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HomeMy WebLinkAbout1.23 DRMS North Hangs Mine 112(c) Construction Material Reclamation Permit Operation Application to the Colorado Division of Reclamation, Mining, and Safety February 2023 By: Western Slope Materials Represented by: North Hangs February 2023 Table of Contents Introduction EXHIBIT A ............................................................................................................................. LEGAL DESCRIPTION EXHIBIT B ........................................................................................................................................... LOCATION MAP EXHIBIT C ................................................................................................... PREMINE AND MINE PLAN MAPS EXHIBIT D ................................................................................................................................................ MINING PLAN EXHIBIT E ......................................................................................................................... RECLAMATION PLAN EXHIBIT F ............................................................................................................................. RECLAMATION MAPS EXHIBIT G ........................................................................................................................... WATER INFORMATION EXHIBIT H ...................................................................................................................... WILDLIFE INFORMATION EXHIBIT I .............................................................................................................................. SOILS INFORMATION ........................................................................................... Appendix I-1 NRCS Web Soil Survey EXHIBIT J ............................................................................................................. VEGETATION INFORMATION EXHIBIT K ....................................................................................................................... CLIMATE INFORMATION EXHIBIT L .......................................................................................................................... RECLAMATION COSTS EXHIBIT M ........................................................................................................ OTHER PERMITS REQUIRED EXHIBIT N ...................................................................................................................................... RIGHT OF ENTRY EXHIBIT O ................................................................................................... OWNERS OF AFFECTED LAND .................................................................................................... AND MINERAL TO BE MINED EXHIBIT P .......................................................................................... MUNICIPALITIES WITHIN TWO MILES EXHIBIT Q ............................... PROOF OF MAILING OF NOTICES TO THE BOARD OF COUNTY ……….……………………………….COMMISSIONERS AND SOIL CONSERVATION DISTRICT EXHIBIT R ........................................................................... PROOF OF FILING WITH COUNTY CLERK EXHIBIT S ................................................................................... PERMANENT MAN-MADE STRUCTURES RULE 1.6.2(1)(B) GEOTECHNICAL STABILITY EXHIBIT North Hangs February 2023 i-1 Introduction The North Hangs Mine is a sand and gravel operation located approximately one mile west southwest of Silt, CO located along the Colorado River just north of Interstate 70. The operation will excavate, process, and send offsite construction materials from a 72.8 acre permit and affected area. Access will be from the existing County Road 316 connection for the property. The owner of the land is North Hangs Ranch LLC. The operator and permittee is Western Slope Materials, LLC (WSM). The current site condition is predominantly irrigated fields. The site will be reclaimed to a groundwater lake, permanent processing area, and surrounding rangeland. Mining will be conducted in two phases. Details of mining and reclamation plans can be seen on the maps in Exhibits C and F. North Hangs February 2023 A-1 EXHIBIT A LEGAL DESCRIPTION The site is approximately 1 mile west southwest of Silt, CO in Garfield County. A legal description is shown on Map C-1 which is included in Appendix 2. A general location map is enclosed in Exhibit B. 1. Legal Description A Parcel of land being a portion of that property described within that Warranty Deed recorded as Reception No. 682731 of the Garfield County records situated in Government Lot 3, Government Lot 4, and the West 1/2 of the Southwest 1/4 of Section 9, Township 6 South, Range 92 West of the Sixth Principal Meridian, Garfield County, State of Colorado lying Northeasterly of the Northeasterly Right-of-Way of Interstate Highway No. 70 and that property lying northerly of said Lot 3 and Lot 4 and Southwesterly of the centerline of the Colorado River within said Section 9; Said Parcel of land being more fully described as follows: Beginning at the West one quarter corner of said Section 9, thence along the westerly boundary of said West 1/2 of the Southwest 1/4 S.00°45'15"E a distance of 595.17 feet to a point on said Northeasterly Right-of-Way of Interstate Highway No.70; thence leaving said westerly boundary and along Northeasterly Right-of-Way the following 3 courses: 1.) N 55°58'53" E 1302.00 feet; 2.) N 75°16'53" E 227.00 feet; 3.) N 55°58'53" E 1067.22 feet to a point in the centerline of said Colorado River thence leaving said Northeasterly Right-of-Way and along said centerline the following seven (7) courses: 1.) N 50°00'00" W 570.12 feet; 2.) N 35°00'00" W 450.00 feet; 3.) N 65°00'00" W 425.00 feet; 4.) N 75°00'00" W 475.00 feet; 5.) S 80°00'00" W 250.00 feet; 6.) N 89°00'00" W 300.00 feet; 7.) S 85°00'00" W 130.00 feet to a point on the westerly boundary of said Section 9; thence leaving said centerline and along said westerly boundary S.00°45'15".E a distance of 1776.33 feet to the Point of Beginning, having an area of 72.8 acres. North Hangs February 2023 A-1 EXHIBIT B LOCATION MAP North Hangs Mine Silt, CO North Hangs Mine Entry: 39.54161°N, -107.67733°W North Hangs February 2023 C-1 EXHIBIT C PREMINE AND MINE PLAN MAPS Map C-1 Current Conditions Map C-2 Mining Plan Map C-3 Cross Sections Map C-4 Mining Snapshot North Hangs February 2023 D-1 EXHIBIT D MINING PLAN 1. Introduction The following is the mining plan for the proposed North Hangs Mine to be operated by permittee WSM. WSM proposes to mine the North Hangs Mine gravel deposit to support its construction materials activities in the Silt, CO area. Material will be mined and processed at the North Hangs Mine. There is sufficient topsoil and overburden onsite to successfully reclaim the site to its final condition of a lake with rangeland slopes. Crushed rock, sand, and washed rock will be produced on site. 2. Pre-Mining and Topsoil Stripping The site of the proposed North Hangs Mine is currently irrigated fields (see Map C-1). The Bernudy Ditch (WDID 4500524)1 is located within the permit area but will not be affected by mining until Phase 2. Prior to the start of Phase 2, a reroute pipe will be installed to maintain the ditch for its users. Prior to beginning activities on the site, the boundaries of the affected area will be clearly marked. Signs and markers will be posted at the mine entrance listing the name of the Operator, Western Slope Materials, LLC (WSM), and the operation name, “North Hangs Mine”; a statement that a reclamation permit for the operation has been issued by the Colorado Mined Land Reclamation Board; and the DRMS permit number. The current access to the property will be used for mining (Maps C-2 & C-4). Internal roads and ramps will be used throughout the life of the mining operation as needed and will all be reclaimed. Exhibit C maps show the pre-mine, mining plan, and cross sections. Topsoil and overburden will be stripped at North Hangs Mine and either placed in stockpiles and berms or direct placed to create final reclamation slopes. This stripping will take place in advance of mining of areas but is not anticipated to happen all at once. Exhibit C maps show the areas of disturbance. Berms will be installed at the start of operations on the site as part of stormwater controls (Maps C-2 & C-4). Berms will be vegetated within 90 days of construction. Topsoil that is stripped and not required for the construction of the stormwater control berms will be immediately placed as part of contemporaneous reclamation, stockpiled on-site in the topsoil storage area, or shipped offsite. Temporary stockpiles of overburden or topsoil required for reclamation will typically be <20 feet in height. Temporary stockpiles will be located in the designated area shown on Exhibit C maps. Mining will take place to the slopes identified on Exhibit C maps. Backfill will take place to achieve final reclamation slopes and grades. Overburden present on site will be stripped during mining and either placed directly on mined 1 https://dwr.state.co.us/Tools/Structures/4500524 North Hangs February 2023 D-2 out ground as part of reclamation, stored in the stockpile area, or be sold as fill. Details on topsoil and overburden quantities and material balance can be found in Table D-3 and Table E- 3. 3. Mining Sequence Once topsoil and overburden are stripped from the site, the deposit will be mined using shovels or loaders and haul trucks. The groundwater table is roughly four feet below ground level based on Western Slope’s experience at their existing mine in the same aquifer, to the southeast (Grand River Park). Since groundwater will be exposed/encountered during mining, the entire pit will be dewatered using a pump. Details regarding this dewatering can be found in Exhibit G. Mining will progress in the dewatered pit areas as shown on Map C-2. All mining will be to final 2H:1V slopes on the perimeter. The active mining highwall will be mined to the halfway point of the final mining slope. This will allow the active mining highwall to be knocked down to the final mining slope with a dozer when mining is complete in an area. No more than 25 acres of total disturbance will take place at any time. Early mining will consist of mine operations on the north and south sides of the Bernudy Ditch with the ditch still in its pre-mining condition. Once the ditch has been moved into its new permanent route in a pipe, mining will commence through the ditch corridor. Prior to mining within 300 feet of the Colorado River, the permittee will submit a technical revision to the Division that includes the approved ditch reroute and designs for inflow/outflow structures along the Colorado River. A discussion on water rights for groundwater exposure can be found in Exhibit G. Prior to the exposure of any groundwater, the permittee will provide the Division with a copy of the approved gravel well permit and any associated water supply plan. North Hangs February 2023 D-3 4. Equipment Table D-1 shows the type of equipment that will be used for the operations of this site. Once operations are complete, all equipment will be removed from the site. Table D-1 - Typical Onsite Equipment Equipment Type Phase 1 Quantity Excavator 1 Bulldozer 1 Water Truck 1 On-highway Dump Truck Varies with production Road Grader 1 (occasionally) Loader 1 A portable fuel tank will be set up in the mining area to supply equipment onsite. It will have full secondary containment. All equipment onsite will have onboard diesel tanks in full secondary containment. Full secondary containment has 110% of the volume of the tank that is in it. 5. General Mining Plan – Method of Mining Once topsoil and overburden are stripped from the site, the deposit will be mined using shovels or loaders and haul trucks. The groundwater table is roughly four feet below ground level based on Western Slope’s experience at their existing mine in the same aquifer, to the southeast (Grand River Park). Since groundwater will be exposed/encountered during mining, the entire pit will be dewatered using a pump. Details regarding this dewatering can be found in Exhibit G. Mining will progress in the dewatered pit areas as shown on Map C-2. All mining will be to final 2H:1V slopes on the perimeter. The active mining highwall will be mined to the halfway point of the final mining slope. This will allow the active mining highwall to be knocked down to the final mining slope with a dozer when mining is complete in an area. No more than 25 acres of total disturbance will take place at any time. Early mining will consist of mine operations on the north and south sides of the Bernudy Ditch with the ditch still in its pre-mining condition. Once the ditch has been moved into its new permanent route in a pipe, mining will commence through the ditch corridor. Prior to mining within 300 feet of the Colorado River, the permittee will submit a technical revision to the Division that includes the approved ditch reroute and designs for inflow/outflow structures along the Colorado River. A discussion on water rights for groundwater exposure can be found in Exhibit G. Prior to the exposure of any groundwater, the permittee will provide the Division with a copy of the approved gravel well permit and any associated water supply plan. North Hangs February 2023 D-4 The overall mining direction will be from south to north and will vary within each pit. The general mining area sequence is shown on Map C-2. Map C-2 also shows the extents of mining throughout the site. Map C-4 shows a snapshot of mining operations. Table D-2 shows the disturbed and undisturbed area in each phase. Crushing and screening of excavated material will take place onsite. Crusher fines may be placed in the lake during final reclamation or sold offsite as fill. Crushed and washed rock will be produced onsite. No asphalt will be produced onsite. All facilities will be removed following mining. Explosives will not be used at this site. Table D-2. Disturbance Area Disturbed Area Undisturbed Area Mining 36 acres 36.8 acres Note: The total affected area is 72.8 acres. Mining Buffers and Limitations Minimum mining setbacks are shown on Map C-3 (Phase 2). Map C-2 shows the setbacks during mining. All mining will be within the 100-year floodplain. Stormwater control structures will be present during mining but removed during reclamation. Additionally, the excavation of topsoil and overburden from the site will create storage volume for storm and flood events onsite. See Map G-1 in Exhibit G for more information on surface water management. 6. Overburden and Topsoil Handling Initial earthmoving will consist of stripping 0-36 inches of topsoil and approximately one to four feet of overburden from areas to be disturbed. These stripping thicknesses are based on the soil survey for the operation and operational experience at the Grand River Park to the east. For the purpose of the material balance, 18 inches of topsoil and two feet of overburden are assumed. All earthmoving will be done using mining equipment suitable for this type of operation including the following: front end loader, dozer, excavator, and water trucks. Topsoil and overburden will be directly placed, as much as possible, with stockpiling as needed in the designated stockpile areas (Map C-3). Stockpiles to be in place longer than 90 days will be seeded with the permanent seed mix to prevent erosion (see Exhibit E for seed mix information). Table D-2 details a breakdown of the overall material balance of the project during mining. Table D-3. Topsoil and Overburden Material Generated During Mining Material Generated (CY) Topsoil 87,120 Overburden 116,160 North Hangs February 2023 D-5 The presence of the lake means that there will be more topsoil and overburden generated by stripping activities than needed for reclamation activities. The excess material will be used to achieve the grading shown in the Exhibit F maps and to augment topsoil thickness in areas above ten feet below the average water level of the lakes. Details pertaining to reclamation can be found in Exhibit E. 7. Stormwater – Diversions and Impoundments. Surface water from storms, known as stormwater runoff, will be collected in the mining pit during operations. As shown on Map G-1, the local drainage area consists principally of the North Hangs Mine and immediate area. The pit will act as a sediment pond during operations. No diversion of upstream waters will occur. Impounding of water will only be temporary, to trap sediment, with all stormwater runoff leaving the site within 72 hours. Exhibit G covers surface water management in detail. 8. Mining Timetable An approximate mining timetable for the mining operation is shown on Table D-4. Table D-4. Mining Timetable Years Activity 1-2 Stripping of processing area and initial pit of Phase 1. 2-15+ Sand and gravel mining. Over the life of the mine, a total of 1.5 million tons of material will be extracted at a rate of roughly 100,000 tons per year. This will result a mine life of approximately 15 years, depending on market conditions. 9. Disturbance Area Concurrent reclamation will take place as much as possible. The maximum unreclaimed disturbance area will be limited to 25 acres. See Exhibit L for a detailed discussion of the reclamation costs and bond calculations. North Hangs February 2023 D-6 10. Deposit and Underlying Stratum Geology Mapped Geology A soil report was generated using the United States Department of Agriculture’s Natural Resources Conservation Services’ (NRCS) Web Soil Survey (WSS)2 and is included with this permit application (Exhibit I Soil Report) along with a site specific soil investigation. The main applicable United States Geological Survey geologic map for the site is from 2001. The area of the North Hangs Mine was mapped by Shroba and Scott (2001)3 as consisting of Holocene and Pliestocene age clast-supported, slightly bouldery, pebble and cobble gravel in a sand to sandy silt matrix. The North Hangs deposit is underlain by the Eocene to Paleocene Wasatch Formation, specifically the Eocene aged Shire Member, a nonmarine, predominantly multicolored fine-grained clastic intervals of thick claystone, mudstone, and siltstone interbedded with less abundant intervals of minor coarse-grained clastic beds of thin fluvial sandstone. Geology and Resource Discussion Details of the Natural Resources Conservation Service (NRCS) site-specific soil report (Exhibit I) indicate that the deposit is a minimum of 5 feet deep in the area of the deposit. Shroba and Scott (2001) indicate that gravel deposits along the Colorado River are typically 1-6 meters (~3 to 18 feet) deep. Material balances for reclamation purposes will be calculated using a topsoil depth of 18 inches. Mining will proceed to two feet off of bedrock or a depth of 25 feet; whichever is encountered first. This depth is based on the operator’s experience within the same deposit in Grand River Park to the east. No bedrock will be exposed by mining. 11. Primary and Secondary Commodities The operation will produce raw materials including sand, gravel, and rock. These materials will all be processed onsite into construction materials such as rock, sand, and fines. Excess overburden will be sold from the site as fill. Excess topsoil may be shipped offsite for use. Necessary overburden and topsoil will be maintained onsite to retain the backfill needed for reclamation. Inert material may be imported for backfilling purposes. Any backfill imported for this purpose will be certified inert with an affidavit signed by the importee. Western Slope Materials will clearly mark the permit/affected area boundary with stakes surveyed on site prior to mining. 2 https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm. 3Shroba R.R. and Scott, R., (2001). Geologic Map of the Silt Quadrangle, Garfield County, Colorado. Denver, CO: United States Geological Survey. North Hangs February 2023 D-7 No designated chemicals or acid-producing materials to be used or stored on-site. 12. Water Information, Rights and Augmentation All water rights issues such as availability of water for this operation, consumption rates, dust control, etc. is presented in Exhibit G - Water Information. North Hangs February 2023 E-1 EXHIBIT E RECLAMATION PLAN 1. Introduction This exhibit describes the plans and processes involved in reclaiming the site and transforming it to its ultimate post-mining use as industrial, rangeland, and a groundwater lake as shown on Exhibit F maps. Reclamation will occur contemporaneously as portions of the permit area are mined. Final reclamation of the permit area will occur after the cessation of all mining activities. Current use of the permit area is irrigated fields. Final use of the permit area is proposed to be rangeland with a groundwater lake. Pursuant to Rule 6.4.5.2.(b), the applicant evaluated the proposed post-mining land use in regard to adopted state and local land use plans for this area and land uses in the vicinity. The proposed post-mining use of industrial and rangeland with an open water pond is compatible with the general character of the area. The affected area of this site is the same as the permit area of this site, 72.8 acres, not all of which will be disturbed and require reclamation. The tables below provide a summary of intended end uses within the affected area upon completion of reclamation in each phase. Table E-1. Reclamation Areas Description Area (Acres) Gravel Access Roads 1.5 Wetlands 6.2 Groundwater Lake 25 Mining Area Reclaimed to Rangeland 3.3 Disturbed Area Total 36 Undisturbed Area within the Permit Area 36.8 Total Affected (Permit) Area 72.8 Note: Undisturbed area includes setbacks and incidental areas within the permit where disturbance is not needed. 2. General Reclamation Plan Mining will take place to the slopes and extents shown in Exhibit C. Reclamation will be conducted to create the final conditions shown in Exhibit F. Backfilling, grading, topsoiling, and revegetation of the disturbed areas outlined in Exhibits C and F will be conducted in a similar manner, as outlined in Exhibit E. Reclamation will start prior to mining with the transplanting of the existing mature cottonwood trees on site to the outskirts of the mine. This will aid in screening during mining and post mine reclamation as the fully grown trees remain intact. Reclamation will be conducted on final slopes by covering the area with an average of 18 inches of topsoil and seeded with the seed mix found in Table E-4. Efforts will be made to not strip any North Hangs February 2023 E-2 topsoil until it can be directly placed on areas ready for reclamation; however, when necessary, topsoil will be stored into either berms or the stockpile area as shown on Map C-2. Dewatering will be conducted throughout the mining operation’s life. Following final topsoiling and revegetation, the pit pump(s) will be removed. Reclamation will be conducted concurrently with mining to minimize disturbed ground. In both phases reclamation will consist of backfilling and grading slopes to variable conditions as shown on Map F-1. Slopes will be no steeper than 3H:1V to at least 10 feet below the anticipated water level of the groundwater lakes. Backfilling of Area A will allow for the development of wetlands in that area prior to the disturbance of wetlands elsewhere onsite. In the event that the ditch reroute does not occur, the reclamation of the site will create two lakes as opposed to one, leaving the Bernudy Ditch and existing wetlands undisturbed. 3. Topsoil and Overburden Handling Topsoil and overburden handling will be identical for all Phases and Options. It is not anticipated that any topsoil will need to be imported for the reclamation process, even at the point of greatest disturbance. The creation of groundwater lakes will lead to an excess in both topsoil and overburden. Topsoil and overburden stripped during mining will either be stored in the temporary stockpile area or will be directly placed as part of final reclamation. Topsoil and overburden will be maintained in separate stockpiles in the temporary stockpile area and berms. Table E-3 outlines the topsoil and overburden material balance calculations during reclamation and during the greatest disturbance area scenario. Excess overburden or topsoil generated during mining will be placed in reclaimed areas or shipped offsite. Overburden will not be stripped from berm or road areas. Topsoil stripping and replacement volumes are based on an average topsoil depth of 18 inches. Overburden stripping is based on two feet of overburden on site. Table E-2. Topsoil and Overburden Material Balances During Reclamation Material Generated by Mining (CY)1 Material Required for Reclamation (CY)2 Note Topsoil 87,120 27,100 Overburden 116,160 150,100 Excess topsoil used to augment backfill. 1Topsoil and overburden stripped during mining. Based on soil survey thicknesses and area mining experience. Total at the conclusion of a given phase. 2Topsoil or overburden needed to reclaim disturbed areas in said scenario. Total at the conclusion of the given phase. Excess topsoil used as general backfill to achieve organic lake shore appearance. North Hangs February 2023 E-3 As demonstrated in Table E-3, topsoil generated by stripping will be more than enough to successfully reclaim all disturbed areas in the greatest disturbance area scenario. WSM will maintain enough topsoil onsite in stockpiles to successfully reclaim the disturbed area to its final uses. 4. Final Use The total affected area on the site is 72.8 acres, the same as the permit area. A maximum of 45.8 acres will be disturbed by mining activities. When the site is fully reclaimed, the final use of the affected area will be as listed in Table E-1 and as depicted on the Exhibit F maps. The post- mining land use will be compatible with the current existing land uses in the surrounding area. 5. Topsoil and Revegetation Plan Throughout the reclamation process, topsoil will be replaced to a depth of 0-36 inches (18 inches on average) on all disturbed areas except those areas that will become the groundwater lake, the industrial/commercial area, and the access roads. However, for the purpose of material balance, it is assumed that the industrial/commercial area will be topsoiled. Table E-3 is calculated based on this assumption. Topsoil available from stripping is in excess of that needed for reclamation. In accordance with Rule 6.4.5(2)(b). The mature cottonwood trees within the mining area will be transplanted prior to mining. They will be moved to the areas in front of the processing area to aid in screening and will remain in their transplanted location for final reclamation. Additional saplings will be planted near the reclaimed lake and towards the river in the northeast of the site. Cottonwood saplings will be planted in accordance with Maps F-2 and C-4. The seed mix for revegetation of the site was chosen because it will establish a diverse, effective, and long-lasting vegetative cover that is capable of self-regeneration without continued dependence on irrigation, soil amendments or fertilizer, and provides equal or better coverage than the existing vegetation of the surrounding area. Plantings will be limited to grasses and forbs that are well-suited to the property considering the soils and climate. Table E- 4 shows the rangeland revegetation seed mix. Table E-5 shows the wetland fringe revegetation seed mix. The wetland mix will be applied in all wetland areas designated on the Exhibit F maps. The revegetation plan considers environmental factors such as seasonal patterns of precipitation; temperature and wind; soil texture and fertility; slope stability; and direction of slope faces to provide the greatest probability of success with plant establishment and vegetation development. Table E-3. Rangeland – Permanent* Seed Mix Species* Percentage of mix (%) Project Drill Seed Mix Rate (lbs PLS** per acre) North Hangs February 2023 E-4 Palome Indian ricegrass 20% 6 Ephraim crested wheatgrass 10% 3 Canbar canby bluegrass 3% 1 Sodar streambank wheatgrass 10% 3 Canada wildrye 20% 2.5 Slender wheatgrass 8% 2.5 Fourwing saltbrush 8% 0.3 Rabbitbrush 1% 0.3 Skunkbrush sumac 1% 0.3 Total 100% 18.9 *Permanent vegetation seed mix consists of native species. **PLS = Pure live seed North Hangs February 2023 E-5 Table E-4. Wetland – Permanent* Seed Mix Species* Percentage of mix (%) Project Drill Seed Mix Rate (lbs PLS** per acre) Nebraska sedge 8% 1 Hardstem bulrush 31% 4 Beaked sedge 8% 1 Alkali bulrush 15% 2 Canada wildrye 19% 2.5 Slender wheatgrass 19% 2.5 Total 100% 13 Cottonwood saplings Min. 1 per 250’ of wetland fringe *Permanent vegetation seed mix consists of native species. **PLS = Pure live seed Note that the rates given in in the seed mix tables are for a drilled application rate and rates will be double for a broadcast application. All temporary seeding and berm seeding will be conducted with the Rangeland seed mix. To ensure the establishment of a diverse and long-lasting vegetative cover, the operator will employ site preparation techniques and protection. The soil shall be mechanically conditioned using disks and rippers, mulch will be spread after seeding, and temporary irrigation may be employed to ensure germination of as many seedlings as possible. Drill seeding will be utilized throughout the site. Certified weed free mulch will be crimped into the surface at 2000 lbs. per-acre. Furrows from disking will be left in the topsoil to provide moisture concentration and shade areas to promote better conditions for successful vegetation establishment. Seeding will occur in the first favorable season following the placement of topsoil. The site will be prepared to provide the best chance of vegetation establishment by completing the following as recommended by the NRCS in the Plant materials Technical Note No. 59: “The seedbed should be well settled and firm but friable enough that seed can be drilled at the recommended depth. Soils that have been compacted by traffic or other equipment should be tilled (deep-chisled or ripped if necessary) to break up restrictive or compacted layers and then harrowed and rolled or packed to prepare the required firm seedbed. Avoid seedbed preparation when the soil is wet to prevent compaction of the seedbed. Planting depth less than 1 inch.” North Hangs February 2023 E-6 6. Reclamation Timing Stormwater berms will be seeded within 90 days of their construction using the permanent rangeland mixture. All reclamation activities will be completed within two years of the completion of mining activities onsite. Table E-6 summarizes the timing of reclamation throughout the life of the mine. The anticipated timing is based on a 15-year mine life, depending on market conditions. If the mine life is extended, the appropriate years will be added to the timeline to accommodate reclamation. Table E-5. Reclamation Timetable Years Activity 1-2 Stripping of processing area and initial mining in Area A. 2-15 Mining of whole site, with concurrent reclamation. 15-17 Final reclamation. Revegetation monitoring (two years minimum). 7. Post-Reclamation Site Drainage Map G-1 shows the post mine drainage conditions in comparison to baseline and mining conditions. 8. Weed Control Measures will be employed for the control of noxious weeds. A Weed Control Plan will be utilized as follows: 1) Every April and October, a weed survey will be taken of the affected area to identify and map the presence of any noxious weeds listed by the county and the state. 2) If any patches or plants are identified, they will be controlled within 30 days. This may include mowing, tillage, or spraying them with an herbicide approved for use by the weed control staff of Garfield County. Other methods of weed control (ie: biological) may be employed from time to time depending on the nature and extent of the targeted species. After reclamation, weed surveys and controls will continue until the perennial vegetation cover on the site meet DRMS requirements and bond release is obtained. 9. Revegetation Success Criteria Revegetation will be deemed adequate when erosion is controlled and vegetation is considered satisfactory according to Division standards. Reclamation is considered a success when a diverse and long-lasting vegetative cover is established and the site is free of prohibited noxious weed species that seriously threatens the continued development of the desired vegetation. Monitoring the reclamation on an ongoing basis will ensure its success. If problems arise, WSM North Hangs February 2023 E-7 will consult with the local NRCS office to get input regarding how to resolve the problem. If minor changes or modifications are suggested by the local NRCS office to the seeding or reclamation plan, revision plans will be submitted to the DRMS prior to their implementation. It is anticipated that the Division will provide assistance and feedback in evaluating the success of the ongoing reclamation process. Information on all areas disturbed and reclaimed as well as any other important items regarding the reclamation will be submitted in the annual reports to the Division. North Hangs February 2023 F-1 EXHIBIT F RECLAMATION MAPS Map F-1 Reclamation Plan North Hangs February 2023 G-1 EXHIBIT G WATER INFORMATION The North Hangs Mine affected area is located adjacent to the Colorado River. Mining will not mine closer than 100-ft of the Colorado River. The entire site is within the Federal Emergency Management Administration (FEMA) Floodplain Zone A (100-YR event). No floodway is mapped in this area, according to FEMA. Groundwater is roughly four feet below the natural grade and is the alluvial aquifer of the Colorado River. This exhibit addresses Rule 3.1.6(1) and demonstrates how the mining and reclamation plans will minimize any disturbance to the prevailing hydrologic balance of the affected land and surrounding lands. 1. Water Quality Protection The main concerns regarding water quality are potential impacts to surface or groundwaters from sediment, hydraulic fluids, or diesel fuel. Sediment will be controlled through the use of stormwater retention within the disturbance area throughout the life of the mine. All stormwater runoff and surface water flows from the local drainage area will be collected with control measures built around the site. This includes mine slopes and the stormwater berms. This will contain all sediment within the site and prevent its unattended discharge from the site. Hydraulic fluids and diesel fuels will be contained within any vehicles through the use of best practices of maintenance and regular inspections of vehicles, hydraulic lines, and any other potential sources of spills. Diesel is proposed to be stored on-site in double walled tanks, the additional wall acting as the required secondary containment. Furthermore, the tanks will be located away from exposed ground water. Inadvertent spills that occur during fueling or refilling operations will be cleaned up immediately utilizing spill kits located adjacent to all fueling areas. The fuel farm location can be seen on Exhibit C maps. During mining, dewatering will take place within the pit. This will be accomplished using a pit pump installed below the pit floor. This pit pump will be surrounded by a gravel filter berm. Mine process and stormwater will discharge via the dewatering system under an approved Colorado Department of Public Health and Environment discharge permit. 2. Floodplain The 100-year floodplain is shown on Exhibit C and F maps. The entire disturbance area is within the floodplain. Temporary stormwater control berms, topsoil, and overburden stockpiles will exist during mining, but will be removed for reclamation. Additionally, the removal of material from the site will create storage space below the existing grade and above the groundwater table, potentially reducing the downstream negative impacts of floods. In the event of flooding of the site, the pit pump will be disabled, and equipment removed from the pit floor. The pit will then be allowed to fill with water. Pumping will only resume once the North Hangs February 2023 G-2 flood has passed. All fuel storage onsite will be maintained elevated at least one foot above the base flood elevation and in secondary containment sufficient to hold 110% of the stored fuel. Mining will not take place within 300 feet of the Colorado River prior to the construction of inlet/outlet structures. These structures are outlined on Map C-3. Prior to mining within 300-ft of the Colorado River, the applicant will provide the Division with a technical revision outlining design specifics of these structures. These design specifications will be in accordance with the Urban Drainage and Flood Control District, Technical Review Guidelines for Gravel Mining & Water Storage Activities Within or Adjacent to 100-Year Floodplains. Map C-3 shows the potential structure designs for reference. 3. Wetlands WSM commissioned a wetlands survey of the site conducted by Environmental Solutions Inc (ESI) to determine the extent of wetlands that are present onsite. This survey is attached to the application in Exhibit J. Wetlands will not be disturbed by early mining. Prior to wetland disturbance, the applicant will secure any applicable US Army Corps of Engineers (USACOE) permits. No fill of wetlands will take place prior to securing said USACOE permits. 4. Location on Map See Map C-1 for the location of all tributary water courses, wells, springs, stock water ponds, reservoirs, and ditches on the affected land and on adjacent lands where such structures may be affected by the proposed mining operations. 5. Known aquifers The only known aquifer in the area is the shallow alluvial aquifer of the Colorado River. Depth to water table is expected to be found at four feet below ground surface, based on the depth to groundwater experienced by the operator at the Grand River Park operation to the southeast. According to the U.S. Geological Survey’s Ground Water Atlas of the United States, the only groundwater aquifer system below the alluvial one in this area is the Unita-Animas Aquifer System.4 This is located beneath the Mancos Shale that underlays the site alluvium and will not be reach by mining or affected by mining. Mining will stop at least two feet above the shale bedrock. 6. Surface Water The North Hangs Mine will interact with surface water in the area via runoff that enters the site. Map G-1 shows a comparison of the drainage patterns in all three stages of operational life. The priority for surface water protection at the North Hangs Mine is preventing the discharge of 4 https://pubs.usgs.gov/ha/ha730/ch_c/ North Hangs February 2023 G-3 sediment, oil, and/or hydraulic fluids from the operational areas. Oil and hydraulic fluids are contained on the site using standard best management practices related to the storage and transfer of such fluids. These include the use of secondary containment around storage and transfer points, spill kits, and employee training on safe handling practices. Sediment is trapped onsite using controls and best management practices related to directing and controlling surface water runoff that enters disturbed areas. Appendix G-1 contains all surface water runoff calculations for the North Hangs Mine. Surface Water Handling – Mining Surface water runoff will be handled the same way throughout North Hangs Mine’s mine life: water from all mining disturbance areas will drain into the active mining and processing areas. The mine’s drainage basin and drainage directions are shown on Map G-1. The majority of the disturbed area drains into the mining pits. The processing area runoff will drain internally against the stormwater control berm that rings the processing area. A stormwater management plan (SWMP) as part of the CDPHE discharge permit for the operation, will be strictly enforced onsite. This includes the proper maintenance of stormwater controls such as berms, the proper storage of potential pollutants such as diesel fuel, and the proper sampling and documentation of sampling from discharge points. Phase 1 Drainage During Phase 1 mining, each active pit will drain internally and the processing area will drain internally. Grading of the site to drain internally, along with the buffers of undisturbed ground between each mine pit, the Colorado River, and the Bernudy Ditch will ensure that no sediment laden water flows enter the river or Bernudy Ditch. Undisturbed areas will continue to drain in the same manner as prior to mining. Once surface water is collected within the mining pit it will be collected in the pit floor perimeter ditches and be routed to the pit dewatering pump. The pit dewatering pump will then pump into existing drainage swales in undisturbed ground onsite to return to the river. Alternatively, pit dewatering will be discharged into the Bernudy Ditch. The pit pump will always be located at least two feet below the active mining floor to ensure clean water pumping. Pit pump discharge will be regulated as a National Pollution Discharge Elimination System (NPDES) discharge point under an approved CDPHE discharge permit for sand and gravel mining. Such permits monitor, limit, and enforce potential pollutants in water discharge to ensure downstream water quality is protected. Phase 2 Drainage During Phase 2 mining, the active pit will drain internally and the processing area will drain internally. Grading of the site to drain internally, along with the buffers of undisturbed ground between each mine pit and the Colorado River will ensure that no sediment laden water flows enter the river. Undisturbed areas will continue to drain in the same manner as prior to mining. North Hangs February 2023 G-4 Once surface water is collected within the mining pit it will be collected in the pit floor perimeter ditches and be routed to the pit dewatering pump. The pit dewatering pump will then pump into existing drainage swales in undisturbed ground onsite to return to the river. The pit pump will always be located at least two feet below the active mining floor to ensure clean water pumping. Pit pump discharge will be regulated as a National Pollution Discharge Elimination System (NPDES) discharge point under an approved CDPHE discharge permit for sand and gravel mining. Such permits monitor, limit, and enforce potential pollutants in water discharge to ensure downstream water quality is protected. Surface Water Handling – Reclamation Following reclamation, drainage patterns will be established that are permanent. These are shown on Map G-1. The post-reclamation drainage patterns will consist of areas of the reclaimed mining pit(s) that drain into the reclaimed ponds, the processing area drainage which will continue to drain internally and against the stormwater control berm, and the undisturbed portions of the site which will drain as they had prior to mining. Dewatering activity will cease following final reclamation. 7. Groundwater Groundwater is located approximately 4 feet below the surface of the ground onsite. No wells are located within 600 feet of the proposed pit 5. Groundwater Handling – Mining Mining activity will expose groundwater from the very beginning of operations. Dewatering of the pit will take place to bring the groundwater table below the operating floor. This allows equipment to safely and effectively mine the alluvial deposit. The pit pump will be active continuously during the mining season, which typically is mid-April to early-November, depending on weather. The pit pump will not run during flood events or when temperatures drop below freezing. Pit dewatering will intercept groundwater from the alluvial aquifer of the Colorado River that is onsite and route it back towards the river via discharge outfalls. This process is common among sand and gravel pits along the rivers and waterways of Colorado. The layout of the dewatering process can be found on Exhibit C maps and Map G-1, including the typical location of the pit pump, its typical installation, and dewatering path to the Colorado River. The pit pump will be a mobile pump with and accompanying diesel generator. This generator will have an onboard fuel tank with secondary containment. The pump and generator will move as needed to ensure a properly dewatered mining pit. The pump will be located two feet below the active pit floor. It will also be surrounded by a gravel filter. Water will then discharge from the dewatering pump via a pipe or drainage channels to the Colorado River to the north. This system of dewatering is proven to move the water out of the way of mining operations while trapping sediment on site. 5 https://gis.colorado.gov/dnrviewer/Index.html?viewer=dwrwellpermit North Hangs February 2023 G-5 Groundwater Handling – Reclamation Once mining and reclamation are completed on site, the pit pumping will cease. Permanent groundwater lakes will form as shown on Map F-1. Groundwater Exposure and Water Rights Prior to any groundwater exposure onsite, an approved permanent augmentation plan will be in place with approval from the Colorado Division of Water Resources and the applicable water courts A technical revision will be supplied to the Division containing this approved augmentation plan prior to any groundwater exposure onsite. This plan for augmentation will ensure that all water depletions are replaced in the system in time, kind, and location. No mining will take place that exposes groundwater without this plan for augmentation. Phase 1 water for dust control will be purchased and used onsite in accordance with an approved Substitute Water Supply Plan. 8. Water Consumption and Sources for the Operation Water for dust control will be the primary consumptive use onsite during mining. Wash plant water usage is also figured into this operation. Water will be purchased as needed. A small amount of evaporation is assumed with the sediment pond onsite. Table G-1 shows a breakdown of estimate water consumption for the operation during mining. Table G-1. Water Consumption Month Gravel Washing Dust Control (crusher and roads) Total (ac-ft) Jan 0.00 0.00 0.00 Feb 0.00 0.00 0.00 Mar 0.02 0.21 0.23 Apr 0.02 0.20 0.22 May 0.02 0.21 0.23 Jun 0.02 0.20 0.22 Jul 0.02 0.21 0.23 Aug 0.02 0.21 0.23 Sep 0.02 0.20 0.22 Oct 0.02 0.21 0.23 Nov 0.02 0.21 0.23 Dec 0.00 0.00 0.00 Total 0.18 1.86 2.04 North Hangs February 2023 H-1 APPENDIX G-1 SURFACE WATER RUNOFF CALCULATIONS All runoff calculations were completed using the Natural Resource Conservation Service TR-55 methodology. Hydrograph Summary Report 1 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft)(ft)(cuft) 1 SCS Runoff 4.447 60 840 92,711 ------ ------------ North Hangs Baseline 2 SCS Runoff 8.447 60 780 157,015 ------ ------------ Phase 1 Mining 3 SCS Runoff 10.94 60 780 190,477 ------ ------------ Phase 2 Mining 4 SCS Runoff 9.224 60 780 167,558 ------ ------------ End of Mining 5 SCS Runoff 7.793 60 840 147,022 ------ ------------ Final Reclamation Surface Hydrology New.gpw Return Period: 100 Year Thursday, 02 / 16 / 2023 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2022 Thursday, 02 / 16 / 2023 Hyd. No. 1 North Hangs Baseline Hydrograph type = SCS Runoff Peak discharge = 4.447 cfs Storm frequency = 100 yrs Time to peak = 840 min Time interval = 60 min Hyd. volume = 92,711 cuft Drainage area = 64.700 ac Curve number = 74* Basin Slope = 0.3 % Hydraulic length = 2000 ft Tc method = LAG Time of conc. (Tc) = 132.40 min Total precip. = 2.17 in Distribution = Type II Storm duration = 24 hrs Shape factor = 484 * Composite (Area/CN) = [(1.400 x 98) + (1.500 x 39) + (4.900 x 74) + (23.200 x 74) + (10.900 x 74) + (22.800 x 74)] / 64.700 2 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 5.00 5.00 Q (cfs) Time (min) North Hangs Baseline Hyd. No. 1 -- 100 Year Hyd No. 1 North Hangs February 2023 H-1 EXHIBIT H WILDLIFE INFORMATION 1. Introduction Given the location of the site 1 mile southwest of Silt, Colorado, with sand and gravel pits to the east and west, Interstate 70 to the south, and the Garfield Regional airport to the west, wildlife habitat fragmentation has already occurred. Colorado Parks & Wildlife (CPW) habitat and range mapping has been used to develop this section. The CPW will be consulted as part of the permit process. Detailed discussion of the wildlife found onsite can be found in Appendix H-1: the Environmental Solutions, Inc. report. 2. Description of Significant Wildlife Resources on the Affected Land The affected land is within summer and winter forage areas for bald eagles, but no nests are present. The permit area is within a wild turkey production area. Black bear overall range is present on the affected land, which is typical of western Colorado lands. The affected area is within mule deer ranges and near bird concentration and migration corridors.6 3. Seasonal Use of the Area All identified significant wildlife resources that have range over the affected area are year around in their usage. 4. Presence and Estimated Population of Threatened or Endangered Species No federally listed threatened and endangered species and/or habitat were identified on the affected land. 5. Effect of Proposed Operation on Existing Wildlife Impacts on wildlife use from the proposed project would include direct temporary elimination of potential habitat within the affected area during mining, and temporary localized displacement associated with additional noise and lighting from the proposed project. This localized loss of habitat would not disrupt regional migration or significant movement patterns and would not threaten the overall health and viability of a species. Nearby lands are also disturbed for 6 https://cpw.state.co.us/learn/Pages/KMZ-Maps.aspx North Hangs February 2023 H-2 industrial uses, and as such the North Hangs Mine disturbance will not be of a significant impact on area wildlife habitat. The affected area will be fully reclaimed at the conclusion of mining which will restore some degree of wildlife habitat over time. Transformation of the bulk of the irrigated fields onsite into a groundwater lake will be permanent change in overall habitat. 6. Impacts to fish Mining will not take place in any water ways or natural lakes. Surface water controls will protect offsite drainages and fish habitats from sediment discharges. WSM will not stock the reclaimed lake with non-native species at any time. North Hangs February 2023 Appendix H-1 Wildlife and Vegetation Report See Garfield County SUP Appendix 2 North Hangs February 2023 I-1 EXHIBIT I SOILS INFORMATION 1. General A soil report was generated using the United States Department of Agriculture’s NRCS Web Soil Survey (WSS)7 and is included in this exhibit as Appendix I-1. The WSS provides soil data and information produced by the National Cooperative Soil Survey. The majority of the site (89.6%) is split between three soil types, Wann, Halaquepts, and Torrifluvents (see Map C-1). Each of these primary soil types is described on the following pages. In addition to the Web Soil Survey, a site-specific soil analysis was conducted by Kumar and Associates. This report is attached as Appendix I-2. It confirms the generally three-foot depth of topsoil on the site 2. Suitability for Reclamation Revegetation All three soil types provide an average of 18 inches of suitable material for revegetation. All three soils are listed as class VII without irrigation. Class VII are not suitable for cultivation and are restricted to grazing by domestic animals or wildlife; all are listed as climatically limited soils. 3. Soil Type Descriptions 72 - Wann sandy loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol: jnzc Elevation: 5,000 to 6,500 feet Farmland classification: Prime farmland if irrigated and reclaimed of excess salts and sodium Map Unit Composition Wann and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Wann Setting Landform:Terraces, valley floors Landform position (three-dimensional):Tread Down-slope shape:Linear, convex Across-slope shape:Linear, convex Parent material:Alluvium derived from sandstone and shale Typical profile H1 - 0 to 8 inches: sandy loam H2 - 8 to 60 inches: fine sandy loam, sandy loam, coarse sandy loam H2 - 8 to 60 inches: H2 - 8 to 60 inches: Properties and qualities 7 https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm. North Hangs February 2023 I-2 Slope:1 to 3 percent Depth to restrictive feature:More than 80 inches Drainage class:Poorly drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat):High (2.00 to 6.00 in/hr) Depth to water table:About 0 inches Frequency of flooding:OccasionalNone Frequency of ponding:None Calcium carbonate, maximum content:10 percent Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water capacity:Very high (about 26.3 inches) Interpretive groups Land capability classification (irrigated): 4w Land capability classification (nonirrigated): 6w Hydrologic Soil Group: A/D Ecological site: R048AY265CO - Salt Meadow Hydric soil rating: Yes Custom Soil Resource Report 18 Minor Components Torrifluvents Percent of map unit:5 percent Hydric soil rating: No Kim Percent of map unit:5 percent Hydric soil rating: No Arvada Percent of map unit:5 percent Hydric soil rating: No 27 - Halaquepts, nearly level Map Unit Setting National map unit symbol: jnxr Elevation: 5,400 to 7,400 feet Frost-free period: 101 to 135 days Farmland classification: Not prime farmland Map Unit Composition Halaquepts, nearly level, and similar soils:85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Halaquepts, Nearly Level Setting Landform:Terraces, fans, valleys Landform position (three-dimensional):Tread Down-slope shape:Convex, linear Across-slope shape:Convex, linear Parent material:Alluvium Typical profile H1 - 0 to 8 inches: clay loam H2 - 8 to 24 inches: loam H3 - 24 to 60 inches: stratified very gravelly cobbly sand Properties and qualities Slope:0 to 6 percent Depth to restrictive feature:More than 80 inches Drainage class:Poorly drained Runoff class: Medium North Hangs February 2023 I-3 Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.60 in/hr) Depth to water table:About 0 inches Frequency of flooding:OccasionalNone Frequency of ponding:None Calcium carbonate, maximum content:10 percent Gypsum, maximum content:5 percent Maximum salinity:Moderately saline to strongly saline (8.0 to 16.0 mmhos/cm) Sodium adsorption ratio, maximum:30.0 Available water capacity:Low (about 3.9 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6w Hydrologic Soil Group: C/D Hydric soil rating: Yes 65 - Torrifluvents, nearly level Map Unit Setting National map unit symbol: jnz3 Custom Soil Resource Report 16 Elevation: 5,000 to 7,000 feet Mean annual precipitation: 12 to 15 inches Mean annual air temperature: 46 to 48 degrees F Frost-free period: 90 to 120 days Farmland classification: Not prime farmland Map Unit Composition Torrifluvents and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Torrifluvents Setting Landform:Distributaries, rivers, flood plains Down-slope shape:Linear, convex Across-slope shape:Linear, convex Parent material:Alluvium Typical profile H1 - 0 to 36 inches: loam H2 - 36 to 60 inches: sand Properties and qualities Slope:0 to 6 percent Depth to restrictive feature:More than 80 inches Drainage class:Moderately well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.60 to 2.00 in/hr) Depth to water table:About 12 to 36 inches Frequency of flooding:OccasionalNone Frequency of ponding:None Calcium carbonate, maximum content:5 percent Gypsum, maximum content:1 percent Maximum salinity:Very slightly saline to moderately saline (2.0 to 8.0 mmhos/cm) Sodium adsorption ratio, maximum:2.0 Available water capacity:Moderate (about 7.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 7w North Hangs February 2023 I-4 Hydrologic Soil Group: C Hydric soil rating: No Minor Components Wann Percent of map unit:10 percent Landform:Terraces Hydric soil rating: Yes Fluvaquents Percent of map unit:5 percent Landform:Marshes Hydric soil rating: Yes North Hangs February 2023 Appendix I-1 NRCS Web Soil Survey United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Rifle Area, Colorado, Parts of Garfield and Mesa Counties North Hangs Pit Natural Resources Conservation Service November 30, 2020 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................12 Map Unit Descriptions........................................................................................12 Rifle Area, Colorado, Parts of Garfield and Mesa Counties............................14 3—Arvada loam, 1 to 6 percent slopes.......................................................14 27—Halaquepts, nearly level......................................................................15 40—Kim loam, 3 to 6 percent slopes..........................................................16 65—Torrifluvents, nearly level.....................................................................16 72—Wann sandy loam, 1 to 3 percent slopes.............................................18 73—Water...................................................................................................19 References............................................................................................................20 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report 6 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 7 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 9 Custom Soil Resource Report Soil Map 43 7 9 9 0 0 43 8 0 0 0 0 43 8 0 1 0 0 43 8 0 2 0 0 43 8 0 3 0 0 43 8 0 4 0 0 43 8 0 5 0 0 43 8 0 6 0 0 43 8 0 7 0 0 43 8 0 8 0 0 43 8 0 9 0 0 43 7 9 9 0 0 43 8 0 0 0 0 43 8 0 1 0 0 43 8 0 2 0 0 43 8 0 3 0 0 43 8 0 4 0 0 43 8 0 5 0 0 43 8 0 6 0 0 43 8 0 7 0 0 43 8 0 8 0 0 269600 269700 269800 269900 270000 270100 270200 270300 269600 269700 269800 269900 270000 270100 270200 270300 39° 32' 49'' N 10 7 ° 4 0 ' 5 5 ' ' W 39° 32' 49'' N 10 7 ° 4 0 ' 2 2 ' ' W 39° 32' 15'' N 10 7 ° 4 0 ' 5 5 ' ' W 39° 32' 15'' N 10 7 ° 4 0 ' 2 2 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 200 400 800 1200 Feet 0 50 100 200 300 Meters Map Scale: 1:5,130 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 13, Jun 5, 2020 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Dec 31, 2009—Oct 12, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background Custom Soil Resource Report 10 MAP LEGEND MAP INFORMATION imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 11 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 3 Arvada loam, 1 to 6 percent slopes 5.1 7.8% 27 Halaquepts, nearly level 23.4 35.6% 40 Kim loam, 3 to 6 percent slopes 1.6 2.5% 65 Torrifluvents, nearly level 12.7 19.4% 72 Wann sandy loam, 1 to 3 percent slopes 22.7 34.6% 73 Water 0.1 0.2% Totals for Area of Interest 65.6 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. Custom Soil Resource Report 12 The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 13 Rifle Area, Colorado, Parts of Garfield and Mesa Counties 3—Arvada loam, 1 to 6 percent slopes Map Unit Setting National map unit symbol: jnxv Elevation: 5,100 to 6,200 feet Farmland classification: Not prime farmland Map Unit Composition Arvada and similar soils:80 percent Minor components:5 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Arvada Setting Landform:Terraces, fans Landform position (three-dimensional):Tread Down-slope shape:Convex, linear Across-slope shape:Convex, linear Parent material:Highly saline alluvium derived from sandstone and shale Typical profile H1 - 0 to 3 inches: loam H2 - 3 to 17 inches: silty clay loam H3 - 17 to 60 inches: silty clay loam Properties and qualities Slope:1 to 6 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat):Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:10 percent Gypsum, maximum content:2 percent Maximum salinity:Slightly saline to strongly saline (4.0 to 16.0 mmhos/cm) Sodium adsorption ratio, maximum:30.0 Available water capacity:Moderate (about 8.0 inches) Interpretive groups Land capability classification (irrigated): 7s Land capability classification (nonirrigated): 7s Hydrologic Soil Group: C Ecological site: R048AY261CO - Salt Flats Hydric soil rating: No Minor Components Wann Percent of map unit:5 percent Landform:Terraces Custom Soil Resource Report 14 Landform position (three-dimensional):Tread Hydric soil rating: Yes 27—Halaquepts, nearly level Map Unit Setting National map unit symbol: jnxr Elevation: 5,400 to 7,400 feet Frost-free period: 101 to 135 days Farmland classification: Not prime farmland Map Unit Composition Halaquepts, nearly level, and similar soils:85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Halaquepts, Nearly Level Setting Landform:Terraces, fans, valleys Landform position (three-dimensional):Tread Down-slope shape:Convex, linear Across-slope shape:Convex, linear Parent material:Alluvium Typical profile H1 - 0 to 8 inches: clay loam H2 - 8 to 24 inches: loam H3 - 24 to 60 inches: stratified very gravelly cobbly sand Properties and qualities Slope:0 to 6 percent Depth to restrictive feature:More than 80 inches Drainage class:Poorly drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat):Moderately high (0.20 to 0.60 in/hr) Depth to water table:About 0 inches Frequency of flooding:OccasionalNone Frequency of ponding:None Calcium carbonate, maximum content:10 percent Gypsum, maximum content:5 percent Maximum salinity:Moderately saline to strongly saline (8.0 to 16.0 mmhos/cm) Sodium adsorption ratio, maximum:30.0 Available water capacity:Low (about 3.9 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6w Hydrologic Soil Group: C/D Hydric soil rating: Yes Custom Soil Resource Report 15 40—Kim loam, 3 to 6 percent slopes Map Unit Setting National map unit symbol: jny7 Elevation: 5,000 to 6,000 feet Farmland classification: Prime farmland if irrigated Map Unit Composition Kim and similar soils:85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Kim Setting Landform:Benches, alluvial fans Down-slope shape:Convex, linear Across-slope shape:Convex, linear Parent material:Alluvium derived from sandstone and shale Typical profile H1 - 0 to 17 inches: loam H2 - 17 to 60 inches: loam Properties and qualities Slope:3 to 6 percent Depth to restrictive feature:More than 80 inches Drainage class:Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.60 to 6.00 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Calcium carbonate, maximum content:15 percent Available water capacity:High (about 9.6 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3c Hydrologic Soil Group: A Ecological site: R048AY298CO - Rolling Loam Hydric soil rating: No 65—Torrifluvents, nearly level Map Unit Setting National map unit symbol: jnz3 Custom Soil Resource Report 16 Elevation: 5,000 to 7,000 feet Mean annual precipitation: 12 to 15 inches Mean annual air temperature: 46 to 48 degrees F Frost-free period: 90 to 120 days Farmland classification: Not prime farmland Map Unit Composition Torrifluvents and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Torrifluvents Setting Landform:Distributaries, rivers, flood plains Down-slope shape:Linear, convex Across-slope shape:Linear, convex Parent material:Alluvium Typical profile H1 - 0 to 36 inches: loam H2 - 36 to 60 inches: sand Properties and qualities Slope:0 to 6 percent Depth to restrictive feature:More than 80 inches Drainage class:Moderately well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat):Moderately high to high (0.60 to 2.00 in/hr) Depth to water table:About 12 to 36 inches Frequency of flooding:OccasionalNone Frequency of ponding:None Calcium carbonate, maximum content:5 percent Gypsum, maximum content:1 percent Maximum salinity:Very slightly saline to moderately saline (2.0 to 8.0 mmhos/cm) Sodium adsorption ratio, maximum:2.0 Available water capacity:Moderate (about 7.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 7w Hydrologic Soil Group: C Hydric soil rating: No Minor Components Wann Percent of map unit:10 percent Landform:Terraces Hydric soil rating: Yes Fluvaquents Percent of map unit:5 percent Landform:Marshes Hydric soil rating: Yes Custom Soil Resource Report 17 72—Wann sandy loam, 1 to 3 percent slopes Map Unit Setting National map unit symbol: jnzc Elevation: 5,000 to 6,500 feet Farmland classification: Prime farmland if irrigated and reclaimed of excess salts and sodium Map Unit Composition Wann and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Wann Setting Landform:Terraces, valley floors Landform position (three-dimensional):Tread Down-slope shape:Linear, convex Across-slope shape:Linear, convex Parent material:Alluvium derived from sandstone and shale Typical profile H1 - 0 to 8 inches: sandy loam H2 - 8 to 60 inches: fine sandy loam, sandy loam, coarse sandy loam H2 - 8 to 60 inches: H2 - 8 to 60 inches: Properties and qualities Slope:1 to 3 percent Depth to restrictive feature:More than 80 inches Drainage class:Poorly drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat):High (2.00 to 6.00 in/hr) Depth to water table:About 0 inches Frequency of flooding:OccasionalNone Frequency of ponding:None Calcium carbonate, maximum content:10 percent Maximum salinity:Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water capacity:Very high (about 26.3 inches) Interpretive groups Land capability classification (irrigated): 4w Land capability classification (nonirrigated): 6w Hydrologic Soil Group: A/D Ecological site: R048AY265CO - Salt Meadow Hydric soil rating: Yes Custom Soil Resource Report 18 Minor Components Torrifluvents Percent of map unit:5 percent Hydric soil rating: No Kim Percent of map unit:5 percent Hydric soil rating: No Arvada Percent of map unit:5 percent Hydric soil rating: No 73—Water Map Unit Composition Water:100 percent Estimates are based on observations, descriptions, and transects of the mapunit. Custom Soil Resource Report 19 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 20 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 21 North Hangs February 2023 Appendix I-2 Kumar & Associates Report See Garfield County SUP Appendix 3 North Hangs February 2023 J-1 EXHIBIT J VEGETATION INFORMATION 1. Existing Vegetation Community The study area contains a mixture of grass-forb herbaceous vegetation in the irrigated pastures. Non-irrigated areas range from mature cottonwood galleries with shrubby midstory and sparse herbaceous understories to very dry, sparse shrublands and grassy areas. Flood irrigation has been heavily applied on the pasture areas, resulting in some areas dominated by hydrophytes along and below the ditches. Irrigation has typically begun in mid-April and does not shut off until October in most years. A detailed vegetation discussion can be found in the Environmental Solutions report in Appendix H-1. Figure J-1 Typical rangeland vegetation found in permit area. North Hangs February 2023 J-2 Figure J-1 Typical mature cottonwood galleries with shrubby midstory 2. Estimated Carrying Capacity The final land use for the site will be a lake with surrounding rangeland. Since the lake is the vast majority of the site area, the rangeland is not anticipated to be used for grazing. North Hangs February 2023 J-3 Appendix J-1 Wetland Report See Appendix 7 of the Garfield County permit. North Hangs February 2023 K-1 EXHIBIT K CLIMATE INFORMATION 1. General Information The proposed North Hangs Mine is located 1 mile southwest of Silt, Colorado at an elevation of approximately 5450 feet. The area is classified as Warm-summer humid continental climate (Dfb) under the Koppen Classification system. This climate classification is dominated by long warm summers and no significant precipitation difference between seasons. Table K-1 shows a summary of the climate for this area based on records from 1901 to 2005. Table K-1 Climate Data of Garfield Regional Airport, Rifle, Colorado, approximately 2 miles southwest of the North Hangs Mine (source: https://wrcc.dri.edu/cgi- bin/cliMAIN.pl?corifl). Average Temperature (F) Average Precipitation (in) Maximum Minimum Total precip. Total snow January 36.8 9.4 0.86 11.1 February 43.8 16.5 0.77 7.7 March 53.7 24.2 0.95 3.7 April 64.2 31.4 1.02 0.8 May 74.0 38.7 1.00 0 June 84.0 45.2 0.73 0 July 90.2 52.0 1.02 0 August 87.6 50.4 1.13 0 September 79.4 41.4 1.11 0 October 67.3 31.1 1.20 0.5 November 51.4 21.3 0.89 3.8 December 39.4 12.4 0.93 11.1 Yearly (avg) 64.3 31.2 11.61 (0.97) 38.6 (3.21) North Hangs February 2023 L-1 EXHIBIT L RECLAMATION COSTS In accordance with Rule 6.4.12, this exhibit outlines the different reclamation scenarios that will inform the bond calculation conducted by Division staff. North Hangs Mine will have a phased bond: Phase 1 will cover reclaiming the site assuming mining does not take place in the footprint of any wetlands, the footprint of the Bernudy Ditch, or within 300 feet of the Colorado River. Prior to initiating any of those three activities, the operator/applicant will post the necessary bond for Phase 2. Each bond calculation is outlined below. Reclamation of the bond scenario will create lakes, wetlands, and rangeland. It will involve the removal of berms and pit pumping infrastructure. It is assumed that mining will be undertaken last in the north side of Phase 1. The maximum highwall that will be in operation at any given time will be 1000 feet long. This maximum active highwall is also 25 feet tall, based on the anticipated maximum depth of mining. To reclaim it will require a dozer push of the near vertical active highwall to an overall slope of 2H:1V, and then backfilling and grading to 5H:1V, 3H:1V, and 2H:1V as shown on the Map C-4 cross sections and in Figure L-1 below. Figure L-1. Highwall Reclamation Cross Section (Typical) All other backfilling and grading of slopes will be completed by this point. The north pit will need dewatering to accomplish this grading and final topsoiling and revegetation. Based on the 5H:1V slopes above the water line, the maximum topsoil and reseeding area can be calculated. Table L-1 shows all quantities needed for reclamation along with a total cost for reclaiming. Final Reclaimed Slopes Active Mining Highwall Mining Slope (knocked down) Lake level North Hangs February 2023 L-2 Table L-1. Phase 1 Reclamation Task and Cost Estimate Description Material Quantity Unit Unit Cost Cost Removal of office, scale house, and scale N/A N/A $5000 $5,000 Pit dewatering for a 25-acre lake 21 feet deep. 525 Acre-ft $105 $55,125 Highwall backfilling from mining to final condition. 1000 SQ. FT. over 1000 FT. 37,000 CY $1.50 $55,500 Topsoiling to 18 inches deep the maximum disturbance area of 11 acres. 26,600 CY $1.50 $39,900 Discing of topsoil to a depth of 18 inches over 11 acres. 11 acres $105 $1,155 Seeding of 11-acre disturbance area 11 acres $400 $4,400 Mulching and crimping of mulch over 11-acre disturbance area 11 acres $850 $9,350 Weed control management for two years on 11 acres 11 acres $220 $2,420 Subtotal $172,850 DRMS cost (28%) $48,398 Total $221,248 North Hangs February 2023 M-1 EXHIBIT M OTHER PERMITS REQUIRED The following permits are necessary for the full operation of the North Hangs Mine 1. Garfield County Land Use Change Permit. 2. Colorado Air Pollution Control Division Fugitive Dust Permit and Air Pollution Emission Notice (APEN) 3. Colorado Water Quality Control Commission Discharge Permit 4. US Army Corps of Engineers permits (as needed) 5. Gravel Well Permit • Substitute Water Supply Plan • Augmentation Plan North Hangs February 2023 N-1 EXHIBIT N RIGHT OF ENTRY As shown on the documents, the surface owners of record of the property which will be mined is North Hangs Ranch LLC. A right of entry agreement is in place for the North Hangs Ranch LLC land and is also attached. North Hangs Ranch LLC 950 Smile Way York Pa 17404 North Hangs February 2023 O-1 EXHIBIT O OWNERS OF AFFECTED LAND AND MINERAL TO BE MINED The owner(s) of record of affected land (surface area) and owners of substance to be mined is North Hangs Ranch LLC. North Hangs Ranch LLC 950 Smile Way York, Pennsylvania 17404 North Hangs February 2023 P-1 EXHIBIT P MUNICIPALITIES WITHIN TWO MILES The North Hangs Mine is located approximately 1 mile southwest of Silt, Colorado, a statutory town in Garfield County. Town of Silt 231 N. 7th Street PO Box 70 Silt, Colorado 81652 North Hangs February 2023 Q-1 EXHIBIT Q PROOF OF MAILING OF NOTICES TO THE BOARD OF COUNTY COMMISSIONERS AND SOIL CONSERVATION DISTRICT Notices were filed with the Garfield County Board of Commissioners and the South Side Conservation District in support of this permit application. Board of County Commissioners 108 8th Street, Suite 101 Glenwood Springs, Colorado 81601 Bookcliff, Mount Sopris and South Side Conservation Districts 258 Center Dr Glenwood Springs, CO 81601 North Hangs February 2023 R-1 EXHIBIT R PROOF OF FILING WITH COUNTY CLERK Garfield County Clerk and Recorder 109 8th Street, Suite 200 Glenwood Springs, Colorado 81601 North Hangs February 2023 S-1 EXHIBIT S PERMANENT MAN-MADE STRUCTURES The following is an inventory of man-made structures within 200 feet of the affected area. All of these structures are shown on Map C-1. Landowner boundaries can also be found on the Map C-1. Proof of delivery of structure agreements is attached to this exhibit. In the event that a structure agreement is unobtainable, we will defer to the Geotechnical Stability Exhibit which indicates that all structures will be protected. Table S-1. Permanent Structures within 200’ of the Affected Area Owner Structures General Location Colorado Dept of Transportation 2829 W. Howard Pl. Denver, CO 80204 Interstate 70; Irrig. Ditches; Fence South Garfield County Road and Bridge District 2-3 facility 0298 County Road 333A Rifle, CO 81650 County Road 346 South Grand River LLC Bernudy Ditch & associated structures Traverses permit area east to west Holy Cross Energy 3799 Highway 82 PO Box 2150 Glenwood Springs, CO 81602 Gas lines South Shidelerosa LLLP 1411 County Road 316 Silt, CO 81652 Fence West North Hangs February 2023 RULE-1 RULE 1.6.2(1)(B) Prior to the submittal of the application, a sign was erected at the entrance to the site which contained all the required information regarding Rule 1.6.2(1)(b). Please see attached sign certification. North Hangs February 2023 GS-1 GEOTECHNICAL STABILITY EXHIBIT There are no known geologic hazards on the proposed site. Based on a slope stability analysis, buildings or other structures within 200’ of the North Hangs Mine affected area will not be affected by mining excavation. Sufficient buffers will be maintained to neighboring property lines. Exhibit C maps shows these buffers. Map C-3 shows the mining and reclamation slopes of the mine in cross section. A single cross section of the mining and reclamation slopes was analyzed for slope stability: the portion closest to the Colorado River. The material properties are derived from Table 2.5 in the SME Mining Reference Handbook 8, as there is no site-specific sample data of the material available. Therefore, all materials are matched to a classification from this table that best matches the materials in terms of description. The native alluvial material is best classified as sand and gravel with a mixed grain size. From the SME table, sand and gravel with a mixed grain size has an internal angle of friction of 45 degrees and no cohesion. An average of 18 inches of topsoil and two feet of overburden lies atop of the sand and gravel. These are described in the soil surveys in Exhibit I as sandy loam. This best matches the description for loose sand, mixed grain size from the SME table, which has an internal angle of friction of 34 degrees and no cohesion. This material will be used as backfill. The slope analyzed was modelled in three scenarios: 1. Maximum mining slopes with the groundwater table at natural level. 2. Maximum mining slopes after rapid draw-down of the groundwater table. 3. Final reclaimed slopes, assuming 100% backfill from mining slopes. Bishop’s Method of Slices was the slope stability calculation methodology uses and the software GALENA was used to model slopes and calculate the factor of safety. The location of slopes modelled in GALENA can be seen on Figure GS-1. This location was selected for the proximity of the Colorado River to the slopes. Table GS-1 lists the slopes and their respective factors of safety. The minimum factor of safety for operations of this type, according to CDRMS technical guidance, is 1.5. The lowest factor of safety calculated at the North Hangs Mine is 1.9. GALENA data tables and analysis result figures are attached as Appendix GS-1. 8 Original source: Houk and Bray 1977 North Hangs February 2023 GS-2 Figure GS-1. Location of Slope Stability Analysis 1 1’ North Hangs February 2023 GS-3 Table GS-1. Factors of Safety for Slope Stability Scenario Lowest Factor of Safety Maximum mining slopes with the groundwater table at natural level. 1.9 Maximum mining slopes after rapid draw-down of the groundwater table. 1.9 Final reclaimed slopes, assuming 100% backfill from mining slopes 2.8 The slope stability analysis in this permit has been prepared according to appropriate engineering standards and practices. Ben Langenfeld, P.E. P.E.# 0047151 North Hangs February 2023 GS-4 APPENDIX GS-1 GALENA INFORMATION GALENA Version 7.2 Project North Hangs Mine Cross Section 1 - Mining Slope with Groundwater File:E:\Work\Dropbox (GLA)\Western Slope Agg\North Hangs\Soils Geology\GALENA\North Hangs Mine Slope Stability.gmf Edited: Processed: 16 Jun 2021 16 Jun 2021 Greg Lewicki and AssociatesLicensed to: Analysis Results 1 Multiple Stability Analysis Bishop Simplified Circular Method: Surface: Critical Factor of Safety: 1.91 Material Keys 1: Sand and gravel, mixed grain size 2: Loose sand, mixed grain size 0 50 100 150 200 250 300 350 5250 5300 5350 5400 5450 5500 GALENA Version 7.2 Project North Hangs Mine Cross Section 1 - Mining Slope with Rapid Drawdown File:E:\Work\Dropbox (GLA)\Western Slope Agg\North Hangs\Soils Geology\GALENA\North Hangs Mine Slope Stability.gmf Edited: Processed: 16 Jun 2021 16 Jun 2021 Greg Lewicki and AssociatesLicensed to: Analysis Results 2 Multiple Stability Analysis Bishop Simplified Circular Method: Surface: Critical Factor of Safety: 1.91 Material Keys 1: Sand and gravel, mixed grain size 2: Loose sand, mixed grain size 0 50 100 150 200 250 300 350 5250 5300 5350 5400 5450 5500 GALENA Version 7.2 Project North Hangs Mine Cross Section 1 - Reclaimed Slope with Groundwater File:E:\Work\Dropbox (GLA)\Western Slope Agg\North Hangs\Soils Geology\GALENA\North Hangs Mine Slope Stability.gmf Edited: Processed: 16 Jun 2021 16 Jun 2021 Greg Lewicki and AssociatesLicensed to: Analysis Results 3 Multiple Stability Analysis Bishop Simplified Circular Method: Surface: Critical Factor of Safety: 2.78 Material Keys 1: Sand and gravel, mixed grain size 2: Loose sand, mixed grain size 0 50 100 150 200 250 300 350 5250 5300 5350 5400 5450 5500 GALENA 7.2 Analysis Results Version: 7.20.1.01 Licensee: Greg Lewicki and Associates —————————————————————————————————————————————————————————————————————————————————————— Project: North Hangs Mine File: E:\Work\Dropbox (GLA)\Western Slope Agg\North Hangs\Soils Geology\GALENA\North Hangs Mine Slope Stability.gmf Processed: 16 Jun 2021 11:46:25 —————————————————————————————————————————————————————————————————————————————————————— 1. Analysis 1 - Cross Section 1 - Mining Slope with Groundwater Material Properties (2 materials) ------------------- Material: 1 (Mohr-Coulomb Isotropic) - Sand and gravel, mixed grain size Cohesion Phi UnitWeight Ru 0.00 45.0 110.00 Auto Material: 2 (Mohr-Coulomb Isotropic) - Loose sand, mixed grain size Cohesion Phi UnitWeight Ru 0.00 34.0 99.00 Auto Water Properties ---------------- Unit weight of water: 62.400 Unit weight of water/medium above ground: 62.400 Material Profiles (2 profiles) ----------------- Profile: 1 (3 points) Material beneath: 2 - Loose sand, mixed grain size 0.00 5389.52 204.04 5391.91 348.51 5390.21 Profile: 2 (3 points) Material beneath: 1 - Sand and gravel, mixed grain size 0.04 5386.02 204.04 5388.41 348.47 5386.71 Slope Surface (4 points) ------------- 0.00 5389.52 204.04 5391.91 256.59 5370.00 348.51 5370.00 Phreatic Surface (2 points) ---------------- 0.00 5385.00 400.00 5385.00 Failure Surface --------------- Initial circular surface for critical search defined by: XL,XR,R Intersects: XL: 176.40 YL: 5391.59 XR: 255.30 YR: 5370.54 Centre: XC: 279.42 YC: 5619.37 Radius: R: 250.00 Variable Restraints ------------------- Parameter descriptor: XL XR R Range of variation: 75.00 75.00 25.00 Trial positions within range: 25 25 25 - -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- RESULTS: Analysis 1 - Cross Section 1 - Mining Slope with Groundwater Bishop Simplified Method of Analysis - Circular Failure Surface --------------------------------------------------------------- Critical Failure Surface Search using Multiple Circle Generation Techniques Initial failure surface approximation - Factor of Safety: 3.349 Analysis Summary ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ There were: 10627 successful analyses from a total of 15625 trial failure surfaces 4998 analyses terminated due to unacceptable geometry Critical (minimum) Factor of Safety: 1.91 —————————————————————————————————————————— Results Summary - Lowest 99 Factor of Safety circles ---------------------------------------------------- Circle X-Left Y-Left X-Right Y-Right X-Centre Y-Centre Radius FoS 1 204.52 5391.71 217.80 5386.17 311.34 5629.21 260.42 1.909 <-- Critical Surface 2 204.52 5391.71 217.80 5386.17 310.94 5628.25 259.38 1.909 3 204.52 5391.71 217.80 5386.17 311.75 5630.17 261.46 1.909 4 204.52 5391.71 217.80 5386.17 312.15 5631.13 262.50 1.909 5 204.52 5391.71 217.80 5386.17 310.54 5627.28 258.33 1.910 6 204.52 5391.71 217.80 5386.17 308.54 5622.48 253.12 1.910 7 204.52 5391.71 217.80 5386.17 309.34 5624.40 255.21 1.910 8 204.52 5391.71 217.80 5386.17 309.74 5625.36 256.25 1.910 9 204.52 5391.71 217.80 5386.17 308.94 5623.44 254.17 1.910 10 204.52 5391.71 217.80 5386.17 310.14 5626.32 257.29 1.910 11 204.52 5391.71 217.80 5386.17 306.93 5618.63 248.96 1.910 12 204.52 5391.71 217.80 5386.17 308.14 5621.51 252.08 1.910 13 204.52 5391.71 217.80 5386.17 307.33 5619.59 250.00 1.911 14 204.52 5391.71 217.80 5386.17 305.73 5615.74 245.83 1.911 15 204.52 5391.71 217.80 5386.17 307.74 5620.55 251.04 1.911 16 204.52 5391.71 217.80 5386.17 304.93 5613.82 243.75 1.911 17 204.52 5391.71 217.80 5386.17 306.53 5617.67 247.92 1.911 18 204.52 5391.71 217.80 5386.17 306.13 5616.70 246.88 1.911 19 204.52 5391.71 217.80 5386.17 305.33 5614.78 244.79 1.911 20 204.52 5391.71 217.80 5386.17 304.13 5611.90 241.67 1.911 21 204.52 5391.71 217.80 5386.17 303.72 5610.93 240.62 1.911 22 204.52 5391.71 217.80 5386.17 304.53 5612.86 242.71 1.911 23 204.52 5391.71 217.80 5386.17 303.32 5609.97 239.58 1.912 24 204.52 5391.71 217.80 5386.17 302.92 5609.01 238.54 1.912 25 204.52 5391.71 217.80 5386.17 302.52 5608.05 237.50 1.912 26 207.65 5390.40 217.80 5386.17 313.32 5629.56 261.46 2.042 27 207.65 5390.40 217.80 5386.17 312.92 5628.60 260.42 2.042 28 207.65 5390.40 217.80 5386.17 313.72 5630.52 262.50 2.043 29 207.65 5390.40 217.80 5386.17 309.71 5620.90 252.08 2.043 30 207.65 5390.40 217.80 5386.17 310.11 5621.86 253.12 2.043 31 207.65 5390.40 217.80 5386.17 310.51 5622.83 254.17 2.043 32 207.65 5390.40 217.80 5386.17 310.91 5623.79 255.21 2.044 33 207.65 5390.40 217.80 5386.17 312.12 5626.67 258.33 2.044 34 207.65 5390.40 217.80 5386.17 311.72 5625.71 257.29 2.044 35 207.65 5390.40 217.80 5386.17 308.51 5618.02 248.96 2.044 36 207.65 5390.40 217.80 5386.17 311.31 5624.75 256.25 2.044 37 207.65 5390.40 217.80 5386.17 312.52 5627.63 259.38 2.044 38 207.65 5390.40 217.80 5386.17 308.91 5618.98 250.00 2.044 39 207.65 5390.40 217.80 5386.17 307.31 5615.13 245.83 2.044 40 207.65 5390.40 217.80 5386.17 309.31 5619.94 251.04 2.044 41 207.65 5390.40 217.80 5386.17 306.10 5612.25 242.71 2.044 42 207.65 5390.40 217.80 5386.17 308.11 5617.06 247.92 2.044 43 207.65 5390.40 217.80 5386.17 305.70 5611.29 241.67 2.044 44 207.65 5390.40 217.80 5386.17 306.90 5614.17 244.79 2.044 45 207.65 5390.40 217.80 5386.17 304.90 5609.36 239.58 2.044 46 207.65 5390.40 217.80 5386.17 306.50 5613.21 243.75 2.044 47 207.65 5390.40 217.80 5386.17 307.71 5616.09 246.88 2.044 48 207.65 5390.40 217.80 5386.17 305.30 5610.32 240.62 2.045 49 207.65 5390.40 217.80 5386.17 304.50 5608.40 238.54 2.045 50 207.65 5390.40 217.80 5386.17 304.10 5607.44 237.50 2.046 51 204.52 5391.71 220.93 5384.87 313.69 5630.43 262.50 2.056 52 204.52 5391.71 220.93 5384.87 312.88 5628.51 260.42 2.056 53 204.52 5391.71 220.93 5384.87 312.08 5626.59 258.33 2.056 54 204.52 5391.71 220.93 5384.87 310.08 5621.78 253.12 2.056 55 204.52 5391.71 220.93 5384.87 312.48 5627.55 259.38 2.056 56 204.52 5391.71 220.93 5384.87 311.68 5625.62 257.29 2.056 57 204.52 5391.71 220.93 5384.87 310.48 5622.74 254.17 2.056 58 204.52 5391.71 220.93 5384.87 313.28 5629.47 261.46 2.056 59 204.52 5391.71 220.93 5384.87 310.88 5623.70 255.21 2.056 60 204.52 5391.71 220.93 5384.87 309.67 5620.81 252.08 2.056 61 204.52 5391.71 220.93 5384.87 308.47 5617.93 248.96 2.057 62 204.52 5391.71 220.93 5384.87 308.87 5618.89 250.00 2.057 63 204.52 5391.71 220.93 5384.87 308.07 5616.97 247.92 2.057 64 204.52 5391.71 220.93 5384.87 311.28 5624.66 256.25 2.057 65 204.52 5391.71 220.93 5384.87 304.46 5608.31 238.54 2.057 66 204.52 5391.71 220.93 5384.87 306.47 5613.12 243.75 2.057 67 204.52 5391.71 220.93 5384.87 309.27 5619.85 251.04 2.057 68 204.52 5391.71 220.93 5384.87 306.87 5614.08 244.79 2.057 69 204.52 5391.71 220.93 5384.87 307.27 5615.04 245.83 2.057 70 204.52 5391.71 220.93 5384.87 306.06 5612.16 242.71 2.057 71 204.52 5391.71 220.93 5384.87 307.67 5616.00 246.88 2.057 72 204.52 5391.71 220.93 5384.87 305.26 5610.23 240.62 2.057 73 204.52 5391.71 220.93 5384.87 304.06 5607.34 237.50 2.057 74 204.52 5391.71 220.93 5384.87 305.66 5611.19 241.67 2.057 75 204.52 5391.71 220.93 5384.87 304.86 5609.27 239.58 2.057 76 201.40 5391.88 217.80 5386.17 295.48 5635.83 261.46 2.116 77 201.40 5391.88 217.80 5386.17 295.82 5636.81 262.50 2.116 78 201.40 5391.88 217.80 5386.17 295.13 5634.84 260.42 2.116 79 201.40 5391.88 217.80 5386.17 294.79 5633.86 259.38 2.116 80 201.40 5391.88 217.80 5386.17 294.45 5632.87 258.33 2.117 81 201.40 5391.88 217.80 5386.17 294.11 5631.89 257.29 2.117 82 201.40 5391.88 217.80 5386.17 293.76 5630.90 256.25 2.117 83 201.40 5391.88 217.80 5386.17 293.42 5629.92 255.21 2.117 84 201.40 5391.88 217.80 5386.17 293.08 5628.94 254.17 2.117 85 201.40 5391.88 217.80 5386.17 292.74 5627.95 253.12 2.117 86 201.40 5391.88 217.80 5386.17 292.39 5626.97 252.08 2.117 87 201.40 5391.88 217.80 5386.17 292.05 5625.98 251.04 2.117 88 201.40 5391.88 217.80 5386.17 291.37 5624.01 248.96 2.117 89 201.40 5391.88 217.80 5386.17 291.71 5625.00 250.00 2.117 90 201.40 5391.88 217.80 5386.17 290.34 5621.06 245.83 2.117 91 201.40 5391.88 217.80 5386.17 291.02 5623.03 247.92 2.117 92 201.40 5391.88 217.80 5386.17 290.68 5622.04 246.88 2.117 93 201.40 5391.88 217.80 5386.17 290.00 5620.08 244.79 2.118 94 201.40 5391.88 217.80 5386.17 289.65 5619.09 243.75 2.118 95 201.40 5391.88 217.80 5386.17 289.31 5618.11 242.71 2.118 96 201.40 5391.88 217.80 5386.17 288.97 5617.12 241.67 2.118 97 201.40 5391.88 217.80 5386.17 288.63 5616.14 240.62 2.118 98 201.40 5391.88 217.80 5386.17 288.28 5615.15 239.58 2.118 99 201.40 5391.88 217.80 5386.17 287.94 5614.17 238.54 2.118 Critical Failure Surface (circle 1) ------------------------ Intersects: XL: 204.52 YL: 5391.71 XR: 217.80 YR: 5386.17 Centre: XC: 311.34 YC: 5629.21 Radius: R: 260.42 Generated failure surface: (20 points) 204.52 5391.71 205.22 5391.40 205.91 5391.09 206.60 5390.79 207.29 5390.48 207.99 5390.18 208.68 5389.88 209.38 5389.58 210.08 5389.29 210.78 5388.99 211.47 5388.70 212.17 5388.41 212.87 5388.13 213.58 5387.84 214.28 5387.56 214.98 5387.28 215.68 5387.00 216.39 5386.72 217.09 5386.45 217.80 5386.17 Slice Geometry and Properties - Critical Failure Surface (circle 1, 39 slices) -------------------------------------------------------- Slice X-S ------------------- Base --------------------- PoreWater Normal Test X-Left Area Angle Width Length Matl Cohesion Phi Weight Force Stress Factor 1 204.52 0.00 24.1 0.35 0.38 2 0.00 34.0 0.17 0.00 0.42 0.95 2 204.87 0.01 24.1 0.35 0.38 2 0.00 34.0 0.55 0.00 1.38 0.95 3 205.22 0.01 24.0 0.35 0.38 2 0.00 34.0 0.90 0.00 2.26 0.95 4 205.56 0.01 24.0 0.35 0.38 2 0.00 34.0 1.22 0.00 3.05 0.95 5 205.91 0.02 23.7 0.35 0.38 2 0.00 34.0 1.52 0.00 3.81 0.95 6 206.25 0.02 23.8 0.35 0.38 2 0.00 34.0 1.81 0.00 4.52 0.95 7 206.60 0.02 23.7 0.35 0.38 2 0.00 34.0 2.08 0.00 5.19 0.95 8 206.95 0.02 23.7 0.35 0.38 2 0.00 34.0 2.33 0.00 5.82 0.95 9 207.29 0.03 23.5 0.35 0.38 2 0.00 34.0 2.55 0.00 6.37 0.95 10 207.64 0.03 23.4 0.35 0.38 2 0.00 34.0 2.77 0.00 6.92 0.95 11 207.99 0.03 23.3 0.35 0.38 2 0.00 34.0 2.94 0.00 7.34 0.95 12 208.34 0.03 23.3 0.35 0.38 2 0.00 34.0 3.13 0.00 7.80 0.95 13 208.68 0.03 23.1 0.35 0.38 2 0.00 34.0 3.26 0.00 8.15 0.94 14 209.03 0.03 23.2 0.35 0.38 2 0.00 34.0 3.40 0.00 8.48 0.94 15 209.38 0.04 23.0 0.35 0.38 2 0.00 34.0 3.49 0.00 8.70 0.94 16 209.73 0.04 22.9 0.35 0.38 2 0.00 34.0 3.59 0.00 8.96 0.94 17 210.08 0.04 22.8 0.35 0.38 2 0.00 34.0 3.64 0.00 9.09 0.94 18 210.43 0.04 22.8 0.35 0.38 2 0.00 34.0 3.69 0.00 9.21 0.94 19 210.78 0.04 22.6 0.35 0.38 2 0.00 34.0 3.72 0.00 9.27 0.94 20 211.12 0.04 22.6 0.35 0.38 2 0.00 34.0 3.70 0.00 9.23 0.94 21 211.47 0.04 22.5 0.35 0.38 2 0.00 34.0 3.69 0.00 9.19 0.94 22 211.82 0.04 22.4 0.35 0.38 2 0.00 34.0 3.65 0.00 9.11 0.94 23 212.17 0.03 22.3 0.25 0.27 2 0.00 34.0 2.58 0.00 8.99 0.94 24 212.42 0.03 22.3 0.25 0.28 1 0.00 45.0 2.71 0.00 8.77 0.89 25 212.68 0.02 22.3 0.20 0.21 1 0.00 45.0 2.16 0.00 9.11 0.89 26 212.87 0.03 22.1 0.35 0.38 1 0.00 45.0 3.79 0.00 8.90 0.89 27 213.22 0.03 22.1 0.35 0.38 1 0.00 45.0 3.65 0.00 8.59 0.89 28 213.58 0.03 22.0 0.35 0.38 1 0.00 45.0 3.49 0.00 8.20 0.89 29 213.93 0.03 22.0 0.35 0.38 1 0.00 45.0 3.30 0.00 7.76 0.89 30 214.28 0.03 21.8 0.35 0.38 1 0.00 45.0 3.10 0.00 7.28 0.89 31 214.63 0.03 21.8 0.35 0.38 1 0.00 45.0 2.87 0.00 6.75 0.89 32 214.98 0.02 21.6 0.35 0.38 1 0.00 45.0 2.63 0.00 6.18 0.89 33 215.33 0.02 21.6 0.35 0.38 1 0.00 45.0 2.34 0.00 5.51 0.89 34 215.68 0.02 21.5 0.35 0.38 1 0.00 45.0 2.06 0.00 4.85 0.89 35 216.04 0.02 21.4 0.35 0.38 1 0.00 45.0 1.72 0.00 4.05 0.89 36 216.39 0.01 21.3 0.35 0.38 1 0.00 45.0 1.38 0.00 3.26 0.89 37 216.74 0.01 21.3 0.35 0.38 1 0.00 45.0 1.02 0.00 2.41 0.89 38 217.09 0.01 21.2 0.35 0.38 1 0.00 45.0 0.64 0.00 1.52 0.89 39 217.45 0.00 21.1 0.35 0.38 1 0.00 45.0 0.21 0.00 0.49 0.89 -------- ------- ---------- X-S Area: 0.95 Path Length: 14.38 X-S Weight: 97.46 ———————————————————————————————————————————————————————————————————————————————————————————————— 2. Analysis 2 - Cross Section 1 - Mining Slope with Rapid Drawdown Material Properties (2 materials) ------------------- Material: 1 (Mohr-Coulomb Isotropic) - Sand and gravel, mixed grain size Cohesion Phi UnitWeight Ru 0.00 45.0 110.00 Auto Material: 2 (Mohr-Coulomb Isotropic) - Loose sand, mixed grain size Cohesion Phi UnitWeight Ru 0.00 34.0 99.00 Auto Water Properties ---------------- Unit weight of water: 62.400 Unit weight of water/medium above ground: 62.400 Material Profiles (2 profiles) ----------------- Profile: 1 (3 points) Material beneath: 2 - Loose sand, mixed grain size 0.00 5389.52 204.04 5391.91 348.51 5390.21 Profile: 2 (3 points) Material beneath: 1 - Sand and gravel, mixed grain size 0.04 5386.02 204.04 5388.41 348.47 5386.71 Slope Surface (4 points) ------------- 0.00 5389.52 204.04 5391.91 256.59 5370.00 348.51 5370.00 Piezometric Surfaces (1 surface) -------------------- Surface within profile: 1 (4 points) - Loose sand, mixed grain size 0.20 5385.10 212.60 5387.70 256.00 5369.20 348.40 5369.70 Failure Surface --------------- Initial circular surface for critical search defined by: XL,XR,R Intersects: XL: 176.40 YL: 5391.59 XR: 255.30 YR: 5370.54 Centre: XC: 279.42 YC: 5619.37 Radius: R: 250.00 Variable Restraints ------------------- Parameter descriptor: XL XR R Range of variation: 75.00 75.00 25.00 Trial positions within range: 25 25 25 - -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- - RESULTS: Analysis 2 - Cross Section 1 - Mining Slope with Rapid Drawdown Bishop Simplified Method of Analysis - Circular Failure Surface --------------------------------------------------------------- Critical Failure Surface Search using Multiple Circle Generation Techniques Initial failure surface approximation - Factor of Safety: 3.645 Analysis Summary ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ There were: 10633 successful analyses from a total of 15625 trial failure surfaces 4992 analyses terminated due to unacceptable geometry Critical (minimum) Factor of Safety: 1.91 —————————————————————————————————————————— Results Summary - Lowest 99 Factor of Safety circles ---------------------------------------------------- Circle X-Left Y-Left X-Right Y-Right X-Centre Y-Centre Radius FoS 1 204.52 5391.71 217.80 5386.17 311.34 5629.21 260.42 1.909 <-- Critical Surface 2 204.52 5391.71 217.80 5386.17 310.94 5628.25 259.38 1.909 3 204.52 5391.71 217.80 5386.17 311.75 5630.17 261.46 1.909 4 204.52 5391.71 217.80 5386.17 312.15 5631.13 262.50 1.909 5 204.52 5391.71 217.80 5386.17 310.54 5627.28 258.33 1.910 6 204.52 5391.71 217.80 5386.17 308.54 5622.48 253.12 1.910 7 204.52 5391.71 217.80 5386.17 309.34 5624.40 255.21 1.910 8 204.52 5391.71 217.80 5386.17 309.74 5625.36 256.25 1.910 9 204.52 5391.71 217.80 5386.17 308.94 5623.44 254.17 1.910 10 204.52 5391.71 217.80 5386.17 310.14 5626.32 257.29 1.910 11 204.52 5391.71 217.80 5386.17 306.93 5618.63 248.96 1.910 12 204.52 5391.71 217.80 5386.17 308.14 5621.51 252.08 1.910 13 204.52 5391.71 217.80 5386.17 307.33 5619.59 250.00 1.911 14 204.52 5391.71 217.80 5386.17 305.73 5615.74 245.83 1.911 15 204.52 5391.71 217.80 5386.17 307.74 5620.55 251.04 1.911 16 204.52 5391.71 217.80 5386.17 304.93 5613.82 243.75 1.911 17 204.52 5391.71 217.80 5386.17 306.53 5617.67 247.92 1.911 18 204.52 5391.71 217.80 5386.17 306.13 5616.70 246.88 1.911 19 204.52 5391.71 217.80 5386.17 305.33 5614.78 244.79 1.911 20 204.52 5391.71 217.80 5386.17 304.13 5611.90 241.67 1.911 21 204.52 5391.71 217.80 5386.17 303.72 5610.93 240.62 1.911 22 204.52 5391.71 217.80 5386.17 304.53 5612.86 242.71 1.911 23 204.52 5391.71 217.80 5386.17 303.32 5609.97 239.58 1.912 24 204.52 5391.71 217.80 5386.17 302.92 5609.01 238.54 1.912 25 204.52 5391.71 217.80 5386.17 302.52 5608.05 237.50 1.912 26 207.65 5390.40 217.80 5386.17 313.32 5629.56 261.46 2.042 27 207.65 5390.40 217.80 5386.17 312.92 5628.60 260.42 2.042 28 207.65 5390.40 217.80 5386.17 313.72 5630.52 262.50 2.043 29 207.65 5390.40 217.80 5386.17 309.71 5620.90 252.08 2.043 30 207.65 5390.40 217.80 5386.17 310.11 5621.86 253.12 2.043 31 207.65 5390.40 217.80 5386.17 310.51 5622.83 254.17 2.043 32 207.65 5390.40 217.80 5386.17 310.91 5623.79 255.21 2.044 33 207.65 5390.40 217.80 5386.17 312.12 5626.67 258.33 2.044 34 207.65 5390.40 217.80 5386.17 311.72 5625.71 257.29 2.044 35 207.65 5390.40 217.80 5386.17 308.51 5618.02 248.96 2.044 36 207.65 5390.40 217.80 5386.17 311.31 5624.75 256.25 2.044 37 207.65 5390.40 217.80 5386.17 312.52 5627.63 259.38 2.044 38 207.65 5390.40 217.80 5386.17 308.91 5618.98 250.00 2.044 39 207.65 5390.40 217.80 5386.17 307.31 5615.13 245.83 2.044 40 207.65 5390.40 217.80 5386.17 309.31 5619.94 251.04 2.044 41 207.65 5390.40 217.80 5386.17 306.10 5612.25 242.71 2.044 42 207.65 5390.40 217.80 5386.17 308.11 5617.06 247.92 2.044 43 207.65 5390.40 217.80 5386.17 305.70 5611.29 241.67 2.044 44 207.65 5390.40 217.80 5386.17 306.90 5614.17 244.79 2.044 45 207.65 5390.40 217.80 5386.17 304.90 5609.36 239.58 2.044 46 207.65 5390.40 217.80 5386.17 306.50 5613.21 243.75 2.044 47 207.65 5390.40 217.80 5386.17 307.71 5616.09 246.88 2.044 48 207.65 5390.40 217.80 5386.17 305.30 5610.32 240.62 2.045 49 207.65 5390.40 217.80 5386.17 304.50 5608.40 238.54 2.045 50 207.65 5390.40 217.80 5386.17 304.10 5607.44 237.50 2.046 51 204.52 5391.71 220.93 5384.87 313.69 5630.43 262.50 2.056 52 204.52 5391.71 220.93 5384.87 312.88 5628.51 260.42 2.057 53 204.52 5391.71 220.93 5384.87 311.68 5625.62 257.29 2.057 54 204.52 5391.71 220.93 5384.87 310.08 5621.78 253.12 2.057 55 204.52 5391.71 220.93 5384.87 312.08 5626.59 258.33 2.057 56 204.52 5391.71 220.93 5384.87 312.48 5627.55 259.38 2.057 57 204.52 5391.71 220.93 5384.87 310.88 5623.70 255.21 2.057 58 204.52 5391.71 220.93 5384.87 310.48 5622.74 254.17 2.057 59 204.52 5391.71 220.93 5384.87 313.28 5629.47 261.46 2.057 60 204.52 5391.71 220.93 5384.87 308.47 5617.93 248.96 2.057 61 204.52 5391.71 220.93 5384.87 309.67 5620.81 252.08 2.057 62 204.52 5391.71 220.93 5384.87 308.87 5618.89 250.00 2.057 63 204.52 5391.71 220.93 5384.87 308.07 5616.97 247.92 2.057 64 204.52 5391.71 220.93 5384.87 311.28 5624.66 256.25 2.057 65 204.52 5391.71 220.93 5384.87 306.47 5613.12 243.75 2.057 66 204.52 5391.71 220.93 5384.87 309.27 5619.85 251.04 2.057 67 204.52 5391.71 220.93 5384.87 306.87 5614.08 244.79 2.057 68 204.52 5391.71 220.93 5384.87 304.46 5608.31 238.54 2.057 69 204.52 5391.71 220.93 5384.87 307.67 5616.00 246.88 2.057 70 204.52 5391.71 220.93 5384.87 307.27 5615.04 245.83 2.057 71 204.52 5391.71 220.93 5384.87 306.06 5612.16 242.71 2.057 72 204.52 5391.71 220.93 5384.87 305.26 5610.23 240.62 2.057 73 204.52 5391.71 220.93 5384.87 304.06 5607.34 237.50 2.058 74 204.52 5391.71 220.93 5384.87 305.66 5611.19 241.67 2.058 75 204.52 5391.71 220.93 5384.87 304.86 5609.27 239.58 2.058 76 201.40 5391.88 217.80 5386.17 295.48 5635.83 261.46 2.116 77 201.40 5391.88 217.80 5386.17 295.82 5636.81 262.50 2.116 78 201.40 5391.88 217.80 5386.17 295.13 5634.84 260.42 2.116 79 201.40 5391.88 217.80 5386.17 294.79 5633.86 259.38 2.116 80 201.40 5391.88 217.80 5386.17 294.45 5632.87 258.33 2.117 81 201.40 5391.88 217.80 5386.17 294.11 5631.89 257.29 2.117 82 201.40 5391.88 217.80 5386.17 293.76 5630.90 256.25 2.117 83 201.40 5391.88 217.80 5386.17 293.42 5629.92 255.21 2.117 84 201.40 5391.88 217.80 5386.17 293.08 5628.94 254.17 2.117 85 201.40 5391.88 217.80 5386.17 292.74 5627.95 253.12 2.117 86 201.40 5391.88 217.80 5386.17 292.39 5626.97 252.08 2.117 87 201.40 5391.88 217.80 5386.17 292.05 5625.98 251.04 2.117 88 201.40 5391.88 217.80 5386.17 291.37 5624.01 248.96 2.117 89 201.40 5391.88 217.80 5386.17 291.71 5625.00 250.00 2.117 90 201.40 5391.88 217.80 5386.17 290.34 5621.06 245.83 2.117 91 201.40 5391.88 217.80 5386.17 291.02 5623.03 247.92 2.117 92 201.40 5391.88 217.80 5386.17 290.68 5622.04 246.88 2.117 93 201.40 5391.88 217.80 5386.17 290.00 5620.08 244.79 2.118 94 201.40 5391.88 217.80 5386.17 289.65 5619.09 243.75 2.118 95 201.40 5391.88 217.80 5386.17 289.31 5618.11 242.71 2.118 96 201.40 5391.88 217.80 5386.17 288.97 5617.12 241.67 2.118 97 201.40 5391.88 217.80 5386.17 288.63 5616.14 240.62 2.118 98 201.40 5391.88 217.80 5386.17 288.28 5615.15 239.58 2.118 99 201.40 5391.88 217.80 5386.17 287.94 5614.17 238.54 2.118 Critical Failure Surface (circle 1) ------------------------ Intersects: XL: 204.52 YL: 5391.71 XR: 217.80 YR: 5386.17 Centre: XC: 311.34 YC: 5629.21 Radius: R: 260.42 Generated failure surface: (20 points) 204.52 5391.71 205.22 5391.40 205.91 5391.09 206.60 5390.79 207.29 5390.48 207.99 5390.18 208.68 5389.88 209.38 5389.58 210.08 5389.29 210.78 5388.99 211.47 5388.70 212.17 5388.41 212.87 5388.13 213.58 5387.84 214.28 5387.56 214.98 5387.28 215.68 5387.00 216.39 5386.72 217.09 5386.45 217.80 5386.17 Slice Geometry and Properties - Critical Failure Surface (circle 1, 39 slices) -------------------------------------------------------- Slice X-S ------------------- Base --------------------- PoreWater Normal Test X-Left Area Angle Width Length Matl Cohesion Phi Weight Force Stress Factor 1 204.52 0.00 24.1 0.35 0.38 2 0.00 34.0 0.17 0.00 0.42 0.95 2 204.87 0.01 24.1 0.35 0.38 2 0.00 34.0 0.55 0.00 1.38 0.95 3 205.22 0.01 24.0 0.35 0.38 2 0.00 34.0 0.90 0.00 2.26 0.95 4 205.56 0.01 24.0 0.35 0.38 2 0.00 34.0 1.22 0.00 3.05 0.95 5 205.91 0.02 23.7 0.35 0.38 2 0.00 34.0 1.52 0.00 3.81 0.95 6 206.25 0.02 23.8 0.35 0.38 2 0.00 34.0 1.81 0.00 4.52 0.95 7 206.60 0.02 23.7 0.35 0.38 2 0.00 34.0 2.08 0.00 5.19 0.95 8 206.95 0.02 23.7 0.35 0.38 2 0.00 34.0 2.33 0.00 5.82 0.95 9 207.29 0.03 23.5 0.35 0.38 2 0.00 34.0 2.55 0.00 6.37 0.95 10 207.64 0.03 23.4 0.35 0.38 2 0.00 34.0 2.77 0.00 6.92 0.95 11 207.99 0.03 23.3 0.35 0.38 2 0.00 34.0 2.94 0.00 7.34 0.95 12 208.34 0.03 23.3 0.35 0.38 2 0.00 34.0 3.13 0.00 7.80 0.95 13 208.68 0.03 23.1 0.35 0.38 2 0.00 34.0 3.26 0.00 8.15 0.94 14 209.03 0.03 23.2 0.35 0.38 2 0.00 34.0 3.40 0.00 8.48 0.94 15 209.38 0.04 23.0 0.35 0.38 2 0.00 34.0 3.49 0.00 8.70 0.94 16 209.73 0.04 22.9 0.35 0.38 2 0.00 34.0 3.59 0.00 8.96 0.94 17 210.08 0.04 22.8 0.35 0.38 2 0.00 34.0 3.64 0.00 9.09 0.94 18 210.43 0.04 22.8 0.35 0.38 2 0.00 34.0 3.69 0.00 9.21 0.94 19 210.78 0.04 22.6 0.35 0.38 2 0.00 34.0 3.72 0.00 9.27 0.94 20 211.12 0.04 22.6 0.35 0.38 2 0.00 34.0 3.70 0.00 9.23 0.94 21 211.47 0.04 22.5 0.35 0.38 2 0.00 34.0 3.69 0.00 9.19 0.94 22 211.82 0.04 22.4 0.35 0.38 2 0.00 34.0 3.65 0.00 9.11 0.94 23 212.17 0.03 22.3 0.25 0.27 2 0.00 34.0 2.58 0.00 8.99 0.94 24 212.42 0.03 22.3 0.25 0.28 1 0.00 45.0 2.71 0.00 8.77 0.89 25 212.68 0.02 22.3 0.20 0.21 1 0.00 45.0 2.16 0.00 9.11 0.89 26 212.87 0.03 22.1 0.35 0.38 1 0.00 45.0 3.79 0.00 8.90 0.89 27 213.22 0.03 22.1 0.35 0.38 1 0.00 45.0 3.65 0.00 8.59 0.89 28 213.58 0.03 22.0 0.35 0.38 1 0.00 45.0 3.49 0.00 8.20 0.89 29 213.93 0.03 22.0 0.35 0.38 1 0.00 45.0 3.30 0.00 7.76 0.89 30 214.28 0.03 21.8 0.35 0.38 1 0.00 45.0 3.10 0.00 7.28 0.89 31 214.63 0.03 21.8 0.35 0.38 1 0.00 45.0 2.87 0.00 6.75 0.89 32 214.98 0.02 21.6 0.35 0.38 1 0.00 45.0 2.63 0.00 6.18 0.89 33 215.33 0.02 21.6 0.35 0.38 1 0.00 45.0 2.34 0.00 5.51 0.89 34 215.68 0.02 21.5 0.35 0.38 1 0.00 45.0 2.06 0.00 4.85 0.89 35 216.04 0.02 21.4 0.35 0.38 1 0.00 45.0 1.72 0.00 4.05 0.89 36 216.39 0.01 21.3 0.35 0.38 1 0.00 45.0 1.38 0.00 3.26 0.89 37 216.74 0.01 21.3 0.35 0.38 1 0.00 45.0 1.02 0.00 2.41 0.89 38 217.09 0.01 21.2 0.35 0.38 1 0.00 45.0 0.64 0.00 1.52 0.89 39 217.45 0.00 21.1 0.35 0.38 1 0.00 45.0 0.21 0.00 0.49 0.89 -------- ------- ---------- X-S Area: 0.95 Path Length: 14.38 X-S Weight: 97.46 ———————————————————————————————————————————————————————————————————————————————————————————————— 3. Analysis 3 - Cross Section 1 - Reclaimed Slope with Groundwater Material Properties (2 materials) ------------------- Material: 1 (Mohr-Coulomb Isotropic) - Sand and gravel, mixed grain size Cohesion Phi UnitWeight Ru 0.00 45.0 110.00 Auto Material: 2 (Mohr-Coulomb Isotropic) - Loose sand, mixed grain size Cohesion Phi UnitWeight Ru 0.00 34.0 99.00 Auto Water Properties ---------------- Unit weight of water: 62.400 Unit weight of water/medium above ground: 62.400 Material Profiles (2 profiles) ----------------- Profile: 1 (3 points) Material beneath: 2 - Loose sand, mixed grain size 0.00 5389.52 204.04 5391.91 348.51 5390.21 Profile: 2 (3 points) Material beneath: 1 - Sand and gravel, mixed grain size 0.04 5386.02 204.04 5388.41 348.47 5386.71 Slope Surface (6 points) ------------- 0.00 5389.52 204.04 5391.91 233.84 5386.99 254.98 5379.99 274.04 5370.00 348.51 5370.00 Phreatic Surface (2 points) ---------------- 0.00 5385.00 400.00 5385.00 Failure Surface --------------- Initial circular surface for critical search defined by: XL,XR,R Intersects: XL: 189.90 YL: 5391.74 XR: 273.40 YR: 5370.34 Centre: XC: 292.81 YC: 5619.58 Radius: R: 250.00 Variable Restraints ------------------- Parameter descriptor: XL XR R Range of variation: 54.50 100.00 25.00 Trial positions within range: 25 25 25 - -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- - - -- -- -- -- -- -- -- -- - RESULTS: Analysis 3 - Cross Section 1 - Reclaimed Slope with Groundwater Bishop Simplified Method of Analysis - Circular Failure Surface --------------------------------------------------------------- Critical Failure Surface Search using Multiple Circle Generation Techniques Initial failure surface approximation - Factor of Safety: 3.613 Analysis Summary ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ There were: 11084 successful analyses from a total of 15625 trial failure surfaces 4541 analyses terminated due to unacceptable geometry Critical (minimum) Factor of Safety: 2.78 —————————————————————————————————————————— Results Summary - Lowest 99 Factor of Safety circles ---------------------------------------------------- Circle X-Left Y-Left X-Right Y-Right X-Centre Y-Centre Radius FoS 1 217.15 5389.75 273.40 5370.34 322.14 5602.78 237.50 2.779 <-- Critical Surface 2 217.15 5389.75 273.40 5370.34 322.48 5603.77 238.54 2.780 3 217.15 5389.75 273.40 5370.34 322.82 5604.77 239.58 2.780 4 217.15 5389.75 273.40 5370.34 323.16 5605.76 240.62 2.780 5 217.15 5389.75 273.40 5370.34 323.51 5606.75 241.67 2.780 6 217.15 5389.75 273.40 5370.34 323.85 5607.74 242.71 2.781 7 217.15 5389.75 273.40 5370.34 324.19 5608.73 243.75 2.781 8 217.15 5389.75 273.40 5370.34 324.53 5609.73 244.79 2.781 9 217.15 5389.75 273.40 5370.34 324.88 5610.72 245.83 2.781 10 217.15 5389.75 273.40 5370.34 325.22 5611.71 246.88 2.782 11 217.15 5389.75 273.40 5370.34 325.56 5612.70 247.92 2.782 12 217.15 5389.75 273.40 5370.34 325.90 5613.69 248.96 2.782 13 217.15 5389.75 273.40 5370.34 326.24 5614.69 250.00 2.782 14 217.15 5389.75 273.40 5370.34 326.59 5615.68 251.04 2.783 15 217.15 5389.75 273.40 5370.34 326.93 5616.67 252.08 2.783 16 217.15 5389.75 273.40 5370.34 327.27 5617.66 253.12 2.783 17 217.15 5389.75 273.40 5370.34 327.61 5618.65 254.17 2.783 18 217.15 5389.75 273.40 5370.34 327.96 5619.64 255.21 2.784 19 217.15 5389.75 273.40 5370.34 328.30 5620.64 256.25 2.784 20 217.15 5389.75 273.40 5370.34 328.64 5621.63 257.29 2.784 21 217.15 5389.75 273.40 5370.34 328.98 5622.62 258.33 2.784 22 217.15 5389.75 273.40 5370.34 329.32 5623.61 259.38 2.784 23 217.15 5389.75 273.40 5370.34 329.67 5624.60 260.42 2.785 24 217.15 5389.75 273.40 5370.34 330.01 5625.59 261.46 2.785 25 217.15 5389.75 273.40 5370.34 330.35 5626.58 262.50 2.785 26 214.88 5390.12 273.40 5370.34 319.56 5603.31 237.50 2.830 27 214.88 5390.12 273.40 5370.34 319.90 5604.30 238.54 2.831 28 214.88 5390.12 273.40 5370.34 320.23 5605.30 239.58 2.831 29 214.88 5390.12 273.40 5370.34 320.57 5606.29 240.62 2.831 30 214.88 5390.12 273.40 5370.34 320.91 5607.29 241.67 2.831 31 214.88 5390.12 273.40 5370.34 321.24 5608.28 242.71 2.832 32 214.88 5390.12 273.40 5370.34 321.58 5609.28 243.75 2.832 33 214.88 5390.12 273.40 5370.34 321.91 5610.27 244.79 2.832 34 214.88 5390.12 273.40 5370.34 322.25 5611.27 245.83 2.832 35 214.88 5390.12 273.40 5370.34 322.59 5612.26 246.88 2.833 36 214.88 5390.12 273.40 5370.34 322.92 5613.26 247.92 2.833 37 214.88 5390.12 273.40 5370.34 323.26 5614.25 248.96 2.833 38 214.88 5390.12 273.40 5370.34 323.60 5615.24 250.00 2.833 39 214.88 5390.12 273.40 5370.34 323.93 5616.24 251.04 2.834 40 214.88 5390.12 273.40 5370.34 324.27 5617.23 252.08 2.834 41 214.88 5390.12 273.40 5370.34 324.60 5618.23 253.12 2.834 42 214.88 5390.12 273.40 5370.34 324.94 5619.22 254.17 2.834 43 214.88 5390.12 273.40 5370.34 325.28 5620.22 255.21 2.835 44 214.88 5390.12 273.40 5370.34 325.61 5621.21 256.25 2.835 45 214.88 5390.12 273.40 5370.34 325.95 5622.20 257.29 2.835 46 214.88 5390.12 273.40 5370.34 326.28 5623.20 258.33 2.835 47 214.88 5390.12 273.40 5370.34 326.62 5624.19 259.38 2.836 48 214.88 5390.12 273.40 5370.34 326.96 5625.19 260.42 2.836 49 214.88 5390.12 273.40 5370.34 327.29 5626.18 261.46 2.836 50 214.88 5390.12 273.40 5370.34 327.63 5627.17 262.50 2.836 51 212.61 5390.50 273.40 5370.34 317.08 5603.78 237.50 2.880 52 212.61 5390.50 273.40 5370.34 317.41 5604.78 238.54 2.880 53 212.61 5390.50 273.40 5370.34 317.74 5605.78 239.58 2.880 54 212.61 5390.50 273.40 5370.34 318.07 5606.78 240.62 2.880 55 212.61 5390.50 273.40 5370.34 318.40 5607.77 241.67 2.881 56 212.61 5390.50 273.40 5370.34 318.73 5608.77 242.71 2.881 57 212.61 5390.50 273.40 5370.34 319.06 5609.77 243.75 2.881 58 212.61 5390.50 273.40 5370.34 319.39 5610.77 244.79 2.881 59 212.61 5390.50 273.40 5370.34 319.73 5611.76 245.83 2.882 60 212.61 5390.50 273.40 5370.34 320.06 5612.76 246.88 2.882 61 212.61 5390.50 273.40 5370.34 320.39 5613.76 247.92 2.882 62 212.61 5390.50 273.40 5370.34 320.72 5614.76 248.96 2.882 63 212.61 5390.50 273.40 5370.34 321.05 5615.75 250.00 2.883 64 212.61 5390.50 273.40 5370.34 321.38 5616.75 251.04 2.883 65 212.61 5390.50 273.40 5370.34 321.71 5617.75 252.08 2.883 66 212.61 5390.50 273.40 5370.34 322.04 5618.74 253.12 2.883 67 212.61 5390.50 273.40 5370.34 322.37 5619.74 254.17 2.884 68 212.61 5390.50 273.40 5370.34 322.70 5620.74 255.21 2.884 69 212.61 5390.50 273.40 5370.34 323.03 5621.73 256.25 2.884 70 212.61 5390.50 273.40 5370.34 323.36 5622.73 257.29 2.884 71 212.61 5390.50 273.40 5370.34 323.69 5623.73 258.33 2.885 72 212.61 5390.50 273.40 5370.34 324.02 5624.72 259.38 2.885 73 212.61 5390.50 273.40 5370.34 324.35 5625.72 260.42 2.885 74 212.61 5390.50 273.40 5370.34 324.68 5626.71 261.46 2.885 75 212.61 5390.50 273.40 5370.34 325.01 5627.71 262.50 2.886 76 217.15 5389.75 269.23 5372.52 317.27 5605.11 237.50 2.900 77 217.15 5389.75 269.23 5372.52 317.60 5606.11 238.54 2.900 78 217.15 5389.75 269.23 5372.52 317.93 5607.10 239.58 2.900 79 217.15 5389.75 269.23 5372.52 318.26 5608.10 240.62 2.901 80 217.15 5389.75 269.23 5372.52 318.59 5609.09 241.67 2.901 81 217.15 5389.75 269.23 5372.52 318.92 5610.09 242.71 2.901 82 217.15 5389.75 269.23 5372.52 319.25 5611.08 243.75 2.901 83 217.15 5389.75 269.23 5372.52 319.57 5612.08 244.79 2.902 84 217.15 5389.75 269.23 5372.52 319.90 5613.07 245.83 2.902 85 217.15 5389.75 269.23 5372.52 320.23 5614.07 246.88 2.902 86 217.15 5389.75 269.23 5372.52 320.56 5615.06 247.92 2.903 87 217.15 5389.75 269.23 5372.52 320.89 5616.06 248.96 2.903 88 217.15 5389.75 269.23 5372.52 321.22 5617.05 250.00 2.903 89 217.15 5389.75 269.23 5372.52 321.55 5618.05 251.04 2.903 90 217.15 5389.75 269.23 5372.52 321.88 5619.04 252.08 2.904 91 217.15 5389.75 269.23 5372.52 322.21 5620.04 253.12 2.904 92 217.15 5389.75 269.23 5372.52 322.54 5621.03 254.17 2.904 93 217.15 5389.75 269.23 5372.52 322.87 5622.03 255.21 2.904 94 217.15 5389.75 269.23 5372.52 323.19 5623.02 256.25 2.905 95 217.15 5389.75 269.23 5372.52 323.52 5624.02 257.29 2.905 96 217.15 5389.75 269.23 5372.52 323.85 5625.01 258.33 2.905 97 217.15 5389.75 269.23 5372.52 324.18 5626.01 259.38 2.906 98 217.15 5389.75 269.23 5372.52 324.51 5627.00 260.42 2.906 99 217.15 5389.75 269.23 5372.52 324.84 5628.00 261.46 2.906 Critical Failure Surface (circle 1) ------------------------ Intersects: XL: 217.15 YL: 5389.75 XR: 273.40 YR: 5370.34 Centre: XC: 322.14 YC: 5602.78 Radius: R: 237.50 Generated failure surface: (20 points) 217.15 5389.75 219.98 5388.38 222.82 5387.04 225.68 5385.75 228.56 5384.49 231.45 5383.28 234.36 5382.10 237.29 5380.95 240.23 5379.85 243.18 5378.79 246.15 5377.76 249.13 5376.78 252.13 5375.83 255.13 5374.93 258.15 5374.06 261.18 5373.24 264.22 5372.45 267.27 5371.71 270.33 5371.00 273.40 5370.34 Slice Geometry and Properties - Critical Failure Surface (circle 1, 42 slices) -------------------------------------------------------- Slice X-S ------------------- Base --------------------- PoreWater Normal Test X-Left Area Angle Width Length Matl Cohesion Phi Weight Force Stress Factor 1 217.15 0.32 25.9 1.41 1.57 2 0.00 34.0 31.55 0.00 19.98 0.99 2 218.56 0.96 25.9 1.41 1.57 2 0.00 34.0 94.80 0.00 60.04 0.99 3 219.98 0.32 25.1 0.34 0.37 2 0.00 34.0 31.74 0.00 84.83 0.99 4 220.31 1.50 25.1 1.25 1.38 1 0.00 45.0 152.26 0.00 103.92 0.95 5 221.57 1.97 25.1 1.25 1.38 1 0.00 45.0 207.37 0.00 141.55 0.94 6 222.82 2.82 24.3 1.43 1.57 1 0.00 45.0 302.06 0.00 181.61 0.94 7 224.25 3.41 24.4 1.43 1.57 1 0.00 45.0 370.19 0.00 222.55 0.94 8 225.68 3.26 23.6 1.19 1.29 1 0.00 45.0 357.65 0.00 260.44 0.94 9 226.87 1.58 23.6 0.53 0.58 1 0.00 45.0 174.21 0.00 283.47 0.94 10 227.40 3.72 23.6 1.16 1.27 1 0.00 45.0 409.66 19.97 307.40 0.94 11 228.56 5.14 22.8 1.45 1.57 1 0.00 45.0 565.67 79.45 346.16 0.94 12 230.01 5.68 22.8 1.45 1.57 1 0.00 45.0 624.51 139.05 386.47 0.94 13 231.45 5.08 22.1 1.19 1.29 1 0.00 45.0 558.47 158.08 423.81 0.94 14 232.65 5.42 22.1 1.19 1.29 1 0.00 45.0 596.11 196.96 455.21 0.94 15 233.84 2.46 22.1 0.52 0.56 1 0.00 45.0 270.16 98.42 473.59 0.94 16 234.36 6.97 21.3 1.46 1.57 1 0.00 45.0 766.60 312.45 484.12 0.94 17 235.82 7.10 21.3 1.46 1.57 1 0.00 45.0 780.50 368.41 496.81 0.94 18 237.29 6.31 20.6 1.28 1.37 1 0.00 45.0 693.84 365.98 508.89 0.94 19 238.57 6.38 20.5 1.28 1.37 1 0.00 45.0 701.77 406.97 517.92 0.94 20 239.85 1.89 20.6 0.38 0.40 1 0.00 45.0 208.09 127.65 527.06 0.94 21 240.23 7.45 19.8 1.48 1.57 1 0.00 45.0 819.54 530.32 550.32 0.94 22 241.71 7.51 19.8 1.48 1.57 1 0.00 45.0 826.52 582.46 585.34 0.94 23 243.18 7.60 19.0 1.48 1.57 1 0.00 45.0 835.52 633.58 620.22 0.94 24 244.67 7.63 19.0 1.48 1.57 1 0.00 45.0 839.02 683.81 653.13 0.94 25 246.15 7.68 18.3 1.49 1.57 1 0.00 45.0 844.27 732.91 685.89 0.94 26 247.64 7.67 18.3 1.49 1.57 1 0.00 45.0 844.11 781.25 716.57 0.94 27 249.13 7.69 17.5 1.50 1.57 1 0.00 45.0 845.71 828.47 747.19 0.94 28 250.63 7.65 17.5 1.50 1.57 1 0.00 45.0 841.93 874.77 775.71 0.94 29 252.13 7.25 16.8 1.43 1.49 1 0.00 45.0 797.12 872.17 803.46 0.94 30 253.55 7.19 16.8 1.43 1.49 1 0.00 45.0 790.46 912.21 828.43 0.94 31 254.98 7.66 16.1 1.59 1.65 1 0.00 45.0 842.43 1056.03 848.19 0.94 32 256.57 7.06 16.0 1.59 1.65 1 0.00 45.0 776.84 1102.52 860.45 0.94 33 258.15 6.17 15.3 1.51 1.57 1 0.00 45.0 679.01 1091.80 872.04 0.94 34 259.67 5.60 15.2 1.51 1.57 1 0.00 45.0 615.46 1132.11 881.27 0.94 35 261.18 5.02 14.5 1.52 1.57 1 0.00 45.0 551.99 1171.68 890.04 0.94 36 262.70 4.41 14.5 1.52 1.57 1 0.00 45.0 484.55 1210.24 897.03 0.94 37 264.22 3.79 13.7 1.53 1.57 1 0.00 45.0 416.54 1247.67 903.35 0.95 38 265.75 3.14 13.7 1.53 1.57 1 0.00 45.0 344.95 1284.27 907.92 0.95 39 267.27 2.48 13.0 1.53 1.57 1 0.00 45.0 272.33 1319.80 911.73 0.95 40 268.80 1.79 13.0 1.53 1.57 1 0.00 45.0 196.65 1354.33 913.96 0.95 41 270.33 1.09 12.2 1.53 1.57 1 0.00 45.0 119.50 1387.85 915.22 0.95 42 271.87 0.36 12.2 1.53 1.57 1 0.00 45.0 39.89 1420.31 915.15 0.95 -------- ------- ---------- X-S Area: 196.14 Path Length: 59.66 X-S Weight: 21521.56 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