The URL can be used to link to this page

Browse Search

Home My WebLink About871326.tiff- .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. RESOLUTION RE: APPROVE CERTIFICATE OF DESIGNATION - XTRA CORPORATION WHEREAS, the Board of County Commissioners of Weld County, Colorado, pursuant to Colorado statute and the Weld County Home Rule Charter, is vested with the authority of administering the affairs of Weld County, Colorado, and WHEREAS, on the 21st day of October, 1987 , a public hearing was held in the Chambers of the Board of County Commissioners of Weld County, Colorado, for the purpose of considering whether to grant a Certificate of Designation to XTRA Corporation, c/o Charles Hayes, 998 East Highway 119 , Longmont, Colorado, 80501 , said site to be located on the following described property: SEi NW* of Section 8 , Township 2 North, Range 68 West of the 6th P.M, Weld County, Colorado WHEREAS , this request for a Certificate of Designation was submitted in conjunction with a request for a Special Review permit for a solid waste disosal site which was approved by the Board, and WHEREAS, Section 32-20-104 , CRS , as amended, requires the Board to take into account certain factors to approve a Certificate of Designation and, having taken into account said factors , finds as follows: 1 . The conditions for approval and stated standards will minimize the impacts on the surrounding property and the area to the greatest extent possible . The conditions for approval and stated standards will also provide adequate protection of the health, safety, and welfare of the inhabitants of the area and the County. 2 . The location of the proposed solid waste disposal site will be convenient and accessible to the potential users . 3 . The applicant has demonstrated in the application materials that there is a need for the proposed solid waste disposal site. 4 . The applicant has demonstrated through the application -materials that they have the ability to comply with the health standards and operating procedures of the Solid Waste Disposal Site and Facilities Act, Title 30-20 , Part J. , CRS 1973 . `,9di I, i, ' � 871326 Page 2 RE: CERTIFICATE OF DESIGNATION — XTRA CORPORATION 5 . She Colorado Department of Health and the Weld County Health Department have reviewed this request -and find, subject to conditions , that the proposal will comply with the Standards of the Solid Waste and Disposal Site, and Facilities Act, Title 30-20 , Part 1 , CRS 1973 . NOW, THEREFORE, BE IT RESOLVED by the Board of County Commissioners of Weld County, Colorado, that the Certificate of Designation for XTRA Corporation, c/o Charles Hayes , 998 East Highway 119 , -Longmont, Colorado 80501 , an the hereinabove described real property be, and hereby is , granted subject to the following conditions: A. The property shall be maintained in compliance with the submitted application materials on file with the Department of Planning Services , Development Standards approved for Special Review -permit #779 : 87 : 3 , all requirements of the Colorado Department of Health and the following stated standards : 1 . The landfill shall receive only solid waste of a nonliquid, nonhazardous , and nonradioactive nature . The waste shall be dry household and commercial refuse, construction and demolition debris . No liquid waste of any nature, including semisolid sludges , septic tank pumpage , or drum containerized waste shall be accepted. No hazardous waste, whether or not detoxified or treated, nor any small quantity generator waste shall be disposed of at the facility. No ash from any commercial coal burning activities shell be accepted at the facility. 2 . The hours of operation shall generally be between 7 : 00 a .m. and x :30 p.m. , Monday through Saturday. The facility shall be closed on the major legal holidays , Thanksgiving, Christmas , and New Year' s . 3 . The fallowing minimum personnel and equipment are expected to be utilized at the site : PERSONNEL: 1 supervisor 1 gate and record keeper 2 heavy equipment operators 1 labor/spotter (as needed) 871326 Page 3 RE: CERTIFICATE OF DESIGNATION - XTRA CORPORATION EQUIPMENT: 1 trash compactor 1 scraper 1 dozer 1 motor -pool (grader) 1 2 , 000 gallon water truck FACILITIES: 1 gatehouse 4 . The site operator shall keep the Poll-owing records on site and available for _review by the Weld County Health Department and the Colorado Department of Health: a. ) Reports of construction quality control. b. ) Litter policing reports . c . ) Volume and types of incoming refuse. d. ) Results of gas and water quality monitoring. e. ) Any special waste areepted. 5 . The following operation measures shall he employed to control blowing litter at the site: a. ) Application of -soil rover during _refuse placement and at the end of each day. b. ) Limiting the size of the working face during windy periods. c. ) Permanent and moveable site fencing. d. ) Litter pick up activities . e. ) Ceasing operations during periods when high winds are present. 6 . Operational inspection of the entire facility shall be made on a quarterly basis for the life of the landfill operation. She inspections shall 'be made by an independent contractor experienced with landfill operations . The inspections shall be made to ensure that the landfill operation is 87132-6 Page 4 RE: CERTIFICATE OF DESIGNATION - XTPA CORPORATION progressing in accordance with all aspects of the approved landfill plan. Inspection reports shall be prepared and submitted to both the Weld County Health Department and the Colorado Department of Health. 7 . All water samples shall be analyzed for the following parameters twice a year: Calcium Magnesium Lead Sodium Potassium Iron Chloride* Sulfate Alkalinity Ammonia Total Dissolved Solids Nitrate Specific Conductance (field) * pH (field) * Chemical Oxygen Demand Phenols Total Organic Halogen* Total Organic Carbon *Indicates parameters to be analyzed quarterly. The operator shall make justifiable changes as needed if the Weld County Health Department or the Colorado Department of Health would like to amend the groundwater sampling parameter list at some later date. 8 . Excavation inspections shall be made in each new excavated area. Inspections shall be made by an independent consultant who will then produce a written report that includes observations made in the newly excavated area and -a map showing the inspected areas . Copies of the excavation inspection reports shall be supplied to both the Weld County Health Department and the Colorado Department of Health. 9 . Filling in the three phases shall be accomplished by a combination of ramp and area-fill methods . The ramp method shall be used to construct the first two lifts in each phase . The area-fill method shall be used to construct subsequent lifts . 10 . Surface water shall be controlled to ensure that run-on is not allowed to enter the active disposal area, and that any surface water which falls on the working face is not allowed to leave the site. Intermittent historic flows from the site shall not be changed due to construction of the landfill. No 871326 Page 5 RE: CERTIFICATE OF DESIGNATION - XTRA CORPORATION significant changes in the amount or quality of water flowing from the site are to occur. Three temporary drainages shall be constructed to divert natural flows away from the active filling areas. As landfilling progresses, and the lifts and phases are completed, the temporary diversions will be abandoned and new permanent diversions shall be constructed at higher elevations on natural slopes , continually routing runoff from undisturbed natural areas around the landfill. 11 . A clay-liner shall be installed following excavation to final depth. Once a section of the liner is constructed and approved, refuse placement can begin. Refuse shall be placed and compacted in loose layers approximately two feet thick. Incoming waste shall be unloaded at the top of the working face , where it shall be pushed downslope and compacted. A minimum of three passes of the trash compactor at an approximate slope angle of 6 : 1 should result in refuse densities of at least 1 , 000 pounds per cubic yard. Refuse material shall be placed in this fashion until a lift thickness of approximately 10 feet is attained. The lift shall be advanced upslope to near the end of the active phase . A minimum soil cover of six inches shall be placed over all exposed refuse each working day. When a lift is completed, the next lift shall be started at the low phase boundary and advanced over the top of the previous lift. Lifts shall be placed in this fashion until the phase is completed. 12 . The completed portion of each phase segment shall he covered with topsoil and seeded as soon as practically possible. The cover will be a minimum of 3 .5 feet consisting of b to 12 inches of uncompacted soil overlain by a minimum of 6 inches of topsoil. All but the topsoil shall be placed as soon as possible over areas in which refuse placement has been completed. 13 . The final top of the landfill shall have a two percent slope and shall have a northeast trending crown approximately 225 feet from the western boundary. The northern, western, and west half of the southern boundaries shall melt into the natural topography. The eastern half of the southern 871326 Paae 6 RE: CERTIFICATE OF DESIGNATION - XTRA CORPORATION boundary and the eastern boundary shall have a 4 : 1 slope. 14 . The construction of the clay liner shall be placed in six inch lifts and compacted with a sheep ' s foot compactor until it reaches a compacted dry density equal to or greater than 95 percent of the standard Proctor density (ASTM-D-698) . The moisture content of the material shall be maintained within 2 percent of optimum moisture content using the same testing criteria. Not less than two feet of material shall be compacted to these specifications . 15 . To ensure that the clay liner and final cover are constructed in accordance with the specifications outlined in the Design and Operations Plan, an independent soils and materials testing firm shall be retained to observe and test liner and cover materials . The program shall consist of material classification tests conducted for every 3 ,000 cubic yards of clay material placed in the liner and for every 3 ,000 cubic yards placed in the cover . This type of testing shall ensure that materials placed are suitable for their intended use . In addition, compaction and moisture content testing shall be conducted on the compacted clay liners and covers . Moisture density testing shall be conducted at no less than 100 feet spacing interval for the liner and 300 foot spacing for the cover. Copies of this testing shall he forwarded to the Weld County Health Department and the Colorado Department of Health. 16 . Unauthorized access to the landfill facility shall be prevented by a permanent site fencing around the landfill entrance area and the final active filling area. A six-foot-high chain-link fence with a 2 foot canopy shall be used around the entrance area in the northeast corner to secure the gatehouse and equipment areas . The filling area perimeter shall be fenced with 6 foot nonclimbable fence topped with three strands of barbed wire. 17 . To ensure that fill excavation volumes , and material balances are being achieved as landfilling progresses, the landfill area topography shall be mapped on an annual basis . Annual mapping shall be used to determine actual annual air space and soil 871326 Page 7 RE: CERTIFICATE OF DESIGNATION - XTRA CORPORATION borrow used. An annual material balance report shall be prepared and shall be available for inspection by the Weld County Health Department and the Colorado Department of Health. 18 . A total of five groundwater monitoring wells shall be installed upon issuance of the Certificate of Designation. Four wells shall be installed at two locations along the southeastern property boundary. Two of the wells shall be installed at one location in the invert of the existing gully where it exits the site along the southeastern boundary. The other two wells shall be installed near the intersections of the southeastern and eastern fill boundaries . At each location, one well shall be installed in the saturated zone while the other is installed in the overlying unsaturated materials. XTRA Corporation anticipates a 6 month construction period prior to the onset of filling. The wells shall be sampled four separate times in that period to provide a good data base to calculate baseline means and standard deviations for each parameter. Upon commencement of the landfill operations, results from routine groundwater monitoring events can then be statistically compared to this base line data. Significant changes in the parameter values would then trigger resampling and, if necessary, a more extensive contaminant characterization effort. 19 . Methane gas monitoring shall be performed simultaneously with groundwater sampling episodes . Methane monitoring wells shall be constructed, or existing wells utilized, around the perimeter of the final landfill boundary to depths equal to the depth of excavation adjacent to the well. New wells shall be placed 500 feet on center on all final landfill boundaries . Wells shall be constructed using 2 inch diameter glue-joint PVC casing placed in 4 inch diameter borings. The PVC shall be slotted and gravel packed to within 10 feet of the ground surface . The annular space above the gravel pack shall be backfilled with dry bentonite . 20 . A manhole and gravel leachate detection structure shall be constructed between the edge of the excavation and the downstream toe of the first list in the lowest part of the excavation. The leachate 871326 Page 8 RE: CERTIFICATE OF DESIGNATION - XTRA CORPORATION detection system shall also include four monitor wells that are inside the fill area and are spaced 50 feet on center along the southeast facing boundary of Phase Three. The wells shall be drilled into the refuse between the excavation cut and the first lift berms . Well depths shall be determined by the depth of refuse , and in no case shall penetrate the clay liner. 21 . If at any time negative groundwater results, methane results, or monitoring results are obtained, the operator shall notify the Weld County Health Department and the Colorado Department of Health of the results within five working days. The operator shall request a meeting to discuss the monitoring results . If necessary, confirmation sampling and testing will be conducted. If an environmental problem is confirmed, the operator shall have an additional 30 days to evaluate the data and present a specific plan of action to both the Weld County Health Department and the Colorado Department of Health. 22 . Post-closure inspections shall include documentation of surface cracking, erosion, slope angles, drainage, and condition of vegetation. One of the inspections each year shall be made in the late spring, when damage would most likely occur due to thaw and runoff . Any damage or other deficiencies shall be promptly repaired. 23 . If wet spots or seeps are encountered during excavation procedures, prior to construction of the liner, the Colorado Department of Health shall be notified before emplacement of the liner. 24 . A base grade plan shall be developed and submitted to the Weld County Health Department and the the State Department of Health as the clay liner is being placed at the landfill. 25 . The Weld County Health Department and the State Department of Health shall be notified if any portion of the clay liner is to be exposed for more than two months and what type of moist miscellaneous fill shall be placed to protect the liner. 871326 Page 9 RE : CERTIFICATE OF DESIGNATION - XTRA CORPORATION 26 . A one foot intermediate cover shall be placed over any lift which will be exposed for more than one month. 27 . The applicant shall obtain a fugitive dust control permit from the State Department of Health , Air Pollution Control Division. 28 . The applicant shall develop and post performance guarantees to handle such issues as : a. Closure of the facility. b. Reclamation and revegetation. c. Contamination issues . d. Off-site litter control. e . Monitoring and maintenance . The County Engineer and the Planning Department shall approve the items listed and cost estimates to guarantee these concerns. The County Attorney' s office shall approve the form of the performance guarantees. The above and foregoing Resolution was, on motion duly made and seconded, adopted by the following vote on the 21st day of October, A.D. , 1987 . 7 J� /24„vitlecAVS0 BOARD OF COUNTY COMMISSIONERS ATTEST: ' WELD COU TY OLORADO Weld County Clerk and Recorder and Clerk to the Board Gor o . €L'acyY' C irman EXCUSED �72iYGira/ �iy C. Kirby, Pro-Tem De uty County C erk Aet APPROVED AS TO FORM: Gene R. Bran ner % \ Ja . e J son A , s srn ° County Attorney s w✓' �^ Frank Ytmagikh i 871326 WELD COUNTY, COLORADO CERTIFICATE OF DESIGNATION SOLID WASTE DISPOSAL SITE In accordance with the provisions of Sections 30-20-101 through 30-20-115 , CRS , as amended, the Board of County Commissioners of Veld County, Colorado, hereby grants a Certificate of Designation for a solid waste disposal site: Location of Site: SEi NW* of Section 8 , Township 2 North, Range 68 West of the 6th P.M. , Weld County, Colorado Name and Address of Responsible Operator: XTRA Corporation c/o Charles Hayes 998 East Highway 119 Longmont, Colorado 80501 This Certificate of Designation may be temporarily suspended or revoked, after reasonable notice and public hearing, for cause as outlined in Section 30-20-112 , CRS , as amended. Issued this 21st day of October, 1987 , at Weld ounty, Colorado. Signed: . a Chairman Board of Co ty Commissioners 871326 TREASURER'S OFFICE,WELD COO ,,NT`' N12 ©28 �J T reeley,,Collorado. ''xQ� , 119 )aoo RECEIVED OF $ Qu/d4tioais, 60, . . . . FOR __CREDIT J ounty General Fund 101 0000 300 O0 Health Department 119 0000 Human Resources 121 0000 Social Services 112 0000 Housing Authority Road & Bridge Fund 111 0000 Airport 177 0000 County Clerk Cash Escrow 810 0803 Fee Fund 900 0912 School District Gen Fund School District C R F School District Bond Fund FRANCIS M. LOUSTALET ` TOTAL AMOUNT County Treasurer Clerk 3©M C) et/y - v oy STATE OF COLORADO COLORADO DEPARTMENT OF HEALTH oF_cozo 4210 East 11th Avenue • Fy�9 Denver, Colorado 80220 Phone (303) 320-8333 ** MIELI COUNTY Cluwii�BNERS 176` June 25, 1987 11.1 r Roy Romer T Governor JUN 2 91987 ; Thomas M. Vernon, M.D. � .. Executive Director Weld County Board of Commissioners - Post Office Box 758 Greeley, Colorado 80632 Gentlemen: The Hazardous Materials and Waste Management Division of the Colorado Department of Health has completed it review of the Design and Operations Plan for the Proposed XTRA Corporation Landfill submitted February -24, 1987 by Industrial Compliance, Inc. The proposed site is located approximately 4 miles east of Longmont and encompasses 40 acres. The application was reviewed to determine if the proposed facility could comply with the minimum standards of the Solid Wastes Disposal Sites and Facilities Act, Sections 30-20-100 to 116, C.R.S. 1973 ("Solid Wastes Act") and with the regulations promulgated thereunder, 6 CCR 1007-2 ("the -Regulations"). Contained within the Design and Operations Plan and March 27, 1987 and June 2, 1987 letters submitted to the Division by Industrial Compliance, Inc. are the following major commitments agreed to by the applicant, XTRA Corporation: 1. Nineteen of the 40 available acres at the landfill site will be used for refuse filling. The remainder of the site will largely be unaffected by operational activities. Refuse filling will occur in three phases. Generally, filling will be accomplished by excavating and lining the active area, placing compacted refuse in controlled lifts, and covering them on a daily basis. 2. The landfill has a total airspace capacity of 933,000 cubic yards and an estimated life of 4 years. The landfill will accept about 1,100 gate yards of trash per day. 13. Only solid waste of a non-liquid nature will lie accepted at this facility. This includes all types of non-hazardous, non-radioactive garbage and other refuse generated from industrial, commercial and residential activities. No liquid -waste of any nature, including semi-solid sludges and septic tank pumpage, will be accepted. No hazardous waste, whether or -not detoxified or treated, will be knowingly accepted from _small quantity generators or any other sources. 4. A minimum of about 285,000 cubic yards of material will be needed to fulfill the soil requirements of the existing and proposed landfills. The City of Longmont has contracted with XTRA Corporation to remove 50,000 cubic yards of clay for the closure of the existing Longmont Landfill. Thi-s materi-al will come from an average 10-foot deep excavation over the entire site. To ensure that excavations in the landfilling area are constructed in accordance with the landfill design, and -that the conditions are consistent with those -described in the Design and Operations Plan, excavation inspections will be made in each new excavated area. Inspections will be made by an independent consultant who will then produce a writt-en report that includes observations made in the newly excavated area and a map showing the inspected areas. Copies -of the excavation inspection reports will be -supplied to both Weld _County and the Colorado Department of Health. 5. Filling in the three phases will be accomplished by a combination of ramp and area-fill methods. The ramp method will be used to construct the first two lifts in each phase. The area-fill -methodwill be used to construct subsequent lifts. 6. Surface water will he controlled to -ensure that runon is not allowed to enter the active _disposal area, and that -any surface water which falls on the working face is not allowed to leave the site. Intermittent historic flows from the site should not be -changed due to construction of the landfill. No significant changes in the amount or _quality of water flowing from the site -are expected. Three temporary drainages will be constructed to divert natural flows away from the active filling areas. As landfilling progr-esses, and the lifts and phases are completed, the temporary diversions will be abandoned and new permanent diversions will be constructed at higher elevations on natural slopes, continually routing runoff from undisturbed natural areas around the landfill. 7. A clay liner will be installed following excavation to final depth. Once a -section of the liner is constructed and approved, refuse placement can begin. Refuse win be placed and compacted in loose layers approximately 2 feet thick. Incoming _waste will be unloaded at the top of the working face, where it will be-pushed -downslope and compacted. A minimum of three passes of the trash compactor at an approximate -slope angle of 6: 1 should result in -refuse densities of at least 1000 pounds per cubic yard. Refuse material will be placed in this fashion until a lift thickness of approximately 10 feet is attained. The lift will be advanced upslope to near the end of the active phase. A minimum soil cover of -6 inches will be placed over all -exposed refuse each working day. When a lift is completed, the next lift will be started -at the low phase boundary and advanced over the top of the previous lift. Lifts will be placed in this fashion until the phase is completed. 871.32E 8. The completed portion of each phase segment will be covered with topsoil and seeded as soon as practically possible. The cover will be a minimum of 3.5 feet thick, with the bottom 2.0 feet consisting of compacted clay and the top 1.5 feet consisting of 6 to 12 inches of uncompacted soil overlain by a minimum of 6 inches of topsoil. All but the topsoil will be placed as soon as possible over areas in which refuse placement has been completed. 9. The final top of the landfill will have a two percent slope and will have a northeast trending crown approximately 225 feet from the western boundary. The northern, western and west half of the southern boundaries will meld into the natural topography. The eastern half of the southern boundary and the eastern boundary will have a 4: 1 slope. 10. The construction of the clay liner is a very important aspect of the landfill operation. The clay will be placed in six inch lifts and compacted with a sheeps foot compactor until it reaches a compacted dry density equal to or greater than 95 percent of the standard Proctor density (ASTM-1J-698) . The moisture content of the material shall be maintained within 2 percent of optimum moisture content using the same testing criteria. Not less than two feet of material will be compacted to these specifications. 11. To ensure that the clay liner and final cover are constructed in accordance with the specifications outlined in the Design and Operations Plan, an independent soils and materials testing firm will be retained to observe and test liner and cover materials. The program will consist of material classification tests conducted for every 3,000 cubic yards of clay material placed in the liner and for every 3,00 cubic yards placed in the cover. This type of testing will ensure that materials placed are suitable for their intended use. In addition, compaction and moisture content testing will be conducted on the compacted clay liners and covers. Moisture density testing will be conducted at no less than 100 foot spacing interval for the liner and 300 foot spacing for the cover. 12. The proposed facility will generally -operate between the hours of 7:00 a.m. and 5:30 p.m. six days a week. Winter hours may be changed depending on available sunlight. The facility will be closed on the major legal holidays. 13. Unauthorized access to the landfill facility will be prevented by permanent site fencing around the landfill entrance area and the final active filling area. A six foot high chain link fence with a 2 foot canopy will be used around the entrance area in the northeast corner to secure the gatehouse and equipment areas. The filling area perimeter will be fenced with 6 foot non-climbable fence topped with three strands of barbed wire. 14. The following operational measures will be employed to control blowing litter at the site: i) Application of soil cover during refuse placement and at the end of each day. 871328 ii) Limiting the size of the working face during windy periods. iii) Permanent and moveable site fencing. iv) Litter pick up activities. v) Ceasing operations during periods when high winds are present. 15. The following personnel and equipment are expected to be utilized at the site: Personnel: 1 supervisor 1 gate and record keeper 2 heavy equipment operators 1 labor/spotter (as needed) Equipment: 1 trash compactor 1 scraper 1 dozer 1 motor pool (grader) 1 2,000 gallon water truck Facilities: 1 gatehouse 16. Operational inspections of the entire facility will be made on a quarterly basis for the life of the landfill operation. The inspections will be made by an independent contractor experienced with landfill operations. The inspections will be made to ensure that the landfill operation is progressing in accordance with all aspects of the approved landfill plan. Inspection reports will be prepared and submitted to both Weld County and the Colorado Department of Health. 17. To ensure that fill, excavation volumes, and material balances are being achieved as landfilling progresses, the landfill area topography will be mapped on an annual basis. Annual mapping will be used to determine actual annual air space and soil borrow used. An annual material balance report will be prepared and will be available for inspection by Weld County and the Colorado Department of Health. 18. The site operator will keep the following records on site and available for county and state review: i) Reports of construction quality control. ii) Litter policing reports. iii) Volume and types of incoming refuse. iv) results of gas and water quality monitoring. v) Any special waste accepted. 19a. A total of five ground water monitoring wells will be installed upon issuance of the Certificate of Designation. Four wells will be installed at two locations along the southeastern property boundary. Two of the wells will be installed at one location 871328 in the invert of the existing gully where it exits the site along the southeastern boundary. The other two wells will be installed near the intersections of the southeastern and eastern fill boundaries. At each location, one well will be installed in the saturated zone while the other is installed in the overlying unsaturated materials. XTRA Corporation anticipates a 6 month construction period prior to the onset of filling. The wells would be sampled four separate times in that period to provide a good data base to calculate baseline means and standard deviations for each parameter. Upon commencement of the landfill operations, results from routine ground water monitoring events can then be statistically compared to this base line data. Significant changes in the parameter values would then trigger resampling and, if necessary, a more extensive contaminant characterization effort. 19b. All water samples will be analyzed for the following parameters twice a year: Calcium Magnesium Lead Sodium Potassium Iron Chloride* Sulfate Alkalinity Ammonia* Total Dissolved Nitrate Solids Specific Conductance (field)* Chemical Oxygen Demand pH (field)* Total Organic Halogen* Total Organic Carbon* Phenols *Indicates parameters to be analyzed quarterly 19c. The operator will make justifiable changes as needed if the Weld County Health Department or the Colorado Department of Health would like to amend the ground water sampling parameter list at some later date. 20 Methane gas monitoring will be performed simultaneously with ground water sampling episodes. Methane monitoring wells will be constructed, or existing wells utilized, around the perimeter of the final landfill boundary to depths equal to the depth of excavation adjacent of the well. New wells will be placed 500 feet on center on all final landfill boundaries. Wells will be constructed using 2 inch diameter glue-joint PVC casing placed in 4 inch diameter borings. The PVC will be slotted and gravel packed to within 10 feet of the ground surface. The annular space above the gravel pack will be backfilled with dry bentonite. 21. A manhole and gravel leachate detection structure will be constructed between the edge of the excavation and the downstream toe of the first lift in the lowest part of the excavation. The leachate detection system will also include four monitor wells that are inside the fill area and are spaced 50 feet on center along the southeast facing boundary of Phase Three. The wells will be drilled into the refuse between the excavation cut and the first lift berms. Well depths will be determined by the depth of refuse, and in no case will penetrate the clay liner. 871323 22. If at any time negative ground water, methane or monitoring results are obtained, the State and County will be notified of the results within five working days. The operator will request a meeting with Weld County and the Colorado Department of Health to discuss the monitoring -results. If necessary, confirmation sampling and testing will be conducted. If an -environmental problem is confirmed, the operator will have an additional 30 days to evaluate the data and present a specific plan of action to both the County and the State. 23. Post-closure inspections will include documentation of surface cracking, erosion, slope angles, drainage, and condition of vegetation. One of the inspections each year will be made in late spring, when damage would most likely occur due to thaw and runoff. Any damage or other deficiencies will be promptly repaired. It is this Department's assessment that if the proposed facility is constructed and operated as summarized above and the construction and operation were to include the Division's recommendations listed herein, the facility can comply with the minimum standards of the Solid Wastes Act and with the Department regulations adopted pursuant thereto. The Department's approval is contingent upon the inclusion of the following recommendations as part of the Certificate of Designation, if issued. i) No ash from any commercial coal burning activities be accepted at the site. ii) During excavation procedures prior to construction of the liner, if -vet spots or seeps are encountered, this Division be notified before emplacement of the liner. iii) A base grade plan be developed and submitted to Weld County and to the Division as the clay liner is being placed at the landfill. iv) This Division be notified if any portion of the clay liner is left exposed for more than two months and what type of moist miscellaneous fill will be placed to protect the liner. v) A one foot intermediate cover be placed over any lift which will be exposed for more than one month. vi) Copies of the annual landfill topography mapping and material balance report be submitted to Weld County and the Department. vii) The applicant obtain a fugitive dust control permit from the Department's Air Pollution Control Division. 871326 Although the Department of Health does not specifically require closure and post-closure financial assurances and off-site access road litter control measures, the Department recommends that Weld County explore developing -commitments from the applicant. If you have any questions, please contact Steve Orzynski at 331-4846. Sincerely, (1:4111- 143/11}144 . Stephen J. Orzynski, P.E. E'er Ken Mesch, Chief Public Health Engineer Land Pollution Control Section Hazardous Materials and Hazardous Materials and Waste Management Division Waste Management Division SJO/KM:nr cc: Mike Stewart, Industrial Compliance, Inc. Wes Potter, Weld County Health Department 87122s t MARY ANN FEUERSTEIN ,'�t _ OFFICE OF WELD COUNTY CLERK AND RECORDER 411.1 DEPARTMENT OF CLERK TO BOARD impe PHONE 13031 356-4000 EXT472 P,O. BOX 459 GREELEY, COLORADO 80631 COLORADO February 23 , 1987 Dennis C. Hotovec State Department of Health Waste Management Division 4210 East 11th Avenue Denver, CO 80220 Dear Mr. Hotovec: This is to advise you that XTRA Corporation has paid the required fee and we are requesting that you review their application for a Certificate of Designation for a new landfill pursuant to the Solid Waste Disposal Sites and Facilities Act. Your prompt attention is required in order that the Weld County Board of Commissioners may proceed with its review. Sincerely, � / ti in�C�Ssv✓ G• L Gordon E. Lacy Chairman • XC: Mike Stewart 871326 luf.C' - .r O 1C C/) cJ 1 fD N GJ t7 fD i C O rt. f7 z DCD fD fD N• ' txj war °' I Cr . i n ft p b • N i w n l l� m O t o rt m °, o 0 IV FS' ft n `n e• t 0 d 0 G r rt fD H+. p' w fv Ci O02 r x+^� ;r, ....a�:. .:...«.r. .,�w r;• $.gild 4. :i p,i. r 4. i a+6a7%r9yr* :1.• r r i 4 k r ,i ` tt ;girt x I" , Y' ,r tc,,L Z f ; ;14p 1 Dennis C. Hotovec , t '';> k State Dept. of Health i Waste Management Division ' m� f " �''f 4210 Ea"t 11 #`Avenue i . ,, i x Denver, CO 80220 .- •,;#, " , .0,-VOW 5. lAdainv at ''''''"41!tYw _ try{' .�%�.._. ,ure 4 ° ',fir� � '.y i t 1 ,C t i sNe 1q y�:��W r +e� • $.`,°°"°fc*v' Iw ii ri: ; i a`.'�,1119,.#4II: ;6Agri `it a G I!, r14+ .•.iv 871326 EASURER'S OFFICE,WELD COUNT" U G b Greeley,Colorado. .% , 1_9 cS pQ X 3p° RECEIVED OF $ Odj FOR CREDIT ,'z/�_D ©0 .—"County General Fund 101 0000 Health Department 119 0000 Human Resources 121 0000 Social Services 112 0000 Housing Authority Road &R3ridge Fund 111 0000 Airport 177 0000 County Clerk Cash Escrow 810 0803 Fee Fund 900 0912 SchooLDistrict Gen Fund School District C R F School District Bond Fund Qry7 S PvUq 2-t, FRANCIS M. LOUSTALET \)_� I TOTAL AMOUNT 3cc © C County Treasurer Clerk Yummary -of the Weld County Planning Commission Meeting August 18, 1987 Page 6 MOTION: Paulette Weaver moved Case Number USR-779:87:2 for XTRA Corporation be forwarded to the Board of County Commissioners with the Planning Commission's recommendation for approval based upon the recommendations as outlined by the Department of Planning Services' staff, the conditions and Development Standards as outlined by the staff and amended by the Planning Commission, and the testimony heard by the members of the Planning Commission. She would also like to say she is impressed with what the City of Longmont is doing about landfills. Motion seconded by Louis Rademacher. 'The Chairman called for discussion from the members of the Planning Commission. Discussion followed. The Chairman asked the Secretary to poll the members of the Planning Commission for their decision. Ivan Gosnell - yes; Bud Halldorson - yes; Ernie Ross - yes; Louis Rademacher - yes; Paulette Weaver - yes; Ann Garrison - yes. Motion carried unanimously. ' . APPLICANT: XTRA Corporation (Charles Hayes) REQUEST: Certificate of Designation for a Solid Waste -Disposal Site. LEGAL DESCRIPTION: Part of the SE} NW} of Section 8, T2N, R68W of the 6th Y.M. , Weld County, Colorado LOCATION: South of State Highway 119, north of Weld County Road 20 1/2, and -east of Weld County Road 2. APPEARANCE: Mike Stewart, Industrial Compliance, Inc., represented the applicant. He stated they have no problem with the Certificate of Designation other than making the hours of operation correspond with Development Standards of the Use -by Special Review permit. AMENDMENT: Louis Rademacher moved Condition #2 be amended to read as follows: 2. the -hours of operation shall.-generally be between 7:00 a.m. and 5:30 p.m. , Monday through Saturday. 'The facility shall be closed on the major legal -holidays of Thanksgiving, Christmas, and New Year's. Motion -seconded $y Bud Halldorson. The Chairman called for -discussion from the members of the Planning Commission. There was no further discussion. 871 326 F XN18i1 Summary of the Weld County Planning Commission Meeting August 18, 1987 Page 7 The Chairman asked the Secretary to poll the members of the Planning Commission _for their -decision. Ivan Gosnell - yes; Bud Halldorson - yes; Ernie Ross - yes; Louis Rademacher - yes; Paulette Weaver - yes; Ann Garrison - yes. Motion carried unanimously. MOTION: Louis Rademacher -moved the Certificate of Designation for XTRA Corporation be forwarded to the Board _of County Commissioners with the Planning Commission's recommendation for approval based upon the recommendation and conditions as outlined by the Department of Planning Services and amended by the Planning Commission. Motion seconded _Paulette Weaver. Th-e Chairman called for discussion Iron the members of the Planning Commission. There was no further discussion. The _Chairman asked the Secretary to poll the members of the Planning Commission for their decision. Ivan Gosnell - yes; Bud Halldorson - yes; Ernie Ross - yes; Louis _Rademacher - yes; Paulette Weaver - yes; Ann Garrison - yes. Motion carried unanimously. Respectfully submitted, Bobbie Good Secretary 871328 BEFORE THE WELD COUNTY, COLORADO, PLANNING COMMISSION RESOLUTION OF RECOMMENDATION TO THE BOARD OF COUNTY COMMISSIONERS Moved by Louis Rademacher that the following resolution be introduced for passage by the Weld County Planning Commission. Be it Resolved by the Weld County Planning Commission that the application for: NAME: XTRA Corporation, c/o Charles Hayes ADDRESS: 998 East Highway 119, Longmont, CO 80501 REQUEST: Certificate of Designation LEGAL DESCRIPTION: SE} NW} of Section 8, T2N, R68W of the 6th P.M. , Weld County, Colorado LOCATION: South of State Highway 119, north of Weld County Road 20-1/2, and west of Weld County Road 1. SIZE OF PARCEL: 40 Acres, more or less be recommended favorably to the Board of County Commissioners for the following reasons: 1. The conditions for approval and stated standards will minimize the impacts on the surrounding property and the area to the greatest extent possible. The conditions for approval and stated standards will also provide adequate protection of the health, safety, and welfare of the inhabitants of the area and the County. 2. The location of the proposed solid waste disposal site will be convenient and accessible to the potential users. 3. The applicant has demonstrated in the application materials that there is a need for the proposed solid waste disposal site. 4. The applicant has demonstrated through the application materials that they have the ability to comply with the health standards and operating procedures of the Solid Waste Disposal Site and Facilities Act, Title 30-20, Part 1, CRS 1973. 5. The Colorado Department of Health and the Weld County Health Department have reviewed this request and find, subject to conditions, that the proposal will comply with the Standards of the Solid Waste and Disposal Site, and Facilities -Act, Title 30-20, Part 1, CRS 1973. This recommendation is based, in part, upon a review of the application submitted by the applicant, other relevant information regarding the request and the responses of the referral entities which have reviewed this request. 4 87i?2S ,Cx HiDi� >..:� XTRA Corporation August 18, 1987 Page 2 The Planning Commission's recommendation for approval is conditional upon the following: The property shall be maintained in compliance with the submitted application materials on file with the Department of Planning Services, Development Standards approved for Special Review Permit #779:87:3, all requirements of the Colorado Department of Health and the following stated standards: 1. The landfill shall receive only solid waste of a nonliquid, nonhazardous, and nonradioactive nature. The waste shall be dry household and commercial refuse, construction and demolition debris. No liquid waste of any nature, including semisolid sludges, septic tank pumpage, or drum containerized waste shall be accepted. No hazardous waste, whether or not detoxified or treated, nor any small quantity generator waste shall be disposed of at the facility. No ash from any commercial coal burning activities shall be accepted at the facility. 2. The hours of operation shall generally be between 7:00 a.m. and 5:30 p.m., Monday through Saturday. The facility shall be closed on the major legal holidays, Thanksgiving, Christmas, and New Year's. 3. The following minimum personnel and equipment are expected to be utilized at the site: PERSONNEL 1 supervisor 1 gate and record keeper 2 heavy equipment operators 1 labor/spotter (as needed) EQUIPMENT 1 trash compactor 1 scraper 1 dozer 1 motor pool (grader) 1 2,000 gallon water truck FACILITIES: 1 gatehouse 871325 XTRA Corporation August 18, 1987 Page 3 4. The site operator shall keep the following records on site and available for review by the Weld County Health Department and the Colorado Department of Health: i) Reports of construction quality control . ii) Litter policing reports. iii) Volume and types of incoming refuse. iv) Results of gas and water quality monitoring. v) Any special waste accepted. 5. The following Operation measures shall be employed to control blowing litter at the site: i) Application of soil cover during refuse placement and at the end of each day. ii) Limiting the size of the working face during windy periods. iii) Permanent and moveable site fencing. iv) Litter pick up activities. v) Ceasing operations during periods when high winds are present. 6. Operational inspection of the entire facility shall be made on a quarterly basis for the life of the landfill operation. The inspections shall be made by an independent contractor experienced with landfill operations. The inspections shall be made to ensure that the landfill operation is progressing in accordance with all aspects of the approved landfill plan. Inspection reports shall be prepared and submitted to both the Weld County Health Department and the Colorado Department of Health. 871.32S XTRA Corporation August 18, 1987 Page 4 7. All water samples shall be analyzed for the following parameters twice a year: Calcium Magnesium Lead Sodium Potassium Iron Chloride* Sulfate Alkalinity Ammonia Total Dissolved Nitrate Specific Conductance Solids pH (field)* (field)* Chemical Oxygen Phenols Total Organic Halogen* Demand Total Organic Carbon *Indicates parameters to be analyzed quarterly. The operator shall make justifiable changes as needed if the Weld County Health Department or the Colorado Department of Health would like to amend the groundwater sampling parameter list at some later date. 8. Excavation inspections shall be made in each new excavated area. Inspections shall be made by an independent consultant -who will then produce a written report that includes observations made in the newly excavated area and a map showing the inspected areas. Copies of the excavation inspection reports shall be supplied to both Weld County Health Department and the Colorado Department of Health. 9. Filling in the three phases shall be accomplished by a combination of ramp and area-fill methods. The ramp method shall be used to construct the first two lifts in each phase. The area-fill method shall be used to construct subsequent lifts. 10. Surface water shall be controlled to ensure that run-on is not allowed to enter the active disposal area, and that any surface water which falls on the working face is not allowed to leave the site. Intermittent historic flows from the site shall not be changed due to construction of the landfill. No significant changes in the amount or quality of water flowing from the site are to occur. Three temporary drainages shall be constructed to divert natural flows away from the active filling areas. As landfilling progresses, and the lifts and phases are completed, the temporary diversions will 0,714::2.13 XTRA Corporation August 18, 1987 Page 5 be abandoned and new permanent diversions shall be constructed at higher elevations on natural slopes, continually routing runoff from undisturbed natural areas around the landfill. 11. A clay—liner shall be installed following excavation to final depth. Once a section of the liner is constructed and approved, refuse placement can begin. Refuse shall be placed and compacted in loose layers approximately 2 feet thick. Incoming waste shall be unloaded at the top of the working face, where it shall be pushed downslope and compacted. A minimum of three _passes of the trash compactor at an approximate _slope angle of 6: 1 should result in refuse densities of at least 1,000 pounds per cubic yard. Refuse material shall be placed in this fashion until a lift thickness of approximately 10 feet is attained. The lift shall be advanced upslope to near the end of the active phase. A minimum soil cover of 6 inches shall be placed over all exposed refuse each working day. When a lift is completed, the next lift shall be started at the low phase boundary and advanced over the top of the previous lift. Lifts shall be placed in this fashion until the phase is completed. 12. The completed portion of each phase segment shall be covered -with topsoil and seeded as soon as practically possible. The cover will be a minimum of 3.5 feet consisting of 6 to 12 inches of uncompacted soil overlain by a minimum of 6 inches of topsoil. All but the topsoil shall be placed as soon as possible over areas in which refuse placement has been completed. 13. The final top of the landfill shall have a two percent slope and shall have a northeast trending crown approximately 225 feet from the western boundary. The northern, western, and west half of the southern boundaries shall melt into the natural topography. The eastern half of the southern boundary and the eastern boundary shall have a 4: 1 slope. 14. The construction of the clay liner shall be placed in six inch lifts and compacted with a sheep's foot compactor until it reaches a compacted dry density equal to or greater than 95 percent of the standard Proctor density (ASTM-D-698) . The moisture content of the material shall be maintained within 2 percent of optimum moisture content using the same testing criteria. Not less than two feet of material shall be compacted to these specifications. 871V?2 XTRA Corporation August 18, 1987 Page 6 15. To ensure that the clay liner and final cover are constructed in accordance with the specifications outlined in the Design and Operations Plan, an independent soils and materials testing firm shall be retained to observe and test liner and cover materials. The program shall consist of material classification tests conducted for every 3,000 cubic yards of clay material placed in the liner and for every 3,000 cubic yards placed in the cover. This type of testing shall ensure that materials placed are suitable for their intended use. In addition, compaction and moisture content testing shall be conducted on the compacted clay liners and covers. Moisture density testing shall be conducted at no less than 100 feet spacing interval for the liner and 300 foot spacing for the cover. Copies of this testing shall be forwarded to the Weld County Health Department and the Colorado Department of Health. 16. Unauthorized access to the landfill facility shall be prevented by a permanent site fencing around the landfill -entrance area and the final active filling area. A six foot high chain-link fence with a 2 foot canopy shall be used around the entrance area in the northeast corner to secure the gatehouse and equipment areas. The filling area perimeter shall be fenced with 6 foot nonclimbable fence topped with three strands of barbed wire. 17. To ensure that fill excavation volumes, and material balances are being achieved as landfilling progresses, the landfill area topography shall be mapped on an annual basis. Annual mapping shall be used to determine actual annual air space and soil borrow used. An annual material balance report shall be prepared and shall be available for inspection by the Weld County Health Department and the Colorado Department of Health. 18. A total of five groundwater monitoring wells shall be installed upon issuance of the Certificate of Designation. Four wells shall be installed at two locations along the southeastern property boundary. Two of the wells shall be installed at one location in the invert of the existing gully where it exits the site along the southeastern boundary. The other two wells shall be installed near the intersections of the southeastern and eastern fill boundaries. At each location, one well shall be installed in the saturated zone while the other is installed in the overlying 871a26 XTRA Corporation -August 18, 1987 Page 7 unsaturated materials. RTRA Corporation anticipates a 6 month construction period prior to the onset of filling. The wells shall be sampled four separate times in that period to provide a good data base to calculate baseline means and standard deviations for each parameter. Upon commencement of the landfill operations, results from routine groundwater monitoring events can then be statistically compared to this base line data. Significant changes in the parameter values would then trigger resampling and, if necessary, a more extensive contaminant characterization effort. 19. Methane gas monitoring shall be performed simultaneously with groundwater sampling episodes. Methane monitoring wells shall be constructed, or existing wells utilized, around the perimeter of the final landfill boundary to depths equal to the depth of excavation adjacent to the well. New wells shall be placed 500 feet on center on all final landfill boundaries. Wells shall be constructed using 2 inch diameter glue-joint PVC casing placed in 4 inch diameter borings. The PVC shall be slotted and gravel packed to within 10 feet of the ground surface. The annular space above the gravel pack shall be backfilled with dry bentonite. 20. A manhole and gravel leachate detection structure shall be constructed between the edge of the excavation and the downstream toe of the first list in the lowest part of the excavation. The leachate detection system shall also include four monitor wells that are inside the fill area and are spaced 50 feet on center along the southeast facing boundary of Phase Three. The wells shall be drilled into the refuse between the excavation cut and the first lift berms. Well depths shall be determined by the depth of refuse, and in no case shall penetrate the clay liner. 21 . If at any time negative groundwater results, methane results, or monitoring results are obtained, the operator shall notify the Weld County Health Department and the Colorado Department of Health of the results within five working days. The operator shall request a meeting to discuss the monitoring results. If necessary, confirmation sampling and testing will be conducted. If an environmental problem is confirmed, the operator shall have an additional 30 days to evaluate the data and present a specific plan of action to both the Weld County Health Department and the Colorado Department of Health. XTRA Corporation August 18, 19_87 Page 8 22. Post—closure inspections shall _include documentation of surface cracking, erosion, slope angles, drainage, and condition of vegetation. One of the inspections each year shall be made in the late spring, when damage would most likely occur due to thaw and runoff. Any damage or other deficiencies shall be promptly repaired. 23. If wet spots or seeps are encountered during excavation procedures, prior to construction of the liner, the Colorado Department of Health shall be notified before emplacement of the liner. 24. A base grade plan shall be developed and submitted to the Weld County Health Department and the the State Department of Health as the clay liner is being placed at the landfill. 25. The Weld County Health Department and the State Department of Health shall be notified if any portion of the clay liner is to be exposed for more than two months and what type of moist miscellaneous fill shall be placed to protect the liner. 26. A one foot intermediate cover shall be placed over any lift which will be exposed for more than one month. 27. The applicant shall obtain a fugitive dust control permit from the State Department of Health , Air Pollution Control Division. 28. The applicant shall develop and post performance guarantees to handle such issues as: - Closure of the facility. - Reclamation and revegetation. - Contamination issues. - Off-site litter control. - Monitoring and maintenance. The County Engineer and the Planning Department shall approve the items listed and cost estimates to guarantee these concerns. The County Attorney's office shall approve the form of the performance guarantees. Motion seconded by Paulette Weaver. n B7 323 XTRA Corporation August 18, 1987 Page Y9 VOTE: For Passage Against Passage Ivan Gosnell Bud Halldorson Ernie Ross Louis -Rademacher Paulette Weaver Ann Garrison The Chairman declared the resolution passed and ordered that a certified copy be forwarded with the file of this case to the Board of County Commissioners for further proceedings. CERTIFICATION OF COPY I, Bobbie Good, Recording Secretary of the Weld County Planning Commission, do hereby certify that the above and foregoing Resolution is a true copy of the Resolution of the Planning Commission of Weld County, Colorado, adopted on August 18, 1987, and recorded in Book No. XI of the proceedings of the said Planning Commission. Dated the 19th day of August, 1987. �ol�l ,c� Bobbie Good Cr,1 Secretary 871323 EXHIBIT INVENTORY V CONTROL SHEET Case (..ei�Lc� P �i �Z /LI/,QC/Ju�- i1 7,4 — U",�///� Exhibit Submitted By Exhibit Description A. 6�/1G4772y��JI��Ccc�, B. B U' C. D. E. F. G. H. I. J. K. L. M. N. 0e 871.323 Date: August 18, 1987 NAME: XTRA Corporation, c/o Charles Hayes ADDRESS: 998 East Highway 119, Longmont, CO 80501 REQUEST: Certificate of Designation LEGAL DESCRIPTION: SEi NW} of Section 8, T2N, -t68W of the -6th P.M. , Weld County, Colorado LOCATION: South of State -Highway 119, north of Weld County -Road 20-1/2, and west of Weld County Road 1 . SIZE OF -PARCEL: 40 Acres, more or less The Department of Planning Service's Staff recommends that this request be approved for the following reasons: 1 . The conditions for approval and stated standards will minimize the impacts on the surrounding property and the area to the greatest -extent possible. The conditions for approval and stated standards will also provide adequate protection of the health, safety, and welfare of the inhabitants of the area and the County. 2. The location of the proposed solid waste disposal site will be convenient and accessible to the potential users. 3. The applicant has demonstrated in the application materials that there is a need for the proposed solid waste disposal site. 4. The applicant has demonstrated through the application materials that they have the ability to comply with the health standards and operating procedures of the Solid Waste Disposal Site and Facilities Act, Title 30-20, part 1, CRS 1973. 5. The Colorado Department of Health and the Weld County Health Department have reviewed this request and find, subject to conditions, that the proposal will comply with the Standards of the Solid Waste and Disposal Site, and Facilities Act, Title 30-20, Part 1, CRS 1973. This recommendation is based, in part, upon a review of the application submitted by the applicant, other relevant information regarding the request and the responses of the referral entities which have reviewed this request. XTRA Corporation August 18, 1987 Page 2 The Department of Planning Services' Staff recommendation for approval is conditional upon the following: The property shall be maintained in compliance with the submitted application materials on file with the Department of Planning Services, Development Standards Approved for Special Review Permit 11779:87:3, all requirements of the Colorado Tepartment of Health and the following stated standards: 1. The landfill shall receive only solid waste of a nonliquid, nonhazardous, and nonradioactive nature. The waste shall be dry household and commercial refuse, construction and demolition debris. No liquid waste of any nature, including semisolid sludges, septic tank pumpage, or drum containerized waste shall be accepted. No hazardous waste, whether or not detoxified or treated, nor any small quantity generator waste shall be disposed of at the facility. No ash from any commercial coal burning activities shall be accepted at the facility. 2. The hours of operation shall be between 7:00 a.m. and 5:00 p.m. , Monday through Saturday. The facility shall be closed on the major legal holidays. 3. The following minimum personnel and equipment are expected to be utilized at the site: PERSONNEL 1 supervisor 1 gate and record keeper 2 heavy equipment operators 1 labor/spotter (as needed) EQUIPMENT 1 trash compactor 1 scraper I dozer 1 motor pool (grader) 1 2,000 gallon water truck FACILITIES: 1 gatehouse XTRA Corporation August 18, 1987 _Page 3 4. The site operator shall keep the following records on site and available for review by the Weld County -Health Department and the Colorado Department of Health: i) Reports of construction quality control. ii) -Litter policing reports. iii) Volume and types of incoming refuse. iv) Results of gas and water quality monitoring. v) Any special waste accepted. 5 . The following Operation measures shall be employed to control blowing litter at the site: i) Application of -soil _cover during refuse placement and at the end of each day. ii) Limiting the size of the working face during windy periods. iii) Permanent and moveable site fencing. iv) Litter pick up activities. v) Ceasing operations during periods when high winds are present. 6. Operational inspection of the entire facility shall be made on a }quarterly basis for the life of the landfill operation. The inspections shall be made by an independent contractor experienced with landfill operations. The inspections shall ±e made to ensure that the landfill operation is progressing in accordance with all aspects of the approved landfill plan. Inspection reports shall be prepared and submitted to both the Weld County Health Department and the Colorado Department of Health. XTRA Corporation August 18, 1987 Page -4 7. All -water samples -shall be analyzed for the following parameters twice a -year: Calcium Magnesium Lead Sodium Potassium Iran Chloride* Sulfate Alkalinity Ammonia Total Dissolved Nitrate Specific Conductance Solids pH (field)* (field)* Chemical Oxygen Phenols Total Organic Halogen* Demand Total Organic Carbon *Indicates parameters to be analyzed 'quarterly. The operator shall make justifiable _changes as needed if the Weld County Health Department or the Colorado Department of Health would like to amend the groundwater sampling parameter list at some later date. 8. Excavation inspections shall be made in each new excavated area. Inspections shall be made by an independent consultant who will then produce a written report that includes observations made in the newly excavated area and a map showing the inspected areas. Copies of the excavation inspection reports shall be supplied to loth Weld County Health Department and the Colorado Department of Health. 9. Filling in the three phases shall be accomplished by a combination of ramp and area—_fill ill methods. The ramp -method shall he used to construct the first two lifts in each phase. The area-fill -method shall be used to construct subsequent lifts. 10. Surface -water shall be controlled to ensure that run-on is not allowed to enter the active disposal area, and that any surface water which falls on the working face is not allowed to leave the site. Intermittent historic flows from the site shall not be changed due to construction of the landfill. No significant changes in the amount or quality of water flowing from the site are to occur. Three temporary drainages shall be constructed to divert natural flows away from the active filling areas. As landfilling progresses, and the lifts and phases are completed, the temporary diversions will 67112D XTRA Corporation August 18, 1987 Page 5 be abandoned and new permanent diversions shall be constructed at higher elevations on natural slopes, continually routing runoff from undisturbed natural areas around the landfill. 11. A clay-liner shall be installed following excavation to final depth. Once a section of the liner is constructed and approved, refuse placement can begin. Refuse shall be placed and compacted in loose layers approximately 2 feet thick. Incoming waste shall be unloaded at the top of the working face, where it shall be pushed downslope and compacted. A minimum of three passes of the trash compactor at an approximate slope angle of 6: 1 should result in refuse densities of at least 1,000 pounds per cubic yard. Refuse material shall be placed in this fashion until a lift thickness of approximately 10 feet is attained. The lift shall be advanced upslope to near the end of the active phase. A minimum soil cover of 6 inches shall be placed over all exposed refuse each working -day. When a lift is completed, the next lift shall be started at the low phase boundary and advanced over the top of the previous lift. Lifts shall be placed in this fashion until the phase is completed. 12. The completed portion of each phase segment shall be covered with topsoil and seeded as soon as practically possible. The cover will be a minimum of 3.5 feet consisting of 6 to 12 • inches of uncompacted soil overlain by a minimum of 6 inches of topsoil. All but the topsoil shall be placed as soon as possible over areas in which refuse placement has been completed. 13. The final top of the landfill shall have a two percent slope and shall have a northeast trending crown approximately 225 feet from the western boundary. The northern, western, and west half of the southern boundaries shall melt into the natural topography. The eastern half of the southern boundary and the eastern boundary shall have a 1+: 1 slope. 14 . The construction of the slay liner shall 6e placed in six inch lifts and compacted with a sheep's foot compactor until it reaches a compacted dry Aensity equal to or greater than 95 percent of the standard proctor density (ASTM-D-698) . The moisture content of the material shall be maintained within 2 percent of optimum moisture content using the same testing criteria. Not less than two feet of material shall be compacted to these specifications. 8'71'32 XTRA Corporation August 18, 1987 page 6 15. To ensure that the slay liner and final cover are constructed in accordance with the specifications outlined in the Design and Operations Plan, an independent soils and materials testing firm shall be retained to observe and test liner and cover materials. The program shall Consist of material classification tests conducted for every 3,000 cubic yards of clay material placed in the liner and for -every 3,000 cubic yards placed in the roves. This type of testing shall ensure that materials -placed are suitable for their intended use. In addition, compaction and moisture content testing shall be conducted on the compacted clay liners and covers. Moisture density testing shall be conducted at no less than 100 feet spacing interval for the liner and 300 foot spacing for the cover. Copies of this testing shall be forwarded to the Weld County Health Department and the Colorado lDepartment of Health. 16. Unauthorized access to the landfill facility shall be prevented by a permanent site fencing around the landfill entrance area and the final active filling area. A six foot high chain-link fence with a 2 foot canopy shall be used around the entrance area in the northeast corner to secure the gatehouse and equipment areas. The filling area perimeter shall ibe fenced with -6 foot nonclimbable fence topped with three strands of barbed wire. 17. To ensure that fill excavation volumes, and -material balances are being achieved as landfilling progresses, the landfill area topography shall be mapped on an annual basis. Annual mapping shall be used to determine actual annual air space and soil borrow used. An annual material balance report shall be prepared and shall be available for inspection by the Weld County Health Department and the Colorado Department of Health. 18 . A total of five groundwater monitoring wells shall be installed upon issuance of the Certificate of Designation. Four wells shall be installed at two locations along the southeastern property boundary. Two of the wells shall be installed at one location in the invert of the existing gully where it exits the site along the southeastern boundary. The other two wells shall be installed near the intersections of the southeastern and eastern fill boundaries. At each location, one well shall be installed in the saturated zone while the other is installed in the overlying %sn XTRA Corporation August 18, 1987 Page 7 unsaturated materials. XTRA Corporation anticipates a 6 month construction period prior to the onset of filling. The wells shall be sampled four separate times in that period to provide a good data base to calculate baseline means and standard deviations for each parameter. Upon commencement of the landfill operations, results from routine groundwater monitoring events can then le statistically compared to this base line data. -Significant changes in the parameter values would then trigger resampling and, if necessary, a more extensive contaminant characterization effort. 19. Methane gas -monitoring shall be performed simultaneously with groundwater sampling episodes. Methane monitoring wells shall be constructed, or existing wells utilized, around the perimeter of the final landfill boundary to depths equal to the depth of excavation adjacent to the well. New wells shall be placed 500 feet on center on all final landfill boundaries. Wells -shall be constructed using 2 inch diameter glue-joint ITC casing placed in 4 inch diameter borings. The PVC shall be slotted and gravel packed to within 10 feet of the ground surface. She annular space above the gravel hack shall be backfilled - with dry bentonite. 20. A manhole and gravel leachate detection structure shall be constructed between the edge of the excavation and the downstream toe of the first list in the lowest part of the excavation. The leachate detection system shall also include four monitor wells that are inside the fill area and are spaced 50 feet on center along the southeast facing boundary of Phase Shree. The wells shall be drilled into the refuse between the excavation cut and the first lift berms. Well depths shall be determined by the depth of refuse, and in no case shall penetrate the clay liner. 21. If at any time negative groundwater results, methane results, or monitoring results are obtained, the operator shall notify the Weld County Health Department and the Colorado Department of Health of the results within five working days. The operator shall request a meeting to discuss the monitoring results. If necessary, confirmation sampling and testing will be conducted. 1f an environmental problem is confirmed, the operator shall have an additional 30 days to evaluate the data and present a specific plan of action to both the Weld County Health Department and the Colorado Department of _Health. 871323 XTRA Corporation August 18, 1987 Page 8 22. Post-closure _inspections shall include documentation of surface cracking, erosion, slope angles, drainage, and condition of vegetation. One of the inspections each year shall be made in the late spring, when damage would most likely occur due to thaw and runoff. Any 4amage or other deficiencies shall be promptly repaired. 23. If wet spots or seeps are -encountered during excavation procedures, prior to construction of the liner, the Colorado Department of Health shall -be notified before emplacement of the liner. 24. A base grade plan shall be developed and submitted to the Weld County Health Department and the the State Department of Health as the clay liner is being placed at the landfill. 25. The Weld County Health Department and the -State Department of Health shall be notified if any portion of the clay liner is to be exposed for more than two months and what type of moist miscellaneous fill shall be placed to protect the liner. 26. A one foot intermediate cover shall be placed over any lift which will be exposed for more than one month. 27. The applicant shall obtain a fugitive dust control permit from the State Department of Health , Air Pollution Control Division. 28. The applicant shall develop and post performance _guarantees to handle such issues as: - Closure of the facility. - Reclamation and revegetation. - Contamination issues. - Off-site litter control. - Monitoring and maintenance. The County Engineer and the Planning Department shall approve the items listed and cost estimates to guarantee these concerns. The County Attorney's office shall approve the form of the performance guarantees. 071.72- JUN 2 5 1979 C7 ...:„ . ecorded at ... o'clock K� 873 1794932 Rec. No...._..---_._....._._..___._��3111 State of Colorado, County Clerk & Recorder ; \ I ORDINANCE NO. 53 C\2 RE: AN ORDINANCE ESTABLISHING A SURCHAI2fF 7O COVER THE ACTUAL ON AND NECESSARY COSTS OF LAND, LABOR, EQUIPMENT AND SERVICES NEEDED IN THE OPERATION OF SOLID WASTES DISPOSAL SITES AND FACILITIES IN WELD COUNTY, COLORADO, AND ESTABLISHING A WELD COUNTY SOLID WASTES DISPOSAL SITE AND FACILITY FUND. o o BE IT ORDAINED BY THE BOARD OF COUNTY COMMISSIONERS OF WELD COUNTY, COLORADO: l' 0 Section 1 a- r There is , hereby, rny, established a Weld County Solid Wastes N Disposal Site and Facilities Fund pursuant to the provisions of Section 30-20-115, CRS 1973 . Said fund shall be administered by the Weld County Treasurer pursuant to law. Section 2 There is, hereby, established a surcharge in the amount of five percent (5%) to be added to all dumping fees received by any operator operating a solid wastes disposal site within Weld County, Colorado. Section 3 It shall be the duty of any operator of any solid wastes disposal site in Weld County, Colarado to collect said surcharge at the time dumping fees are collected and to remit the same to the Weld County Treasurer on or before the 20th day of the month following the month in which said surcharge is collected. Section 4 The surcharge contemplated by this Ordinance shall be deposited in the Weld County Solid Wastes Disposal Site and Facilities fund for the purpose of financing the operation at all Weld County solid wastes disposal sites and in particular to cover the costs of health inspections , removal of litter from roadsides , establishment and construction of road accesses to Weld County solid wastes disposal sites , financing the Landfill 871326 1,23 x,873 s a Management Program, equalizing costs for transfer sites in Weld County, Colorado, capital outlay associated with the transfer site system, insurance costs, Weld County staff support costs, financing the requirements for compliance with the Resource Conservation and Recovery Act, costs of designation of future site locations, and rectifying environmental problems created by past andfuture solid wastes disposal sites. Section 5 All operators of solid waste disposal sites in Weld County, Colorado, shall make available to the Board of County Commis- sioners of Weld County, Colorado or their designated agents, all books of account of said operator of solid wastesdisposal sites for auditing purposes to ensure compliance by said operators of solid wastes disposal sites in Weld County, Colorado with the provisions of this Ordinance. Section 6 If any section, subsection, paragraph, sentence, clause or phrase of this Ordinance is, for any reasons, held or decided to be invalid or unconstitutional, such decisions shall not affect the validity of the remaining portions. The Board of County Com- missioners of Weld County, Colorado, hereby declare that it would have passed this. Ordinance and each and every section, subsection , paragraph, sentence, clause and phrase thereof irrespective of the fact that any one or -more sections, subsections, paragraphs , sentences, clauses, or phrases might be declared to be unconsti- tutional or invalid. Section 7 This Ordinance shall take effect on August 1, 1979 pursuant to Section 3-14 (2) of the Weld County Home Rule Charter. -2- 871326 J73 1794932 The above and foregoing Ordinance No. 53 -was passed, approved -and adopted this 25th day of June , A.D. , 1979 . BOARD OF COUNTY COMMISSIONERS WELD COUNTY, COLORADO %c oj,.. ,Q(. c' 4 ' 1 a 1 / II) 7r aii14 t d2�, ne te et ATTEST: ' 1cu (,,,t., ,, Weld County Clerk and Recorder a lerk to the B D puty County Clerk APP ED AS II E RM: a County Attorney PUBLICATION: June 28, 1979 -in the Platteville -Herald Date _Presented: June 25, 1979 u a'3►a�l2� —3— Industrial — = Compliance r — a Incorporated DESIGN AND OPERATIONS PLAN FOR THE PROPOSED XTRA CORPORATION LANDFILL WELD COUNTY, COLORADO Project Number 1-1$02 Prepared for: -XTRA Corporation 998 E. Highway119 Longmont , Colorado H0501 Prepared by: Industrial Compliance , Inc . 511 Orchard Street Golden Colorado 80401 January 1927 871325 511 Orchard Street Golden, Colorado 80401 (303)277-1400 TABLE OF CONTENTS Page 1 . 0 INTRODUCTION 1 2 . 0 GENERAL INFORMATION 2 2 . 1 Facility Need 2 2 . 2 Facility Description 2 2 . 3 Zoning and Land Use 3 3 . 0 SITE DESCRIPTION 3 . 1 Existing Site Topography and Vegetation. 4 3 . 2 Climate 4 3 . 3 General Geology 5 3 .3 . 1 Bedrock Stratigraphy 5 3 . 3 . 2 General Surficial Geology 5 3 . 3 . 3 Geologic Structure 6 3 . 3 . 4 Economic Geology 6 3 . 4 Site Geology and Soil Properties 7 3 . 4 . 1 Site Surficial Deposits 7 3 . 4 . 2 Site bedrock Deposits 8 3 . 4 . 3 Material Properties 8 3 . 5 Hydrogeologic Considerations 11 3 . 5 . 1 Regional Hydrogeology 11 3 . 5 . 2 Local Surface-Water Hydrology 12 3 . 5 . 3 Local Hydrogeology 12 4 . 0 FACILITY DESIGN 4 . 1 Waste Characteristics and Volume Assumptions and Requirements 16 4 . 2 Disposal Area Design 4 . 2 . 1 General Filling Plan 16 4 . 2 . 2 Filling Procedures 18 4 . 2 . 3 Excavation and Refuse Placement 18 4 . 2 . 4 Clay Liner and Cover Construction. 19 4 . 2 . 5 Material Quantities 19 4 . 2 . 6 Surface Water Control 20 4 . 3 Support Facilities 20 4 . 3 . 1 Access 20 87132E TABLE OF CONTENTS CONTINUED 4 . 4 Permanent Site Fencing 22 4 . 5 Resource Recovery 22 5 . 0 CONSTRUCTION AND OPERATION QUALITY CONTROL 24 5 . 1 General 24 5 . 2 Excavation and Inspection 24 5 . 3 Clay Liner and Final Cover Construction Inspection and Quality Control 2-4 5 . 4 General Operational Inspections 25 5 . 5 Fill and Excavation 25 6 . 0 FACILITY OPERATION 6 . 1 Site Management 26 6 . 1 . 1 Operations Schedule 26 6 . 1 . 2 Equipment and Personnel Requirements 26 6 . 1 . 3 Control and Record Keeping 26 6 .1 . 4 Safety Control 27 8 . 1 . 5 Water Requirements and Supplies 27 6 . 1 . 6 Site Operator 22 6 .2 Control of Nuisance Conditions 28 6 . 2 . 1 Litter Control 28 6 . 2 . 2 Vector Control 29 6 . 2 . 3 Odor Control 29 6 . 2 . 4 Dust Control 30 6 . 2 . 5 Fire Control 30 6 . 2 . 6 Methane Gas Control 30 6 . 3 Environmental Monitoring 30 6 . 3 . 1 Leachate Detection Monitoring 31 6 . 3 . 2 Ground Water Monitoring 31 6 . 3 . 3 Methane Gas Monitoring 33 6 . 3 . 4 Proposed Action In Case of Negative Monitoring Results 33 7 . 0 CLOSURE AND POST CLOSURE 7 . 1 Reclamation and Reveg-etation 35 7 . 2 Post Closure Monitoring 35 7 . 3 Post Closure Inspections and Maintenance 3-6 7 . 4 Post Closure Land Use 36 8 . 0 REFERENCES 37 CJ Y 132S LIST OF FIGURES After -Figure No . Page 2 . 2-1 Site Location & Vicinity Map 2 3 . 3-1 Generalized Stratigraphic Column For the Area Surronding the Proposed Longmont Landfill 5 3 .5-1 Surface Water Conditions Map 12 3 . 5-2 Potentiometric Surface 8 Approximate Extent of Semi Confined Ground Water 14 4 . 2-1 Phase Start Detail 18 4 . 2-2 Stage Advancement Details 18 4 . 3-1 Proposed Facility Layout 22 6 . 3-1 Monitoring Program for the Longmont Zandfill 30 6 . 3-2 Zeachate Detection Systems Details 31 LIST OF TABLES Table No . Page 3 . 4-1 Representative Materials Properties 10 3 . 5-1 Summary of Well & Test -Hole Elevations & Water Levels 15 4 . 2-1 Material & Refuse Volumes 21 LIST OF APPENDICES Appendix A Soil and Laboratory Results Appendix B Surface Water & Diversion Design Details Appendix C Erosion Calculations Appendix D Water Balance Calculations Appendix E Surrounding Property Owners Within 500 Feet of Site Boundaries 1 . 0 INTRODUCTION This document presents the proposed Design and Operations Plan for a landfill in Weld County, Colorado that -will service eastern Weld and western Boulder Counties , the areas currently serviced by the existing Longmont Landfill . Only dry, non-hazardous solid waste from private , commercial and industrial sources will be accepted. The landfill has a total airspace capacity of 933 , 000 cubic yards and an estimated life of 4 ,years . The proposed landfill is located immediately west of the existing Longmont Landfill . XTRA Corp, the owner of the proposed landfill , is not associated with the existing operation and the new facility will be considered independent from the current operation. The technical information used to design the landfill and prepare this report came from both new sources and previously prepared reports (Fox and Associates of Colorado , May 1983 , and November , 1983 ) . The engineering investigations and the facility design were prepared to conform with Colorado solid waste siting , design and operations regulations as amended 30 October 1985 . The major sections of the plan include : Background Information Site Description Facility Design Facility Construction and Quality Control Facility Operations Closure and Post-Closure The results of all investigation activities indicate that the site can be developed, operated and closed in an environmentally safe fashion provided that the design , operational , and monitoring requirements set forth in this document are followed. 1 871323 2 . 0 GENERAL INFORMATION 2 . 1 Facility Need The city of Longmont ' s active landfill is located in Weld County on Highway 119 , approximately 4 miles east of Longmont. As of October , 1986 , the projected life for the current operation was 14 months . Upon completion of filling at this site , Longmont and the surrounding area will be left with no approved solid waste disposal site unless an alternative site is permitted and preoperational activities are completed within this time frame . The proposed site described in this report will satisfy -Longmont ' s solid waste disposal needs and, provided preconstruction activities can begin in early summer of 1987 , will be available for use when the existing site is closed. 2 . 2 Facility Description The proposed site for the new landfill consists of 40 acres located west of and adjacent to the existing -Longmont landfill ( Figure 2 . 2-1 ) . The proposed site is in the southeast quarter of the northwest quarter, of Section 8 , Township 2 North , Range 68 West of the Sixth Principal Meridian . The approximate site boundary is shown on Plate 1 . The proposed landfill will receive only dry household and commercial refuse and construction demolition debris . No liquid waste, radioactive waste or drum containerized waste will be accepted. No hazardous waste , whether or not detoxified or treated, nor any small quantity generator waste will he disposed of at the facility Only about 19 of the 40 available acres will be used for refuse filling . The remainder of the site will largely be unaffected by operational activities . Refuse filling will occur in three phases ( filling areas ) . Detailed filling procedures -are presented in this plan. Generally, filling will be accomplished by excavating and lining the active area, placing compacted refuse in controlled lifts , and covering them on a daily basis . Completed portions of the landfill will be covered with a minimum of 3 . 5 feet of compacted clay and topsoil and then revegetated to return the site to an environmentally suitable condition . The site has been designed so that completed portions of the fill will be reclaimed throughout the life of the facility to minimize the size of the disturbed areas . 2 871.326 hn ;. II 4, ,tI % I j N yp - - �1 �. `1' cd J _... • l dv z l �o � � } J'� p w0 - ` w0p P M _ _ -\ �---1 [ \,4-:::, ,,_, J Y�y�d✓_ , — � o IIII $ ,.�� — — — _ G _ _ I 1 '� W——^ .c ) \, ,\ ) (2— •-I. I __LtL))), 1 0(i)-- • ..4- 4 i I w• \ / ill.; (� pi I i iI j z . [ da SJ 7. I ) cn I / _ .,�j�/ I o '��, p C 1 I _?. I " Jl a i i� r I __- 11 r ID r J ( , r 4- 1� � Al' t i t _ • � - ,✓a i ' ,— J ` III ;�..I ".h .,7 c �` \ H i e II/ I i i ..,, I {{ - I SITE LOCATION a VICINITY MAP FIGURE 2.2-I 871326 2 . 3 Zoning and Land Use The proposed site is currently zone-d A/Agricultural . The zoning and land uses of adjacent properties are : North boundary - Great Western Sugar Company - Agricultural - Grazing or Fallow South boundary - Mr. Chuck Hayes - Agricultural - Grazing or Fallow East boundary - City of Longmont - Shown on map as Agricultural - Existing sanitary landfill West boundary - Mr . Chuck Hayes - Agricultural - Grazing or Fallow 3 871326 3 . 0 SITE DESCRIPTION 3 . 1 Existing Site Topography and Vegetation Plate 1 shows the existing topography. An east-west trending gully in the southern half of the site drains the entire filling area. In general , the ground surface slopes from the northwest to the southeast . The maximum elevation of the site is 4987 feet on the western boundary while the minimum elevation is 4278 feet at the southeast corner. The topography in the proposed filling area slopes at an average of between 5 and 6 percent . Natural vegetation consists of native grasses and shrubs typical of most areas along the urban front range corridor . No vegetation that is indicative of shallow ground-water conditions ( e . i . , phreatophytes ) is present . 3 . 2 Climate Long term regional climatological data were obtained from the Colorado Climate Center , Department of Atmospheric Sciences , Colorado State University in Fort Collins , Colorado and the National Oceanic and Atmospheric Administration -Station at Stapleton International Airport . The lowest recorded temperature for the area is minus 36 degrees Fahrenheit and the mean annual temperature is 49 degrees Fahrenheit . The mean annual humidity is 52 percent , with mean annual evaporation of about 60 inches and mean annual precipitation of about 13 -inches . Maximum 24-hour precipitation was 4 . 04 inches in May of 1957 . Water balance calculations , included in Appendix D, indicate that the potential evapotranspiration at this site greatly exceeds the precipitation. Infiltration is limited to periods of sustained precipitation, an infrequent event in this type of climate . Also , dry refuse has an enhanced capacity to retain moisture . The potential for significant saturation of trash _luring the site ' s operational life and following closure is negligabl-e , so the probability for the generation of leachate is minimal . The prevailing wind direction is southeasterly with the winds averaging between 8 and 2 miles per hour. Stronger winds occur frequently and are generally easterly to southeasterly. 4 3 . 3 General Geology Th-is section describes the general geology of the area surrounding the facility as well as the site specific geology. Figure 3 . 3-1 is a generalized stratigraphic column of the important bedrock and surficial deposits . 3 . 3 . 1 General Bedrock Stratigraphy The uppermost bedrock beneath the proposed site is a thick section of the Upper Cretaceous Pierre Shale . The Pierre is a sedimentary marine deposit that is primarily composed of shales and sandy shales . The Pierre is approximately 6000- 7000 feet thick in this area and is divided into three lithologic units . The site lies at the very top of the formation in the upper transitional member. This member is approximately 2000 feet thick and consists of sandstone layers with abundant sandy shales and brown to dark grey- brown shales . The sandstones decrease with depth in this interval . The Pierre Shale is characterized by very low permeabilities and the presence of impermeable clay layers throughout the formation. As discussed in Section 3 . 5 . 1 , the Pierre Shale lies below, and thus outside of , the regional aquifers of the Denver Basin. Also , no aquifers of either local or regional significance lie below the Pierre in this area, so the underlying units do not warrant discussion. 3 . 3 . 2 General Surficial Geology The surficial deposits present in and around the site include the Slocum, Piney Creek and Post-Piney Creek Alluvium, eolian deposits , and recent alluvium. The Slocum, Piney Creek and Past-Piney Creek Alluvium are part of a set of terrace deposits that have been mapped over an extensive area east of the Front Range . The Slocum Alluvium is a Pleistocene Alluvium that typically contains cobbles and boulders in a sandy-clay matri-x . It is the oldest of the deposits and, because of its ability to withstand erosion, it often occurs as low relief , shallow terraces on the top of bluffs associated with recent perennial streams and gullies . The Piney Creek and Post-Piney Creek Alluvium are young (Upper Holocene ) alluvial deposits . Both are described as dark gray humic sandy to gravelly alluvium ( Colton, 127$ ) . The -Piny Creek alluvium varies in thickness from 0 to 20- 5 (..i7.1c..2,*brc) � RECENT ALLUVIUM: Fluvial deposits associated with St. Vrain Creek. _ - _— 'T'- EOLIAN DEPOSITS : Light brown to reddish brown •I - • - to olive gray silty clays . Generally less than 3 . feet thick, but locally up to 15 — • • feet thick. IW '. '� ' .• POST-PINEY CREEK ALLUVIUM: Dark gray humis , Io ;m ::°: �'. sandy to gravelly alluvium containing Jo ; ;; '•� . .• plant remains . Thickness varies from 5 - I .• 15 feet. Associated with historic terraces °, ._.• .i .,. less than 10 feet above current streams . w a I , a m •. 4-‘.4.4- I4,4-1 ,. PINEY CREEK ALLUVIUM: Dark gray humic sand, • 1• "0 -•ti• � to gravelly alluvium that varies from 0 - l .° • �• .a �.a' 'b °�'° �/ 2A feet in thickness. -Underlies terraces y that are 10 - 2D feet above the current .•!•ad"��_: flood plain. I . `�ie''' qr dD r .7 . _Q0k i 0 0 is_ oY b:C. CV �yt 'n.O'OU• U..4 ≥Oob+OA ° •' SLOCUM ALLUVIUM: Cobbles and boulders in a o .n•°°6°' sandy clay matrix. -Thickness varies from H lefx0 1 '• . 0 :••4:0'°• '•:' 0 - 20 feet. Generally underlies terraces noO•.C J oopn°Qo400°•' that are 100 - 130 feet above existing a o.0.4.•.t0;0• Jb.:4:2••;D aa.[ stream elevations. $Nl?°°:,?<er e& ";'--�- PIERRE SHALE - UPPER TRANSITION MEMBER: I ,.-. ` Soft shaley sandstones , thinly bedded, m L_—, sandy shales and large calcareous sand- ix w = stone concretions. Locally, brown to I w " -_e__---A- ' dark gray brown shales , sandy shales, and act _ __= sandstones with the sandstones decreasing with depth. Approximately 2 , 000 feet thick. I GENERALIZED STRATIGRAPHIC COLUMN FOR THE AREA SURROUNDING THE PROPOSED LOIVOIONT LANDFILL 1 FIGURE 3.3-I 871326 feet thick and is generally found beneath terraces that are 10 to 20 feet above the current flood plain. The Post-Piney Creek alluvium, the younger of the two deposits , is 5 to 15 feet thick and is associated with terraces less than 10 feet above current stream levels . The eolian deposits cover large areas of -north-central Colorado , east of the front range . Near the site , they are primarily light to medium brown, silty clays . The deposits are generally less than 3-feet t-hick , but they are locally up to 15 feet in thickness . They were deposited over an interval from the late Pleistocene to Holocene , but after deposition of the Slocum Alluvium. The recent alluvial deposits are associated with the existing St . Vrain Creek fluvial system. The types of deposits vary from fluvial sands to clayey overbank deposits . These recent deposits immediately overlie the Post-Piney Creek Alluvium. 3 . 3 . 3 Geologic Structure The site lies about 15 miles west of the axis of the Denver Basin. The Denver Basin is an asymmetric basin that extends from about Pueblo , Colorado in the south to Torrington , Wyoming in the north . The western limb is vertical to steeply dipping near its boundary with the Front Range , but dips rapidly decrease toward the center of the basin. The bedrock near the site generally has a northeasterly strike and southeasterly dips of approximately 3 degrees . The site is north of the heavily-faulted area found in southeastern Boulder County and southwest-ern -Weld County. Davis ( 1976 ) shows one basement fault near the site while Colton ( 1978 ) shows concealed faults 2 miles to the north and west . The published information strongly suggests that the area immediately surrounding the site has not been disrupted by major faulting . 3 . 3 . 4 Economic Geology The site is on the western boundary of the Wattenberg Field, a major oil and gas producing area in the Denver Basin. The actual fill area is fairly small and would not interfere with exploration and production activities if oil or gas was found in commercial quantities near the site . The Slocum Alluvium and recent alluvial deposits associated with St . Vrain Creek are potential aggregate resources . The fill area is below the majority of the Slocum materials and 6 871325 is above the St . Vrain Creek floodplain; therefore , placement of fill in this area will not remove any of these resources from potential development . There are no other known potentially economic deposits at the site . 3 . 4 Site Geology and Soil Properties Fourteen test holes were drilled at the proposed site to provide data for site-specific geologic and subsoil characterization activities . Twelve of the holes are in the proposed filling area. Boring locations are shown on Plate 1 . Three cross sections were prepared to assist in interpretations . The cross sections and their locations are presented on Plate 2 . The geologic information suggests that the materials can be divided into three surficial and two bedrock deposits . The three surficial deposits include eolian silty clays , colluvial clays , and the Slocum Alluvium and associated recent fluvial deposits . The two bedrock deposits are an interbedded sandstone and claystone and an underlying claystone . Each deposit is discussed below. 3 . 4 . 1 Site Surficial Deposits The uppermost surficial deposit beneath the site is an eolian silty clay. This deposit was found in all test holes and appears to mantle the entire site at thicknesses that vary between 2 and 12 . 5 feet . The average thickness of this deposit is 5 . 1 feet , with the thickest deposits occurring in the upland areas and at the base of the gullies . The material is a light to medium-brown silty clay with a Unified Soil Classification of CL. It is firm to stiff and varies in moisture content from dry to moist . Between _50 and 75 percent of this material passes the #200 sieve - the size boundary between sands and silts . One of the surficial materials underlying the eolian clay is medium to dark-brown colluvial clay. This material appears to be irregularly distributed because it was only noted in the eastern part of the proposed filling area, although it might occur at depth in some parts of the western area. The measured thicknesses of the deposits varied between 2 and 18 .5 feet . Approximately 80 percent of the material is either a silt or a clay. This deposit is thought to be either colluvium or heavily weathered bedrock. 871326 The Slocum Alluvium is the oldest surficial deposit . It was noted beneath the eolian deposit in the two holes in the uplands area ( holes 24 and 27 ) at elevations above 4940 feet . The thicknesses varied between 12 and 12 feet . The material is a light to dark brown gravel (Unified Soil Classification GC ) that typically contains cobbles and boulders in a sandy clay matrix. Thin gravel deposits were noted in the bottoms of the gullies filling area. These gravels are discontinuous and unsaturated. The materials are similar to , and appear to originate from, the overlying Slocum Alluvium. Several thin layers ( <6 inches ) were noted in holes in the eastern part of the filling areas at depths between 5 and 15 feet . These -zones appear to be horizontal fractures that were subsequently filled with a calcareous cement . Further discussion on these zones is in Section 3 .5 . 3 3 . 4 .2 Site Bedrock Deposits Two major bedrock deposits are found at depths less than 70 feet . The uppermost one is a sandy claystone . The deposit thickness varies from 1 to greater than 25 feet , with the thickest parts found beneath the uplands . The average overall deposit thickness is 10 feet . The material colors vary from yellow brown to grey. The deepest unit encountered was a claystone bedrock . It is composed of gray to brown, medium to high-plasticity clays . The material is usually very hard and contains cemented zones similar to those in the surficial deposits that appear to be healed fractures . These deposits are thin (average thickness of 1 foot ) , well cemented, and discontinuous . This type of layer is thought to be a confining aquitard for localized ground water . The hydrologic significance of this water is discussed in Section 3 . 5 . 3 . 4 . 3 Material Properties A total of 10 test borings ( TB-1 to TB-10 ) were drilled to characterize the subsoil conditions at the proposed landfill . All of these borings wereadvanced with -a CME 55 drilling rig using 4-inch diameter , continuous-flight , solid-stem auger . Field testing in the borings included standard penetration resistance testing with either a modified California sampler or a split spoon sampler, and packer type permeability testing . In addition to the recently completed test holes , three monitoring wells and one test hole were completed 8 871&-s during a 1983 evaluation. Plate 1 shows the location of all test toles and monitoring wells as well as boring logs for all holes . Results from the field testing program are also presented on the boring logs . Geotechnical laboratory testing was conducted on disturbed and undisturbed soil and bedrock samples obtained during the recent and 1083 programs . The tests completed included moisture content , natural dry density, liquid and plastic limits , percentage passing a number 200 sieve, proctor compaction, and natural and remolded permeability testing . The testing results for all samples collected during the recent program, and the samples collected during the -1983 program that are applicable to this site , are in Appendix A. The above results were reviewed and statistically analyzed to derive important properties for each of the material types . The results are in Table 3 . 4-1 . Mean moisture contents ranged from 7 . 4 to 11 . 0 percent by weight . These values indicate that the materials are relatively dry in a natural state . The moisture contents of the two surficial clays are _particularly important because of their potential use as liner material . The low moisture contents imply that water will have to be added to these materials during construction of the liner and cap to ensure compaction within the required specifications . The average natural dry densities are higher than the maximum density ( 114 pcf ) obtained from the proctor test . If the proctor result is considered representative , the bulking factor for the clays and two bedrock materials varies between 0 . 975 and 1 . 116 . Four of the five materials are classified under the Unified Soil Classification System as CL - a low plasticity clay. This type of material is excellent for use as a liner and cover material because of its low primary permeability, resistance to erosion, and ease of compaction. The Slocum Alluvium is a gravelly clay, but it will not be used as a liner material . The three clayey materials tested all had low natural permeabilities . Laboratory permeabilities varied between lx10 -7 and 8x10 -7 em/sec . Packer testing results on the claystone bedrock indicate that it has an in place permeability of approximately 2x10-6 cm/sec - a low value that implies an excellent hydraulic-isolation capacity. 9 871325 C 0 4+ O r0 VI u J J 94- 0 0 0 -I a,.,- u '^ N W N - 'a C C r.- n =U N N 9 N N FJ a w al A N ( n ‘1/40 E ^ n co .r G E o e u x o x x n 0 y 0, x ti n Ot at") , (f N + N to O)O) N C m L u ti Cr)N n e In 11) m O H T O N N CC Yl O. N ^ 4) CC^ Q) n ae a O T C 4, 1 r min aI L X O • N U:1 K N Cl N u') , ti N ^•CO W N N H d r Q 'Cr w 9 n n H N. •P E -N 1.0N 11... CI' W Q J J N of n ,p J I- N 6n Z m -CJ N Q W .--. 1- N 4 w c y a Lo ¢ T y O L'^ ,W N CC ZOCT o''..0- N� CV Q1-4 £ N r4 CO + M L rl ^ J C C C ^ 4., ID y 4' O O N N ~ C I--C N C3 P a, O O CO• £U �� VD.--1 f�� N• 0• a Cu 03 01 b+ w c m -Tc m Cnc me E L fJ a C '0 ClN L m U OI r0 CV L E L a — T E 4+ U C r '1 L- L T > — 9 _ N 0 m n \ C T Q a C _v o C j E 4, U _ 0 N o u 9 L >, O Q 0 a 9 co 0 0 ,— '0 0, VI N C 0 10 87132 One remolded permeability was completed on a sample of the eolian clay, the material containing the highest percentage of sand. The resulting value of 9x10 -8 cm/sec at 9-6 percent of maximum density indicates that this material , as well as the less-sandy alluvial plays , should prove to be an excellent Liner when constructed according to the specifications contained in this plan. 3 . 5 Hydrogeologic Considerations A primary goal of any landfill operation is to isolate the refuse from potential ground-water resources . This is done through a combination of siting and engineering -design . This section presents information on the natural -ground-water system including : 1 ) where ground water is present ; 2 ) where the ground water is moving and; 3 ) what long-term -impacts , if any, -will the landfill have on the natural system. 3 . 5 . 1 Regional Hydrogeology -Even though the site is in the upper transitional member of the Pierre Shale , and thus technically beneath the regionally important Laramie-Fox Hills ( L-F) Aquifer, Robson ( 1881 ) includes the site in the L--F subcrop zone . This was done because of the potential presence of significant thicknesses of sandstones in the upper transitional zone that might be potential aquifers . The importance of this member in the subcrop zone is minimal in this area for several reasons . 1 ) Robson' s map is regional in nature , covering an area of over -6 , 700 square miles at a scale of 1 : 500 , 002 ( 1 inch equals 8 miles ) . The nearest control points used to generate this map are 3 miles from the site , and no control paints exist between the site and the L-F boundary. The complex stratigraphic relationships in this area make site specific verification a mandatory requirement . 2 ) Local drilling has shown that the site is underlain by sandy claystones and -claystones that will retard or prevent the lateral and vertical migration of surface water. In addition, the hydraulic conductivities of those deposits are too low to warrant their use as aquifers . 11 87132 g 3 ) As discussed -in Section 4 , the entire filling area will be lined and thus protected by a 2-font thick compacted clay liner with an overlying leachate collection system. These features , coupled with a policy of accepting no saturated refuse and a ban on placing wastes below the water table , will prevent the release of leachate into the unsaturated soils and bedrock . 3 . 5 . 2 Local Surface-Water Hydrology The major surface-drainage features near the proposed landfill are shown on Figure 3 . 5-1 . The proposed filling area is in the uppermost reach of a small , isolated drainage area. The two gullies within this area are both dry, and no plants that are indicative of near-surface water grow in them. Slopes in the area have a southerly aspect which should promote the rapid melting of snow and evaporation of ponded waters , thus minimizing surface infiltration. The filling area is completely outside of the 100-year flood plain (Plate 1 ) . The channel in the vicinity of the site has been improved to minimize flooding . The confluence of St . Vrain and Boulder Creeks is approximately 1 .-125 miles downstream. The confluence of St .Vrain Creek and the South Platte River is roughly 15 miles downstream from the site . The area surrounding the site contains numerous irrigation ditches . One lateral from the Oligarchy Ditch runs parallel to , but north of, the surface drainage divide north of the site . There are no apparent direct connections between St .Vrain Creek and any reservoirs used to store drinking water . 3 . 5 . 3 Local Hydrogeology The existing hydrogeologic system has been modified by recharge resulting from the irrigation of the fields immediately north of the site . Oligarchy Ditch provides a seasonal source of water to crops . Much of the water is transpired by the crops ; however , some is not utilized and percolates into the subsurface . Irrigation water that infiltrates to the subsurface appears to intersect a series of hori2ontal fractures in low- permeability claystone bedroc-k and begin to move laterally. Most of this water probably flows to the northeast in a manner that mimics surface-water flow; however , some of the water apparently moves south under the existing surface 12 87t326 \_ e v N- I ul ci1-4 J �� f 1 o z iii rill 2(ae.t3)_( I - 1 7 ZLIP p V o—� J © '�- O P o I'LL) 1 1 Al - 7CT ° m liI N\lu ce-,\\ IL L. } i' 1 rt._ 2 __ \ , \ [ \2 ----- lii./ / i 7 ,,,,,ct r_. , I � 0�.� �2-_` �� Tai TT m VJ 1 n m o tocos 1 _ , __5 1; II el ) I u treo \\ ,\( -- E- \� v � i� � ° .O "� 's � „ 2 p �� Cr \___IT-'0 \\I ‘ // 7 fp Ictir• , a — —. - �� 3 I PI i K7 "it ?;t/ay;X.& ^�A 1/NIC1N B�SJ , col 490 Q- 17 f\\ err Lt 871323 drainage divide to an area beneath the northern part of the proposed filling area . The -ground water, and the fractures that carry it , -were discovered and delineated during the field exploration program. Five test hales , TH-1 to TH-5 , were drilled and sampled to supplement information collected in a _previous study ( Fox and Associates of Colorado , 1983 ) . Test hole 2 , drilled an a hillslope outside of the gully, was found to make water . A hole drilled in this location will not generally contain water in a natural hydrogeologic system typical for this region. An additional five holes were drilled after water was found in TH-2 to further define the extent and degree of saturation. Thin ( less than 6-inch) hard zones were encountered in several of the test holes in the northern part of the filling area ( see drilling logs , Plate 1 ) . No saturated materials were encountered either above or below these -zones . These zones are thought to result from secondary cementation. This type of water-bearing fracture typically has very low permeabilities , and releases of a very small volume of waters at extremely slow rates from the test holes substantiates this hypothesis . The distribution of these fractures , and their relationship to measured water depths are shown on cross-section A-A, Plate 2 . The fractures at an elevation of 4890 feet are believed to be the primary water-filled fractures for the following reasons : 1 ) This set can be traced to the north through holes TH-2 , 6 and 10 . Other cemented fractures were noted, particularly in holes TH-6 and 10 , but these zones are not laterally continuous and/or they exist at elevations -above the measured water levels . One deep fracture in hole TH-8 is _probably responsible for the water measured in that hole . 2 ) The cemented fractures disappear in the area between TH-8 and TH-3 . This is also the area where ground water is no longer present . The water in this area apparently exists under semi-confined conditions . The potentiometric surface does follow the topography, but no saturated materials were encountered at the elevation of the potentiometric surface in -any of the holes . The water from these zones filled to the present 13 871.^2s levels over a three week period showing that the hydraulic conductivity of the fractures is extremely low. A potentiometric map of the water confined An the fracture system is shown in Figure 3 . 5 . 2 . Also shown on Figure 3 . 5 . 2 is the approximate boundary of the extent of water associated with this system. The -water in hole TH-5 and well MW-26 is probably not associated with this system. The water in TH-5 probably originated from a deep fracture set ( 54 feet ) with the ultimate source again from deep percolation to the north . The water in MW-26 is thought to be part of the alluvial system associated with St .Vrain Creek . The materials beneath the rest of the site appear to be unsaturated to minimum depths of 50 feet . Table 3 . 5-1 is a summary of well and test hole elevations , depths to water, and water elevations for all wells and test holes . In the northern part of t-he filling area, where the artificially induced system exists , the potentiometric surface comes within 2 feet of the proposed 10-foot excavation depth . Again , water is not physically present at this depth . Instead, it is confined under pressure in fractures at depths that vary between 25 and 4D feet below land surface . All of the natural materials tested had low hydraulic conductivities . Measured laboratory values ranged from 1x10- 7 to 8x10-7 cm/sec . With one exception, field values from packer testing ranged from 4x10-7 to 2x10-6 cm/sec . One zone in the claystone bedrock had a permeability of 5x10 -4 cm/sec ( Fox & Associates of Colorado , 1983 ) . This zone is thought to contain a fracture similar to those discussed above . The materials above and below this zone had permeabilities less than 1x10-6 cm/sec . The Slocum Alluvium was not tested for permeability; however , it will not be used in the liner, will not be below any refuse , and is not saturated anywhere in the proposed area, so the information is not necessary. • 4 w.4-r,ln _0 — "A%-- -- 1.-411.1.1.0r kl OS' Ir' IIIIIIIMIC ILLING / I -i4 r_ 1 `y�° LIMIT �; r---� II ' It: to . . __. ,....., • „,_,..., , ,\.... Ni. tor. ,_ „it 4 . „,.., . te..._„,.. , __A an..... .----- 0 sat / IticW . ,Irmarlin \ < 92 e.5 I� � '� ' \� Val// Val r . .. �t� \\ II iiiej I J'�, s \' . III . 0 I - ,411.. i .. . ihlhjitk. rii z tr 11 � 1 .J, w � OI d <4919 Pr ,� . Sr T .,,,id, ich , ,,,....: .. ". ... J IF tritstraHl: g - ' ri ll lieLl r sate r I1 /r _ _ r Test Hole with Water Elevation ` A: �— Contour of PDtentiametric Elevation of "'— Water in the Northern filling Area 'N Y / Approximate Limit of Ground Water 41 • 'a' Beneath the Northern Filling Area p . FIGURE 3. -2 POTENTIOMETRIC SURFACE a APPROXIMATE EXTENT OF SEMIOONFI NED GROUND WATER 871326 Table 3 .5-1 Summary of Well and Test Hole Elevations and Water -Levels Approximate Water Depth to Test Hole Elevation Elevation Water TH-1 4$8E feet 4869 feet 17 feet TH-2 4930 4914 . 25 13 .75 TH-3 4905 Dry Dry TH-4 4931 4910 21 . 0 TH-5 4916 Dry Dry TH-6 4924 4998 . 25 15 . 75 TH-7 4923 4911 12 ' TH-8 4911 4882 . 75 28 . 25 TH-9 4929 4915 . 1 13 . 9 TH-10 4916 4901 . 2 14 . 8 MW-24 49S4 Dry Dry MW-25 4908 Dry Dry MW-26 4881 4864 . 4 16 . 6 MW-27 4963 Dry Dry 15 871326 4 .0 FACILITY DESIGN 4 . 1 Waste Characteristics and Volume Assumptions and Requirements Only solid waste of a non-liquid nature will be acceptedat this facility. This includes all types of non-hazardous , non-radioactive garbage and other refuse generated from industrial , commercial and residential activities . No liquid waste of any nature , including semi-solid sludges and septic tank pumpage , will be accepted. No hazardous waste , -whether or not detoxified or treated, will be knowingly accepted from small quantity generators or any other sources . We have assumed an annual gate volume of 350 , 000 cubic yards of uncompacted refuse . This is based on 1985 gate receipts from the existing Longmont landfill . We have also assumed a 2 : 1 compaction ratio and a 3 : 1 refuse to soil ratio with no bulking factors . Using these assumptions , and a 4-year site life , 233 , 000 cubic yards of soil will be necessary to cover the 700 , 000 cubic yards of compacted refuse . The City of Longmont has contracted with XTRA Corp to excavate and utilize a minimum of 50 , 000 cubic yards of soil at their existing operation, resulting in a final minimum soil requirement of 283 , 000 cubic yards . If the existing landfill requires additional soil to fulfill it ' s closure requirements , _XTRA Corp. can adjust it ' s excavation depths in the southern filling area to provide the _necessary soil . 4 . 2 Disposal Area Design 4 . 2 .-1 General Filling Plan The propossd facility will be constructed in three phases . Each phase will consist of a series of 10-foot refuse lifts . The phase locations , lift development sequence , v-ertical and horizontal dimensions , and operation directions were selected to ensure that : 1 ) no wastes are placed into or near any ground water . 2 ) surface water runon to both the site and the working faces is minimized. 3 ) soil use and movement is balanced and optimized, and 4 ) completed fill slopes can be covered and reclaimed while other active areas are still being filled. 16 871326 No liquids will be placed in the disposal area. Surface water runon will be eliminated, and refuse will not be placed in ground water. The entire landfill area will be underlain by a 2-foot thick compacted clay liner. Plate 3 shows the Landfill Phase Development Plan. Phase One is in the northeast quarter of the site . The location of Phase One was selected to minimize surface water control requirements . The first 50 , 000 cubic yards of material to be used at the existing Longmont Landfill should be excavated along the entire southern Phase One border . The excavat-ion of these soils will result in an initial filling area. Filling operations in Phase One will move uphill from south to north in 10 foot lifts . The temporary f-ill slopes on the southern and western sides will be constructed on a 1 horizontal to 1 vertical ( 1 : 1 ) slope . The final slopes that face to the southeast will be constructed on an average slope of 4 : 1 . Final reclamation ( ie . topsoil and revegetation ) will occur on this final slope as the phase is completed. Phase Two filling will begin upon completion of Phase One . Phase Two filling will begin along the eastern phase boundary and progress uphill toward the west in 10-foot lifts in the same manner as described for Phase One . As Phase Two is filled, the western slope of phase One will be covered. The south slope of Phase Two will be constructed on top of, and in a fashion similar to the south slope of Phase One , and the final contours will be tied together. The east-west trending draw in the southern half of the area will be filled during Phase Three . Filling -will begin along the eastern boundary and will progress uphill toward the west . The southern slopes of bath Phases One and Two will be covered as filling progresses . The southeast facing slope of this phase will be joined to the final slope on Phase One . The lower portion of the southern slope will also have a 4 : 1 slope , but it will gradually merge with the natural topography as filling progresses toward the east . Phase Three will be filled in three stages to minimize surface water runon to the working face . Each stage consists of two to three lifts . Filling will proceed in the manner discussed in Section 4 . 2 . 3 . The final topography is shown on Plate 4 . The top of the l-andfill will have a two percent slope and will have a northeast trending crown approximately 225 feet from the western boundary. The northern, western and and west half of the southern boundaries will meld into the natural 17 071226 topography . The eastern half of the southern boundary and the eastern boundary will have a 4 : 1 slope . 4 . 2 . 2 Filling Procedures Filling in both phases will be accomplished by a combination of ramp and area-fill methods . The ramp method will be used to construct the first two lifts in each phase . The area fill method will be used to construct subsequent lifts . Stage start and stage advancement details are shown on Figures 4 . 2- 1 and 4 . 2-2 . 4 . 2 . 3 Excavation and Refuse Placement A minimum of about 285 , 000 cubic yards of material will be needed to fulfill the soil requirements of the existing and proposed landfills . This material will come from an average 10-foot deep excavation over the entire site . This excavation depth can be changed to 12-14 feet if additional soil is needed for proper closure of the existing landfill . If fractures containing water are uncovered during excavation , the soils will be replaced and compacted. The filling plan will then be modified to ensure that the possibility of refuse coming into contact with free water is eliminated. A clay liner will be installed following excavation to final depth . Details on liner installation are presented in Section 4 . 2 . 4 and construction quality control procedures are presented in Section 5 . 0 . Once a section of the liner is constructed and approved, refuse placement can begin. Refuse will be placed and compacted in loose layers approximately 2 feet thick . Incoming waste will be unloaded at the top of the working face , wher-e it will be pushed downslope and compacted. -A minimum of three passes of the trash compactor at an approximate slope angle of 6 : 1 should result in refuse densities of at least 1O00 pounds per cubic yard. Refuse material will be placed in this fashion until a lift thickness of approximately 10 feet is attained . The lift will be advanced upslope to near the end of the active phase . A minimum soil cover of 6 inches will be placed over all exposed refuse each working day. When a lift is completed, the next lift will be started at the low phase boundary and advanced over the top of the previous lift . Lifts will be placed in this fashion until the phase is completed. Schematic cross sections are shown on Figures 2 and 3 , Plate 1 . 18 871326 M t0 m c I 2 P • W t• r NI-- o co o a o .-..!.�� o OE ce . • v t / 2 0 vI. e i v Ii o 0 Z • / i d a -J w OW ri Ww W ZD V J J J O Q S-) .47.o m co - - N (n= 3 1 i •CC .- Z `o W W > 2 r d W C9 _ w �� .r�J A cu F J= J / a a) J 1� i4- -� a A W /* _�1 ra _!1� m a) ro o e o a) a A w " - '., a)• C . 0 o O r1 -r w "' > �E �N 01 a a) a) O A x o / 0 o . .In ° • �• % „Z m O 0 o 3 a w (DO Id -41 — 9 ! u . W a+ a) a) w Li1 '� n A SS C 4 (.0 '�^ h O1-u ) b- F`FI-- V - C 4-1 15) 0 b, to C i -'i >'1 a a) 1) a) la 0 0 .a03 aim ow cn Ui wo +Ia alga, a) a -$ E-•• ai m o o *En %=-E O• .• 0)O•C.A O w UN -.i M 1J j a i O '-- a A �C �lE I Itnr°3 / J -I _ J_ / �� % , _ _ r J t IluJ. I i.`. IN I n CO J • I� I i,1 ' a L� I Si 1- N I /", W CD W \ II _H %* 0 H \ = e J I— /' to \ / y W \ / e / I W 5I, ,. -o r . Z Q In 5 Q c N 0o I o N W N Q W O > / n`\0 to o a. I- ¢ a / % u o V) F / 0 0 OW l � F \\ E o _Cr M ( �N 2 I " 87/323 As portions of each phase reach their final elevations , the site , they will be covered with 2 feet of compacted clay, 1 foot of uncompacted soil and 6 inches and of previously- stockpiled topsoil . The final cover will then be revegetated in accordance with the revegetation recommendations described in Section 7 . 0 . 4 . 2 . 4 Clay Liner and Cover Construction The construction of the clay liner is a very important aspect of the landfill operation . The clay will be placed in six inch lifts and compacted with a Sheeps _Foot Compactor until it reaches a compacted dry density equal to or greater than 95 percent of the Standard Procter density (ASTM-D-698 ) . The moisture content of the material shall be maintained within 2 percent of optimum moisture content using the same testing criteria. Not less than two feet of material will be compacted to these specifications . The material used for clay liner construction shall have a Unified Soil Classification of Cl or CL-CH and shall have no more than 50 percent plus 200 mesh size material . In addition , the soil used for liner construction shall have a plasticity index greater than 10 . Material which meets these specifications will have a re-compacted permeability of 10 -7 cm/sec or less . Based on these material specifications , and the soils testing data collected during the field program, approximately 80 percent of the materials present at depths less than 10 feet will meet the specifications . The two foot compacted clay portion of the cover will consist of material which has a plus 200 mesh size specification of less than 50 percent . The material will be compacted to a minimum of 95 percent of optimum proctor density ( ASTM-D- 698 ) with a moisture content of plus or minus 4 percent . Construction quality control procedures for liner and cover construction are presented in Section 5 . 4 . 4 . 2 . 5 Material Quantities Soil volume requirements for daily cover , final cover and landfill liners are based on average refuse to soil ration of 3 : 1 ( ie . 25% of the total airspace within the landfill will be filled with soil ) . Even though the site is designed with a two foot clay liner and a thicker than normal final cover ( 3 .5 feet ) , this is a conservative estimate because of the 19 87132S thickness of the refuse , the ideal shape of the filling area, and the amount of intermediate cover which will be reused. Material volumes are summarized on Table 4 . 2-1 . The material balance indicates that the balance between the soil excavated and the soil required is even; however , additional material is readily available from the Phase Three area if necessary. No ground water exists at shallow depths in this area , so the excavation depth can be much greater than 10 feet . 4 . 2 . 6 Surface Water Control Surface water will be controlled to ensure that runon is not allowed to enter the active disposal area and that any surface water which falls on the working face -is not allowed to leave the site. Intermittent historic flows from the site should not changed due to construction of the landfill . No significant changes in the amount or quality of water flowing from the site are expected. To control the surface water , two types of diversions will be constructed on the site . Three temporary drainages will be constructed to divert natural flows away from the active filling areas . As landfilling progresses , and the lifts and phases are completed, the temporary diversions will be abandoned and new diversions will be constructed at higher elevations on natural slopes , continually routing runoff from undisturbed natural areas around the landfill . The approximate locations of the temporary diversions are shown on Plate 3 . Permanent diversion channels will prevent surface water runon to the completed landfill and safely route runoff away from the completed slopes . These diversions will be constructed along all landfill boundaries and the temporary diversions will discharge into them. Permanent diversion locations are also shown on Plate 3 . Design information on them is in Appendix B . 4 . 3 Support Facilities 4 . 3 . 1 Access Access to the site will initially be via the existing landfill road. This road -will be extended westward along the northern perimeter of the current landfill until it intersects the eastern boundary of the proposed landfill ; the ingress/egress point . Eventually, access to the site may be provided by a new road 20 871226 Table 4 . 2-1 Material and Refuse Volumes Phase 1 Phase 2 Phase 3 Total Total Air Space 297 118 508 923 Total Soil Excavated 84 48 150 282 Total Soil Required 74 30 127 231 Soil Surplus 50 0 0 50 ( from fill area) Note : All values x 1000 cubic yards 21 871326 from State Highway 119 . The road will run due south and will intersect the site at its northeastern corner . The road will be constructed once right-of-way and easements are obtained over the land between the site and the highway. Both roads will be 40 feet wide to safely accommodate entering and exiting traffic and will have no grades in excess of 6 percent . The roads will be covered with gravel and elevated where necessary to promote drainage and prevent soft spots that could cause traffic slowdowns or hazards . The facility entrance will be at the northeast corner . A gatehouse will be constructed to provide shelter for the gatekeeper and to serve as a lunchroom for employees . A sheltered area may be constructed for vehicle storage and maintenance activities . The proposed facility layout is shown on Figure 4 . 3-1 . Withi-n the landfill site , temporary access roads will be constructed to the active area as -needed. These roads will not exceed an 8 percent slope . The main access road on the site will be the temporary haul road to the working face . Gravel may be utilized during inclement weather and calcium chloride or water will be applied during dry periods to control dust . Temporary road directional -devices , such as signs , barricades , pylons , etc . will be used as necessary to control landfill traffic within and around the -working area. Separate roadways or lanes will be utilized for ingress and egress to the active face . 4 . 4 Permanent Site Fencing Unauthorized access to the landfill facility will be prevented by permanent site fencing around the landfill entrance area and the final active filling area . Six foot high chain link fence with a 2-foot canopy will be used around the -entrance area in the northeast corner to _secure the gatehouse and equipment areas . The filling area perimeter will be fenced with 6-foot nanclimbable fence topped with three strands of barbed wire . Additional portable fencing will be installed to control blowing litter. Details on this fencing are in Section 6 . 2 . 1 . 4 . 5 Resource Recovery Resource recovery activities in the Rocky Mountain Region have been attempted in the past . They generally fall into one of two categories . First methane gas generated from landfill sites , as a by-product of decomposition, has been proposed as a possible source of energy. Experience in this 22 871325 Imo_ Me .r)li N cI a I\ i , co I ,,•d o mow, a U U Q,SCALE a �� 010 t z 250 la INITIAL ACCESS VIA o� EXISTING ROA�� 0‘Iiiihaliiihm<� - ;ATE OUSE �� .. g' \Jrrroler .w � tt 4 . 'E- {VENT FENCE 1EQUIPMENTI . r�.ra`-- �. AREA ','ii r�r \`, ` n`J illib to III///-I��) ai_ y.e? \ \ 4iS IlL NIL -S---'7%_ __ �� i " ' 0XIM'TE t'r' 'E-M NENT FENCE,' 'a 'FILLING i / . Illt----.. .al la i11/411 \ � arlitiri X‘ al t ..mirNin3/4N-141/271,7-7416,--:-,-;71);FitHrr Ta-CAIL ___\>4 Ihir %Lie oftreri tsii_ . 5,- art \ le:/// ri: 1 .-- lig - r- It lel flWSr FIGURE 4.3-I PR0P* . . - . - , 871326 region, even at old uncontrolled landfills with saturated refuse , is that the volume of gas generated is not sufficient to make resource recovery economical . Water is generally required to increase the rate of refuse decomposition and gas production . The site climate is relatively dry, infiltration is minimal , and a primary operational goal is to keep water away from the refuse ; therefore , it is unlikely that refuse decomposition will generate economical volumes of landfill gas . The second type of resource recovery involves separating recyclable materials from the refuse . National experience indicates that economical recovery of recyclable materials generally requires separation of the recoverable items at the source ; that is , the generator of the refuse must separate the recoverable items prior to pickup at their site or home . If Weld County is interested in investigating the possibility of source control of refuse material , the operator of this facility would support this activity. 23 871326 5 . 0 CONSTRUCTION AND OPERATION QUALITY CONTROL 5 . 1 General Construction quality control is extremely important to ensure that facility designs are implemented and landfilling progresses in accordance with the approved landfill plan. There are four key quality control areas that will be monitored during the development of this landfill . Each is discussed separately in this section of the report . 5 . 2 Excavation and Inspection To ensure that excavations in the landfilling area are constructed in accordance with the landfill design , and that the conditions are consistent with those described in this report , excavation inspections will be made in each new excavated area. Inspections will be made by an independent consultant who will then produce a written report that includes observations made in the newly excavated area and a map showing the inspected areas . Copies of the excavation inspection reports will be supplied to both Weld County and the Colorado State Department of Health . 5 . 3 Clay Liner and Final Cover Construction Inspection and Quality Control To ensure that the liners and covers are constructed in accordance with the specifications outlined in Section 4 . 2 . 3 , an independent soils and materials testing firm will be retained to observe and test materials placed for both clay liners and final clay covers . The program will consist of material classification tests conducted for every 3 , 000 cubic yards of clay material placed in the liner and for every 3 , 000 cubic yards placed in the cover . This type of testing will ensure that materials placed are suitable for their intended use . In addition, compaction and moisture content testing will be conducted on the compacted clay liners and covers . Moisture density testing will be conducted at no less than a 100 foot spacing interval for the liner and 300 foot spacing for the cover . If compacted clays are found to be below 95% of standard Procter density ( ASTM D698 ) for the liner and 90 percent for the cover the materials will be removed and recompacted. Initial landfilling will not be allowed over lined portions of the landfill area without an engineering report from the construction quality control contractor indicating that the materials have been placed in accordance with the recommended design. Copies of the 24 871326 construction quality control reports will be provided to both Weld County and the Color-ado -State Department of Health. Lined areas will be covered as soon as possible with the first refuse lift . However ,to -ensure that the clay liners are not allowed to dry -and/or otherwise deteriorate prior to covering with refuse , they will be moistened on a regular basis . If any part of -a liner is left uncovered for more than 2 months , it will be inspected by the quality control contractor prior to covering . If repairs and/or recompaction are required, the work will be conducted prior to refuse placement . If the operator knows that a lined portion of the site will not be covered with the first refuse lift within a 2 month period, a 1—foot layer of moist miscellaneous fill will be placed over the liner for protection . 5 . 4 -General Operational Inspections Operational inspections of the entire facility will be made on a quarterly basis for the life of the landfill operation . The inspections will be made by an independent contractor experienced with landfill operations . The inspections will be made to ensure that the landfill operation is progressing in accordance with all aspects of the approved landfill plan. Inspection reports will be prepared and submitted to both Weld County and the Colorado State Department of Health . 5 . 5 Till and Excavation To ensure that fill , excavation volumes , and material balances are being achieved as landfilling progresses , the landfill area topography will be mapped on an annual basis . Annual mapping will be used to determine actual annual air space and soil borrow used. An annual material balance report will be prepared and will be available for inspection by Weld County and the Colorado State Department of Health . 25 871226 6 . 0 FACILITY OPERATION 6 . 1 Site Management 6 . 1 . 1 Operations Schedule The proposed facility will generally operate betweem the hours of 7 : 00 A.M. and 5 : 30 P .M. six days -a week . Winter hours may be changed depending on available sunlight . The facility will be closed on the major legal holidays . 6 . 1 . 2 Equipment and Personnel Requirements The following personnel and equipment are expected to be utilized at the site : Personnel : 1 supervisor 1 gate and record keeper 2 heavy equipment operators 1 labor/spotter (as needed) Equipment : 1 trash compactor 1 scraper 1 caterpillar 1 motor pool ( grader ) 1 2 , 000 gal . water truck Facilities : 1 gatehouse 6 . 1 . 3 Control and -Record Keeping Incoming waste verification and record keeping will be performed by trained gate attendants . These attendants will be familiar with the types of wastes allowed at the facility and will have the authority to deny vehicles carrying hazardous and/or other unacceptable waste admission to the facility . They will be made familiar with the Operations Plan and Permit conditions for the facility. Accurate records will be kept of gate receipt volumes . In addition, results of all of the monitoring activities discussed above will be retained. Copies of all reports will be forwarded to Weld County and the Colorado State Department 26 87132 of Health. Copies will be also be maintained by the site operator and will be made available for inspection by authorized public agencies . The site operator will keep the following records on site and available for county and state review: 1 ) Reports of construction quality control . 2 ) Litter policing reports . 3 ) Volume and types of incoming refuse . 4 ) Results of gas and water quality monitoring . 5 ) Any special waste accepted. 6 . 1 . 4 Safety Control Safety control at the facility will be the responsibility of the site supervisor . Normal safety precautions will be observed while people are near or are operating the landfill equipment . At least two employees on site at any time during operating hours will be trained in first aid techniques . A well stocked first aid kit will be kept in the landfill office at all times . Emergency telephone numbers will be prominently posted in the landfill office . Posted telephone numbers will include local police and fire departments , the nearest hospital site , Weld County Health Department and the Colorado State Department of Health . 6 . 1 . 5 Water Requirements and Supplies Both potable and nan-potable water will be required during site operation . Potable water will be supplied by a bottled water service and will be available on site at all times . Non-potable water may be required for compaction of clay liners and covers and occasionally for dust control . The quantity of non-potable water will be highly variable depending upon the type of activity being conducted at the site . Non-potable water will be purchased off-site , transported to the facility , and stored and utilized on an as-needed basis . 27 871326 6 . 1 . 6 Site Operator In the event of non-compliance with any regulation or permit condition, the following person should be contacted: Mr . Chuck Hayes XTRA Corporation 998 E . Highway 119 Longmont , CO 80501 ( 303 ) 772-3905 Mr . Hayes , an immediate neighbor to the site , will have the authority to initiate corrective action . 6 . 2 Control of Nuisance Conditions 6 . 2 . 1 Litter Control The topography of the site and surrounding areas with respect to the prevalent wind direction will help to reduce problems associated with blowing refuse . However , windy days will occur and additional measures will be implemented as necessary to control litter . The following operational measures will be employed to control blowing litter at the site : 1 ) Application of soil cover during refuse placement and at the end of each day. 2 ) Limiting the size of the working face during windy periods . 3 ) Permanent and moveable site fencing . 4 ) Ceasing operations during periods when high winds are present . 5 ) Litter pickup activities . Application of soil cover during refuse placement and controlling the size of the working face are the most effective means of controlling blowing litter . Generally a working face size of 100 to 150 feet will be maintained. On windy days the size of the working face will be reduced. In addition to soil cover control , fencing will be used to control blowing litter . Permanent site fencing for the facility is described in Section 4 . 4 . Temporary fencing will be placed on each stage, so that the fencing increases in 28 871326 elevation as the fill elevation increases . In this manner, the fence will remain above the height of the working face or the fill to reduce the possibility of blowing trash reaching the permanent site fencing . Temporary removable fencing will also be used in the working face area as necessary to further control litter during windy periods . The use and placement of refuse working face fencing will be left to the judgement of the site supervisor who can best adjust the fencing for local topography and temporal variations and wind directions . Wind velocity measuring equipment will be maintained at the proposed facility. The landfill supervisor will place his daily cover and cease landfill operations during periods when high wind warnings are verified. High wind warnings are defined as sustained winds of 40 miles per hour or greater , or gusts of 55 miles per hour or greater that are expected to persist for one hour or longer . In the event that litter escapes from the working face for any reason, it will be manually picked up and returned to the working face by site personnel and, if required, additional temporary labor. The operator will make every reasonable attempt to satisfy the concerns of the surrounding private property owners with respect to cleanup and removal of blown litter . If needed, this will include scheduling pickup from those properties . Blowing refuse often times comes from vehicles transporting materials to the facility for disposal . To minimize this type of littering , the operator will maintain a fee schedule that will penalize all uncovered loads which come to the site . The penalty for bringing an uncovered load to the landfill will be a fee which is twice the normal disposal fee . 6 . 2 . 2 Vector Control Disease and nuisance vectors will be controlled by expeditious application of refuse cover to minimize food and harborage . If additional vector control is required, the services of a professional exterminator will be obtained by the site supervisor . 6 . 2 . 3 Odor Control Odors at sanitary landfills result from a variety of sources , usually contained in the incoming refuse . The odors generally dissipate within a few hundred feet of the working 29 87132s face . Application of soil cover as described in this plan, is the only effective procedure for controlling these odors . 6 . 2 . 4 Dust Control Dust and particulate matter originating from winds , vehicular traffic and operational equipment will be controlled by the site supervisor. During dry periods the operator will have the option of using either calcium chloride or water to minimize the amount of dust generated at the facility. Applications of these materials will be made whenever deemed necessary by the landfill supervisor . -6 . 2 . 5 Fire Control No burning of waste will be permitted at the landfill site . If a fire occurs in the refuse , it will be extinguished by excavating and removing the burning refuse and covering it with soil . In addition , all equipment operators will keep fire extinguishers on their machines to control small fires that do not require excavation and covering . 6 . 2 . 6 Methane Gas Control Methane gas is a by-product of decomposition of organic refuse . Methane gas generation rates increase as the moisture content of the refuse increases . Refuse moisture content will be minimized through an outright ban on both saturated wastes and the placement of refuse below the water table . These practices in themselves will not eliminate methane gas generation within the landfill , so migration of methane gas below the natural ground surface will be prevented by the landfill liners and the low permeability natural geologic materials . Methane gas will migrate and escape from elevated portions of the landfill through the covered surfaces . Methane gas monitoring procedures are discussed in Section 6 . 3 . 3 . 6 . 3 Environmental Monitoring Environmental monitoring at the site will be conducted to ensure that the facility design and construction is performing as planned. Components include leachate detection monitoring , ground water quality monitoring and methane gas monitoring . Monitoring locations as shown on Figure 6 . 3-1 and on Plate 1 . 30 871325 MONITORING PROGRA" FOR THE LONGMONT LA "FILL Y Ii r-7—"n9 ' 999 I _ ise � ILLING / .` J 'yx LIMo � �- • ` sk. ' �� '' \494,.,_ —� — , - �► ��" -1_ ___ - """-C- -7— ''''',"--- 7,1".• _— ti�� 1 (IR: 7 , ------, ,,..........t. . „-N. \ 4,,.,... \ ACT i er,.......t, \ 9b ,...., - - /7 • ,,‘„ , .. \ , 1 {I vvII ; � _ ,; , I m II A II 11 ( I IL Va C. i \I / . ----- II \`` �''7�� / 'se r p Jr do 7 f br \r � � � Leachate Detection System j _ ________ • Monitor Well Cluster P � _:�� • Leachate Monitoring Well —_ — a,. Methane Monitoring Well N Monitor Well Cluster with .,„r Methane Monitoring 7i p FIGURE 6.3- 1 6 . 3 . 1 Leachate Detection Monitoring Construction details for the system are presented on Figure 6 . 3-2 . A manhole and gravel detection structure will be constructed between the edge of the excavation and the downstream toe of the first lift in the lowest part of the excavation at the location shown in Figure 6 . 3-1 . The leachate detection system will also include four monitor wells that are inside the fill area and are spaced 50 feet on-center along the southeast facing boundary of Phase Three . The wells will be drilled into the refuse between the excavation cut and the first lift berms . Well depths will be determined by the depth of refuse , and in no case will they penetrate the clay liner . The wells will be constructed using 2-inch diameter thread coupled PVC pipe placed in 6- inch diameter drilled borings . The bottom ten feet of the casing will be slotted and the annular space will be filled with gravel pack to within ten feet of the surface . A two foot bentonite plug will be placed on top of the gravel pack and the remaining annular space will be filled with concrete . Since these wells will not contact any ground water , permits or waivers from the Colorado Department of Natural Resources will not be necessary . The leachate detection system should never contain water , however ; each well and the manhole will be checked quarterly during every monitoring period. 6 . 3 . 2 Ground Water Monitoring The ground water will be monitored at key points on a quarterly basis as a back up to the leachate detection monitoring system. Well locations and sampling intervals were selected in a fashion that would: 1 ) Provide representative background data on the natural waters 2 ) Intercept the ground water along flow paths directly in-line and down gradient from the the landfill 3 ) Monitor the waters nearest to the surface that would be the first impacted if a release were to occur . The topographic configuration of the site is similar to an open-ended trough . Any shallow ground water that is present near the surface should flow in basically the same directions 31 87132'S A. T 0 O c i a F 1A w v c W Hu E ti ¢ f n9 v w E o Z UI ISC co W . \ eO. U e ; NN 2 w ?.Q o.. De v D •_z Z W �: :Q Z 0 d i O O — Cpp.�:o:. W v- ct �z o':;:O:c::.Q0: aco " � w •aQ::.' oQ W w �OJ C'• p:Q•O:' � � OD° pc• 2 .-m ZZ 0. ..Q .: W a W ¢ 0Q';'0..o.. ..p' D. . � � A O O o `'O t to CO N • � ..o .. W / W \ r cn m J _ U ^ W y co IX Jj N o I CO LJ CO N� 41 = W U CC 4 a. W 0 J E. -871 325 as the surface water - toward the low point beneath the center of the gully at the southeastern boundary. Four wells will be installed at two locations along the southeastern property boundary ( Figure 4 . 3-1 ) . Two of the wells will be installed at one location near the thalweg of the existing gully where it exits the site along the southeastern boundary. The other two wells will be installed near the intersections of the southeastern and eastern fill boundaries . At each location , one well will be installed in the saturated zone while the other is installed in the overlying unsaturated materials . The uppermost saturated zone is thought to lie at the boundary between the sandy claystone and claystone ; however , the zone is thin and not easily located by conventional auger drilling and sampling techniques . This information is critical to ensure the placement of a slotted interval that will access the proper zone , so the first hole will be advanced in a fashion that will permit the collection of continuous soil samples . Continuous sampling will start at land surface and continue to a depth that is 5 feet below the saturated zone . The placement of the slotted interval will depend upon the conditions encountered. If the water originates from a fracture system and is under confined conditions , the slotted interval will be restricted to the saturated interval . If the water is under water-table conditions ( seasonal fluctuations in the water table that result in increased or decreased material saturated thicknesses ) the slotted interval will be increased to include the entire zone where water table fluctuations are expected to occur . Another well will be installed in the same approximate interval at the other location . The interval will be selected using the continuous core information from the first location combined with the cuttings and split spoon samples collected during the drilling of the second hole . Wells will also be completed at both locations in the outlying unsaturated zones . These wells will be dry, so they will be used to monitor for the presence of water in previously dry horizontal fractures . The wells containing water will be sampled in accordance with EPA sampling procedures , and chain-of-custody procedures will be followed. Sampling will be conducted on a quarterly basis , and results of the water quality analyses will be 32 871326 submitted to both Weld County and the Colorado State Department of Health . All water samples will be analyzed for the following parameters twice a year : -Calcium Magnesium Lead Sodium Potassium Iron Chloride* Sulfate Alkalinity Ammonia* Total Dissolved Nitrate- Solids Nitrite Specific Conductance ( field) * Chemical Oxygen Demand pH( field) * Total Organic halogen* Total Organic Carbon* Phenols ( *indicates parameters to be analyzed quarterly) The operator will make justifiable changes as needed if the Weld County Health Department or the Colorado State Department of Health would like to amend the ground water sampling parameter list at some later date . 6 . 3 . 3 Methane Gas Monitoring Methane gas monitoring will be performed simultaneously with the ground-water sampling episodes . Methane monitoring wells will be constructed, or existing wells utilized, around the perimeter of the final landfill boundary to depths equal to the depth of excavation adjacent to the well . New wells will be placed 500 foot on center on all final landfill boundaries . Wells will be constructed using 2-inch diameter glue-joint PVC casing placed in 4-inch diameter borings . The PVC will be slotted and gravel packed to within 10 feet of the ground surface . The annular space above the gravel pack will be backfilled with dry bentonite . Proposed monitoring locations are shown on Figure 6 . 3-1 . 6 . 3 . 4 Proposed Action In Case Of Negative Monitoring Results If at any time negative monitoring results are obtained, the state and county will be notified of the results within five working days . -The operator will request a meeting with Weld County and the Colorado State Department of Health to discuss the monitoring results . If necessary, confirmation sampling and testing will be conducted. If an environmental problem 33 is confirmed, the operator will have an additional 30 days to evaluate the data and present a plan of action to both the county and the state . The plan will include specific actions and a time schedule required to correct the situation. On approval , the plan will be implemented. 34 871?26 7 . 0 CLOSURE AND POET CLOSURE 7 . 1 Reclamation and Revegetation During landfill -excavation, a minimum of 6 inches of topsoil will be removed and stockpiled outside the filling area. This will be done for any disturbed area of the site . Only that area required for operation of each subsequent refuse lift will be stripped of topsoil , so as to minimize disturbance and exposure of the topsoil . Topsoil stockpiles will be revegetated as necessary to minimize -erosion and to increase the organic matter in the topsoil . Signs will also be posted on the topsoil stock piles so that they are not mistakenly used for cover . The completed portion of each phase segment will be covered with topsoil and seeded as soon as practically possible . The cover will be a minimum of 3 .5 feet thick , with the bottom 2 . 0 feet consisting of compacted clay and the top 1 . 5 f-eet consisting of 6 to 12 inches of uncompacted soil overlain by a minimum of 6 inches of topsoil . All but the topsoil will be placed as soon as possible over areas in which r-efus-e placement has been completed. The topsoil will be placed immediately prior to seeding . The subsoil surface will be roughed with a disc plow scraper or similar equipment to ensure proper binding of topsoil to subsoil , and all large rocks and debris will be removed from the topsoil prior to seeding . Analyses will be performed on all topsoils to determine fertilizer requirements for supporting the species to be planted. When fertilizers and/or soil amendments are necessary, they shall be applied i-mmediately before or after seeding . Prior to the establishment of grass , the seed bed will be protected from wind and water erosion by application of a straw mulch or biodegradable jute , or by planting a cover crop. Seed species , and planting times and rates will be determined through experimentation with revegetation test plots . The Weld County Soil Conservation Service will be contacted to provide input as necessary. The mix will be selected for compatibility with the climate , surrounding vegetation , wildlife , and site-specific soil conditions as well as landfill reclamation potential . 7 . 2 Post Closure Monitoring The five water monitoring wells , the leachate detection system and the methane monitoring wells will be sampled or checked quarterly during the post closure period of 5 years . 35 328 Analyses will be identical to those conducted during the life of the facility. If monitoring results for a given sampling vary significantly from previous samplings , additional samples will be collected and analyzed. If the additional results confirm a significant and adverse change in conditions , the _proposed action described in Section 6 . 3 . 4 will be undertaken. 7 . 3 Post Closure Inspections and Maintenance Post closure maintenance should not be required for the completed landfill ; however , refuse settlement may occur, even though it will be minimized by the compaction procedures detailed in this plan. Similar compaction procedures are used at landfills along the Front Range , and no detectable settlement has occurred during the life of these facilities . The potential for settlement -does still exist so inspections of site grading and vegetation will be performed semi- annually during the 5 year post closure period. The inspections will include documentation of surface cracking , erosion, slope angles , drainage , and condition of vegetation. One of the inspections each year krill be made in late spring, -when damage would most likely occur due to thaw and runoff. Any damage or other deficiencies will be promptly repaired. 7 . 4 Post Closure Land Use Future land use and development will probably be determined by the land owner . No specific development plans exist beyond site revegetation. -Existence of a closed landfill does not prohibit future land use , but such use will necessarily take into account location and size of the property, actual and potential settlement , landfill gas generation, land slope , zoning , and needs of the land owner. Prepared by: INDUSTRIAL COMPLIANCE INCORPORATED M. �1. / j a�aaanmmwrnnii i�, ZE vp* filsons. la 8-43:44 o y!`� /4 1•103 ,yam 1648 So t Michael H. Stewart, P.E . 4331 n300 �� 'Ley� Senior Engineer -.o; G 1!'T 4caln •144 a1r a yip 6.01N u�VA"� �p ELH.W 36 8 . 0 REFERENCHS Cotton, Roger B . , 1978 , Geologic Map of the lBaulder-Fart Collins-Gr-eeley Area , Colorado , U . S . Geological Survey Map I-855-G. Davis , 1'. L . and Weimer , R . J . , 1976 , Late Cretaceous Growth Faulting , Denv-er Basin , Colorado , in Prof-essional Contributions of Colorado School of Mines , Number 8 , pp . 280-300 . Fox and Associates of Colorado , May 1983 , Landfill Site Suitability Evaluation for Expansion of the Longmont Landfill , Pr-epared for the City of Longmont Colorado . Fox and Associates of Colorado , November 1983 , Environmental Impace Assessment , Closure and Operation Flan for the Longmont Landfill , prepared for the City of Longmont Colorado . Rob-son , S . G . , Wacinski , Andrew, Zawistowski , Stanley and Romero , John C . , 1981 , Geologic Structure , Hydrology , and Water Quality of the Laramie Fox -Hills Aquifer in the Denver Basin, Colorado , U. S . Geological Surv-ey Map -HA-650 . 37 -t ": 226 APPENDIX A SDIL Pi LABORATORY RESULTS e71.,n5 Engineering and ibsting Consultants, Inc. /alt. 8888 West 51st Avenue litr.= ;, ;I Arvada, Colorado 80002 r 1303) 424-0892 Industrial Compliance, Inc. November 25 , 19186 511 Orchard Street Project No. : Golden, Colorado 80401 86-62210 Attention: Mr. Scot . Donato Subject: Laboratory Testing Results on Liners Submitted on _November 17, 1986 , Project No. 1608 Dear Mr. Donato: This letter is to inform you of the results of the laboratory testing performed on samples obtained from you. The results of the tests are as follows: Percent Sample Depth Passing Moisture Dry Liquid Plasticity No. (ft) #200 Sieve Content Density Limit Index 1 14 . 0 -- 16.2 118 . 0 -- -- 1 20 . 0 -- 9.5 -- 2-6 11 2 4. 0 -- 9. 0 125. 7 -- -- 2 10 . 0 -- 8.2 -- 28 11 2 14 . 0 -- 11.5 107. 9 -- -- 2 2D.D -- 12. 4 -- 27 12 2 3D .D 98. 7 1D.5 -- -- -- 2 60.0 -- 15.9 -- 29 17 3 4 .0 -- 3. 7 -- 24 24 3 14 .0 59. 2- 6.2 -- -- -- 4 4 .D • -- 5.3 -- 23 23 4 14 .D -- 11. 4 111 . 0 -- -- 4 24 .D -- -- -- -- -- 4 518 .18 -- 17 .3 -- 27 14 5 1D .D -- 11.3 -- 29 14 5 14 . 0 -- 12.1 98.6 -- -- The results of the Proctor test for sample #2 at a depth of 25-33 feet is 113.0 pounds per cubic foot at 14 . 0 percent moisture content. The permeability test on sample 44 at a depth of 24 feet has not -been completed at this time. You will be informed of t#ie results when the test is completed. 871.725 Site Investigations Engineering Inspections Field Instrumentation Laboratory Testing Plansand Specifications Please contact our -office if you have any questions concerning these results or when additional tasting is required. Engineering and Testing Consultants, Inc. Reviewed by: • /1/4-10114miturei" -aaderf 9 4/V177/ -Mohammad Jadid Daniel F. Schneider, P.E. Staff Engineer Principal Gaotechnical lEngineer MJ/kh o. Ei • , • „-nil 84 02 4%.• t :c7= Engineering and Testing Consultants, Inc. 87 326 • Engineering and Testing Consultants, Inc. ;J 8888 West 51st Avenue Arvada, Cnlorazio 80002 (303) 424-0892 Industrial Compliance, Inc. December 2 , 198$ 511 Orchard Street Project No. : Golden, Colorado 80401 866221-0 Attention: Mr. Scot Donato Subject: Permeability Testing Results on -a Liner Submitted on November 17, 198-6 , Project No. 1608 Dear Mr. Donato: This letter is to inform yon of the results of the permeability testing performed -on a sample obtained from you. This sample was labeled #4 at a depth of 2-4 feet. The permeability of this sample is 5 . 7 x 107 centimeters per second. Please contact our office if you have any questions concerning this result or when additional testing is required. Engineering and Testing Consultants, Inc. Reviewed by:Agyinneit_Mohammad Jadid Daniel F. Sd nieder, P.E. Staff Engineer Principal Geoteohnical Engineer MJ/kh `\`\�NNNNNTIMIti �i�i�i, O f ..y. R ' c G!• . ' :e O- 20484 Site Investigations Engineering Inspections Field Instrumentation Laboratory Testing Plansand Specifications RECEIVE) N Engineering and Testing Consultants, Inc. �� p- 8888 West 51st Avenue -Arvada, Colorado 80002 1303) 424-0892 Industrial Compliance, Inc. December 8 , 1986 511 Orchard Street Project No. : Golden, Colorado 80401 8662224 Attention: Mr. Scot Donato Subject: Laboratory Testing Results on Samples Submitted on December 4 , 1986 , Project No. 1608 Dear Mr. Donato: This letter is to inform you of the results of the laboratory testing performed on samples obtained from you. The results of the tests are as follows : Percent Sample Depth Passing Moisture Dry Liquid Plasticity No. (ft) #200 Sieve Content Density Limit Index 2 10 . 0 75 . 5 -- -- -- -- 2 20 . 0 82 . 9 -- -- -- -- 4 20 . 0 92 . 3 -- -- -- -- 3 4. 0 32 . 2 -- -- -- -- Composite -- 16 .1 -- -- -- -- Please contact our office if you have any questions concerning these results or when additional testing is required . Engineering and Testing Consultants, inc. Reviewed by: ' 7. �p�@\1n01IR Ull4,�j��d // �' ��rr oQpo,A,..F�isr�� i ZL.10117tzrtl� arh ' , . eft, %., ,i•oC04r• ." Mohammad Jadid 3lanielz�:y$chnei4�r,P.E. Staff Engineer PrincT��G2048 h}nJc Engineer — ptac MJ/kh �+' ti errirnun Trim ia`°° IPP Site Investigations engineering Inspections Field Instrumentation Laboratory Testing Plans and Specifications Engineering and Testing Consultants, Inc. /`. � 8888 Nest 51st Avenue l Arvada, Colorado 80002 (303) 42-.4-0892 Industrial Compliance, Inc. January 's , 198"1 511 Orchard Street Project No. : Golden, Colorado 80401 86-'2227 Attention : Mr. -Scot Donato Subject : Laboratory Testing Dear Mr. Donato: At your request, laboratory testing was performed on sample number 3 -at a depth of 3 feet. Testing included a remolded permeability, standard proctor, -and a minus #209 wash. The results of the laboratory testing are presented below: Maximum Optimum Percent Remolded Dry Density Moisture Sample Depth Passing -Permeability ASTM D-698 Content No. (feet) #200 _Sieve (cm/sec) (pcf ) ( % ) 3 3 47.3 -- -- -- 3 3 -- S .D3X1-0-B -- -- 3 3 -- -- 109 . 0 -- 3 3 -- -- -- 1b . 5 Note: Remolded permeability taken at 95% of proctor denstty(103.6-pcf) Please call us if you have any questions regarding the laboratory testing. Engineering and Testing Consultants, Inc. Reviewed by:- min /01 S-andra L. Erskine Daniel6: 4Mesg E. Project Geologist Prinic GeotechnitprI -Engineer 871126 Site Investigations Engineering Inspections Field Instrumentation Laboratory Testing Plans and Specifications 2-M Industrial Compliance Incorporated 15955 West 5th Avenue Golden, Colorado 80401 (303)279-2636 PACKER PERMEABILITY - DATA SHEET . Boring No. I Job No. /607 • Boring Radius (r) 4 •' (ft) Engineer Depth of Boring (d) 2`1 • (ft) Date /O - ' - 6"6 - Depth to Static Water (A) — (ft) Flow Meter No. >7 o 440-5‘r 1 Depth to Center of Packer (8) 1 K (ft) Height of Gauge above c Gauge Pressure (P) Slts1 ,-S (osi ) Ground Surface (C) (ft) • Flow Data Notes` -1 ER j- v fTn� UI:F . ; FJa- 1f1 1�') 3 � 4 Cubic ItJ tf' L. Time Gallons Feet Flow Rate n1-0 C1AN6L �Nq�C4 Pr C 6751 /Soo �6(-(9, °''lr,�� 8,41 to''i No CNA✓c£ 6 p 7,SI f c\y ,I•nt to 9 ).o0 3‘t(II GS,I _3 In a2 00 36 U4'i 3S Z. 23 y to Air-z- a --0F5I WA-rciz- @ oZSf ,, 61 11bw51' 2 23X1° 3 I' 3I :oo 3 Q' 1,x,`4` • .6 Kw fo,; 3,-oui eac�ct ..r.,t-t. C 3 (.7b 3st, �l , S r .t/z6091 b ,,_ a 1 , 34 xro E / Ua 3Goo /4, g .1-17-, brio Z Sob 3 z • Average Q - ft3/min CALCULATIONS K - Q In L :1- 1Dr L - d-B Tr1 H . B + C + (L/2) + (0(2.31 )-S K - sinti1 L : 1Dr>Lar where S - B + L/2 - A "rLH ₹r Note: If no free water is encountered. - Si " 5 es; i I{.: 411.1‘41 61 `i'tvc- 8.4 x td4 C-3'w,.. i ?..= I. o3x to-6 �1va._- Y ill C 13xioSc43(w,.n ter, 1,02X (o 91VAn a S3( ro Cw' S*L 1 Q is V( 64.1 t t/�✓5 - , ' _t Eii.•,., : 7i to l °'"t Sec Ic- 13 iv ® 25 Ps,i iisB'l.} c.11: �5: s c S„6 usx4CI" VuI✓.' vlvFusoli hotc rook I�.�JroF..��,..eal �`6 e...,,71�te ;��c lS P •i' � Industrial -4- Compliance Incorporated 15955 West 5th Avenue Golden, Colorado 80401 (303)279-2636 ' PACKER PERMEABILITY - DATA SHEET ( r Boring No. Job No. Boring Radius (r) 4 " (ft) Engineer Depth of Boring (d) 63 (ft) Date / tr. -L- 1<C Depth to Static Water (A) 601S,- (ft) flow Meter No. Depth to Center of Packer (B) r}O (ft) Height ofGauge above Gauge Pressure (P) (psi ) Ground Surface (C) 4 (ft) • flow Data Notes .i. c A 7SD(P-d , N i T. P/Sas.<£o_ Cubic t,sl Time Gallons Feet Flow Rate 0� 30 .6,3 N o e.-n is 3 1 ,,p- /go Z.67xio 1,?Srto '5677o 1 3. 5O0 a,000 -z b vx�-3 17 ( 1.310 ° 3 a�� 1 .34.)116 2_,(az* "' Q3 00 W61.117..; 1 - ! 1 o0 3672 3 !,}�tx�o'" 3,3Sxio3 i! ;;-00 -5617.3 Average Q =3, `I 4 x io 3 ft3/mi n CALCULATIONS K = Q lnL : LZlOr L = d-B 2rLH r H = B + C + (L/2) + (P)(2.31 )-S K = _.,._ sink 1 L : 10r>L2tr where S = B + L/2 - A 2rrL„ 'fir Note: If no free wateris encountered, S = 0 • ® 5. its—wet q= 1.>>�x P , -s ' % Ix i , 5ya � G.'SK O Mwrw = 113.`1 3.4Sx�° �^- 1`={ QZM es, I A 14 ' 871 325 e—_ — Industrial Compliance Incorporate° 15955 West 5th Avenue Golden, Colorado 80401 (303)279-2636 PACKER PERMEABILITY-- DATA SHEET / Boring No. S Job No. /6 0 Boring Radius (r) L1 ., (ft) Engineer Depth of Boring (d) 5-411&. (ft) Date 'Oil— Depth to Static Water (A) DR-/ (ft) Flow Meter No. Depth to Center of Packer (B) LEO (ft) Height of Gauge above (ft) Gauge Pressure (P) z (Dsi ) Ground Surface (C) Flow Data Notes Cubic Time Gallons Feet Flow Rate l2--() (10/*-) No cNk t-as ;,S?Yio} / so) 36e r 0O-3 -70o 36g1, 0 366O 361 , b {�rgcZ3Ylle }��/w� Average Q • ), ft3/min CALCULATIONS K 1nL : L≥lOr L - d-B L r H . B + C + (L/2) + (P)(2.31 )-S K QQ Binh 1 L : 10r>Lzr where S ■ B + L/2 - A 2trLH !r Note: If no free water is encountered. 3 Se 0 ® 2-5 ps:) (i = 1°1 q = 2.3V/x (0-1 4(.�w.n) (c: Q,e, -_ Sx(e c-+(pL • 871_22•S APPENDIX B SURFACE WATER & DIVERSION DESIGN DETAILS 871326 bURFACE WATER DIVERSION DESIGN CALCULATIONS 100 year 1 -hour rainfall is 2.7 inches (Wright-McLaughlin, 1969) PERMANENT DRAINAGE STRUCTURES Drainage areas considered (Figure B- I ): Area 1 draining to southern perimeter drainage ditch: 5.9 acres Area 2 draining to northeastern and eastern perimeter drainage ditch: 12.0 acres Area 3 draining to northern perimeter drainage ditch: 1.2 acres Area 4 draining to northwestern perimeter drainage ditch: 2.9 acres Area S draining to western perimeter drainage ditch: 1. 1 acres note: I ) for all drainages lei than 160 acres, use of Rational method for discharge is satisfactory 2)all areas planimetered from 1"=100' final topographic base map Assumptions I )All runoff from existing landfill into drainage ditches. 2)All perimeter drainage channels will have 14' bottoms (scraper width). 3)All channel side slopes will be 4 horizontal to 1 vertical. 4) Time of concentration estimated at 10 minutes. Resulting 100 year rainfall intensity is 7.29 inches per hour. Discharge Information Rational formula used Q=CIA, where: Q=maximum calculated discharge in cfs C= runoff coefficient.40 (non-urban rangeland with clayey soils) 1= 100 year rainfall intensity 7.29 inches per hour A= drainage area in acres (Figure B- I ) Area 1= 5.9 acres Area 2= 12.0 acres Area 3= 1.2 acres Area 4= 2.9 acres Area 5= 1. 1 acres 871326 Resulting maximum discharges: Area 1= 17.2 CFS Area 2= 35.0 CFS Area 3= 3.5 CFS Area 4= 6.5 CFS Area 5= 3.2 CFS Channel Designs Slopes Drainage ditch for Area 1: minimum 1Z and maximum 15% Drainage ditch for Area 2: minimum 3Z and maximum 12% Drainage ditch for Area 3: minimum 3Z and maximum 3Z Drainage ditch for Area 4: minimum 3Z and maximum 4Z Drainage ditch for Area S: minimum 1Z and maximum I % Roughness is .035 (Wright McLaughlin, 1969) Depths are calculated using Manning's Equation Results from analysis using Manning's Equation for 14' base width and 4: 1 side slopes. Area % Slope AR2/3 Depth Depth w/ Area Velocity (feet) 1' freeboard (ft2) (ft/sec) Area 1 I 4.03 0.46 1.46 7.29 2.4 5 1.82 0.29 1.29 4.40 3.9 15 1.03 0.20 1.20 2.96 5.8 Area 2 3 4.77 0.50 1.50 8.0 4.4 5 3.69 0.45 1.45 7. 11 4.9 12 2.38 0.35 1.35 5.39 6.5 -Area 3 3 0.46 0. 13 1. 13 1.89 1.8 Area 4 4 1.00 0.20 1.20 2.96 2.9 Area 5 1 0.74 0. 16 1.16 2.34 1.4 Protection Criteria All slopes can be adequately protected with grass according to criteria set forth in Wright McLaughlin, 1969. The protection is based upon ditch slopes. See Figure B-2 for typical section 87132 TEMPORARY DIVERSION DITCHES Climatic information is the same as used above. Total maximum runoff area for a temporary drainage ditch is 6.0 acres. By the Rational Formula: Q= 0.4*7.29*6.0 = 17.5 cfs The natural channel will carry the flow until it encounters the temporary ditch. ALL TEMPORARY CHANNELS WILL BE BUILT ON AN APPROXIMATE 1 Z SLOPE Manning's roughness is again assumed at 0.035 By Manning's Formula AR2/3 = [ 17.540.035]/[ 1.49(.01)112]= 4. 1 1 With a triangular channel with 2: I slopes (see Figure B-2 for typical section) y=1.6 feet, add 1 foot freeboard for contingency y= 2.6 feet solving for the velocity using Q= 17.5 cfs and y= 1.6 feet, v= 3.4 fps minimal problems with erosion because of clayey type material, temporary nature of channel and continual monitoring and inspection during operations. 871326 i -{ Y r Ir / ir a II I 1,I / / / / I I�II 2 �I1 'CZt CO Zcc \\\C \ YY Id /l'i Li ,/ , .\\ V.'\\\\,,,:\\ \ , , I V \ (8) ‘ ,N al I ,, I \ '',, ' \ M z ;I K \ ` \ a .�.. te= `i A V . crw 5 >iii r— tit h? / �I It 0,415 ' ',J.> 0 ‘f) iiiiTh i aaq i I X OP/ '<s i 1// / 0 n to. > II : y / (/ (Y'`11 _ - _r_=7, 871326 TYPICAL SECTION FOR PERMANENT CHANNEL --I-175- feet 4 f 14 14 feet NOTES: 1 ) All channels can be adequately protected with grass according to criteria set forth in Wright McLaughlin, 1969. The protection is based upon ditch slopes. 2) Depths for all drainage area channels will be 1 .5 feet. This depth will result in a minimum freeboard of 1.0 feet over the calculated depth for the 100 year, 24 hour design storm for all permanent ditches. TYPICAL SECTION FOR TEMPORARY CHANNEL T eet 2.6 f 1 2 NOTES: 1 ) All temporary channels will be built on a minimum I slope to promote drainage while minimizing erosion. Slopes will be maintained at this gradient whenever possible. 2) Temporary channels will be inspected and maintained on a routine basis to minimize gullying and soil erosion problems. A channel will be completely constructed prior to the onset of filling that stage. Figure 6-2 071326 APPENDIX C EROSION CALCULATIONS 871326 EROSION POTENTIAL CALCULATIONS UNIVERSAL SOIL LOSS EQUATION (USE) A=RKLSP, where: A=-soil loss in tons/acre/year R=rainfall index K=erodibiiity factor LS=slope 1-ength gradient C=crop management factor P=conservation practice factor Taken from-Soil Conservation Service, 1982. R=50 K=0. 10 & 0.35 L5=9.0 C=0.008 P=1.0 A= (50)(0. 10)(9.0)(0.008)( 1.0) = 0.36 tons/acre/year 0.36 tons = 720 lbs/year 720 Ibs/year / 137pcf =5.26 cu ft/acre/year (specific gravity=2.2) 5.26cu ft/acre/year / 43,560 sq ft/acre- .00012 ft/year .00012 ft/year x 12 inches/ft = .0014 inches/year A= (50)(0.35)(9.0)(0.008)( 1.0) = 1.26 tons/acre/year 1.26 tons = 2520 lbs/year 2520 lbs/year / 137pcf = 18.39 cu ft/acre/year 18.39 cu ft/acre/year / 43,560 sq ft/acre = .00042 ft/year .00042 ft/year x 12 in/ft = .0051 inches/year NOTE: 1 ) The steepest slopes occur on the terrace faces. LS was determined for these conditions and the maximum (9.0) was used for the calculations. 2) Higher temporary losses (approximately 4 tons/acre/year) may occur on unplanted surfaces for short periods of time. 871326 APPENDIX D WATER BALANCE CALCULATIONS 871326 t. VI - 0 a 871326 APPENDIX E SURROUNDING PROPERTY OWNERS WIT#IIN 500 FEET OF SITE BOUNDARIES 871.32s PROPERTY OWNERS WITHIN 500 ASSESSOR'S PARCEL FEET OF SITE BOUNDARIES IDENTIFICATION C&M Ready Mix Concrete-Co. Mf Boulder 621313-OB-0-00-018 P.O. Box 315 Boulder, CO 80306 C.P.Richardson, c/o J.H. VanZanten, etal. 621313-08-0-00-020 1st Nat'l Bank Bldg, *3; S-ecor Realty Longmont,-CO 80501 Frank & Andrea Bigelow 621313-08-0-00-028 990E. Highway 119 Longmont, CO 80501 City of Longmont 621313-08-0-00-032 Longmont, CO 80501 Charles &Shirli Mae Hayes 621313-08-0-00-033 998 E. Highway 119 Lonbgmont, CO 80501 Margaret Ayres 621313-08-0-00-034 966-E. Highway 119 Longmont, CO 80501 Hello