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HomeMy WebLinkAbout1.17 Noise assessmentNOISE ASSESSMENT RTZ GRAVEL PIT GARFIELD COUNTY, COLORADO January 2009 Prepared by: Howard N. McGregor Registered Professional Engineer State of Colorado License No. 3928 # eerfr:g namics nrorated EDI JOB .I4. C3758 Page 1 of 9 3925 S. Kalamath St., Englewood, Colorado 80110 • voice: 303 -761 -4367 . fax: 303 -761 -4379 englneeri'7 dyrrnmiss i�rorpora #ed FOREWORD This noise assessment report was prepared by Engineering Dynamics Inc. in response to the request of Mr. Tony Zancanella of Zancanella and Associates, 10:11 Grand Avenue, Glenwood Springs, Colorado. The pit is located southeast of U. S. Interstate Highway 1 -70 in Garfield County, Colorado. The applicant proposes to mine alluvial deposits of sand and gravel from the pit using surface mining equipment and methods that are typical of mineral extraction operations along the Colorado River in Garfield County. The mined sand and gravel is expected to be used for road bed material and ail and gas pads. Engineering Dynamics has prepared noise impact assessment analyses and reports for the surface mining industry since 1972. All of the work reported herein was performed by Mr. McGregor or under his direct supervision. Howard N. McGregor is a registered professional engineer licensed to practice engineering in the State of Colorado. Mr. McGregor holds Colorado License Number 3928, which was obtained by examination. ECI JOB JO. 03758 Page 2 of 9 3925 S. Kalamath St., Englewood, Colorado 80110 ■ voice: 303- 761 -4367 • fax: 303 -761 -4379 TABLE OF CONTENTS Foreword Table of Contents I. Introduction e die,ng 'nee''n7 ynamic ncorate Page 2 3 4 € €. Applicable Laws, Regulations, ordinances and Land Zoning A. Community Noise 5 B. State of Colorado Noise Law 5 C. Garfield County 5 D. Zoning of Adjacent Land 6 111, Equipment Inventory and Noise Emission Levels 7 IV. Analysis A. Pit Development — Phases I, 11 and 111 8 B. Pit Mining 8 V. Conclusions /Recommendations 9 ED JOB JO. C3758 Page 3 of 9 3925 S. Kalamath St., Englewood, Colorado 80110 . voice: 303- 761 -4367 • fax: 303 -781 -4379 * errgirteeri�g eir3carpar ted INTRODUCTION The Appficant, RTZ Industrial Inc., LLC, is requesting a Special Use Permit (SUP) to mine and process sand and gravel from a deposit at the RTZ Pit. The pit is located southeast of U. S. Highway 1 -70 in Garfield County, Township 75, 96W. The Special Use Permit is for the extraction, processing, storage and material handling of a natural resource in an Agricultural Residential Rural Density Zone District. The mining plan is to conduct mining operations in a three -phase sequence starting operations at the southeast corner of the Phase 1 Mining Area. Phase 1 will commence with the removal and relocation of topsoil and overburden. A processing plant, including screening and crushers, to be used during mining in Phase 1 and 2, will be located in the northeast section of Phase 3 mining. Reclamation will begin in areas within Phase 1 within one year of the completion of this phase of mining. Mining in Phase 2 will begin with stripping and stockpiling of topsoil and overburden as in Phase 1. The overburden will be used as reclamation of Phase 1. The mining will start in the southeast corner of the Phase 2 miring area. After the completion of Phase 2 and prior to the mining of Phase 3, the excess overburden and top soil will be removed from Phase 3 and the processing plant, including screening and crushers will be moved to the Phase 2 area. The mining of Phase 3 will continue with the stripping of topsail and overburden from Phase 3. The mining will begin in the southeast corner of Phase 3 and move northwest. The Phase 3 is the final section of the pit area to be mined and reclamation will begin within one year of completing mining in this phase. The significant noise sources during pit development, mining and reclamation are: a Caterpillar D9T, track type dozer * Case 921, 5 -yard wheel front -end loader ■ Caterpillar 345, or Link Belt 700 a Case 1840 Skidster * Jaw Crusher, portable ■ Engine /Generator a Screening Plant a Wash Plant The dozer, a Caterpillar D9T is the noisiest of all of the equipment to be used during pit development, mining and reclamation and will produce 81 dB(A) at a distance of 104 ft. EDI JOB dO. C3758 Page 4 of 9 3925 S. Kalamath St., Englewood, Colorado 80110 • voice: 303- 761 -4367 • fax: 303 - 761 -4379 di, enginnle dynamics ncarparaeeriied 11. APPLICABLE LAWS, REGULATIONS, ORDINANCES and LAND ZONING A. Community Noise Community noise has been addressed by the Federal Government starting with the U. S. Environmental Protection Agency, (EPA) "Noise Control Act of 1972 ". In concert with that act, state and local governments have enacted laws or ordinances regulating noise emission levels. Furthermore, these laws clearly define measurement methodology and decibel limits in scientific terms. Some laws do, however, include subjective assessments which is outside of rigorous scientific evaluation and for this reason can be highly variable. Subjective assessments or considerations will not be addressed in this report. B. State of Colorado Noise Law Section 25 -12 -103. Maximum Permission Noise Levels §(1) Every activity to which this article is applicable shall be conducted in a manner so that any noise produced is not objectionable due to intermittence, beat frequency, or shrillness. Sound levels of noise radiating from a property line at a distance of twenty -five feet or more therefrom in excess of the dB(A) established for the following time periods and zones shall constitute prima facie evidence that such noise is a public nuisance: Maximum Allowable Noise Levels Zone 7am to next 7 m 7 m to next lam Residential 55 dB(A) 50 dB(A) Commercial 130 dB(A) 55 dB LA) Industrial 80 dB(A) 75 dB(A) Light Industrial 70 dB(A) 65 dB(A) §(2) In the hours between 7:00am and the next 7:00pm, the noise levels permitted in subsection (1) of this section may be increased by ten dB(A) for a period of not -to- exceed fifteen minutes in any one -hour period. §(3) Periodic, impulsive, or shrill noises shall be considered a public nuisance when such noises are at a sound level of five dB(A) less than those listed in subsection (1) of this section. §(5) Construction projects shall he subject to the maximum permissible noise levels specified for industrial zones for the period within which construction is to be completed pursuant to any applicable construction permit issued by proper authority or, if no time limitation is imposed, for a reasonable period of time for completion of project. Section 25 -12 -104 Action to Abate The entire section was amended in 2008 and effective August 5. The last sentence of this section reads: The court may stay the effect of any order issued under this section for such time as is reasonably necessary for the defendant to come into compliance with the provisions of this article. Engineering Dynamics's staff has contacted the Garfield County Building and Planning Department and requested the County's opinion regarding the interpretation of this section; CRS 25 -1 -104. C. Garfield County Garfield County has no ordinance or regulation addressing noise and relies upon Colorado Revised Statutes, Title 25, Article 12, Noise Abatement for determination of compliance. ED[ J013 JO. 03758 Page 5 of 8 3925 S. Kalamath St., Englewood, Colorado 80110 . voice: 343 -761 4367 9 Fax: 303 - 761 -4379 errgi?neering ii�110fli ►CS incn5,ni, rted D. Zoning of Adjacent Land 1. North of RTZ Site The land along the north boundary is zoned as "Resource Lands" as described in Article III, Zoning Division 1, Section 3 -101, §K of the Garfield County Unified Land Use Resolution. Resource Lands can be considered as "industrial" as described in CRS 25 -12 -102 and the noise limits would be 80 dB(A) during the daytime and 75 dB(A) during the nighttime. 2. South of RTZ Site The RTZ property extends southward to the Colorado River. The land beyond the south boundary of the Colorado River is zoned "Agricultural/Residential/Rural Density" (ARRD). Section 3 -501 of Article Ill of the Unified Land Use Resolution allows, under use permitted by right, occupied structures, which can be considered residential as described in CRS 25 -12 -102 and the noise limits would be 55 dB(A) during the daytime and 50 dB(A) during the nighttime. 3. West of RTZ Site The land to the west is owned by the Applicant resulting in a buffer zone that extends to the west by about 2500 ft. 4. Bast of RTZ Site The land along the east boundary is currently a sand and gravel surface mine pursuant to a special Use Permit zoning and accordingly the activity can be considered industrial as described in CRS 25- 12 -102 and the noise limits would be 80 dB(A) during the daytime and 75 dB(A) during the nighttime. However, although the present usage, mining of sand and gravel, is industrial the underlying zoning is ARRD. At some time in the future when mining in this area to the east of the RTZ site is completed or terminated, the zoning of that land could change. ED3 JOB J©. C375D Page 6 of 9 3925 S. Kalamath 5t., Englewood, Colorado 80110 . voice. 303- 7614367 a fax: 303- 761 -4379 edii-e�,.7d,,Y'.in.;,e,a.yen,r.i'tn,ig III. EQUIPMENT INVENTORY AND NOISE EMISSION LEVELS Table I presents a list of the equipment that will be in Operation at the pit during development, mining and reclamation on site, including a description and noise emission level expressed in A- weighted decibels. The decibel levels occurring at 100 ft. as listed in the table can be reduced in value for distances greater than 100 ft. using the values presented in Table 2, The reduction values listed in Table 2 do not include the effects of terrain, vegetation, vertical thermal gradients and wind and should be used only for estimating purposes. Table 1 Mine Site Construction and Development Description Qty Mfg. I.D. Equipment Function dB(A) 100 ft. Flak Bed 1 Transport of Equipment 66 Dozer* 1 CAT —D9T Overburden Removal - Mining of Material -- 81 Distribution of Overburden during Reclamation Front -End S Ad Loading Crusher Bin - Loading Haul Trucks — Loader 2 Wheel Loader On Site Transportation 75 CAT -345 or Back Hoe 2 Link Belt Sand and Gravel Excavation 75 700 Skidster 1 CASE- Area Cleanup — Material Loading, Small Loads 71 1840 Jaw Crusher 1 Production 76 Screening 1 Production 70 Plant Wash Plant 1 Production 68 "'EnglGen 1 250 DQ Electrical Power for Crusher, Screening Plant, 74 Wash Plant, Conveyors Water Truck 1 Dust Control 69 Backup Alarm BRS107 White Noise Backup Alarm 68 " Data obtained from Wagner Equipment Co, Denver, CO, December 2008 *' Engine /Generator noise emission level based upon Cummins Bulletin msp -10265 and F201 — Quiet Site If, First Stage Configuration. Table 2 Noise Reduction with Distance based upon 100 ft. Data Distance from Noise Source Noise Reduction - dB 100 0 200 -6 40€3 -12 80€3 -18 1000 -20 1600 -24 For example, the noisiest piece of equipment that will be operated at the RTZ pit is the Caterpillar 139T dozer which produces 81 dB(A) at 100 ft. At 200 ft., it will produce 75 d8(A) and at 400 ft. it will produce 69 dB(A). EDI JOB J0_ C3758 Page 7 of 9 3925 S. Kalamath St., Englewood, Colorado 80110 . voice: 303 -761 -4367 • fax: 303 -761 -4379 engf►reerJrrg dyrtumirs inrwporniterf IV. ANALYSIS A. Pit Development— Phases 1, II and III The State of Colorado Noise Law, Section 25- 12- 103 §(5), (see page 5 of this report) allows the noise limit to be increased to 80 dB(A) at a distance of 25 ft. beyond the property line during construction. Pit development will only occur during the daytime hours; 7;00am to next 7:00pm. Three areas of the RTZ pit will be developed and mined. These areas are shown as Phases 1, II and III on the Applicant's site plans. The time between mining and reclamation of each phase will be about every five years. The development time for each of the phases will be about one week barring any delays due to inclement weather. The noise limits of CRS 25 -12 -103 are applicable to all equipment once it is operating on the RTZ property. For example, the flat bed tractor trailer hauling the CAT D9T dozer is allowed to produce 86 dB(A) at 50 ft. when on a public road or highway, CRS 25 -12 -106 § (d). Then when the tractor trailer is on the RTZ site, its noise limit is 80 dB (A) at 25 ft. beyond the RTZ property line. The tractor trailer only produces 66 dB(A) at 100 ft. and would always be more than 100 ft. from the 25 ft. noise boundary. Once unloaded the dozer will start moving topsoil and overburden to the edges of the Phase I area. The dozer will produce 80 dB(A) at a distance of 75 ft. when at maximum engine speed and power. This can be visualized as a circular footprint that moves with the dozer as it moves about on the pit site. During pit development, there initially will be no berms, barriers or stock piles that would reduce the size of the noise footprint especially along the eastern boundaries of the RTZ property. Overburden and topsoil will be pushed by the dozer to the east and south and a small berm will be formed along the eastern boundary of Phase 1 and Phase 111 boundaries. During Phase II pit development, the distance to the nearest RTZ parcel boundary is 222 ft. to the north and the maximum noise level of the dozer will be 73 dB(A) at 25 ft/ beyond the property line.. During Phase Ill pit development, the distance to the nearest RTZ parcel boundary is 87 ft. to the east and the maximum dozer noise level will be 81 dB(A) at 25 ft. beyond the parcel boundary. This means that the noise level 25 ft. beyond the RTZ parcel boundaries during Phase I, 11 and Ill development will not exceed the 80 dB(A) industrial zone limit. All other mobile and fixed equipment will have noise footprints smaller than the Caterpillar 139T dozer. B. Pit Mining During pit mining during Phases I, II and 111, the allowable noise limit 25 ft. beyond the RTZ parcel boundary will depend upon the zoning of the adjacent properties. These zoning are shown on the Applicant's Site Maps, Section 6.4.1, Exhibit D — Mining Plan states that the topsoil depth ranges from 6 to 12 ft. Initially the processing plant will be located in the northeast section of Phase II mining area and will be 6 to 12 ft. below ground level. This depression of the equipment will provide a small, about 2 dB(A), reduction in noise at the pit boundary. Additional and more significant will be the reduction provided by the berm made of overburden located along the eastern and southern pit boundaries. A 15 ft. high berm made of overburden will provide the following noise reductions and resulting noise levels when the dozer is operating within 25 ft. of the berm and pit boundary. These data are presented in Table 4. Table 4 Noise Reduction of 15 ft. High Berm along l=ast and South Pit boundaries plus 25 ft. Distance, Pit Boundary Noise Reduction Distance Dozer Noise Location plus 25 ft. at 25 ft. Reduction Level East 104 15 2 64 dB(A) South 375 15 11 55 dB(A) EDI JOB JO. C3758 Page 8 of g 3925 S. Kalamath St., Englewood, Colorado 80110 s voice: 303 -761 -4367 s fax: 303 -761 -4379 errgt�reerhrg dynamics inrarporated V. CONCLUSIONSIRECOMMENDATIONS 1. During pit development /construction the noise limits are those listed in Colorado Revised Statues 2408, CRS 25 -12 -103 for industrial zones: 80 dB(A) daytime t7:00am to next 7:00pm) and 75 dB(A) nighttime (7:OOpm to next 7:00am)- 2. The dozer (a Caterpillar D9T or equal) is the loudest noise source that will be operated at the RTZ pit. During pit development/construction, the noise emissions from the dozer will not exceed the daytime limit of 80 dB(A) at any location 25 ft. beyond the RTZ parcel boundaries. 1 Stationary equipment such as the crusher, screens, washers, conveyors and electrical generators will not exceed the limits listed in CRS 25 -12 -103 during Phase I, Il and III mining operations at the RTZ pit. 4. Noise control methods such as barriers or berms using overburden or stockpiles may be used to mitigate the noise emissions from stationary equipment. 5. All equipment operated by the Applicant will be fitted with noise control devices such as mufflers, intake silencers, baffles and screens that are equal to or better than manufacturer's original configurations. 6, Applicant's haul trucks used to transport mined rock products shall not exceed the noise limits listed in CRS 25 -12 -107. 7. Customer' haul trucks shall not exceed the noise limits listed in CRS 25 -12 -107. The Applicant or the Applicant's pit operator may monitor the noise emissions of Customer' haul trucks and prohibit their access to the pit unti€ they are in compliance with the noise emission limits detailed in CRS 25 -12 -107. 8. All of the Applicant's mobile equipment used at the pit shall be fitted with the "White Noise" Backup Alarms that have been installed and adjusted to meet the requirements setforth by the U. S. Department of tabor, Mine Safety and Health Administration (MSHA). e.` EDI JOB JO. 03758 Page 9 of 9 3925 S. Kalamath St., Englewood, Colorado 80110 • voice: 303 -761 -4367 ■ fax: 343 -761 -4379 December 31, 2008 Mr. Tony Zancanella Zancanella & Associates Inc. 1011 Grand Avenue Glenwood Springs, CO 81602 Re: Noise Assessment — RTZ Gravel Pit EDI Job Number C3758 Approved by Zancanella and Associates on 12/30/08 Dear Mr. Zancanella: ii� engineering dynamics rncorparated Page 1 of 1 (V) 970- 945 -5700 (Fax) 970 -945 -1253 azancanellaca iza- engineering.com Engineering Dynamics Inc. (EDI) has been authorized by Zancanella and Associates to start work on 12/30/08. EDI is currently in the process of preparing a Noise Assessment Report similar in content to other reports submitted to Garfield County. Work is currently in progress to determine zoning and description of adjacent properties so that the applicable noise limits in accordance with CRS 25 -12 can be defined. An initial listing of mobile and stationary equipment that will be in operations at the proposed pit has been received from Zancanella and noise emissions for these equipment will be obtained from either manufacturer's data sheets or EDI data base. Once the analysis has been completed, mitigation methods will be developed to control noise emissions within the limits set forth in CRS 25 -12. In addition, once pit development has been started, noise measurements will be taken to verify compliance with CRS 25 -12. If an equipment exceeds the limits during pit development, operations will either be changed or equipment replaced that is in compliance with CRS 25 -12. When the pit is in the mining phase, noise measurements will be taken to assure compliance with the applicable section of CRS 25 -12, for example, for adjacent residentially zoned property, the daytime limit of 55 dB(A) and the nighttime limit of 50 dB(A). Any equipment either stationary or mobile that is not in compliance with CRS 25 -12 will be mitigated. Mitigation may consist of equipment replacement or modification or the construction of noise barriers made of stockpile or overburden material. Verification of noise mitigation will be documented by EDI and submitted to Garfield County. Baring any unforeseen calamities, the Noise Assessment Report will be delivered to Garfield County on or before January 15, 2009. If you have any questions regarding this information, please contact me at our Englewood office. Sincerely, ENGINEERING DYNAMICS, INC. Howard N. McGregor, P.E, Senior Acoustical Engineer 3925 south kalamath street • englewood, colorado 80110 .303.761.4367 • Fax 303.761.4379 11 Iasi, [-111 it -[ii nicilial 5c1C1it is, I -i and Ftii,i11cer,, LLC 1 Mr. Thomas A. Zancanella April 3, 2007 RTZ Industrial 1011 Grand Av ennue Glenwood Springs, CO 8160I Subject: Sound Suii,ey of Proposed RTZ Gravel Quarry Parachtile, Colorado WALSli 11rojecI No. 6 769- 010 Dear Mr. Zancanella: Walsh Environmental Scientists and I?ngineers, LLC (WALSH) prel'onned a soured survey of a proposed gravel quarry adjacent to an operating gravel quarry located approximately live miles south of Parachute, Colorado. Sound IeveIs were collected using Metrosonics'm brand 3084 portable dosimeters. The sound levels were measured using a slow (1 second) response curve. Sound was measured oil the "A" scale of the sound meter as defined by the Arnerican National Standards lustitute. Blair Rollins, a WALS11 Environmental Scientist, performed the field investigations on March 30, 21007. During the survey, the grinder, one excavator, three dozers, and many dump trucks vvere observed working at the adjacent operating gravel quarry. Souird A9easurernerrts Sound measurements were recorded from six Iocations around the proposed gravel quarry as shown on Figure 1. All locations had line -of -sight views of the existing gravel quarry operations. Point I was located just south of the railroad on the northeast corner of the proposed gravel quarry approximately 400 yards northwest of the current gravel operations. Point 2 was located on the northwest edge of the proposed gravel quarry approximately 600 yards west of the current gravel operations. Point 3 was located oil top of a five-foot high gravel pile located oil the west edge of the proposed gravel quarry approximately 1000 yards west of the current gravel operations. Point 4 Nvas located oil the south edge of the proposed gravel quarry against the Colorado River and approximately 600 yards southwest of the current gravel operations. Point 5 was located on a hill across the Colorado River and approxinnatcly 800 yards south of the current gravel operations. Point 6 was located oil the east edge of the proposed gravel quarry adjacent to the current gravel quarry and approximately 300 yards from the current gravel operations. All sound meters were attached to tree branches or fences, unless otherwise described. The sound levels were collected for tirne weighted average (TWA), maximum, and average sound levels and are listed in Table 1. If you have any qucstiorns, please contact nie at (970) 241 -4636. Thank you for selecting WALSII for your project. Sincerely, fr. - �~ -V-•r Blair Rollins Environmental Scienlist Reviewed 13y: d/ rd i3altzer, d1lVINI District Manager l�eyiern Slope Di%ision-, i hind Ak,:pue (rand .1ODOiors, C's i lorado N 1501 -27 90 . Phone i9701 24 t -4636 . FAX (.9711) 241- 4.+12 . kkakhent.com Corporate Office: ik�� f' ;.niI 1-- .i,rCirkle" senile IM Bouldkr. Colorado X113111 -2475 . Phone (3031443-3282 I-AN ( ?113)443 -0167 Table 1 Sound Survey Results TWA — Time - weighted Average Avg. — Numeric average of sound levels I Sample dB Sound Level Point Location Time Dominant Sounds Start Stop TWA Max Avg. 1 NE corner 0745 0824 44.1 86.3 62.9 Vehicle traffic, gravel crusher, slight wind 2 NW edge by RR 0753 0837 38.7 63.3 46.6 Vehicle traffic, gravel tracks crusher, slight wind 3 West edge 0829 0906 39.0 61.2 46.1 highway traffic, slight wind 4 South edge by 0955 1424 38.7 55.4 44.7 Colorado River, slight wind river 5 Against south 0919 0949 38.7 72.4 50.2 Small GreelE to the north hill across aver and cattle East property Heavy vehicle traffic, gravel 6 line adjacent to 1007 1037 39.0 85.1 59.0 crusher, dump trucks and existing u loaders TWA — Time - weighted Average Avg. — Numeric average of sound levels I