of 8 feet in the area of Zone 1 would be as follows: 𝑷𝒂𝒍𝒍 (𝒍𝒍𝒍𝒊𝒂𝒍)=(𝟑−𝟎) 𝒙 𝟎.𝟑𝟑 𝒙𝟎,𝟎𝟎𝟎 𝟎.𝟑 = 𝟑,𝟑𝟑𝟑 𝒍𝒂𝒍 The provided skin friction values are applicable for piles that are driven using a Vermeer PD-10 pile driver with a hydraulically operated hammer. If a smaller or larger drive hammer is used, we recommend Terracon be consulted to determine the minimum drive time based on the actual equipment to be used. Geotechnical Lateral Capacity Lateral load response of pile foundations was calculated using the computer program LPILE 2019, by Ensoft, Inc. The stiffness of the pile and the stress-strain properties of the surrounding soils determine the lateral resistance of the foundation. Recommended LPILE input parameters for lateral load analysis for driven pile foundations are shown in the following table: LPILE Parameters (All PLT Locations) Depth (feet bgs) LPILE Soil Model Effective Unit Weight γ, (pcf) Friction Angle, phi (°) Undrained Cohesion c, (psf) Strain Factor, Є501 0–7 Stiff Clay w/o free water 120 --1,000 Default 7–16½Sand (Reese)115 34 --Default 1.Use default value for Strain Factor,Ɛ𝟑𝟎 The lateral load test results were varied between the different embedment depths and zones. Therefore, we are providing the following table of p-multiplier values that should be used for the corresponding embedment depth: P-Multiplier Table Zone Embedment Depth (feet bgs)P-Multiplier1, 2, 3 Zone A (PLT-2, -3, and -4)1-5 5.5 Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 15 P-Multiplier Table Zone Embedment Depth (feet bgs)P-Multiplier1, 2, 3 5-8 6 Zone B (PLT-1) 1-5 2 5-8 0.85 1.The p-multiplier value between 0 to 1 foot should be 70% of the values provided in the table or linearly interpolated values. 2.For piles embedded between 5 and 8 feet, the p-multiplier value should be linearly interpolated using the values provided in the table. 3.For embedment depths below 8 feet, use a p-multiplier of 6 in Zone A and 0.85 in Zone B. LPILE analyses were performed by applying the field test load that resulted in approximately ½-inch deflection at a point about 6 inches above the ground surface. The shear load was applied at approximately 4 feet above the ground surface. The effective unit weight, cohesion, and strain factor were based on the results of the soil borings. The p-multiplier was then adjusted (by trial-and-error method) such that the applied load resulted in a deflection value that matched the load test results. Please note that this procedure was based on only one discrete set of data determined at about 6 inches from the ground surface during the field load testing. These p-multipliers were calculated based on the lateral load test results completed on piles embedded to 5 and 8 feet below grade. In our evaluation, the piles were modeled as a Steel AISC Section Strong Axis. The p-multiplier for the 8-foot embedded piles should be used for deeper piles in the respective zones. Construction Considerations Based on the field exploration and laboratory testing, it is our opinion that the soils on the site are generally suitable for dynamic pile installation. Underlying dense granular soils may cause refusal of piles. The geotechnical engineer should be engaged to observe pile driving operations. Penetration resistance, depth of embedment, drive times, and general pile driving operations should be recorded. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 16 Pile Design Recommendations for Other Structures Some structures may require piles to be driven to greater depths than 8 feet in order to achieve the required axial capacities. For allowable strength design, we recommend the allowable skin friction and end bearing be determined by applying a factor of safety of at least 2 to the ultimate values provided in this section for piles embedded greater than 8 feet. Recommended ultimate skin friction, end bearing, and factor of safety are presented below: Pile Embedment Depth (ft) Ultimate Skin Friction qs (psf) Ultimate End Bearing Qult-(end) (lbs) Factor of Safety Zone 1 (PLT-1, -2, -3, and -4) 0 to 1 --------- 1 to 5 1,000 ---1.5 5 to 8 1,000 3000 1.5 8+750 3000 2.0 For piles embedded between depths of 8 and 16½ feet throughout the site: When determining embedment depths, the perimeter of a wide flange beam should be taken as twice the sum of the flange width and web depth, and the upper 12 inches of soil for each pile should be neglected. For W6x9 piles with embedment depths between 8 and 16½ feet: The ultimate unit end bearing for alternate pile sections should be assumed to be the same as the W6x9 piles tested for this project. We recommend Terracon be consulted to determine the minimum drive time based on the proposed equipment to be used for driving of the piles. Piles should have a minimum center-to-center spacing of at least five times their largest cross-sectional dimension to prevent reduction in the axial capacities due to group effects. Deep Foundation Recommendations for Other Structures Deep foundations consisting of drilled shaft foundations and/or direct embedment foundations with concrete backfill may be utilized for the support of substation structures for the project. Design and construction considerations for drilled shafts are provided in the following sections. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 17 Recommended geotechnical design parameters provided in the following table are based on a composite lithology developed from reviewing the subsurface conditions encountered in the exploratory borings drilled at this site. The following table does not consider any cuts or fills. Preliminary Drilled Shaft Design Parameters (Based on Boring SUB-1) Depth 1 (feet) Curve Model (p-y) Effective Unit Weight (pcf) Cohesion or Friction Angle MFAD Ed 5 (ksi) Strain 50 6 Static Lateral Subgrade Modulus K (pci) Allowable Side Friction 3 (psf) (FS = 2) Allowable End Bearing 4 (psf) (FS = 3) 0 to 3 Stiff clay w/out free water (Reese) 115 700 psf 0.5 Allow LPILE to use default values based on the cohesion or friction angle of the soil. ---- 3 to 7 Stiff clay w/out free water (Reese) 120 1,000 psf 0.8 300 3,500 7 to 16.5 Sand (Reese)115 34°2.0 375 8,000 1.Depth below existing grade at the time of our field program. Adjust depths from final grade based on site grading plans. The labels below the depth range correspond to the MFAD and LPILE models, respectively. 2.Groundwater was assumed to be at a depth greater than 16.5 feet. 3.In designing to resist uplift loading,⅔ of the allowable side friction values provided for compressive loading could be used along with the effective weight of the drilled shaft. Buoyant unit weights of the concrete should be used below the maximum water level in the calculations. Friction resistances should be ignored if cardboard (sonotubes) are used for drilled shaft construction. 4.Drilled shafts should penetrate at least 5 feet or two shaft diameters into the bearing stratum when designing for the allowable end bearing pressures. 5.MFAD software deformation modulus. 6.Static lateral subgrade modulus (k) and ε50 strain values are intended for the LPILE program and should not be used as inputs in other design software programs. Piers should be considered to work in group action if the center-to-center horizontal spacing is less than three pier diameters. A minimum practical center-to-center horizontal spacing between piers of at least three diameters should be maintained, and adjacent piers should bottom at the same elevation. The capacity of individual piers must be reduced when considering the effects of group action. Capacity reduction is a function of pier spacing and the number of piers within a group. The following table presents capacity reductions for closely spaced piers. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 18 Description Value Drilled Pier Spacing (Center to Center)>3 diameters >2 to 3 diameters 1 to 2 diameters Pier Capacity Reduction None 30 percent 50 percent 1.End bearing values do not need to be reduced for closely spaced piers if bottom of piers are at the same elevation. Lateral analysis should account for the center-to-center spacing and P-Y multiplier values per the following table: Pier Center-to- Center Spacing (In Direction of Loading) P-multiplier, PM Row 1 P-multiplier, PM Row 2 P-multiplier, PM Row 3 and Higher 3 x diameter 0.8 0.4 0.3 5 x diameter 1.0 0.85 0.7 The structural engineer should determine the reinforcement necessary for the piers. At a minimum, all piers should be reinforced full depth for the applied axial, lateral, and uplift stresses imposed. We recommend a minimum reinforcement of at least 1 percent of the cross-sectional area of the pier. Drilling to design depth should be possible with conventional single-flight power augers; however, very hard and potentially cemented bedrock layers could require the use of heavy-duty equipment. Pier casing may be required if groundwater, loose soils, or caving soils are encountered. Casing should be withdrawn in a slow continuous manner maintaining a sufficient head of concrete to prevent infiltration of water or caving soils or the creation of voids in pier concrete. Pier concrete should have a relatively high fluidity when placed in cased pier holes or through a tremie. Pier concrete with slump in the range of 5 to 7 inches is recommended for uncased piers. For cased piers, a slump in the range of 7 to 9 inches is recommended. Groundwater (if encountered) should be removed from each pier hole prior to concrete placement. Pier concrete should be placed immediately after completion of drilling and cleaning. If pier concrete cannot be placed in dry conditions, a tremie should be used for concrete placement. Free-fall concrete placement in piers will only be acceptable if provisions are taken to avoid striking the concrete on the sides of the hole or reinforcing steel. The use of a bottom-dump hopper or an elephant's trunk discharging near the bottom of the hole where concrete segregation will be reduced, is recommended. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 19 Due to potential sloughing and raveling, foundation concrete quantities may exceed calculated geometric volumes. Pier-bearing surfaces must be cleaned prior to concrete placement. A Terracon representative should observe the bearing surface and shaft configuration. The top of the piers should be cylindrical in shape. Forms may be necessary at the top of the piers in order to minimize the disturbance of the soils and to maintain a cylindrical shape. Earthwork Earthwork is anticipated to include clearing and grubbing, excavations, and engineered fill placement. The following sections provide recommendations for use in the preparation of specifications for the work. Recommendations include critical quality criteria, as necessary, to render the site in the state considered in our geotechnical engineering evaluation for foundations. Site Preparation Prior to placing fill, any existing vegetation, topsoil, and root mats should be removed. Complete stripping of the topsoil should be performed in the proposed shallow foundation and access road areas. Soil Stabilization Complete stripping of the topsoil should be performed in the proposed shallow foundation and access road areas. Site preparation is not necessary in the PV Array field or where inverters will be supported on driven piles except to improve site drainage where necessary. We recommend that the exposed subgrade be thoroughly evaluated by a geotechnical engineer prior to placement of new fill. The soils on the site are sensitive to disturbance from construction equipment traffic, particularly during wet periods. Excessively wet or dry material should either be removed, or moisture conditioned and recompacted. The exposed subgrade should be proofrolled where possible to aid in locating loose or soft areas. Proofrolling can be performed with a fully loaded, tandem-axle dump truck. If unsuitable areas are observed during construction, subgrade improvement will then be necessary to establish a suitable subgrade support condition. Potential subgrade stabilization techniques are discussed below. ■Scarification and Recompaction — It may be feasible to scarify, dry, and recompact the exposed soils. The success of this procedure would depend primarily Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 20 upon favorable weather and sufficient time to dry the soils. Stable subgrades likely would not be achievable if the thickness of the unstable soil is greater than about 1 foot or if construction is performed during a period of wet or cool weather when drying is difficult. ■Crushed Stone — The use of crushed stone or gravel ranging in particle size between 3 to 12 inches is a common procedure to improve subgrade stability. In addition, the use of aggregate materials, such as CDOT Class 5 and 6, can also be used to improve unstable subgrade soils. Typical undercut depths would be expected to range from about 6 to 30 inches below finished subgrade elevation with this procedure. The use of high modulus geosynthetics (i.e., geotextile or geogrid) could also be considered when used with aggregate materials to reduce the aggregate thickness needed. It is difficult to predict rock thicknesses that will be needed until the conditions are observed during construction; however, for budgeting and contract pricing purposes 12 or 18 inches of aggregate over a geosynthetic or 18 or 24 inches of aggregate (without a geosynthetic) is expected. A test section could be used to observe the effectiveness of the chosen section. Prior to placing the fabric or geogrid, we recommend that all below-grade construction, such as utility line installation, be completed to avoid damaging the fabric or geogrid. Equipment should not be operated above the fabric or geogrid until one full lift of crushed stone fill is placed above it. The maximum particle size of granular material placed over geotextile fabric or geogrid should meet the manufacturer’s guidelines and generally should not exceed 1½ inches. ■Chemical Treatment - Use of Fly ash or cement could also be considered as a stabilization technique. For preliminary planning purposes, amendment with fly ash at 10 percent or Portland cement at 5 percent by dry unit weight may be considered. Sampling and laboratory testing prior to construction is necessary to determine the correct percentage of chemical stabilization. This testing can be completed during the design-level study. Fill Material Types All fill materials should be inorganic soils free of vegetation, debris, and fragments larger than 4 inches in size. Pea gravel or other similar non-cementitious, poorly graded materials should not be used as fill or backfill without the prior approval of the geotechnical engineer. On-site soils or approved imported materials may be used as fill material at all locations and elevations. Refer to table below for fill types. It should be understood that placement and compaction of fine-grained soils encountered at this site will require adequate moisture control, which can be difficult to achieve during the wet and cold Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 21 seasons. Additional effort, stabilization or amendment of the native soils may be necessary if used as general fill. Imported soils (if needed) should be sampled, tested, and approved by Terracon prior to being hauled to the site. Imported soils used for the support of structural elements should meet the following specifications: Fill Type 1,2 Application Requirements Gradation PlasticitySize Percent finer by weight Structural Engineered Fill Suitable for all applications 3 inch No. 4 Sieve No. 200 Sieve 100 35–65 20–40 Liquid Limit 30 max Plasticity Index 6 max Stabilization Fill Stabilize subgrades (with geogrid) 3 inch No. 4 Sieve No. 200 Sieve 100 35 max. 15 max. Non-Plastic/Crushed Aggregate Stabilize subgrades (no geogrid) 6 inch3 ¾” No. 200 Sieve 100 35 max. 15 max. Non-Plastic/Coarse Rock and Aggregate Native Soils Suitable for all applications ------ Aggregate Base Course Alternative Pavement section Meet CDOT Class 5 or 6 specifications 1.All fill should consist of approved materials that are free of organic matter and debris. Frozen material should not be used, and fill should not be placed on a frozen subgrade. A sample of each material type should be submitted to the geotechnical engineer for evaluation. 2.Imported soils should be tested for analytical properties. Analytical properties of imported fill should have less detrimental properties than that of native soils tested. 3.Rock sizes larger than 6” can be accommodated with thicker lifts but may hinder placement and compaction. Fill Placement and Compaction Requirements Structural and General Fill should meet the following compaction requirements. Item Structural Fill/Aggregate Base Course General Fill/Native Soils Maximum Lift Thickness 8 inches or less in loose thickness when heavy, self-propelled compaction equipment is used 4 to 6 inches in loose thickness when hand- guided equipment (e.g., jumping jack or plate compactor) is used Same as Structural Fill Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 22 Item Structural Fill/Aggregate Base Course General Fill/Native Soils Minimum Compaction Requirements1, 2 98% of max below foundations and within 1 foot of finished pavement subgrade 95% of max above foundations, below slabs-on- grade, and more than 1 foot below finished roadway surface 92% of max Water Content Range1 Cohesive: 0% to +4% of optimum Granular: -3% to +3% of optimum As required to achieve minimum compaction requirements 1.Maximum density and optimum water content as determined by the Modified Proctor test (ASTM D1557). 2.If the granular material is a coarse sand or gravel, of a uniform size, or has a low fines content, compaction comparison to relative density may be more appropriate. In this case, granular materials should be compacted to at least 70% relative density (ASTM D4253 and D4254). Materials not amenable to density testing should be placed and compacted to a stable condition observed by the Geotechnical Engineer or representative. 3.Stabilization Fill is not testable. Fill should be tamped in place and visually inspected. Utility Trench Backfill Any soft or unsuitable materials encountered at the bottom of utility trench excavations should be removed and replaced with Structural Fill or bedding material in accordance with public works specifications for the utility to be supported. This recommendation is particularly applicable to utility work requiring grade control and/or in areas where subsequent grade raising could cause settlement in the subgrade supporting the utility. Trench excavation should not be conducted below a downward 1:1 projection from existing foundations without engineering review of shoring requirements and geotechnical observation during construction. Trench backfill should be mechanically placed and compacted as discussed earlier in this report. Compaction of initial lifts should be accomplished with hand-operated tampers or other lightweight compactors. Where trenches are placed beneath slabs or footings, the backfill should satisfy the gradation and expansion index requirements of engineered fill discussed in this report. Flooding or jetting for placement and compaction of backfill is not recommended. Thermal resistivity values typically decrease with increasing density, particularly for drier soils. Note that Terracon performed the thermal resistivity testing on samples compacted to a relative density of 85% and 90% of the material’s maximum dry density based on ASTM D698. For the thermal resistivity values in this report to remain valid, the trench backfill should be compacted to a minimum relative density of 85% based on Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 23 ASTM D698. If lower relative compactions are being considered, Terracon recommends performing additional thermal resistivity tests. Grading and Drainage All grades must provide effective drainage away from the structures during and after construction and should be maintained throughout the life of the structure. Water retained next to the structures can result in soil movements greater than those discussed in this report. Exposed ground should be sloped and maintained at a minimum of 5% away from the structures for at least 10 feet beyond the perimeter of the structures. Grades around the structures should also be periodically inspected and adjusted. Earthwork Construction Considerations Shallow excavations for the proposed structure are anticipated to be accomplished with conventional construction equipment. Upon completion of filling and grading, care should be taken to maintain the subgrade water content prior to construction of grade- supported improvements such as floor slabs and pavements. Construction traffic over the completed subgrades should be avoided. The site should also be graded to prevent ponding of surface water on the prepared subgrades or in excavations. Water collecting over or adjacent to construction areas should be removed. If the subgrade freezes, desiccates, saturates, or is disturbed, the affected material should be removed, or the materials should be scarified, moisture conditioned, and recompacted prior to floor slab construction. As a minimum, excavations should be performed in accordance with OSHA 29 CFR, Part 1926, Subpart P, “Excavations” and its appendices and in accordance with any applicable local and/or state regulations. Construction site safety is the sole responsibility of the contractor who controls the means, methods, and sequencing of construction operations. Under no circumstances shall the information provided herein be interpreted to mean Terracon is assuming responsibility for construction site safety or the contractor's activities; such responsibility shall neither be implied nor inferred. Construction Observation and Testing The earthwork efforts should be observed and tested by a qualified representative of the Geotechnical Engineer. Observation and testing should include documentation of adequate removal of vegetation and topsoil, proofrolling, and mitigation of soft/unstable areas delineated by the proofroll. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 24 In areas of foundation excavations, the bearing subgrade should be evaluated under the direction of the Geotechnical Engineer. If unanticipated conditions are encountered, the Geotechnical Engineer should be contacted to discuss mitigation options. In addition to the documentation of the parameters necessary for construction, the continuation of the Geotechnical Engineer’s presence into the construction phase of the project provides the continuity to maintain the Geotechnical Engineer’s evaluation of subsurface conditions, including assessing variations and associated design changes. Mat/Slab Foundations Mat Foundations for Support of Inverters We understand the main foundation component in the array area will include driven pile foundations for support of solar arrays; however, some lightly loaded, inverter structures are typically required across the site. In general, small, lightly loaded inverter structures may be supported on driven piles or isolated mat/slab foundation systems. If the site has been prepared in accordance with the requirements noted in the Earthwork section of this report, the mat/slab foundations should be designed based on the criteria outlined below. Frost Susceptible Soils The frost depth for local building code for the design of shallow spread footing and mat foundations for unheated structures is 36 inches (3 feet). If frost action needs to be accommodated for local building code, the use of non-frost susceptible (NFS) fill extending to the building code frost depth requirement of 3 feet could be implemented. Material commonly used as NFS fill consists of granular soils that are free draining and have a relatively high in-place permeability. It has been our experience that using NFS fill consisting of granular materials on sites with low permeable collapsible soils can create zones where water collects, and the underlying collapsible soils become wetted and settle rapidly. This can result in undesirable downward movement for foundations constructed on these materials. An alternative to a free draining NFS material, while not commonly used, is an appropriate low permeable Controlled Low Strength Material (CLSM). If a low permeable NFS fill material cannot be obtained or is cost prohibitive, structural slabs (for instance, structural stoops in front of building doors), supported on frost- depth footings, should be used. Placement of low permeable NFS material in large areas may not be economically feasible; however, the following recommendations are provided to help reduce potential frost heave for grade supported structures: Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 25 ■Provide surface drainage away from the structures and slabs, and toward the site storm drainage system. ■Install drains around the perimeter of the structures as well as below exterior slabs and access roadways and connect them to the storm drainage system. ■Grade clayey subgrades, so groundwater potentially perched in overlying more permeable subgrades, such as sand or aggregate base, slopes toward a site drainage system. ■Place low permeable CLSM fill as backfill beneath slabs and access roadways critical to the project. ■Consider structural slabs supported on frost-depth footings. ■Consider placing another type of Frost Protected Shallow Foundation (FPSF) system Mat Foundation Design Recommendations Design Item Description/Recommendations Minimum Embedment Depth 36 inches (shallow foundations) 12 inches if underlain by 2 feet of CLSM fill (mat/slab foundations) Lateral Extent of CLSM 2 feet outside of mat perimeter Bearing Material Stiff native soils or engineered fill extending to native soils Design Modulus of Subgrade Reaction,k 75 pci Minimum Width 4 feet Modulus Correction Factor1 kc=k((b+1)/2b)2 Maximum Design Contact Stress (FOS of 3)2 500 psf Total Estimated Settlement About 1 inch Coefficient of Base Friction 0.30 1.The k-value should be reduced to account for the dimensional effects of the loaded area. Where kc is the corrected or design modulus value and b is the mat width (short dimension) or tributary loaded area. 2.Bearing capacity is controlled by total estimated settlement. Foundations should be reinforced as necessary to reduce the potential for distress caused by differential foundation movement. The use of joints at openings or other discontinuities in walls is recommended. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 26 Foundation excavations should be observed by the geotechnical engineer. If the soil conditions encountered differ significantly from those presented in this report, supplemental recommendations will be required. Mat Foundation Construction Considerations The mat foundation excavations should be evaluated under the direction of the Geotechnical Engineer. The base of all foundation excavations should be free of water and loose soil prior to placing concrete. Concrete should be placed soon after excavating to reduce bearing soil disturbance. Care should be taken to prevent wetting or drying of the bearing materials during construction. Excessively wet or dry material or any loose/disturbed material in the bottom of the foundation excavations should be removed/reconditioned before the foundation concrete is placed. Placement of a lean concrete mud-mat, 12 inches thick, over the bearing soils should be considered if the excavations must remain open for an extended period of time. Access Roadways We understand that new roadways for postconstruction traffic within the proposed substation area site will consist of aggregate-surfaced roadways. Design truck load frequencies postconstruction have not been provided. Therefore, we have assumed one pickup truck per day and one fully loaded truck per week with a maximum weight of 80,000 pounds for fire truck loading. Aggregate sections based on a more detailed design could be provided. Subgrade soils beneath aggregate-surfaced roadways should be prepared and constructed as outlined in the Earthwork section of this report. An analysis of the proposed pavement section was performed as outlined in the 1993 AASHTO Design of Pavement Structures for aggregate-surfaced roads (Section 4.1.2). The design analysis evaluates the allowable rutting depth, traffic loading, and subgrade strength as design considerations. The unpaved road sections for postconstruction use have been developed under the following assumptions: Aggregate Roadway Design Parameters Parameter Design Value Comments Design life 30 years Provided U.S. Climate Region VI Provided Resilient Modulus 4, 5 7,800 psi (dry) Based on CBR Results20,000 psi (frozen) 3,900 psi (wet/saturated) Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 27 Aggregate Roadway Design Parameters Parameter Design Value Comments Chemically Treated Subgrade Resilient Modulus 4, 5 12,000 psi (dry) Assumed20,000 psi (frozen) 10,000 psi (wet/saturated) Aggregate Base Elastic Modulus 30,000 psi Assumed Allowable Rut Depth 2 inches Assumed Design Serviceability Loss 2.0 Assumed Vehicle Tire Pressure 80 psi Assumed 1.ESAL = 18-kip Equivalent Single Axle Load 2.Array access roads assume traffic loading consisting of pickup trucks and a limited number of fire trucks. We have assumed the fire truck load to be equivalent to a HS-20 vehicle. 3.Substation access road assumes traffic loading consisting of pickup trucks and heavy delivery or fire trucks (equivalent to a HS-20 vehicle). 4.MR value correlation based 1993 AASHTO Design of Pavement Structures. 5.AASHTO low volume subgrade support characteristics for lean clay. Recommended minimum aggregate surfacing thickness is provided in the table below. Traffic Level (ESALs)Fly Ash or Cement Chemically Treated Depth (in.) Aggregate-Surfacing Material Thickness (in.) 500 --4 6 4 1,000 --4 6 4 5,000 --5 6 4 10,000 --7 6 5 A concern regarding the use of permeable aggregate materials in large pavement areas is that surface water cannot be drained over the surface before it permeates through the aggregate surfacing, which would create a condition where the subgrade soils become elevated in moisture content. If the subgrade soils do become elevated in moisture content, the overall performance of the aggregate-surfaced pavement areas will be reduced, and it could result in excessive rutting and may require maintenance or reconstruction of the gravel surface pavement. To help direct surface water over the aggregate surface, we suggest surface slopes of 2% to 3% be constructed and maintained. Surface drainage should be directed away from the pavement areas, and no Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 28 ponding of water should be allowed on the paved surface or adjacent to the edges of the pavement areas. General Comments Our analysis and opinions are based on our understanding of the project, the geotechnical conditions in the area, and the data obtained from our site exploration. Variations will occur between exploration point locations or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. Terracon should be retained as the Geotechnical Engineer, where noted in this report, to provide observation and testing services during pertinent construction phases. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on-site, we should be immediately notified so that we can provide evaluation and supplemental recommendations. Our Scope of Services does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials, or hazardous conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken. Our services and any correspondence are intended for the sole benefit and exclusive use of our client for specific application to the project discussed and are accomplished in accordance with generally accepted geotechnical engineering practices with no third- party beneficiaries intended. Any third-party access to services or correspondence is solely for information purposes to support the services provided by Terracon to our client. Reliance upon the services and any work product is limited to our client and is not intended for third parties. Any use or reliance of the provided information by third parties is done solely at their own risk. No warranties, either express or implied, are intended or made. Site characteristics as provided are for design purposes and not to estimate excavation cost. Any use of our report in that regard is done at the sole risk of the excavating cost estimator as there may be variations on the site that are not apparent in the data that could significantly affect excavation cost. Any parties charged with estimating excavation costs should seek their own site characterization for specific purposes to obtain the specific level of detail necessary for costing. Site safety and cost estimating including excavation support and dewatering requirements/design are the responsibility of others. Construction and site development have the potential to affect adjacent properties. Such impacts can include damage due to vibration, modification of groundwater/surface water flow during construction, foundation movement due to undermining or subsidence from excavation, as well as noise or air quality concerns. Evaluation of these items on nearby Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials 29 properties is commonly associated with contractor means and methods and is not addressed in this report. The owner and contractor should consider a preconstruction/precondition survey of the surrounding development. If changes in the nature, design, or location of the project are planned, our conclusions and recommendations shall not be considered valid unless we review the changes and either verify or modify our conclusions in writing. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Figures Contents: GeoModel 82 84 86 88 90 92 94 96 98 100 102 ELEVATION (MSL) (feet)AES - Eagle Springs Solar Rifle, Colorado Terracon Project No. 61225141 Layering shown on this figure has been developed by the geotechnical engineer for purposes of modeling the subsurface conditions as required for the subsequent geotechnical engineering for this project. Numbers adjacent to soil column indicate depth below ground surface. NOTES: B-01 B-02 B-03 B-04 B-05 B-06 B-07 B-08 TP-01 TP-02 TP-03 TP-04 GEOMODEL This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions. LEGEND Lean Clay with Sand Poorly-graded Gravel with Silt and Sand Silty Clay Silty Sand with Gravel Sandy Lean Clay Silty Sand Silty Clay with Sand Topsoil Model Layer General DescriptionLayer Name Clay and silt with varying amounts of sand and gravel1 Sand and gravel with varying amounts of clay and silt2 Native Clay and Silt Native Sand and Gravel 7 16.5 1 2 7 13.5 1 2 13 16.5 1 2 10 16.5 1 2 12 16.5 1 2 13.5 16.5 1 2 10 16.5 1 2 10 16.5 1 2 Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Attachments Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Exploration and Testing Procedures Field Exploration Type of Exploration Number of Explorations Depth or Description Location Soil Borings 8 About 16½ feet bgs Array Area Test Pit 4 About 10 feet bgs Array Area Field electrical resistivity 4 shallow/ 2 deep “Shallow” 1, 2, 3, 5, 10, 20, and 50 feet “Deep” 1, 2, 3, 5, 10, 20, 50, 100, 200, and 300 feet Array Area Boring Layout and Elevations: Terracon personnel provided the boring layout using handheld GPS equipment (estimated horizontal accuracy of about ±10 feet) and referencing existing site features. If elevations and a more precise boring layout are desired, we recommend borings be surveyed. Subsurface Soil Boring Exploration Procedures: We advanced the borings with a truck-mounted, rotary drill rig using continuous flight hollow-stem augers. Five samples were obtained in the upper 10 feet of each boring and at intervals of 5 feet thereafter. In the thin-walled tube sampling procedure, a thin-walled, seamless steel tube with a sharp cutting edge was pushed hydraulically into the soil to obtain a relatively undisturbed sample. In the split-barrel sampling procedure, a standard 2-inch outer diameter split-barrel sampling spoon was driven into the ground by a 140-pound automatic hammer falling a distance of 30 inches. The number of blows required to advance the sampling spoon the last 12 inches of a normal 18-inch penetration is recorded as the Standard Penetration Test (SPT) resistance value. The SPT resistance values, also referred to as N-values, are indicated on the boring logs at the test depths. A 3-inch O.D. split-barrel sampling spoon with a 2.5-inch I.D. ring-lined sampler was also used for sampling. Ring-lined, split-barrel sampling procedures are similar to standard split spoon sampling procedures; however, blow counts are typically recorded at 6-inch intervals for a total of 12 inches of penetration. For safety purposes, all borings were backfilled with auger cuttings after their completion. We also observed the boreholes while drilling and at the completion of drilling for the presence of groundwater. The sampling depths, penetration distances, and other sampling information was recorded on the field boring logs. The samples were placed in appropriate containers and taken to our soil laboratory for testing and classification by a Geotechnical Engineer. Our exploration team prepared field boring logs as part of the drilling operations. These field Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials logs included visual classifications of the materials observed during drilling and our interpretation of the subsurface conditions between samples. Final boring logs were prepared from the field logs. The final boring logs represent the Geotechnical Engineer's interpretation of the field logs and include modifications based on observations and tests of the samples in our laboratory. Test Pit Exploration Procedures: Bulk samples from about 1 to 5 feet were collected at the four TP locations using the track-mounted excavator. Field Electrical Resistivity Testing Procedures: Terracon performed six in-situ field electrical resistivity surveys in general accordance with the Wenner Four Point method (ASTM G57) as presented in the following table. Two mutually perpendicular arrays were performed for each test. The results of these tests are expected to assist the designer of electrical grounding components for corrosion protection. In Situ Resistivity Test Location Proposed Test Array Quantity “A” Spacing Interval Shallow “A” spacing 4 pairs (8 arrays)1, 2, 3, 5, 10, 20, and 50 feet Deep “A” spacing 2 pair (4 arrays)1, 2, 3, 5, 10, 20, 50, 100, 200 and 300 feet Laboratory Testing The project engineer reviewed the field data and assigned laboratory tests. The laboratory testing program included the following types of tests: ■Moisture Content ■Dry Unit Weight ■Liquid Limit, Plastic Limit, and Plasticity Index of Soils ■Percent Passing #200 Sieve ■Particle-Size Analysis of Soils ■Standard Proctor ■California Bearing Ratio (CBR) ■Unconfined Compression Based on the results of our field and laboratory programs, we described and classified the soil samples in accordance with the Unified Soil Classification System. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Laboratory Thermal Resistivity Testing A total of three bulk samples of near-surface soils were obtained from the PV array areas for thermal resistivity testing. A total of six laboratory thermal resistivity tests were performed. The near-surface materials were remolded at 85 percent and 90 percent of the maximum dry density as determined by ASTM D698. These samples were tested in the laboratory for thermal resistivity. These results are presented in the Exploration and Laboratory Results section of this report. Corrosivity Testing Samples of the near-surface soils obtained from the PV array areas at the 8 boring locations were tested in the laboratory for the following properties in general accordance with the corresponding standards: ■pH Analysis (ASTM G51) ■Chloride (ASTM D512) ■Sulfate (ASTM C1580) ■Sulfide Content (AWWA 4500-S D) ■Oxidation-Reduction Potential (ASTM G200) ■Electrical Resistivity Testing (ASTM G187) These results are presented in the Soil Corrosivity section of this report as well as the Exploration and Laboratory Results section. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Site Location and Exploration Plans Contents: Site Location Plan Exploration Plan Zoning Plan Note: All attachments are one page unless noted above. Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Note to Preparer: This is a large table with outside borders. Just click inside the table above this text box, then paste your GIS Toolbox image. When paragraph markers are turned on you may notice a line of hidden text above and outside the table – please leave that alone. Limit editing to inside the table. Site Location DIAGRAM IS FOR GENERAL LOCATION ONLY,AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Note to Preparer: This is a large table with outside borders. Just click inside the table above this text box, then paste your GIS Toolbox image. When paragraph markers are turned on you may notice a line of hidden text above and outside the table – please leave that alone. Limit editing to inside the table. Exploration Plan - Borings DIAGRAM IS FOR GENERAL LOCATION ONLY,AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Note to Preparer: This is a large table with outside borders. Just click inside the table above this text box, then paste your GIS Toolbox image. When paragraph markers are turned on you may notice a line of hidden text above and outside the table – please leave that alone. Limit editing to inside the table. Exploration Plan – Field Electrical Resistivities DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Note to Preparer: This is a large table with outside borders. Just click inside the table above this text box, then paste your GIS Toolbox image. When paragraph markers are turned on you may notice a line of hidden text above and outside the table – please leave that alone. Limit editing to inside the table. Exploration Plan – Test Pits DIAGRAM IS FOR GENERAL LOCATION ONLY,AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Note to Preparer: This is a large table with outside borders. Just click inside the table above this text box, then paste your GIS Toolbox image. When paragraph markers are turned on you may notice a line of hidden text above and outside the table – please leave that alone. Limit editing to inside the table. Exploration Plan – Pile Load Testing DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Note to Preparer: This is a large table with outside borders. Just click inside the table above this text box, then paste your GIS Toolbox image. When paragraph markers are turned on you may notice a line of hidden text above and outside the table – please leave that alone. Limit editing to inside the table. PLT Zoning Plan DIAGRAM IS FOR GENERAL LOCATION ONLY,AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Exploration and Laboratory Results Contents: General Notes Unified Soil Classification System Boring Logs (B-1 through B-8) Test Pit Logs (TP-1 to TP-4) Grain Size Distribution (3 pages) Atterberg Limits Consolidation Field Electrical Resistivity (6 pages) Triaxial CBR (3 pages) Corrosivity Thermal Resistivity (4 pages) Moisture Density Relationship (3 pages) Note: All attachments are one page unless noted above. Facilities | Environmental | Geotechnical | Materials less than 0.25 0.25 to 0.50 0.50 to 1.00 1.00 to 2.00 2.00 to 4.00 > 4.00 Unconfined Compressive Strength Qu (tsf) 6949 S High Tech Dr Ste 100 AES - Eagle Springs Solar County Road 315 and 346 | Rifle, Colorado Midvale, UT Terracon Project No. 61225141 Descriptive Soil Classicification N (HP) (T) (DCP) UC (PID) (OVA) Standard Penetration TestResistance (Blows/Ft.) Hand Penetrometer Torvane Dynamic Cone Penetrometer Unconfined CompressiveStrength Photo-Ionization Detector Organic Vapor Analyzer Water Level After aSpecified Period of Time Water Level After a Specified Period of Time Cave In Encountered Water Level Field Tests Water InitiallyEncountered Sampling Water levels indicated on the soil boring logs are the levels measured in the borehole at the times indicated. Groundwater level variations will occur over time. In low permeability soils, accurate determination of groundwater levels is not possible with short term water level observations. General Notes Location And Elevation Notes Auger Cuttings ModifiedDames &MooreRingSampler Grab Sample Shelby Tube StandardPenetrationTest Exploration point locations as shown on the Exploration Plan and as noted on the soil boring logs in the form of Latitude and Longitude are approximate. See Exploration and Testing Procedures in the report for the methods used to locate the exploration points for this project. Surface elevation data annotated with +/- indicates that no actual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area. Soil classification as noted on the soil boring logs is based Unified Soil Classification System. Where sufficient laboratory data exist to classify the soils consistent with ASTM D2487 "Classification of Soils for Engineering Purposes" this procedure is used. ASTM D2488 "Description and Identification of Soils (Visual-Manual Procedure)" is also used to classify the soils, particularly where insufficient laboratory data exist to classify the soils in accordance with ASTM D2487. In addition to USCS classification, coarse grained soils are classified on the basis of their in-place relative density, and fine-grained soils are classified on the basis of their consistency. See "Strength Terms" table below for details. The ASTM standards noted above are for reference to methodology in general. In some cases, variations to methods are applied as a result of local practice or professional judgment. Exploration/field results and/or laboratory test data contained within this document are intended for application to the project as described in this document. Use of such exploration/field results and/or laboratory test data should not be used independently of this document. Relevance of Exploration and Laboratory Test Results Strength Terms < 30 - 3 0 - 6 3 - 47 - 184 - 9 5 - 919 - 5810 - 29 Hard Very Stiff Stiff Medium Stiff Soft Very Soft > 30 15 - 30 10 - 1859 - 98 Relative Density of Coarse-Grained Soils (More than 50% retained on No. 200 sieve.)Density determined by Standard PenetrationResistance 30 - 50 19 - 42> 99> 50 > 42 8 - 15 4 - 8 2 - 4 0 - 1 Consistency of Fine-Grained Soils (50% or more passing the No. 200 sieve.)Consistency determined by laboratory shear strength testing, fieldvisual-manual procedures or standard penetration resistance Very Loose Loose Medium Dense Dense Very Dense Standard Penetration or N-Value (Blows/Ft.) Ring Sampler (Blows/Ft.) Standard Penetration or N-Value (Blows/Ft.) Ring Sampler (Blows/Ft.)Relative Density Consistency Design -Level Geotechnical Engineering Report Eagle Springs Solar | Garfield County, Colorado October 4, 2022 | Terracon Project No. 61225141 Facilities | Environmental | Geotechnical | Materials Unified Soil Classification System Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A Soil Classification Group Symbol Group Name B Coarse-Grained Soils: More than 50% retained on No. 20 0 sieve Gravels: More than 50% of coarse fraction retained on No. 4 sieve Clean Gravels: Less than 5% fines C Cu≥4 and 1≤Cc≤3 E GW Well-graded gravel F Cu<4 and/or [Cc<1 or Cc>3.0] E GP Poorly graded gravel F Gravels with Fines: More than 12% fines C Fines classify as ML or MH GM Silty gravel F, G, H Fines classify as CL or CH GC Clayey gravel F, G, H Sands: 50% or more of coarse fraction passes No. 4 sieve Clean Sands: Less than 5% fines D Cu≥6 and 1≤Cc≤3 E SW Well-graded sand I Cu<6 and/or [Cc<1 or Cc>3.0] E SP Poorly graded sand I Sands with Fines: More than 12% fines D Fines classify as ML or MH SM Silty sand G, H, I Fines classify as CL or CH SC Clayey sand G, H, I Fine-Grained Soils: 50% or more passes the No. 200 sieve Silts and Clays: Liquid limit less than 50 Inorganic: PI > 7 and plots above “A” line J CL Lean clay K, L, M PI < 4 or plots below “A” line J ML Silt K, L, M Organic: 𝐿𝐿 𝑛𝑣𝑑𝑛 𝑑𝑟𝑖𝑑𝑑 𝐿𝐿 𝑛𝑛𝑡 𝑑𝑟𝑖𝑑𝑑<0.75 OL Organic clay K, L, M, N Organic silt K, L, M, O Silts and Clays: Liquid limit 50 or more Inorganic: PI plots on or above “A” line CH Fat clay K, L, M PI plots below “A” line MH Elastic silt K, L, M Organic: 𝐿𝐿 𝑛𝑣𝑑𝑛 𝑑𝑟𝑖𝑑𝑑 𝐿𝐿 𝑛𝑛𝑡 𝑑𝑟𝑖𝑑𝑑<0.75 OH Organic clay K, L, M, P Organic silt K, L, M, Q Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3 -inch (75-mm) sieve. B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name. C Gravels with 5 to 12% fines require dual symbols: GW -GM well- graded gravel with silt, GW -GC well-graded gravel with clay, GP -GM poorly graded gravel with silt, GP -GC poorly graded gravel with clay. D Sands with 5 to 12% fines require dual symbols: SW -SM well-graded sand with silt, SW-SC well-graded sand with clay, SP -SM poorly graded sand with silt, SP -SC poorly grade d sand with clay. E Cu = D 60/D10 Cc = F If soil contains ≥ 15% sand, add “with sand” to group name. G If fines classify as CL -ML, use dual symbol GC -GM, or SC -SM. H If fines are organic, add “with organic fines” to group name. I If soil contains ≥ 15% gravel, add “with gravel” to group name. J If Atterberg limits plot in shaded area, soil is a CL -ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant. L If soil contains ≥ 30% plus No. 200 predominantly sand, add “sandy” to group name. M If soil contains ≥ 30% plus No. 200, predominantly gravel, add “gravelly” to group name. N PI ≥ 4 and plots on or above “A” line. O PI < 4 or plots below “A” line. P PI plots on or above “A” line. Q PI plots below “A” line. 6010 2 30 DxD )(D 2-3-12 N=15 4-6-5 N=11 5-8-12 N=20 28-54-38 N=92 33-31-26 N=57 45-36-49 N=85 7.7 25-17-8 LEAN CLAY WITH SAND (CL), light brown, stiff to very stiff, with organics (fine roots 0.0' - 4.5') POORLY GRADED GRAVEL WITH SILT AND SAND (GP-GM), fine to coarse grained, gray and brown, very dense Boring Terminated at 16.5 Feet 7.0 16.5 4 2 7 2 12 2 85 Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 15 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5286° Longitude: -107.7035°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Advancement Method: 8 in. Hollow Stem Auger Abandonment Method: Backfilled with auger cuttings and capped with bentonite Notes: Project No.: 61225141 Drill Rig: Geoprobe 3100 BORING LOG NO. B-01 AES Clean Energy Development LLCCLIENT: Driller: MW Boring Completed: 08-15-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Boring Started: 08-15-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS Groundwater not encountered Recovery (In.)PERCENT FINES1 2 SAMPLE TYPE 0-12-20 N=32 5-1-1 N=2 2-8-11 N=19 16-14-12-17 14-15-16 N=31 31-57-70 7.0 SPT N-value may not be accurate at 2.5', sampling error. SILTY CLAY (CL-ML), light brown, very stiff to hard, with organics (fine roots 0.0' - 4.5') - trace gravel SILTY SAND WITH GRAVEL (SM), fine to coarse grained, gray, medium dense to very dense - increase in gravel Auger Refusal at 13.5 Feet 7.0 13.5 9 0 2 18 1 12 39 Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI Advancement Method: 8 in. Hollow Stem Auger Abandonment Method: Backfilled with auger cuttings and capped with bentonite Notes: Project No.: 61225141 Drill Rig: Geoprobe 3100 BORING LOG NO. B-02 AES Clean Energy Development LLCCLIENT: Driller: MW Boring Completed: 08-14-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Boring Started: 08-14-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5277° Longitude: -107.6970°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Groundwater not encountered Recovery (In.)PERCENT FINES1 2 SAMPLE TYPE 7-8-9 N=17 17-29-20 N=49 4-7-8 N=15 13-20-16 N=36 10-22-20 N=42 5.1 6.5 28-18-10 31-16-15 LEAN CLAY WITH SAND (CL), light brown, very stiff to hard, with organics (fine roots 0.0' - 4.5') SANDY LEAN CLAY (CL), light brown, hard SILTY SAND (SM), trace gravel, fine to coarse grained, light brown, dense Boring Terminated at 16.5 Feet 7.0 13.0 16.5 4 13 5 15 18 2 78 69 Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 15 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5257° Longitude: -107.7000°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Advancement Method: 8 in. Hollow Stem Auger Abandonment Method: Backfilled with auger cuttings and capped with bentonite Notes: Project No.: 61225141 Drill Rig: Geoprobe 3100 BORING LOG NO. B-03 AES Clean Energy Development LLCCLIENT: Driller: MW Boring Completed: 08-14-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Boring Started: 08-14-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS Groundwater not encountered Recovery (In.)PERCENT FINES1 2 SAMPLE TYPE 8-13-27 N=40 7-10-7 N=17 6-8-7-5 5-5-7 N=12 8-6-7 N=13 5.7 6.9 8.4 23-16-7 SILTY CLAY WITH SAND (CL-ML), light brown, very stiff to hard, with organics (fine roots 0.0' - 4.5') - evaporative mineralization SILTY SAND (SM), fine to coarse grained, brown, medium dense Boring Terminated at 16.5 Feet 10.0 16.5 0 6 20 18 2 15 71 Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 15 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5233° Longitude: -107.6969°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Advancement Method: 8 in. Hollow Stem Auger Abandonment Method: Backfilled with auger cuttings and capped with bentonite Notes: Project No.: 61225141 Drill Rig: Geoprobe 3100 BORING LOG NO. B-04 AES Clean Energy Development LLCCLIENT: Driller: MW Boring Completed: 08-14-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Boring Started: 08-14-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS Groundwater not encountered Recovery (In.)PERCENT FINES1 2 SAMPLE TYPE 2-5-8 N=13 13-20-15 N=35 8-15-18 N=33 52-22-28-27 11-10-7 N=17 19-36-29 N=65 4.7 5.4 8.2 33-15-18 LEAN CLAY WITH SAND (CL), light brown, stiff to hard, with organics (fine roots 0.0' - 4.5') POORLY GRADED GRAVEL WITH SILT AND SAND (GP-GM), fine to coarse grained, grayish brown, very dense Boring Terminated at 16.5 Feet 12.0 16.5 3 6 5 18 11 5 74 Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 15 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5281° Longitude: -107.7018°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Advancement Method: 8 in. Hollow Stem Auger Abandonment Method: Backfilled with auger cuttings and capped with bentonite Notes: Project No.: 61225141 Drill Rig: Geoprobe 3100 BORING LOG NO. B-05 AES Clean Energy Development LLCCLIENT: Driller: MW Boring Completed: 08-15-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Boring Started: 08-15-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS Groundwater not encountered Recovery (In.)PERCENT FINES1 2 SAMPLE TYPE 7-6-9 N=15 11-14-12 N=26 13-10-11-18 10-12-15 N=27 15-23-21 N=44 14-25-25 N=50 5.2 6.4 30-18-12 SANDY LEAN CLAY (CL), light brown, very stiff to hard, with organics (fine roots 0.0' - 4.5'), pin holes SILTY SAND (SM), fine to coarse grained, brown, dense Boring Terminated at 16.5 Feet 13.5 16.5 5 7 18 2 6 10 63 Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 15 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5272° Longitude: -107.6998°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Advancement Method: 8 in. Hollow Stem Auger Abandonment Method: Backfilled with auger cuttings and capped with bentonite Notes: Project No.: 61225141 Drill Rig: Geoprobe 3100 BORING LOG NO. B-06 AES Clean Energy Development LLCCLIENT: Driller: MW Boring Completed: 08-15-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Boring Started: 08-15-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS Groundwater not encountered Recovery (In.)PERCENT FINES1 2 SAMPLE TYPE 8-13-21 N=34 7-11-11-16 5-12-12 N=24 7-14-13 N=27 8-7-7 N=14 6-7-10 N=17 4.8 9.2 26-20-6 SILTY CLAY (CL-ML), light brown, very stiff to hard, with organics (fine roots 0.0' - 4.5') SILTY SAND (SM), fine to coarse grained, brown, medium dense Boring Terminated at 16.5 Feet 10.0 16.5 6 12 2 5 10 10 78 Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 15 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5248° Longitude: -107.6981°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Advancement Method: 8 in. Hollow Stem Auger Abandonment Method: Backfilled with auger cuttings and capped with bentonite Notes: Project No.: 61225141 Drill Rig: Geoprobe 3100 BORING LOG NO. B-07 AES Clean Energy Development LLCCLIENT: Driller: MW Boring Completed: 08-14-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Boring Started: 08-14-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS Groundwater not encountered Recovery (In.)PERCENT FINES1 2 SAMPLE TYPE 5-10-19 N=29 4-15-3 N=18 3-8-10 N=18 8-16-16 N=32 8-11-10 N=21 7-6-7 N=13 6.0 6.0 9.9 33-16-17 LEAN CLAY WITH SAND (CL), light brown, very stiff to hard, with organics (fine roots 0.0' - 4.5') SILTY SAND (SM), fine to coarse grained, brown, medium dense Boring Terminated at 16.5 Feet 10.0 16.5 10 6 5 9 6 12 73 Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 15 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5219° Longitude: -107.6957°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Advancement Method: 8 in. Hollow Stem Auger Abandonment Method: Backfilled with auger cuttings and capped with bentonite Notes: Project No.: 61225141 Drill Rig: Geoprobe 3100 BORING LOG NO. B-08 AES Clean Energy Development LLCCLIENT: Driller: MW Boring Completed: 08-14-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Boring Started: 08-14-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS Groundwater not encountered Recovery (In.)PERCENT FINES1 2 SAMPLE TYPE 3.8 TOPSOIL, brown, dry SILTY CLAY (CL-ML), brown, moist-dry, contains organics SILTY CLAY WITH SAND (CL-ML), brown, moist-dry Test Pit Terminated at 10 Feet 1.0 7.0 10.0 89 Stratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5279° Longitude: -107.7027°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Advancement Method: Trackhoe Abandonment Method: Backfilled with cuttings Notes: Project No.: 61225141 Excavator: Kobeko TEST PIT LOG NO. TP-01 AES Clean Energy Development LLCCLIENT: Operator: Eric Test Pit Completed: 09-13-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Test Pit Started: 09-13-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS Groundwater not encountered Recovery (In.)PERCENT FINESSAMPLE TYPE TOPSOIL, brown, dry SILTY CLAY (CL-ML), brown, dry, contains organics SILTY SAND (SM), with cobbles Test Pit Terminated at 10 Feet 1.0 3.0 10.0 35 Stratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5277° Longitude: -107.6970°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Advancement Method: Trackhoe Abandonment Method: Backfilled with cuttings Notes: Project No.: 61225141 Excavator: Kobeko TEST PIT LOG NO. TP-02 AES Clean Energy Development LLCCLIENT: Operator: Eric Test Pit Completed: 09-13-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Test Pit Started: 09-13-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS Groundwater not encountered Recovery (In.)PERCENT FINESSAMPLE TYPE TOPSOIL, brown, dry SILTY CLAY (CL-ML), brown, slightly moist, contains organics SILTY SAND WITH GRAVEL (SM), brown, slightly moist, with cobbles Boring Terminated at 10 Feet 1.0 8.5 10.0 65 Stratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5262° Longitude: -107.6990°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Advancement Method: Trackhoe Abandonment Method: Backfilled with cuttings Notes: Project No.: 61225141 Drill Rig: Kobeko BORING LOG NO. TP-03 AES Clean Energy Development LLCCLIENT: Driller: Eric Boring Completed: 09-12-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Boring Started: 09-12-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS Groundwater not encountered Recovery (In.)PERCENT FINESSAMPLE TYPE 5.6 TOPSOIL, brown, dry SILTY CLAY (CL-ML), brown, dry, contains organics SILTY SAND (SM), brown, slightly moist Boring Terminated at 10 Feet 1.0 9.0 10.0 86 Stratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22DEPTH (Ft.)5 10 WATER LEVELOBSERVATIONSFIELD TESTRESULTSWATERCONTENT (%)LL-PL-PI ATTERBERG LIMITSLOCATIONSee Exploration Plan Latitude: 39.5241° Longitude: -107.6982°GRAPHIC LOGMODEL LAYERDEPTH Page 1 of 1 Advancement Method: Trackhoe Abandonment Method: Backfilled with cuttings Notes: Project No.: 61225141 Drill Rig: Kobeko BORING LOG NO. TP-04 AES Clean Energy Development LLCCLIENT: Driller: Eric Boring Completed: 09-12-2022 PROJECT: AES - Eagle Springs Solar See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. County Road 315 and 346 Rifle, Colorado SITE: Boring Started: 09-12-2022 6949 S High Tech Dr Ste 100 Midvale, UT WATER LEVEL OBSERVATIONS Groundwater not encountered Recovery (In.)PERCENT FINESSAMPLE TYPE 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 0.0010.010.1110100 ASTM D422 / ASTM C136 6 16 20 30 40 501.5 200681014413/4 1/2 60 GRAIN SIZE IN MILLIMETERSPERCENT FINER BY WEIGHTHYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 4 3/8 3 100 14032 GRAIN SIZE DISTRIBUTION SILT OR CLAY B-01 B-02 B-03 B-03 B-04 mediumcoarsecoarsefine fineCOBBLESGRAVELSAND LEAN CLAY with SAND (CL) SILTY SAND with GRAVEL (SM) LEAN CLAY with SAND (CL) SANDY LEAN CLAY (CL) SILTY CLAY with SAND (CL-ML) 25 28 31 23 8 10 15 7 17 18 16 16 5 - 6.5 7.5 - 9.5 2.5 - 4 7.5 - 9 7.5 - 9.5 7.7 5.1 6.5 6.9 B-01 B-02 B-03 B-03 B-04 84.7 39.0 78.0 68.6 71.3 5 - 6.5 7.5 - 9.5 2.5 - 4 7.5 - 9 7.5 - 9.5 15.5 45.5 0.075 25 0.075 0.075 0.075 0.188 6949 S High Tech Dr Ste 100 Midvale, UT PROJECT NUMBER: 61225141 SITE: County Road 315 and 346 Rifle, Colorado PROJECT: AES - Eagle Springs Solar CLIENT: AES Clean Energy Development LLC LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22WC (%)LL PL PI Cc Cu %Clay%Fines%Silt%Sand%GravelD100D60D30D10 USCS Classification %Cobbles 0.0 Boring ID Depth (Ft) Boring ID Depth (Ft) 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 0.0010.010.1110100 ASTM D422 / ASTM C136 6 16 20 30 40 501.5 200681014413/4 1/2 60 GRAIN SIZE IN MILLIMETERSPERCENT FINER BY WEIGHTHYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 4 3/8 3 100 14032 GRAIN SIZE DISTRIBUTION SILT OR CLAY B-05 B-06 B-07 B-08 TP-01 mediumcoarsecoarsefine fineCOBBLESGRAVELSAND LEAN CLAY with SAND (CL) SANDY LEAN CLAY (CL) SILTY CLAY with SAND (CL-ML) LEAN CLAY with SAND (CL) SILTY CLAY (CL-ML) 33 30 26 33 18 12 6 17 15 18 20 16 7.5 - 9.5 5 - 7 2.5 - 4.5 7.5 - 9 1 - 6 8.2 6.4 4.8 9.9 B-05 B-06 B-07 B-08 TP-01 74.1 63.3 78.4 72.6 88.7 7.5 - 9.5 5 - 7 2.5 - 4.5 7.5 - 9 1 - 6 0.0 11.3 0.075 0.075 0.075 0.075 4.75 6949 S High Tech Dr Ste 100 Midvale, UT PROJECT NUMBER: 61225141 SITE: County Road 315 and 346 Rifle, Colorado PROJECT: AES - Eagle Springs Solar CLIENT: AES Clean Energy Development LLC LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22WC (%)LL PL PI Cc Cu %Clay%Fines%Silt%Sand%GravelD100D60D30D10 USCS Classification %Cobbles 0.0 Boring ID Depth (Ft) Boring ID Depth (Ft) 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 0.0010.010.1110100 ASTM D422 / ASTM C136 6 16 20 30 40 501.5 200681014413/4 1/2 60 GRAIN SIZE IN MILLIMETERSPERCENT FINER BY WEIGHTHYDROMETERU.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 4 3/8 3 100 14032 GRAIN SIZE DISTRIBUTION SILT OR CLAY TP-02 TP-03 TP-04 mediumcoarsecoarsefine fineCOBBLESGRAVELSAND SILTY SAND (SM) SILTY CLAY (CL-ML) SILTY CLAY (CL-ML) 1 - 6 1 - 6 1 - 6 TP-02 TP-03 TP-04 35.0 65.3 86.3 1 - 6 1 - 6 1 - 6 21.1 5.1 0.0 43.9 29.7 13.7 75 75 4.75 0.758 6949 S High Tech Dr Ste 100 Midvale, UT PROJECT NUMBER: 61225141 SITE: County Road 315 and 346 Rifle, Colorado PROJECT: AES - Eagle Springs Solar CLIENT: AES Clean Energy Development LLC LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22WC (%)LL PL PI Cc Cu %Clay%Fines%Silt%Sand%GravelD100D60D30D10 USCS Classification %Cobbles 0.0 0.0 0.0 Boring ID Depth (Ft) Boring ID Depth (Ft) 0 10 20 30 40 50 60 0 20 40 60 80 100CH or OHCL or OLML or OL MH or OH"U" Line"A" Line ATTERBERG LIMITS RESULTS ASTM D4318 P L A S T I C I T Y I N D E X LIQUID LIMIT 6949 S High Tech Dr Ste 100 Midvale, UT PROJECT NUMBER: 61225141 SITE: County Road 315 and 346 Rifle, Colorado PROJECT: AES - Eagle Springs Solar CLIENT: AES Clean Energy Development LLC LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 10/5/22 25 28 31 23 33 30 26 33 17 18 16 16 15 18 20 16 8 10 15 7 18 12 6 17 PIPLLL B-01 B-03 B-03 B-04 B-05 B-06 B-07 B-08 84.7 78.0 68.6 71.3 74.1 63.3 78.4 72.6 Fines 5 - 6.5 2.5 - 4 7.5 - 9 7.5 - 9.5 7.5 - 9.5 5 - 7 2.5 - 4.5 7.5 - 9 CL CL CL CL-ML CL CL CL-ML CL LEAN CLAY with SAND LEAN CLAY with SAND SANDY LEAN CLAY SILTY CLAY with SAND LEAN CLAY with SAND SANDY LEAN CLAY SILTY CLAY with SAND LEAN CLAY with SAND DescriptionUSCSBoring ID Depth (Ft) CL-ML 33 19 74.1 CL Project Number: 61225141 CONSOLIDATION TEST DATA ASTM D 2435-04 119 7 Before Consolidation 2.41 1.00 Sample Diameter (in): Sample Height (in): Moist Unit Weight (pcf): Moisture Content (%): 0.0026 2.41 0.89 After Consolidation 142 13 Sample Volume (cf):Dry Unit Weight (pcf):112 Project: AES - Eagle Springs Solar Location: Rifle, Colorado Sample Diameter (in): Sample Height (in): Sample Volume (cf): Liquid Limit: Plasticity Index: Soil Properties Percent Fines: Classification: Moist Unit Weight (pcf): Moisture Content (%): Dry Unit Weight (pcf):0.0024 126 Sample: B-5 @ 7.5 -1.0 1.0 3.0 5.0 7.0 9.0 11.0 13.0 0.1 1 10 100VERTICAL STRAIN, %VERTICAL STRESS, ksf FIELD ELECTRICAL RESISTIVITY TEST DATA Eagle Springs Solar ■ Rifle, Colorado August 23, 2022 ■ Terracon Project No. 61225141 Array Loc. Instrument Weather Serial #Ground Cond. Cal. Check Tested By Test Date Method Notes & Conflicts Apparent resistivity ρ is calculated as : Measured Resistance R Apparent Resistivity ρ Measured Resistance R Apparent Resistivity ρ Ω (Ω-cm)Ω (Ω-cm) 1 30 6 15 79.95 19830 119.30 29590 2 61 6 15 27.14 11410 27.38 11510 3 91 6 15 14.16 8470 14.96 8940 5 152 6 15 10.55 10240 10.59 10280 10 305 6 15 6.97 13420 7.37 14180 20 610 6 15 5.22 20040 5.25 20160 50 1524 6 15 1.99 19030 1.87 17910 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A (feet)(centimeters)(inches)(centimeters) August 23, 2022 Wenner 4-pin (ASTM G57-06 (2012); IEEE 81-2012) Electrode Spacing a Electrode Depth b N-S Test E-W Test PG/JA FER-01 Supersting R8 Clear 84° F SS1412014 Light brush 1.0 10.0 100.0 1,000.0 10,000.0 100,000.0 1 10 100 1000 10000Apparent Resistivity R(Ω-cm)Electrode Spacing a (cm) Apparent resistivity vs a spacing N-S Array E-W Array 𝜋=4𝜋𝑎𝑅 1 +2𝑎 𝑎2 +4𝑎2 −𝑎 𝑎2 +𝑎2 FIELD ELECTRICAL RESISTIVITY TEST DATA Eagle Springs Solar ■ Rifle, Colorado August 23, 2022 ■ Terracon Project No. 61225141 Array Loc. Instrument Weather Serial #Ground Cond. Cal. Check Tested By Test Date Method Notes & Conflicts Apparent resistivity ρ is calculated as : Measured Resistance R Apparent Resistivity ρ Measured Resistance R Apparent Resistivity ρ Ω (Ω-cm)Ω (Ω-cm) 1 30 6 15 29.47 7310 43.94 10900 2 61 6 15 21.99 9240 23.81 10010 3 91 6 15 13.60 8130 16.06 9600 5 152 6 15 12.29 11930 11.23 10910 10 305 12 30 9.92 19320 8.29 16140 20 610 12 30 7.17 27600 6.70 25790 50 1524 12 30 5.82 55800 1.97 18870 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A PG/JA FER-02 Supersting R8 Clear 83° F SS1412014 Light brush Wenner 4-pin (ASTM G57-06 (2012); IEEE 81-2012) Electrode Spacing a Electrode Depth b N-S Test E-W Test (feet)(centimeters)(inches)(centimeters) August 23, 2022 1.0 10.0 100.0 1,000.0 10,000.0 100,000.0 1 10 100 1000 10000Apparent Resistivity R(Ω-cm)Electrode Spacing a (cm) Apparent resistivity vs a spacing N-S Array E-W Array 𝜋=4𝜋𝑎𝑅 1 +2𝑎 𝑎2 +4𝑎2 −𝑎 𝑎2 +𝑎2 FIELD ELECTRICAL RESISTIVITY TEST DATA Eagle Springs Solar ■ Rifle, Colorado August 23, 2022 ■ Terracon Project No. 61225141 Array Loc. Instrument Weather Serial #Ground Cond. Cal. Check Tested By Test Date Method Notes & Conflicts Apparent resistivity ρ is calculated as : Measured Resistance R Apparent Resistivity ρ Measured Resistance R Apparent Resistivity ρ Ω (Ω-cm)Ω (Ω-cm) 1 30 6 15 128.70 31920 140.90 34950 2 61 6 15 26.44 11110 33.14 13930 3 91 6 15 18.43 11020 23.28 13920 5 152 6 15 17.39 16890 15.15 14710 10 305 12 30 13.34 25990 13.16 25640 20 610 12 30 8.59 33040 9.11 35070 50 1524 12 30 2.05 19660 2.58 24760 100 3048 12 30 0.57 10960 0.57 10940 200 6096 12 30 0.16 6080 0.12 4780 300 9144 12 30 0.10 5850 0.06 3390 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A (feet)(centimeters)(inches)(centimeters) August 23, 2022 Wenner 4-pin (ASTM G57-06 (2012); IEEE 81-2012) Electrode Spacing a Electrode Depth b N-S Test E-W Test PG/JA FER-03 Supersting R8 Clear 83° F SS1412014 Light brush 1.0 10.0 100.0 1,000.0 10,000.0 100,000.0 1 10 100 1000 10000Apparent Resistivity R(Ω-cm)Electrode Spacing a (cm) Apparent resistivity vs a spacing N-S Array E-W Array 𝜋=4𝜋𝑎𝑅 1 +2𝑎 𝑎2 +4𝑎2 −𝑎 𝑎2 +𝑎2 FIELD ELECTRICAL RESISTIVITY TEST DATA Eagle Springs Solar ■ Rifle, Colorado August 23, 2022 ■ Terracon Project No. 61225141 Array Loc. Instrument Weather Serial #Ground Cond. Cal. Check Tested By Test Date Method Notes & Conflicts Apparent resistivity ρ is calculated as : Measured Resistance R Apparent Resistivity ρ Measured Resistance R Apparent Resistivity ρ Ω (Ω-cm)Ω (Ω-cm) 1 30 6 15 77.03 19110 158.00 39190 2 61 6 15 22.14 9310 18.09 7600 3 91 6 15 15.82 9460 13.97 8350 5 152 6 15 6.53 6340 7.31 7100 10 305 12 30 3.33 6480 3.63 7060 20 610 12 30 2.87 11060 2.63 10140 50 1524 12 30 1.71 16400 1.47 14050 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A (feet)(centimeters)(inches)(centimeters) August 23, 2022 Wenner 4-pin (ASTM G57-06 (2012); IEEE 81-2012) Electrode Spacing a Electrode Depth b N-S Test E-W Test PG/JA FER-04 Supersting R8 Cloudy 83° F SS1412014 Light brush 1.0 10.0 100.0 1,000.0 10,000.0 100,000.0 1 10 100 1000 10000Apparent Resistivity R(Ω-cm)Electrode Spacing a (cm) Apparent resistivity vs a spacing N-S Array E-W Array 𝜋=4𝜋𝑎𝑅 1 +2𝑎 𝑎2 +4𝑎2 −𝑎 𝑎2 +𝑎2 FIELD ELECTRICAL RESISTIVITY TEST DATA Eagle Springs Solar ■ Rifle, Colorado August 23, 2022 ■ Terracon Project No. 61225141 Array Loc. Instrument Weather Serial #Ground Cond. Cal. Check Tested By Test Date Method Notes & Conflicts Apparent resistivity ρ is calculated as : Measured Resistance R Apparent Resistivity ρ Measured Resistance R Apparent Resistivity ρ Ω (Ω-cm)Ω (Ω-cm) 1 30 6 15 36.83 9140 62.20 15430 2 61 6 15 32.63 13720 19.52 8210 3 91 6 15 10.99 6570 12.69 7590 5 152 6 15 5.93 5760 7.20 6990 10 305 12 30 2.61 5090 2.38 4630 20 610 12 30 0.77 2960 0.64 2470 50 1524 12 30 0.32 3110 0.35 3360 100 3048 12 30 0.25 4720 0.24 4640 200 6096 12 30 0.11 4330 0.12 4550 300 9144 12 30 0.07 4180 0.08 4670 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A (feet)(centimeters)(inches)(centimeters) August 23, 2022 Wenner 4-pin (ASTM G57-06 (2012); IEEE 81-2012) Electrode Spacing a Electrode Depth b N-S Test E-W Test PG/JA FER-05 Supersting R8 Clear 83° F SS1412014 Light brush 1.0 10.0 100.0 1,000.0 10,000.0 100,000.0 1 10 100 1000 10000Apparent Resistivity R(Ω-cm)Electrode Spacing a (cm) Apparent resistivity vs a spacing N-S Array E-W Array 𝜋=4𝜋𝑎𝑅 1 +2𝑎 𝑎2 +4𝑎2 −𝑎 𝑎2 +𝑎2 FIELD ELECTRICAL RESISTIVITY TEST DATA Eagle Springs Solar ■ Rifle, Colorado August 23, 2022 ■ Terracon Project No. 61225141 Array Loc. Instrument Weather Serial #Ground Cond. Cal. Check Tested By Test Date Method Notes & Conflicts Apparent resistivity ρ is calculated as : Measured Resistance R Apparent Resistivity ρ Measured Resistance R Apparent Resistivity ρ Ω (Ω-cm)Ω (Ω-cm) 1 30 6 15 120.20 29820 96.21 23870 2 61 6 15 19.29 8110 22.62 9510 3 91 6 15 20.35 12170 16.42 9820 5 152 6 15 8.68 8420 11.39 11060 10 305 12 30 5.79 11280 5.23 10190 20 610 12 30 2.40 9240 2.70 10380 50 1524 12 30 0.75 7200 0.70 6750 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A (feet)(centimeters)(inches)(centimeters) August 23, 2022 Wenner 4-pin (ASTM G57-06 (2012); IEEE 81-2012) Electrode Spacing a Electrode Depth b N-S Test E-W Test PG/JA FER-06 Supersting R8 Clear 83° F SS1412014 Light brush 1.0 10.0 100.0 1,000.0 10,000.0 100,000.0 1 10 100 1000 10000Apparent Resistivity R(Ω-cm)Electrode Spacing a (cm) Apparent resistivity vs a spacing N-S Array E-W Array 𝜋=4𝜋𝑎𝑅 1 +2𝑎 𝑎2 +4𝑎2 −𝑎 𝑎2 +𝑎2 Maximum Dry Density, lb/ft3:111 Test Method:ASTM 698CGRADATION RESULTS Optimum Moisture, %:12 (ZERO AIR VOIDS FOR SPECIFIC GRAVITY OF 2.58) SIEVE PERCENT SIZE PASSING 3"100 2"97 1"96 3/4"95 1/2"95 3/8"95 No. 4 95 No. 8 94 No. 10 93 No. 20 88 No. 40 84 No. 80 79 No. 100 78 No. 200 65 Liquid Limit: Plasticity Index: CALIFORNIA BEARING RATIO Dry Density, Before Soaking, lb/ft3:101.5 After Soaking, lb/ft3:100.9 Relative Compaction, %:91 Moisture Content, Before Compaction, %:11.4 Top 1-inch After Soaking, %:22.1 Average After Soaking, %:21.3 Surcharge Weight, lb:10 Soaking Period, hr:96 Swell, %:0.5 CBR Value, %:3.2 SAMPLE - IDENTIFICATION CLASSIFICATION TP-01 Sandy Lean Clay GRADATION, MOISTURE-DENSITY AND CALIFORNIA BEARING RATIO TEST RESULTS Project Name:AES - Eagle Springs Solar Location:TP-01 Project No.:61225141 Date:9/30/2022 0 10 20 30 40 50 60 70 0.00 0.10 0.20 0.30 0.40 0.50 0.60STRESS ON PISTON, lb/in2PENETRATION, inches 90 95 100 105 110 115 120 5 7 9 11 13 15 17 19 21 23 25DRY DENSITY, lb/ft3WATER CONTENT, % Maximum Dry Density, lb/ft3:112 Test Method:ASTM 698CGRADATION RESULTS Optimum Moisture, %:14.5 (ZERO AIR VOIDS FOR SPECIFIC GRAVITY OF 2.58) SIEVE PERCENT SIZE PASSING 3"100 2"95 1-1/2"94 3/4"87 1/2"84 3/8"83 No. 4 79 No. 8 70 No. 10 68 No. 16 62 No. 20 59 No. 30 56 No. 40 54 No. 50 51 No. 80 46 No. 100 44 No. 200 35 Liquid Limit: Plasticity Index: CALIFORNIA BEARING RATIO Dry Density, Before Soaking, lb/ft3:99.6 After Soaking, lb/ft3:119.6 Relative Compaction, %:89 Moisture Content, Before Compaction, %:13.3 Top 1-inch After Soaking, %:20.7 Average After Soaking, %:20.7 Surcharge Weight, lb:10 Soaking Period, hr:96 Swell, %:-16.3 CBR Value, %:1.8 SAMPLE - IDENTIFICATION CLASSIFICATION TP-02 Clayey Sand GRADATION, MOISTURE-DENSITY AND CALIFORNIA BEARING RATIO TEST RESULTS Project Name:AES - Eagle Springs Solar Location:TP-02 Project No.:61225141 Date:9/30/2022 0 5 10 15 20 25 30 35 40 0.00 0.10 0.20 0.30 0.40 0.50 0.60STRESS ON PISTON, lb/in2PENETRATION, inches 90 95 100 105 110 115 120 5 7 9 11 13 15 17 19 21 23 25DRY DENSITY, lb/ft3WATER CONTENT, % Maximum Dry Density, lb/ft3:110.5 Test Method:ASTM 698CGRADATION RESULTS Optimum Moisture, %:13.5 (ZERO AIR VOIDS FOR SPECIFIC GRAVITY OF 2.58) SIEVE PERCENT SIZE PASSING 3"100 2"97 1-1/2"97 1"96 3/4"95 1/2"95 3/8"95 No. 4 95 No. 8 94 No. 10 93 No. 16 90 No. 20 88 No. 30 86 No. 40 84 No. 50 82 No. 80 80 No. 100 78 Liquid Limit:48 Plasticity Index:25 CALIFORNIA BEARING RATIO Dry Density, Before Soaking, lb/ft3:102.0 After Soaking, lb/ft3:97.1 Relative Compaction, %:92 Moisture Content, Before Compaction, %:15.7 Top 1-inch After Soaking, %:21.5 Average After Soaking, %:21.8 Surcharge Weight, lb:10 Soaking Period, hr:96 Swell, %:2.4 CBR Value, %:1.5 SAMPLE - IDENTIFICATION CLASSIFICATION TP-03 Lean Clay (CL) GRADATION, MOISTURE-DENSITY AND CALIFORNIA BEARING RATIO TEST RESULTS Project Name:AES - Eagle Springs Solar Location:TP-03 Project No.:61225141 Date:9/30/2022 0 5 10 15 20 25 30 35 0.00 0.10 0.20 0.30 0.40 0.50 0.60STRESS ON PISTON, lb/in2PENETRATION, inches 90 95 100 105 110 115 120 5 7 9 11 13 15 17 19 21 23 25DRY DENSITY, lb/ft3WATER CONTENT, % Project Number: Service Date: Report Date: Client B-2 B-4 2 1 8.3 8.4 27 47 nil nil 100 113 +425 +433 589 902 2,375 2,994 Analyzed By: The tests were performed in general accordance with applicable ASTM, AASHTO, or DOT test methods. This report is exclusively for the use of the client indicated above and shall not be reproduced except in full without the written consent of our company. Test results transmitted herein are only applicable to the actual samples tested at the location(s) referenced and are not necessarily indicative of the properties of other apparently similar or identical materials. 61225141 Engineering Technician III 08/31/22 Louisville, CO 80027 Sample Location Sample Depth (ft.) Rifle, CO 09/02/22 10400 State Highway 191 Midland, Texas 79707 432-684-9600 County Road 315 and 346 Project AES Clean Energy Development LLC CHEMICAL LABORATORY TEST REPORT Zach Robertson pH Analysis, ASTM - G51-18 Water Soluble Sulfate (SO4), ASTM C 1580 (mg/kg) Sulfides, ASTM - D4658-15, (mg/kg) Chlorides, ASTM D 512 , (mg/kg) RedOx, ASTM D-1498, (mV) Total Salts, ASTM D1125-14, (mg/kg) Resistivity, ASTM G187, (ohm-cm) 282 Century Place Suite 2000 AES - Eagle Springs Solar COOL SOLUTIONS FOR UNDERGROUND POWER CABLES THERMAL SURVEYS, CORRECTIVE BACKFILLS & INSTRUMENTATION Serving the electric power industry since 1978 21239 FM5 29 Rd., Bldg. F Cypress, TX 77433 Tel: 281-985-9344 Fax: 832 -427-1752 i nfo@geothermusa.com http://ww w.geothermu sa .com October 3, 2022 Terracon 6949 S. High Tech Drive, S uite 100 Midvale, Utah 84047 A ttn: Josh White, P.E. Re: Thermal Analysis of Native Soil Sample s AES Eagle Springs Solar – Rifle, CO (PO No. 61225141) The following is the report of th ermal dryout c hara cte rizatio n tests conducted on three (3 ) s ample s of native soil from the referenced project sent to our laboratory . Thermal Resistivity Tests: T he sample s w ere test ed at the ‘optimum ’ moisture content and 85% and 90% of the standard Proctor dry densit y p rovided by Terracon . Th e tests were conducted in accordance with the IEEE standard 442 -2017. The results are tabulated below and the thermal dryout curve s are presented in Figures 1 to 3. Sampl e ID, Description, Therm a l Resis t ivity, Moisture Conte nt and Densi t y Samp le I D Effort (%) Description (Terracon ) Thermal Resistivity (°C -cm/W) Moistur e Content (%) Dry Density (lb/ft 3 ) Wet Dry TP-01 85 Lean clay with sand 88 218 12 95 90 80 181 100 TP-02 85 Lean clay with sand 82 201 14 95 90 74 178 101 TP-03 85 Lean clay with sand 9 3 235 14 94 90 79 190 100 P lea se conta ct u s if you have any questi ons or if we can be of further assistance. Geo t herm USA Nimesh Patel 2 3 4 75 80 85 90 95 100 105 110 115 120 125 130 135 0 5 10 15 20 25 30 35 40 45DRY DENSITY, pcfWATER CONTENT, % Z A V f o r G s = 2 . 8 Z A V f o r G s = 2 . 7 Z A V f o r G s = 2 . 6 MOISTURE-DENSITY RELATIONSHIP ASTM D698/D1557 6949 S High Tech Dr Ste 100 Midvale, UT PROJECT NUMBER: 61225141 SITE: County Road 315 and 346 Rifle, CO PROJECT: AES - Eagle Springs Solar CLIENT: AES Clean Energy Development LLC Louisville, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. COMPACTION - V2 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 9/22/22ASTM D698 Method C TP-01 @ 1 - 6 feetSource of Material Description of Material Remarks: Test Method PCF % TEST RESULTS Maximum Dry Density % LL 111.2 Optimum Water Content PIPL ATTERBERG LIMITS 12.4 Percent Fines 75 80 85 90 95 100 105 110 115 120 125 130 135 0 5 10 15 20 25 30 35 40 45DRY DENSITY, pcfWATER CONTENT, % Z A V f o r G s = 2 . 8 Z A V f o r G s = 2 . 7 Z A V f o r G s = 2 . 6 MOISTURE-DENSITY RELATIONSHIP ASTM D698/D1557 6949 S High Tech Dr Ste 100 Midvale, UT PROJECT NUMBER: 61225141 SITE: County Road 315 and 346 Rifle, CO PROJECT: AES - Eagle Springs Solar CLIENT: AES Clean Energy Development LLC Louisville, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. COMPACTION - V2 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 9/22/22ASTM D698 Method A TP-02 @ 1 - 6 feetSource of Material Description of Material Remarks: Test Method PCF % TEST RESULTS Maximum Dry Density % LL 111.9 Optimum Water Content PIPL ATTERBERG LIMITS 13.6 Percent Fines 75 80 85 90 95 100 105 110 115 120 125 130 135 0 5 10 15 20 25 30 35 40 45DRY DENSITY, pcfWATER CONTENT, % Z A V f o r G s = 2 . 8 Z A V f o r G s = 2 . 7 Z A V f o r G s = 2 . 6 MOISTURE-DENSITY RELATIONSHIP ASTM D698/D1557 6949 S High Tech Dr Ste 100 Midvale, UT PROJECT NUMBER: 61225141 SITE: County Road 315 and 346 Rifle, CO PROJECT: AES - Eagle Springs Solar CLIENT: AES Clean Energy Development LLC Louisville, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. COMPACTION - V2 61225141 AES - EAGLE SPRIN.GPJ TERRACON_DATATEMPLATE.GDT 9/22/22ASTM D698 Method C TP-03 @ 1 - 6 feetSource of Material Description of Material Remarks: Test Method PCF % TEST RESULTS Maximum Dry Density % LL 110.6 Optimum Water Content PIPL ATTERBERG LIMITS 14.0 Percent Fines Revised Design-Level Geotechnical Engineering Report Eagle Springs Organic Solar | Garfield County, Colorado February 17, 2023 | Terracon Project No. 61225141 Facilities | Environmental |Geotechnical | Materials Pile Load Testing Results Contents: Test Pile Driving Records (2 pages) Axial Tension Pile Load Testing Results (8 pages) Lateral Pile Load Testing Results (8 Pages) Compression Pile Load Testing Results (4 pages) Note: All attachments are one page unless noted above. Depth, feet PLT-3A PLT-3B PLT-3C PLT-4A PLT-4B PLT-4C 1 1.2 1.3 1.7 12.6 11.5 2.2 2 4.2 4.4 4.7 23.8 22.9 9.7 3 13.6 15.2 16.6 31.2 34.2 22.1 4 22.7 22.3 27.2 42.6 46.3 34.4 5 29.6 29.6 37.5 58.1 49.0 47.6 6 36.6 74.9 7 44.7 91.1 8 56.2 109.2 Embedment Depth, ft 8 5 5 8 5 5 Total Drive Time, sec 56.2 29.6 37.5 109.2 49.0 47.6 Average, sec/ft 7.0 5.9 7.5 13.7 9.8 9.5 NOTES: Piles advanced with a track mounted Vermeer PD 10 Pile Driver with a high-frequency hydraulic hammer on September 7, 2022. EAGLES SPRINGS SOLAR - TEST PILE DRIVING RECORDS Cumulative Drive Time, seconds Cumulative Driving Time, seconds 0 2 4 6 8 10 12 14 0 20 40 60 80 100 120 Depth, feetPLT-3A PLT-3B PLT-3C PLT-4A PLT-4B PLT-4C Project Information Project Name:Eagle Springs Solar Tension Test Results Davisson Offset Limit Lines Project Location:Rifle, Colorado % of Axial Elastic Davisson Offest Project Number:61225141 Design Load Deflection Δ (in.)Data (in)Limit (in) Load [lbs]Gauges #1 & #2 (PL/AE)(0.15+D/120+(PL/AE)) 0%0 0.000 0.000 0.199 Axial Load Test Set Up 17%500 0.001 0.001 0.200 Number of Gauges:2 33%1000 0.002 0.001 0.200 Height of Gauges [in]:6 50%1500 0.003 0.002 0.201 Load Cell:Dillion Ed Junior 67%2000 0.004 0.002 0.201 83%2500 0.006 0.003 0.202 100%3000 0.008 0.003 0.202 Test Date and Representative 117%3500 0.010 0.004 0.203 Tested By Terracon Rep:CO/JA 133%4000 0.013 0.004 0.203 Date Tested:150%4500 0.017 0.005 0.204 167%5000 0.020 0.005 0.205 183%5500 0.026 0.006 0.205 Pile Information 200%6000 0.037 0.006 0.206 Pile ID:PLT-1A 217%6500 0.043 0.007 0.206 Latitude:39.52864 233%7000 0.052 0.008 0.207 Longitude:-107.70353 250%7500 0.059 0.008 0.207 Pile Type:W6X9 267%8000 0.069 0.009 0.208 Pile Embedment Depth [in]:84 283%8500 0.076 0.009 0.208 Pile Diameter [in]:5.9 300%9000 0.088 0.010 0.209 Pile Stick-Up [in]:60 317%9500 0.103 0.010 0.209 Axial Design Load [lbs]:3000 333%10000 0.123 0.011 0.210 Pile Area [sq. in]:2.68 0%0 0.071 0.000 0.199 Elastic Modulus [ksi]: Drive Time [sec]:304 Tension Load Test Result for PLT-1A Comments 9/13/2022 29,000 0.00 0.20 0.40 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500Deflection (inches)Uplift Axial Load (lbs) Axial Deflection Davisson Offset Limit Project Information Project Name:Eagle Springs Solar Tension Test Results Davisson Offset Limit Lines Project Location:Rifle, Colorado % of Axial Elastic Davisson Offest Project Number:61225141 Design Load Deflection Δ (in.)Data (in)Limit (in) Load [lbs]Gauges #1 & #2 (PL/AE)(0.15+D/120+(PL/AE)) 0%0 0.000 0.000 0.199 Axial Load Test Set Up 17%500 0.000 0.000 0.200 Number of Gauges:2 33%1000 0.000 0.001 0.200 Height of Gauges [in]:6 50%1500 0.002 0.001 0.200 Load Cell:Dillion Ed Junior 67%2000 0.007 0.002 0.201 83%2500 0.008 0.002 0.201 100%3000 0.010 0.002 0.201 Test Date and Representative 117%3500 0.011 0.003 0.202 Tested By Terracon Rep:CO/JA 133%4000 0.013 0.003 0.202 Date Tested:150%4500 0.014 0.003 0.203 167%5000 0.021 0.004 0.203 183%5500 0.023 0.004 0.203 Pile Information 200%6000 0.032 0.005 0.204 Pile ID:PLT-1B 217%6500 0.036 0.005 0.204 Latitude:39.52864 233%7000 0.041 0.005 0.205 Longitude:-107.70353 250%7500 0.048 0.006 0.205 Pile Type:W6X9 267%8000 0.065 0.006 0.205 Pile Embedment Depth [in]:60 283%8500 0.075 0.007 0.206 Pile Diameter [in]:5.9 300%9000 0.093 0.007 0.206 Pile Stick-Up [in]:48 317%9500 0.112 0.007 0.207 Axial Design Load [lbs]:3000 333%10000 0.138 0.008 0.207 Pile Area [sq. in]:2.68 0%0 0.084 0.000 0.199 Elastic Modulus [ksi]: Drive Time [sec]:142.3 Tension Load Test Result for PLT-1B Comments 9/13/2022 29,000 0.00 0.20 0.40 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500Deflection (inches)Uplift Axial Load (lbs) Axial Deflection Davisson Offset Limit Project Information Project Name:Eagle Springs Solar Tension Test Results Davisson Offset Limit Lines Project Location:Rifle, Colorado % of Axial Elastic Davisson Offest Project Number:61225141 Design Load Deflection Δ (in.)Data (in)Limit (in) Load [lbs]Gauges #1 & #2 (PL/AE)(0.15+D/120+(PL/AE)) 0%0 0.000 0.000 0.199 Axial Load Test Set Up 17%500 -0.001 0.001 0.200 Number of Gauges:2 33%1000 -0.002 0.001 0.200 Height of Gauges [in]:6 50%1500 -0.002 0.002 0.201 Load Cell:Dillion Ed Junior 67%2000 -0.003 0.002 0.202 83%2500 -0.002 0.003 0.202 100%3000 -0.002 0.004 0.203 Test Date and Representative 117%3500 -0.001 0.004 0.203 Tested By Terracon Rep:CO/JA 133%4000 0.005 0.005 0.204 Date Tested:150%4500 0.005 0.006 0.205 167%5000 0.004 0.006 0.205 183%5500 0.004 0.007 0.206 Pile Information 200%6000 0.006 0.007 0.207 Pile ID:PLT-2A 217%6500 0.006 0.008 0.207 Latitude:39.52770 233%7000 0.007 0.009 0.208 Longitude:-107.69700 250%7500 0.007 0.009 0.208 Pile Type:W6X9 267%8000 0.011 0.010 0.209 Pile Embedment Depth [in]:96 283%8500 0.011 0.010 0.210 Pile Diameter [in]:5.9 300%9000 0.014 0.011 0.210 Pile Stick-Up [in]:48 317%9500 0.014 0.012 0.211 Axial Design Load [lbs]:3000 333%10000 0.014 0.012 0.212 Pile Area [sq. in]:2.68 0%0 0.015 0.000 0.199 Elastic Modulus [ksi]: Drive Time [sec]:257.3 Tension Load Test Result for PLT-2A Comments 9/13/2022 29,000 0.00 0.20 0.40 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500Deflection (inches)Uplift Axial Load (lbs) Axial Deflection Davisson Offset Limit Project Information Project Name:Eagle Springs Solar Tension Test Results Davisson Offset Limit Lines Project Location:Rifle, Colorado % of Axial Elastic Davisson Offest Project Number:61225141 Design Load Deflection Δ (in.)Data (in)Limit (in) Load [lbs]Gauges #1 & #2 (PL/AE)(0.15+D/120+(PL/AE)) 0%0 0.000 0.000 0.199 Axial Load Test Set Up 17%500 0.002 0.000 0.200 Number of Gauges:2 33%1000 0.008 0.001 0.200 Height of Gauges [in]:6 50%1500 0.008 0.001 0.200 Load Cell:Dillion Ed Junior 67%2000 0.007 0.002 0.201 83%2500 0.011 0.002 0.201 100%3000 0.006 0.002 0.201 Test Date and Representative 117%3500 0.012 0.003 0.202 Tested By Terracon Rep:CO/JA 133%4000 0.014 0.003 0.202 Date Tested:150%4500 0.013 0.003 0.203 167%5000 0.011 0.004 0.203 183%5500 0.011 0.004 0.203 Pile Information 200%6000 0.020 0.005 0.204 Pile ID:PLT-2B 217%6500 0.014 0.005 0.204 Latitude:39.52770 233%7000 0.015 0.005 0.205 Longitude:-107.69700 250%7500 0.016 0.006 0.205 Pile Type:W6X9 267%8000 0.021 0.006 0.205 Pile Embedment Depth [in]:60 283%8500 0.021 0.007 0.206 Pile Diameter [in]:5.9 300%9000 0.019 0.007 0.206 Pile Stick-Up [in]:48 317%9500 0.025 0.007 0.207 Axial Design Load [lbs]:3000 333%10000 0.026 0.008 0.207 Pile Area [sq. in]:2.68 0%0 0.017 0.000 0.199 Elastic Modulus [ksi]: Drive Time [sec]:55.2 Tension Load Test Result for PLT-2B Comments 9/13/2022 29,000 0.00 0.20 0.40 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500Deflection (inches)Uplift Axial Load (lbs) Axial Deflection Davisson Offset Limit Project Information Project Name:Eagle Springs Solar Tension Test Results Davisson Offset Limit Lines Project Location:Rifle, Colorado % of Axial Elastic Davisson Offest Project Number:61225141 Design Load Deflection Δ (in.)Data (in)Limit (in) Load [lbs]Gauges #1 & #2 (PL/AE)(0.15+D/120+(PL/AE)) 0%0 0.000 0.000 0.199 Axial Load Test Set Up 17%500 0.001 0.001 0.200 Number of Gauges:2 33%1000 0.001 0.001 0.200 Height of Gauges [in]:6 50%1500 0.003 0.002 0.201 Load Cell:Dillion Ed Junior 67%2000 0.004 0.002 0.202 83%2500 0.005 0.003 0.202 100%3000 0.005 0.004 0.203 Test Date and Representative 117%3500 0.009 0.004 0.203 Tested By Terracon Rep:CO/JA 133%4000 0.008 0.005 0.204 Date Tested:150%4500 0.008 0.006 0.205 167%5000 0.008 0.006 0.205 183%5500 0.008 0.007 0.206 Pile Information 200%6000 0.008 0.007 0.207 Pile ID:PLT-3A 217%6500 0.009 0.008 0.207 Latitude:39.52572 233%7000 0.009 0.009 0.208 Longitude:-107.70004 250%7500 0.010 0.009 0.208 Pile Type:W6X9 267%8000 0.010 0.010 0.209 Pile Embedment Depth [in]:96 283%8500 0.012 0.010 0.210 Pile Diameter [in]:5.9 300%9000 0.012 0.011 0.210 Pile Stick-Up [in]:48 317%9500 0.016 0.012 0.211 Axial Design Load [lbs]:3000 333%10000 0.017 0.012 0.212 Pile Area [sq. in]:2.68 0%0 0.011 0.000 0.199 Elastic Modulus [ksi]: Drive Time [sec]:56.2 Tension Load Test Result for PLT-3A Comments 9/13/2022 29,000 0.00 0.20 0.40 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500Deflection (inches)Uplift Axial Load (lbs) Axial Deflection Davisson Offset Limit Project Information Project Name:Eagle Springs Solar Tension Test Results Davisson Offset Limit Lines Project Location:Rifle, Colorado % of Axial Elastic Davisson Offest Project Number:61225141 Design Load Deflection Δ (in.)Data (in)Limit (in) Load [lbs]Gauges #1 & #2 (PL/AE)(0.15+D/120+(PL/AE)) 0%0 0.000 0.000 0.199 Axial Load Test Set Up 17%500 0.000 0.000 0.200 Number of Gauges:2 33%1000 0.001 0.001 0.200 Height of Gauges [in]:6 50%1500 0.004 0.001 0.200 Load Cell:Dillion Ed Junior 67%2000 0.005 0.002 0.201 83%2500 0.006 0.002 0.201 100%3000 0.009 0.002 0.201 Test Date and Representative 117%3500 0.011 0.003 0.202 Tested By Terracon Rep:CO/JA 133%4000 0.013 0.003 0.202 Date Tested:150%4500 0.013 0.003 0.203 167%5000 0.018 0.004 0.203 183%5500 0.021 0.004 0.203 Pile Information 200%6000 0.035 0.005 0.204 Pile ID:PLT-3B 217%6500 0.036 0.005 0.204 Latitude:39.52572 233%7000 0.044 0.005 0.205 Longitude:-107.70004 250%7500 0.044 0.006 0.205 Pile Type:W6X9 267%8000 0.062 0.006 0.205 Pile Embedment Depth [in]:60 283%8500 0.063 0.007 0.206 Pile Diameter [in]:5.9 300%9000 0.080 0.007 0.206 Pile Stick-Up [in]:48 317%9500 0.080 0.007 0.207 Axial Design Load [lbs]:3000 333%10000 0.100 0.008 0.207 Pile Area [sq. in]:2.68 0%0 0.078 0.000 0.199 Elastic Modulus [ksi]: Drive Time [sec]:29.6 Tension Load Test Result for PLT-3B Comments 9/13/2022 29,000 0.00 0.20 0.40 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500Deflection (inches)Uplift Axial Load (lbs) Axial Deflection Davisson Offset Limit Project Information Project Name:Eagle Springs Solar Tension Test Results Davisson Offset Limit Lines Project Location:Rifle, Colorado % of Axial Elastic Davisson Offest Project Number:61225141 Design Load Deflection Δ (in.)Data (in)Limit (in) Load [lbs]Gauges #1 & #2 (PL/AE)(0.15+D/120+(PL/AE)) 0%0 0.000 0.000 0.199 Axial Load Test Set Up 17%500 0.000 0.001 0.200 Number of Gauges:2 33%1000 0.000 0.001 0.200 Height of Gauges [in]:6 50%1500 0.000 0.002 0.201 Load Cell:Dillion Ed Junior 67%2000 0.001 0.002 0.202 83%2500 0.002 0.003 0.202 100%3000 0.003 0.004 0.203 Test Date and Representative 117%3500 0.004 0.004 0.203 Tested By Terracon Rep:CO/JA 133%4000 0.006 0.005 0.204 Date Tested:150%4500 0.007 0.006 0.205 167%5000 0.006 0.006 0.205 183%5500 0.007 0.007 0.206 Pile Information 200%6000 0.009 0.007 0.207 Pile ID:PLT-4A 217%6500 0.010 0.008 0.207 Latitude:39.52332 233%7000 0.012 0.009 0.208 Longitude:-107.69691 250%7500 0.012 0.009 0.208 Pile Type:W6X9 267%8000 0.013 0.010 0.209 Pile Embedment Depth [in]:96 283%8500 0.019 0.010 0.210 Pile Diameter [in]:5.9 300%9000 0.019 0.011 0.210 Pile Stick-Up [in]:48 317%9500 0.020 0.012 0.211 Axial Design Load [lbs]:3000 333%10000 0.030 0.012 0.212 Pile Area [sq. in]:2.68 0%0 0.009 0.000 0.199 Elastic Modulus [ksi]: Drive Time [sec]:109.2 Tension Load Test Result for PLT-4A Comments 9/12/2022 29,000 0.00 0.20 0.40 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500Deflection (inches)Uplift Axial Load (lbs) Axial Deflection Davisson Offset Limit Project Information Project Name:Eagle Springs Solar Tension Test Results Davisson Offset Limit Lines Project Location:Rifle, Colorado % of Axial Elastic Davisson Offest Project Number:61225141 Design Load Deflection Δ (in.)Data (in)Limit (in) Load [lbs]Gauges #1 & #2 (PL/AE)(0.15+D/120+(PL/AE)) 0%0 0.000 0.000 0.199 Axial Load Test Set Up 17%500 0.001 0.000 0.200 Number of Gauges:2 33%1000 0.002 0.001 0.200 Height of Gauges [in]:6 50%1500 0.001 0.001 0.200 Load Cell:Dillion Ed Junior 67%2000 0.002 0.002 0.201 83%2500 0.003 0.002 0.201 100%3000 0.004 0.002 0.201 Test Date and Representative 117%3500 0.004 0.003 0.202 Tested By Terracon Rep:CO/JA 133%4000 0.006 0.003 0.202 Date Tested:150%4500 0.008 0.003 0.203 167%5000 0.009 0.004 0.203 183%5500 0.015 0.004 0.203 Pile Information 200%6000 0.016 0.005 0.204 Pile ID:PLT-4B 217%6500 0.023 0.005 0.204 Latitude:39.52332 233%7000 0.028 0.005 0.205 Longitude:-107.69691 250%7500 0.037 0.006 0.205 Pile Type:W6X9 267%8000 0.047 0.006 0.205 Pile Embedment Depth [in]:60 283%8500 0.056 0.007 0.206 Pile Diameter [in]:5.9 300%9000 0.068 0.007 0.206 Pile Stick-Up [in]:48 317%9500 0.080 0.007 0.207 Axial Design Load [lbs]:3000 333%10000 0.098 0.008 0.207 Pile Area [sq. in]:2.68 0%0 0.073 0.000 0.199 Elastic Modulus [ksi]: Drive Time [sec]:49 Tension Load Test Result for PLT-4B Comments 9/12/2022 29,000 0.00 0.20 0.40 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500Deflection (inches)Uplift Axial Load (lbs) Axial Deflection Davisson Offset Limit Project Information % of Design Lateral Load Deflection Δ (in.) Project Name:Eagle Springs Solar Load [lbs]Gauges #1 & #2 Project Location:Rifle, Colorado 0%0 0.000 Project Number:61225141 14%500 0.113 29%1000 0.250 43%1500 0.385 Lateral Load Test Set Up 0%0 0.064 Number of Top Gauges:0 43%1500 0.411 Number of Bottom Gauges:2 57%2000 0.531 Height of Top Gauges [in]:48 71%2500 1.124 Height of Bottom Gauges [in]:6 86%3000 1.894 Fail at 2600lbs Height of Applied Load [in]:48 0%0 1.014 Load Cell:Dillion Ed Junior 86%3000 100%3500 114%4000 Test Date and Representative 129%4500 Tested By Terracon Rep:CO/JA 0%0 Date Tested:129%4500 143%5000 157%5500 Pile Information 171%6000 Pile ID:PLT-1A 0%0 Latitude:39.52864 171%6000 Longitude:-107.70353 186%6500 Pile Type:W6X9 200%7000 Pile Embedment Depth [in]:84 0%0 Pile Stick-Up [in]:60 Lateral Design Load [lbs]:3500 Drive Time [sec]:304 Lateral Load Test Result for PLT-1A Comments 9/13/2022 0.00 0.50 1.00 1.50 2.00 0500100015002000250030003500Deflection (inches)Lateral Load (lbs) Lateral - Gauges at 6-inches Project Information % of Design Lateral Load Deflection Δ (in.) Project Name:Eagle Springs Solar Load [lbs]Gauges #1 & #2 Project Location:Rifle, Colorado 0%0 0.000 Project Number:61225141 14%500 0.107 29%1000 0.276 43%1500 0.426 Lateral Load Test Set Up 0%0 0.097 Number of Top Gauges:0 43%1500 0.449 Number of Bottom Gauges:2 57%2000 0.593 Height of Top Gauges [in]:48 71%2500 0.987 Height of Bottom Gauges [in]:6 86%3000 1.770 Fail at 2700lbs Height of Applied Load [in]:48 0%0 1.237 Load Cell:Dillion Ed Junior 86%3000 100%3500 114%4000 Test Date and Representative 129%4500 Tested By Terracon Rep:CO/JA 0%0 Date Tested:129%4500 143%5000 157%5500 Pile Information 171%6000 Pile ID:PLT-1B 0%0 Latitude:39.52864 171%6000 Longitude:-107.70353 186%6500 Pile Type:W6X9 200%7000 Pile Embedment Depth [in]:60 0%0 Pile Stick-Up [in]:48 Lateral Design Load [lbs]:3500 Drive Time [sec]:142.3 Lateral Load Test Result for PLT-1B Comments 9/13/2022 0.00 0.50 1.00 1.50 2.00 0500100015002000250030003500Deflection (inches)Lateral Load (lbs) Lateral - Gauges at 6-inches Project Information % of Design Lateral Load Deflection Δ (in.) Project Name:Eagle Springs Solar Load [lbs]Gauges #1 & #2 Project Location:Rifle, Colorado 0%0 0.000 Project Number:61225141 14%500 0.042 29%1000 0.069 43%1500 0.124 Lateral Load Test Set Up 0%0 0.016 Number of Top Gauges:0 43%1500 0.136 Number of Bottom Gauges:2 57%2000 0.174 Height of Top Gauges [in]:48 71%2500 0.224 Height of Bottom Gauges [in]:6 86%3000 0.243 Height of Applied Load [in]:48 0%0 0.016 Load Cell:Dillion Ed Junior 86%3000 0.270 100%3500 0.314 114%4000 0.372 Test Date and Representative 129%4500 0.429 Tested By Terracon Rep:CO/JA 0%0 0.043 Date Tested:129%4500 0.324 143%5000 0.334 157%5500 0.346 Pile Information 171%6000 0.556 Pile ID:PLT-2A 0%0 0.092 Latitude:39.52770 171%6000 0.785 Longitude:-107.69700 186%6500 2.000 Fail at 6200 Pile Type:W6X9 200%7000 Pile Embedment Depth [in]:96 0%0 0.988 Pile Stick-Up [in]:48 Lateral Design Load [lbs]:3500 Drive Time [sec]:257.3 Lateral Load Test Result for PLT-2A Comments 9/13/2022 0.00 0.50 1.00 1.50 2.00 05001000150020002500300035004000450050005500600065007000Deflection (inches)Lateral Load (lbs) Lateral - Gauges at 6-inches Project Information % of Design Lateral Load Deflection Δ (in.) Project Name:Eagle Springs Solar Load [lbs]Gauges #1 & #2 Project Location:Rifle, Colorado 0%0 0.000 Project Number:61225141 14%500 0.044 29%1000 0.079 43%1500 0.130 Lateral Load Test Set Up 0%0 0.003 Number of Top Gauges:0 43%1500 0.135 Number of Bottom Gauges:2 57%2000 0.173 Height of Top Gauges [in]:48 71%2500 0.200 Height of Bottom Gauges [in]:6 86%3000 0.213 Height of Applied Load [in]:48 0%0 -0.006 Load Cell:Dillion Ed Junior 86%3000 0.242 100%3500 0.296 114%4000 0.353 Test Date and Representative 129%4500 0.398 Tested By Terracon Rep:CO/JA 0%0 0.029 Date Tested:129%4500 0.413 143%5000 0.461 157%5500 0.524 Pile Information 171%6000 0.643 Pile ID:PLT-2B 0%0 0.098 Latitude:39.52770 171%6000 0.818 Longitude:-107.69700 186%6500 1.643 Fail at 6400lbs Pile Type:W6X9 200%7000 Pile Embedment Depth [in]:60 0%0 1.163 Pile Stick-Up [in]:48 Lateral Design Load [lbs]:3500 Drive Time [sec]:55.2 Lateral Load Test Result for PLT-2B Comments 9/13/2022 0.00 0.50 1.00 1.50 2.00 05001000150020002500300035004000450050005500600065007000Deflection (inches)Lateral Load (lbs) Lateral - Gauges at 6-inches Project Information % of Design Lateral Load Deflection Δ (in.) Project Name:Eagle Springs Solar Load [lbs]Gauges #1 & #2 Project Location:Rifle, Colorado 0%0 0.000 Project Number:61225141 14%500 0.026 29%1000 0.076 43%1500 0.127 Lateral Load Test Set Up 0%0 -0.001 Number of Top Gauges:0 43%1500 0.153 Number of Bottom Gauges:2 57%2000 0.186 Height of Top Gauges [in]:48 71%2500 0.233 Height of Bottom Gauges [in]:6 86%3000 0.287 Height of Applied Load [in]:48 0%0 0.007 Load Cell:Dillion Ed Junior 86%3000 0.310 100%3500 0.343 114%4000 0.383 Test Date and Representative 129%4500 0.434 Tested By Terracon Rep:CO/JA 0%0 0.049 Date Tested:129%4500 0.458 143%5000 0.485 157%5500 0.539 Pile Information 171%6000 0.604 Pile ID:PLT-3A 0%0 0.042 Latitude:39.52572 171%6000 0.703 Longitude:-107.70004 186%6500 0.835 Pile Type:W6X9 200%7000 2.000 Fail at 6700lbs Pile Embedment Depth [in]:96 0%0 0.804 Pile Stick-Up [in]:48 Lateral Design Load [lbs]:3500 Drive Time [sec]:56.2 Lateral Load Test Result for PLT-3A Comments 9/13/2022 0.00 0.50 1.00 1.50 2.00 05001000150020002500300035004000450050005500600065007000Deflection (inches)Lateral Load (lbs) Lateral - Gauges at 6-inches Project Information % of Design Lateral Load Deflection Δ (in.) Project Name:Eagle Springs Solar Load [lbs]Gauges #1 & #2 Project Location:Rifle, Colorado 0%0 0.000 Project Number:61225141 14%500 0.065 29%1000 0.113 43%1500 0.159 Lateral Load Test Set Up 0%0 0.010 Number of Top Gauges:0 43%1500 0.168 Number of Bottom Gauges:2 57%2000 0.208 Height of Top Gauges [in]:48 71%2500 0.254 Height of Bottom Gauges [in]:6 86%3000 0.311 Height of Applied Load [in]:48 0%0 0.015 Load Cell:Dillion Ed Junior 86%3000 0.351 100%3500 0.391 114%4000 0.424 Test Date and Representative 129%4500 0.478 Tested By Terracon Rep:CO/JA 0%0 0.047 Date Tested:129%4500 0.508 143%5000 0.552 157%5500 0.603 Pile Information 171%6000 0.715 Pile ID:PLT-3B 0%0 0.110 Latitude:39.52572 171%6000 0.866 Longitude:-107.70004 186%6500 1.483 Pile Type:W6X9 200%7000 Pile Embedment Depth [in]:60 0%0 0.883 Pile Stick-Up [in]:48 Lateral Design Load [lbs]:3500 Drive Time [sec]:29.6 Lateral Load Test Result for PLT-3B Comments 9/13/2022 0.00 0.50 1.00 1.50 2.00 05001000150020002500300035004000450050005500600065007000Deflection (inches)Lateral Load (lbs) Lateral - Gauges at 6-inches Project Information % of Design Lateral Load Deflection Δ (in.) Project Name:Eagle Springs Solar Load [lbs]Gauges #1 & #2 Project Location:Rifle, Colorado 0%0 0.000 Project Number:61225141 14%500 0.044 29%1000 0.086 43%1500 0.139 Lateral Load Test Set Up 0%0 0.008 Number of Top Gauges:0 43%1500 0.148 Number of Bottom Gauges:2 57%2000 0.175 Height of Top Gauges [in]:48 71%2500 0.226 Height of Bottom Gauges [in]:6 86%3000 0.251 Height of Applied Load [in]:48 0%0 0.022 Load Cell:Dillion Ed Junior 86%3000 0.288 100%3500 0.331 114%4000 0.377 Test Date and Representative 129%4500 0.418 Tested By Terracon Rep:CO/JA 0%0 0.051 Date Tested:129%4500 0.428 143%5000 0.465 157%5500 0.521 Pile Information 171%6000 0.626 Pile ID:PLT-4A 0%0 0.106 Latitude:39.52332 171%6000 0.917 Longitude:-107.69691 186%6500 2.000 Fail at 6400lbs Pile Type:W6X9 200%7000 Pile Embedment Depth [in]:96 0%0 1.297 Pile Stick-Up [in]:48 Lateral Design Load [lbs]:3500 Drive Time [sec]:109.2 Lateral Load Test Result for PLT-4A Comments 9/12/2022 0.00 0.50 1.00 1.50 2.00 05001000150020002500300035004000450050005500600065007000Deflection (inches)Lateral Load (lbs) Lateral - Gauges at 6-inches Project Information % of Design Lateral Load Deflection Δ (in.) Project Name:Eagle Springs Solar Load [lbs]Gauges #1 & #2 Project Location:Rifle, Colorado 0%0 0.000 Project Number:61225141 14%500 0.046 29%1000 0.096 43%1500 0.147 Lateral Load Test Set Up 0%0 0.013 Number of Top Gauges:0 43%1500 0.148 Number of Bottom Gauges:2 57%2000 0.180 Height of Top Gauges [in]:48 71%2500 0.227 Height of Bottom Gauges [in]:6 86%3000 0.257 Height of Applied Load [in]:48 0%0 0.025 Load Cell:Dillion Ed Junior 86%3000 0.276 100%3500 0.323 114%4000 0.368 Test Date and Representative 129%4500 0.421 Tested By Terracon Rep:CO/JA 0%0 0.066 Date Tested:129%4500 0.428 143%5000 0.465 157%5500 0.509 Pile Information 171%6000 0.562 Pile ID:PLT-4B 0%0 0.119 Latitude:39.52332 171%6000 0.926 Longitude:-107.69691 186%6500 1.558 Fail at 6350lbs Pile Type:W6X9 200%7000 Pile Embedment Depth [in]:60 0%0 1.019 Pile Stick-Up [in]:48 Lateral Design Load [lbs]:3500 Drive Time [sec]:49 Lateral Load Test Result for PLT-4B Comments 9/12/2022 0.00 0.50 1.00 1.50 2.00 05001000150020002500300035004000450050005500600065007000Deflection (inches)Lateral Load (lbs) Lateral - Gauges at 6-inches Project Information Project Name:Eagle Springs Solar Project Location:Rifle, Colorado % of Axial Project Number:61225141 Design Load Deflection Δ (in.) Load [lbs]Gauges #1 & #2 0%0 0.000 Axial Load Test Set Up 10%500 0.000 Number of Gauges:2 20%1000 0.003 Height of Gauges [in]:6 30%1500 0.007 Load Cell:Rice Lake Compression 40%2000 0.009 50%2500 0.013 60%3000 0.015 Test Date and Representative 70%3500 0.019 Tested By Terracon Rep:CO/JA 80%4000 0.027 Date Tested:90%4500 0.029 100%5000 0.032 110%5500 0.035 Pile Information 120%6000 0.038 Pile ID:PLT-1C 130%6500 0.042 Latitude:39.52864 140%7000 0.045 Longitude:-107.70353 150%7500 0.048 Pile Type:W6X9 160%8000 0.051 Pile Embedment Depth [in]:60 170%8500 0.054 Pile Diameter [in]:5.9 180%9000 0.058 Pile Stick-Up [in]:18 190%9500 0.058 Axial Design Load [lbs]:5000 200%10000 0.065 Pile Area [sq. in]:2.68 210%10500 0.069 Elastic Modulus [ksi]:220%11000 0.071 Drive Time [sec]:0 230%11500 0.074 240%12000 0.075 250%12500 0.078 260%13000 0.081 0%0 0.016 29,000 Compression Load Test Result for PLT-1C Compression Test Results Comments 9/13/2022 0.00 0.10 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500110001150012000125001300013500Deflection (inches)Compression Axial Load (lbs) Axial Deflection Project Information Project Name:Eagle Springs Solar Project Location:Rifle, Colorado % of Axial Project Number:61225141 Design Load Deflection Δ (in.) Load [lbs]Gauges #1 & #2 0%0 0.000 Axial Load Test Set Up 10%500 0.001 Number of Gauges:2 20%1000 0.001 Height of Gauges [in]:6 30%1500 0.001 Load Cell:Rice Lake Compression 40%2000 0.001 50%2500 0.002 60%3000 0.002 Test Date and Representative 70%3500 0.004 Tested By Terracon Rep:CO/JA 80%4000 0.004 Date Tested:90%4500 0.004 100%5000 0.005 110%5500 0.006 Pile Information 120%6000 0.007 Pile ID:PLT-2C 130%6500 0.007 Latitude:39.52770 140%7000 0.009 Longitude:-107.69700 150%7500 0.008 Pile Type:W6X9 160%8000 0.012 Pile Embedment Depth [in]:60 170%8500 0.014 Pile Diameter [in]:5.9 180%9000 0.014 Pile Stick-Up [in]:18 190%9500 0.015 Axial Design Load [lbs]:5000 200%10000 0.015 Pile Area [sq. in]:2.68 210%10500 0.017 Elastic Modulus [ksi]:220%11000 0.019 Drive Time [sec]:70.9 230%11500 0.022 240%12000 0.025 250%12500 0.026 260%13000 0.028 0%0 0.003 29,000 Compression Load Test Result for PLT-2C Compression Test Results Comments 9/13/2022 0.00 0.10 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500110001150012000125001300013500Deflection (inches)Compression Axial Load (lbs) Axial Deflection Project Information Project Name:Eagle Springs Solar Project Location:Rifle, Colorado % of Axial Project Number:61225141 Design Load Deflection Δ (in.) Load [lbs]Gauges #1 & #2 0%0 0.000 Axial Load Test Set Up 10%500 0.001 Number of Gauges:2 20%1000 0.001 Height of Gauges [in]:6 30%1500 0.001 Load Cell:Rice Lake Compression 40%2000 0.002 50%2500 0.004 60%3000 0.005 Test Date and Representative 70%3500 0.005 Tested By Terracon Rep:CO/JA 80%4000 0.006 Date Tested:90%4500 0.007 100%5000 0.008 110%5500 0.008 Pile Information 120%6000 0.009 Pile ID:PLT-3C 130%6500 0.010 Latitude:39.52572 140%7000 0.010 Longitude:-107.70004 150%7500 0.017 Pile Type:W6X9 160%8000 0.017 Pile Embedment Depth [in]:60 170%8500 0.017 Pile Diameter [in]:5.9 180%9000 0.018 Pile Stick-Up [in]:18 190%9500 0.018 Axial Design Load [lbs]:5000 200%10000 0.019 Pile Area [sq. in]:2.68 210%10500 0.019 Elastic Modulus [ksi]:220%11000 0.020 Drive Time [sec]:37.5 230%11500 0.021 240%12000 0.023 250%12500 0.024 260%13000 0.026 0%0 0.011 29,000 Compression Load Test Result for PLT-3C Compression Test Results Comments 9/13/2022 0.00 0.10 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500110001150012000125001300013500Deflection (inches)Compression Axial Load (lbs) Axial Deflection Project Information Project Name:Eagle Springs Solar Project Location:Rifle, Colorado % of Axial Project Number:61225141 Design Load Deflection Δ (in.) Load [lbs]Gauges #1 & #2 0%0 0.000 Axial Load Test Set Up 10%500 -0.001 Number of Gauges:2 20%1000 -0.001 Height of Gauges [in]:6 30%1500 -0.001 Load Cell:Rice Lake Compression 40%2000 -0.001 50%2500 0.000 60%3000 0.000 Test Date and Representative 70%3500 0.000 Tested By Terracon Rep:CO/JA 80%4000 0.000 Date Tested:90%4500 0.000 100%5000 0.000 110%5500 0.000 Pile Information 120%6000 0.001 Pile ID:PLT-4C 130%6500 0.002 Latitude:39.52332 140%7000 0.003 Longitude:-107.69691 150%7500 0.003 Pile Type:W6X9 160%8000 0.003 Pile Embedment Depth [in]:60 170%8500 0.004 Pile Diameter [in]:5.9 180%9000 0.004 Pile Stick-Up [in]:18 190%9500 0.006 Axial Design Load [lbs]:5000 200%10000 0.007 Pile Area [sq. in]:2.68 210%10500 0.008 Elastic Modulus [ksi]:220%11000 0.009 Drive Time [sec]:47.6 230%11500 0.011 240%12000 0.011 250%12500 0.012 260%13000 0.018 0%0 0.005 29,000 Compression Load Test Result for PLT-4C Compression Test Results Comments 9/12/2022 0.00 0.10 05001000150020002500300035004000450050005500600065007000750080008500900095001000010500110001150012000125001300013500Deflection (inches)Compression Axial Load (lbs) Series6 AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 62 Please see the following pages for the AES’ planned Operations and Maintenance Schedule for AES Eagle Springs Organic Solar. OPERATIONS AND MAINTENANCE SCHEDULE Appendix C12 SCHEDULE 1 SCHEDULE 1 1. System-Wide Maintenance System-wide maintenance includes but is not limited to the following: Item Service Description Frequency 1 Complete and submit Maintenance Reports. As Needed SCHEDULE 1 2 Inspect the mechanical functionality of the Project – including but not limited to randomly inspecting a reasonable quantity of the fastening/mounting elements, equipment connection and coupling cases, visual inspection of overhead poles and lines, verifying that the threaded connections are tight, visual inspection of all parts of the equipment and checking the cabling. Quantity inspected shall be not less than 10% and is acknowledged as sufficient to make informed recommendation if follow-up or additional remediation is required. 1x per year 3 Inspect all electrical boxes, combiner boxes and electrical equipment for water damage or signs of significant water accumulation in underground conduit. 1x per year 4 Scan combiner boxes with Infrared camera to identify loose of broken connections. 1x per year 5 Visually Inspect the medium-voltage components and conduct grounding measurements and verification. 1x per year 6 Visually inspect each AMPT DC/DC String Optimizer 1x per year 7 Inspect accessible cabling for signs of cracks, defects, pulling out of connections, overheating, arcing, short or open circuits, and ground faults. 1x per year 8 Check for abnormal corrosion on parts of the Project and perform minor service on any parts with the potential for corrosion to remove long-term risks. 1x per year 9 Check the mechanical functionality of the built-in components and interrupters (ground fault circuit interrupters and circuit breakers). 1x per year 10 Check the functionality of the meters. For avoidance of doubt, functionality of the meters means that meters are operating, communicating reliably and measuring coherent values as compared to the backup meters. 1x per year 11 Maintain pyranometers on a regular basis according to the manufacturer's recommendations, including but not limited to: calibration, cleaning, checking electrical connections and mechanical supports, verifying installation tilt and azimuth, checking desiccant and filters. As Needed 12 Maintenance of the structure that will support the Panels shall be by various means including visual inspection, searching for impacts, corrosion and condition of the protective paint, and absence of water deposits. 1x per year 13 Thermal camera testing of electrical current connections and circuit breakers. 1x per year SCHEDULE 1 14 Carryout maintenance of Project transformer(s) in accordance with manufacturer’s recommendation. As Needed 2. Panel Maintenance Ongoing panel maintenance includes but is not limited to the following operations: Item Service Description Frequency 1 Check for possible glass breakage, normally caused by external actions, and rarely by thermal fatigue arising from assembly errors. 1x per year 2 Visually check for oxidation in the circuits and welding of the photovoltaic cells, normally due to the entrance of dampness into the panel because of a fault or breakage of the sealing layers. 1x per year 3 Check for change of color to yellow or brown (known as yellowing and browning) of the sealant or encapsulant. 1x per year 4 Check for issues with the panel backsheet, as inflammations in this area could be a symptom of a hot point in the module. 1x per year 5 Check for deformations in the junction boxes of the module due to overheating of the bypass diodes and/or high contact resistance because of bad tightness of an electrical terminal. 1x per year 6 Check the tightness and condition on not less than 10% of the module series connections. 1x per year 7 Where feasible, visually check the watertight integrity of the terminal boxes or the condition of the protective hoods of the terminals, depending on the type of Panel. 1x per year 8 In the event that faults are detected in the watertight integrity, either 1) make minor repairs that do not compromise the panel warranty or 2) process a panel warranty claim. 1x per year 9 Undertake comparative measurement of string DC currents and/or conduct aerial thermal imaging of the solar array. 1x per year SCHEDULE 1 3. Inverter Maintenance Ongoing inverter maintenance includes but is not limited to the following: Item Service Description Frequency 1 Annual maintenance performed by O&M Contractor as required to meet the manufacturer’s warranty requirements. O&M Contractor will provide a detailed report of findings. As required 2 General visual observation of the condition and functioning of the inverter. 1x per year 3 Check wiring and the connection tightness of the parts. 1x per year 4 Verify that the site of the inverter is clean, dry and well ventilated and insulated. 1x per year 5 Check that the inverter works properly and that unusual noises are not coming from inside it. 1x per year 6 Check that where the inverter is placed maintains suitable temperatures so that this equipment can always work within the temperature range specified by the inverter manufacturer such that it does not derate. 1x per year 7 Check the equipment protection and alarms. 1x per year 8 Inspect air filters annually. Replace or clean as necessary. 1x per year 4. Component Testing Component tests required include: Item Service Description Frequency 1 Test all DC source circuits and input circuits, VOC and ISC 1x per year 2 Test all OCPDs and disconnects 1x per year 3 Test equipment grounding/continuity 1x per year 4 Verify accuracy of all meters, sensors, monitoring devices, communications equipment, weather station. 1x per year 5. Ground-Mount Project Maintenance Ongoing general Project maintenance includes but is not limited to the following: Item Service Description Frequency 1 Visual inspection of the general Project conditions, vegetation, animal damage, and erosion. As needed when at Project SCHEDULE 1 2 Maintain weeds, grasses and ground cover to prevent shading and risk of fire. This includes: mowing, and reseeding grass when necessary to mitigate erosion. 2x per year, plus as needed following a quoted price 3 Monitor trees and larger vegetation to prevent shading. If shading is present or imminent, O&M Contractor will assist Owner in identifying a third-party service to conduct the needed trimming. O&M Contractor will provide direction to that third As needed 4 Remove all rubbish, excessive vegetation, animal nests, dead animals, and other obstructions from underneath array, electrical equipment servicing zones and other key access areas. As needed 6. Racking Maintenance Ongoing tracking and non-tracking racking maintenance includes but is not limited to the following: Item Service Description Frequency 1 Visually inspect all racking hardware and components for abnormal wear or excessive corrosion. 1x per year 2 Verify torque of bolted connections at the racking and/or tracking systems. At least 1x per year 3 Inspect all ground mounts, visually inspect structural footings and check for abnormal wear and physical damage from vehicles. 1x per year 7. Cleaning Requirements Ongoing cleaning requirements include but is not limited to the following: Item Service Description Frequency 1 Clean PV modules with pressurized plain water. Do not use brushes, any types of solvents, abrasives, or harsh detergents. The timing of cleanings are at the discretion of the O&M Contractor but preferably before summer, and after a period of no rainfall or when there is an event that affects the production of the Project. As Requested for Additional Fee 2 Clean weather station as necessary to provide accurate data readings. As Needed 8. Battery Plant SCHEDULE 1 For all equipment in the Battery Plant, inclusive containers and support systems, complete the full visual/mechanical/electrical inspections and tests as recommended by ANSI/NETA and the OEM owner manuals per the respective intervals. SCHEDULE 1 Item Service Description Frequency 1 Battery Plant – 10MW/20MWh, Samsung batteries, integrated via DC/DC converters behind four (4) 2.8MW Inverter Skid (derated to 2.5MW). Per Above 2 Battery Energy Storage Systems – One (1) system, comprised of (8) CEN container containing Samsung batteries and associated Auxiliary Power, HVAC and Fore Suppression systems. Per Above 3 DC/DC Converter Modules – eight (8) units serving the BESS Per Above 4 All associated Disconnect Switches and BESS Recombiners Per Above 5 Inspect all fire extinguishers in accordance with regulations; monthly, annually, As Applicable Operator Rates for Non-Covered Services All expenses for Non-Covered Services, including labor, materials and equipment related thereto, will be billed to Owner at Operator’s cost on a time and materials, cost plus 10% basis at Operator’s reasonable, documented rates. Such services include, but are not limited to, additional panel washings and additional vegetation management beyond the frequencies or intervals listed in the Maintenance Services Scope. Should the Customer, the utility or the transmission provider require reporting and operating services materially different in scope than those required in any operating agreements for the System as of the effective date of this agreement, these additional services will also be billed at Operator’s reasonable and documented rates. Operator Rates Field Technician $75/hr Supervisor/Manager $100/hr Overtime 150% Standard Billing Rate Holiday Time 200% Standard Billing Rate Travel Time 50% Standard Billing Rate Parts & Materials Cost plus 10% 3rd Party Services Cost plus 10% Vegetation Management services will be provided according to negotiated and approved fee. Module Washing services will be provided according to negotiated and approved fee. AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 63 Please see the following pages for a copy of the MOU signed between AES and Aspen Valley Land Trust to support conservation efforts in the area of Game Management Unit 42 to help offset big game habitat loss from the approximately 54 acres of fenced off project area. ASPEN VALLEY LAND TRUST AND AES MEMORANDUM OF UNDERSTANDING Appendix C12 13th Rob Cooper Authorized Person Community Development Department 108 8th Street, Suite 401 Glenwood Springs, CO 81601 (970) 945-8212 www.garfield-county.com LAND USE CHANGE PERMIT APPLICATION FORM TYPE OF APPLICATION Administrative Review Development in 100-Year Floodplain Limited Impact Review Development in 100-Year Floodplain Variance Major Impact Review Code Text Amendment Amendments to an Approved LUCP LIR MIR SUP Rezoning Zone District PUD PUD Amendment Minor Temporary Housing Facility Administrative Interpretation Vacation of a County Road/Public ROW Appeal of Administrative Interpretation Location and Extent Review Areas and Activities of State Interest Comprehensive Plan Amendment Accommodation Pursuant to Fair Housing Act Pipeline Development Variance Time Extension (also check type of original application) INVOLVED PARTIES Owner/Applicant Name: ________________________________________________ Phone: (______)_________________ Mailing Address: ______________________________________________________________________ City: _______________________________________ State: _______ Zip Code: ____________________ E-mail:_______________________________________________________________________________ Representative (Authorization Required) Name: ________________________________________________ Phone: (______)_________________ Mailing Address: ______________________________________________________________________ City: _______________________________________ State: _______ Zip Code: ____________________ E-mail:_______________________________________________________________________________ PROJECT NAME AND LOCATION Project Name: _____________________________________________________________________________________ Assessor’s Parcel Number: ___ ___ ___ ___ - ___ ___ ___ - ___ ___ - ___ ___ ___ Physical/Street Address: ________________________________________________________________ Legal Description: ______________________________________________________________________ _____________________________________________________________________________________ Zone District: ___________________________________ Property Size (acres): __________________ Eagle Springs Organic LLC 954 249-5674 PO Box 351 Rifle CO 81650 kensack@me.com AES Eagle Springs Organic Solar, LLC / Rob Cooper 720 514-2957 282 Century Place, Suite 2000 Louisville CO 80027 joshua.mayer@aes.com "AES Eagle Springs Organic Solar" Off Mamm Creek Rd. Silt, CO See legal description in the deeds attached in Section A3 Parcels: 21791800691, 217917300732, and 217917200710 Rural up to 95acres ✔ ✔ ✔ PROJECT DESCRIPTION REQUEST FOR WAIVERS Submission Requirements The Applicant requesting a Waiver of Submission Requirements per Section 4-202. List: Section: ______________________________ Section: _________________________________ Section: ______________________________ Section: _________________________________ Waiver of Standards The Applicant is requesting a Waiver of Standards per Section 4-118. List: Section: ______________________________ Section: _________________________________ Section: ______________________________ Section: _________________________________ I have read the statements above and have provided the required attached information which is correct and accurate to the best of my knowledge. ______________________________________________________ __________________________ Signature of Property Owner or Authorized Representative, Title Date OFFICIAL USE ONLY File Number: __ __ __ __ - __ __ __ __ Fee Paid: $_____________________________ Existing Use: ____________________________________________________________________________________ Proposed Use (From Use Table 3-403): ____________________________________________________ Description of Project: __________________________________________________________________ 1.The Decision you are appealing. 2.The date the Decision was sent as specified in the notice (date mailed). 3.The nature of the decision and the specified ground for appeal. Please cite specific code sections and/or relevant documentation to support your request. 4.The appropriate appeal fee of $250.00. 5.Please note a completed Appeal Application and fees must be received within 30 calendar days of the date of the final written Administrative Interpretation. For Appeal of Administrative Interpretation please include: Agricultural and grazing land Solar Energy System, Large 10 MW AC and 20 MWh Solar Photovoltaic and Battery Energy Storage generating facility on up to 95 acres of parcels.Fenced area expected to be 53 acres. 4-203 J. Development Agreement 4-203 K. Improvements Agreement 4-203 N. Wastewater Mgmt Plan 4-203 M. Water Supply Plan 7-1001 Industrial setback standards Rob Cooper Digitally signed by Rob Cooper Date: 2023.03.28 16:04:10 -06'00'3/28/2023 AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 14 Name Address Parcel Public Service Company of Colorado 1225 17th Street, Suite 400 Denver, CO 80202 217916300119 EAGLE SPRINGS ORGANIC LLC PO BOX 351 RIFLE, CO 81650 217916300723 EAGLE SPRINGS ORGANIC LLC PO BOX 351 RIFLE, CO 81650 217917200710 VARDAMAN, CRAIG & DIANA 001065 COUNTY RD 315 SILT, CO 81652 217917300679 EAGLE SPRINGS ORGANIC, LLC PO BOX 351 RIFLE, CO 81650 217917300732 EAGLE SPRINGS ORGANIC, LLC PO BOX 351 RIFLE, CO 81650 217917400686 EAGLE SPRINGS ORGANIC, LLC PO BOX 351 RIFLE, CO 81650 217917400731 EAGLE SPRINGS ORGANIC LLC PO BOX 351 RIFLE, CO 81650 217918100691 BEDROCK RESOURCES LLC PO BOX 1167 SILT, CO 81652-1167 217918400720 B & B MAMM CREEK LLC 1831 RAILROAD AVENUE RIFLE, CO 81650 217919100511 TEP ROCKY MOUNTAIN LLC 1058 COUNTY ROAD 215 PARACHUTE, CO 81635 217920100510 ANCHONDO, MANUEL PO BOX 1461 BASALT, CO 81621 217920100666 RAMIREZ, GILBERT 1530 E 12TH STREET RIFLE, CO 81650 217920100735 HERRERA, MARTIN R & MARIA A 76 MARBLE COURT CARBONDALE, CO 81623 217920400667 LARSEN, ROBERT E & JOELY L 1188 EAGLE SPRINGS RANCH ROAD SILT, CO 81652 217920400668 EAGLE SPRINGS ORGANIC LLC PO BOX 351 RIFLE, CO 81650 217921200698 EAGLE SPRINGS ORGANIC LLC PO BOX 351 RIFLE, CO 81650 217921200700 NAMES AND ADDRESSES OF PROPERTY OWNERS WITHIN 200FT Section A5 AES Eagle Springs Organic Solar – Land Use Change – Major Impact permit application (4/6/2023) AES Eagle Springs Organic Solar – Garfield County 15 TEP ROCKY MOUNTAIN LLC 1058 COUNTY ROAD 215 PARACHUTE, CO 81635 217921300704 COLLINS LAND ACQUISITIONS, LLC 5241 S OLIVE ROAD EVERGREEN, CO 80439 217917200122 ORGANIC GROWERS LLC PO BOX 351 RIFLE, CO 81650 217917200687 PORT EVERGLADES RESTAURANT CORP 150 PAULARINO AVENUE, BUILDING C COSTA MESA, CA 92626 217918100123 SNYDER, JAMES G TRUST 3495 COUNTY ROAD 346 SILT, CO 81652 217918100124 SACK, KENNETH J PO BOX 351 RIFLE, CO 81650 217918100681 March 3, 2023 Philip Berry Garfield County – Community Development 108 8th Street, Suite 401 Glenwood Springs, CO 81601 Subject: Letter of Authorization for AES Eagle Springs Organic, LLC Garfield County Planning department, The undersigned is the fee landowner for parcels 217917300732, 217917200710, and 21791800691 located off Mamm Creek Rd (CR 315), Silt, Colorado 81650 in Garfield county, and as such, landowner hereby grants and allows AES Eagle Springs Organic Solar, LLC, to submit an application as an Authorized Representative to Garfield County for a Land Use Change – Major Impact Permit for the construction and operation of a solar and battery storage facility on said parcels. ACE DevCo NC, LLC (an AES affiliate that intends to assign the agreement to AES Eagle Springs Organic Solar, LLC) entered into an Option to Lease Agreement on May 31, 2022, with Eagle Springs Organic LLC for the estimated 70-85 acres of the project site, subject to exercise upon the facility reaching Notice to Proceed with Construction status. The Option to Lease Agreement is in full force and effect as of the date of this Letter. Sincerely, Ken Sack Eagle Springs Organic LLC 5454 County Rd 346 Silt, CO 81652 1.5"VARIES BASED ON GRADE SLOPEWORKING SURFACE ELEVATION(4" ROAD BASE GRAVEL)FINISH FLOOR ELEVATION(MIN 1' ABOVE FLOODPLAIN)2.0%3.0' (MIN.)3:1 MAX (TYP)STABILIZE ALL SLOPES> 5:1 WITH RETENTIONBLANKET PER CDOT STDM-216 OR APPROVEDEQUIVALENT5'-0"70'-0"42'-0"1'-5"4'-1"1'-6"2'-2"40'-0"6'-0"8'-0" 4'-2" 5'-3" 5'-0"14'-1134"33'-312"18'-334"55.0°55.0°SINGLE AXIS TRACKERSEE MANUFACTURER DRAWINGS FOR ADDITIONALDETAILSZXM7-SHLDD144-540W MODULESPILE32" MAX 9'-1" 14'-1114" 24" MIN. 8'-5" 14'-314"NTSDATEPROJECT TITLE:DESCRIPTIONAPV:PROJECT LOCATION:NO.KEY PLAN:PE STAMP:REVISIONS:SHEET NO:REV:SCALE AT 24" x 36":CHK:DWN:DES:DATE:PROJNUM:SHEET TITLE & DESCRIPTION:2180 South 1300 East, Suite 600Salt Lake City, UT 84106-2749(801) 679 - 3500ELECTRIC POWER ENGINEERING, INC.12600 W. COLFAX AVE, STE. C500LAKEWOOD, CO 80215(303) 431-7895 www.neieng.comSITE DETAILS----PLOTTED: 5/5/2023 2:33 PMH:\Project\4000\4084.001-Eagle Springs PV BESS-30pct PV BESS-AES\4_DWGs\2_NEI\Solar\PV CIV\PV-C.08.01 SITE DETAILS.dwgXREFs: H:\Project\4000\4084.001-Eagle Springs PV BESS-30pct PV BESS-AES\4_DWGs\2_NEI\2_Sheetset References\AES Titleblock Outline.dwg; H:\Project\4000\4084.001-Eagle Springs PV BESS-30pct PV BESS-AES\4_DWGs\2_NEI\Solar\PV ELEC\PV-E.06.06 INVERTER LAYOUT DETAILS.dwg AES Titleblock 24X36 v210209 EAGLE SPRINGSORGANICSILT, CO4084.001JPDJPDBCBC3/29/23PV-C.08.01 DA 1/23/23 30% SUBMITTALB 2/16/23 30% RESUBMITTALC 3/17/23 30% RESUBMITTALD 3/29/23 30% RESUBMITTALE 5/05/23 30% RESUBMITTAL- - -- - -- - -8" MIN3NTS12 FT AND 20 FT WIDTH IMPROVED EXISTING ROAD DETAILC.08.016'1:1 2-3% SLOPE6'NOTES:1. EXISTING ROADS SHALL BE IMPROVED ON AN AS NEEDED BASIS PER SHEET PV-C05.01.2. THE EXISTING PERIMETER FIELD ROAD PER SHEET PV-C05.01 SHALL BE IMPROVED PER THE ABOVE DETAIL .3. CONTRACTOR SHALL CONSTRUCT CROSS-SLOPE ROAD SECTION WHERE ACCESS ROADS ARE CONSTRUCTED ON A SIDESLOPE, AND WHERE OTHERWISE NOTED ON PLANS, TO ENSURE THAT ROADS AND SHOULDERS REMAIN WELL DRAINEDAT ALL TIMES.4. COMPACTED SUBGRADE SHALL BE A MINIMUM 12-INCHES OF SCARIFIED, MOISTURE CONDITIONED, AND RECOMPACTEDSOIL.5. 4:1 MAXIMUM SLOPE FROM EDGE OF GRAVEL TO EXISTING GROUND.6. AGGREGATE BASE COMPACTED TO A MINIMUM OF 98% OF THE SOIL'S MODIFIED PROCTOR MAXIMUM DRY DENSITY (OREQUIVALENT).7. AGGREGATE BASE COURSE SHOULD CONSIST OF A BLEND OF SAND AND GRAVEL WHICH MEETS COLORADODEPARTMENT OF TRANSPORTATION (CDOT) CLASS 5 OR 6 SPECIFICATIONS8. ROAD GRADES ARE TYPICALLY INTENDED TO MATCH ADJACENT GRADE ALLOWING DRAINAGE TO SHEET FLOW ON ANDOFF ROADS EVENLY. FIELD ADJUST ROAD GRADES OR ROADSIDE SWALE LOCATIONS AS NECESSARY TO PREVENTRUNOFF FROM CONCENTRATING ALONG ROAD EDGES CAUSING EROSION.9. ROAD DESIGN BASED ON DESIGN-LEVEL GEOTECHNICAL ENGINEERING REPORT PREPARED BY TERRACON DATEDMARCH 1, 202310. ROADS SHALL HAVE 2" OF AGGREGATE BASE ADDED EVERY 5 YEARS, OR AS NEEDED TO MAINTAIN MINIMUM DEPTH.ROADS SHALL UNDERGO SEMI-ANNUAL MAINTENANCE.1NTSEQUIPMENT PAD GRADING DETAILC.08.0112' IMPROVED EXISTING ROAD - CROWNEDEDGE OFGRAVELEDGE OFGRAVEL2-3% SLOPE8" MINLC6'2-3% SLOPE6'12' IMPROVED EXISTING ROAD - CROSS SLOPEEDGE OFGRAVELEDGE OFGRAVEL2-3% SLOPEEXISTINGGRADEEXISTINGGRADE1:1 EXISTINGGRADEEXISTINGGRADE8" MINLC10'1:1 2-3% SLOPE10'20' IMPROVED EXISTING ROAD - CROWNEDEDGE OFGRAVELEDGE OFGRAVEL2-3% SLOPE8" MINLC10'2-3% SLOPE10'20' IMPROVED EXISTING ROAD - CROSS SLOPEEDGE OFGRAVELEDGE OFGRAVEL2-3% SLOPEEXISTINGGRADEEXISTINGGRADE1:1 EXISTINGGRADEEXISTINGGRADE8" MIN10'1: 1 2-3% SLOPE10'2'2'20' SOLAR ACCESS ROAD - CROWNEDEDGE OF GRAVEL EDGE OF SUBGRADE EDGE OF GRAVEL EDGE OF SUBGRADE 2-3% SLOPE8" MINSLOPE TO MATCHLC10'2-3% SLOPE10'2'2'20' SOLAR ACCESS ROAD - CROSS SLOPEEDGE OF GRAVEL EDGE OF SUBGRADE EDGE OF GRAVEL EDGE OF SUBGRADE SLOPE TO MATCH1: 1 2-3% SLOPE2NTS20 FT WIDTH SOLAR ACCESS ROAD DETAILC.08.01NOTES:1. CONTRACTOR SHALL CONSTRUCT CROSS-SLOPE ROAD SECTION WHERE ACCESS ROADS ARE CONSTRUCTED ON A SIDESLOPE, AND WHERE OTHERWISE NOTED ON PLANS, TO ENSURE THAT ROADS AND SHOULDERS REMAIN WELL DRAINEDAT ALL TIMES.2. COMPACTED SUBGRADE SHALL BE A MINIMUM 12-INCHES OF SCARIFIED, MOISTURE CONDITIONED, AND RECOMPACTEDSOIL.3. 4:1 MAXIMUM SLOPE FROM EDGE OF GRAVEL TO EXISTING GROUND.4. AGGREGATE BASE COMPACTED TO A MINIMUM OF 98% OF THE SOIL'S MODIFIED PROCTOR MAXIMUM DRY DENSITY (OREQUIVALENT).5. AGGREGATE BASE COURSE SHOULD CONSIST OF A BLEND OF SAND AND GRAVEL WHICH MEETS COLORADODEPARTMENT OF TRANSPORTATION (CDOT) CLASS 5 OR 6 SPECIFICATIONS6. ROAD GRADES ARE TYPICALLY INTENDED TO MATCH ADJACENT GRADE ALLOWING DRAINAGE TO SHEET FLOW ON ANDOFF ROADS EVENLY. FIELD ADJUST ROAD GRADES OR ROADSIDE SWALE LOCATIONS AS NECESSARY TO PREVENTRUNOFF FROM CONCENTRATING ALONG ROAD EDGES CAUSING EROSION.7. ROAD DESIGN BASED ON DESIGN-LEVEL GEOTECHNICAL ENGINEERING REPORT PREPARED BY TERRACON DATEDMARCH 1, 2023.8. ROADS SHALL HAVE 2" OF AGGREGATE BASE ADDED EVERY 5 YEARS, OR AS NEEDED TO MAINTAIN MINIMUM DEPTH.ROADS SHALL UNDERGO SEMI-ANNUAL MAINTENANCE.MIN 8" PROPERLY COMPACTEDAGGREGATE BASE12" COMPACTED SUBGRADE EXTENDED 2'ON EACH SIDE OF AGGREGATE BASEMIN 8" PROPERLY COMPACTEDAGGREGATE BASE12" COMPACTED SUBGRADE EXTENDED 2'ON EACH SIDE OF AGGREGATE BASELCLCMIN 8" PROPERLY COMPACTEDAGGREGATE BASE12" COMPACTED SUBGRADEMIN 8" PROPERLY COMPACTEDAGGREGATE BASECOMPACTED SUBGRADE EXTENDED 2' ONEACH SIDE OF AGGREGATE BASEMIN 8" PROPERLY COMPACTEDAGGREGATE BASECOMPACTED SUBGRADE EXTENDED 2' ONEACH SIDE OF AGGREGATE BASEMIN 8" PROPERLY COMPACTEDAGGREGATE BASECOMPACTED SUBGRADE EXTENDED 2' ONEACH SIDE OF AGGREGATE BASEPLAN VIEWSECTION VIEW4NTSRACKING DETAILC.08.01NOTES:1. RACKING DIMENSIONS SHOWN ARE TYPICAL FOR FLAT GRADE. DIMENSIONS MAY VARY WHERE SLOPES EXIST.2. ALL MINIMUM LEADING EDGE MODULE CLEARANCE HEIGHTS SHOWN FROM TOP OF FLOOD PLAIN ELEVATION