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Home My WebLink About20093805.tifft Weld County Planning Department to-S!/L-815 GREELEY OFFICE RECEIVE!) nme 2299nn9 11TN WELD LANDPLLL wtre ww�n�rr ee�M�r 40,000 Weld, County Road 25 Ault, Colorado 80610-9748 (970) 686-2800 (970) 686-1031 Fax December 23, 2009 Ms. Marley Shoaf Colorado Department of Public Health and Environment Stationary Sources Program Air Pollution Control Division (APCD-SS-B1) 4300 Cherry Creek Drive South. Denver, CO 80246-1530 CERTIFIED MAIL RE: ANNUAL NMOC EMISSION RATE REPORT NORTIFWELD LANDFILL Dear Ms. Shoaf, As required under the State Emissions Guideline Program for Municipal Solid Waste Landfills, attached is the completed Annual NMOC Emission Rate Report for 2009 for the North Weld Landfill (NWLF5 located -at 40,000 Weld County Road 25 in Ault, Colorado. Should you have any questions regarding the information contained in this report, please contact Bill Hedberg at 970.686.2800 ext.23 or Alan Scheere at 303.644.4305 ext. 1. Sincerely, Bill Hedberg Sr. District Manager Attachment cc: Troy Swain, WCDPHE .ferry Henderson, CDPFIE • Kim Ogle; WCDPS D:\N W LI.INMOC Report 2009 N W LF.doc F: 1.4 (2009) 200q-- Nos 110111 2009 TIER 2 NMOC EMISSION RATE REPORT NORTH WELD LANDFILL Because the site does not have scales, volume of waste accepted is estimated based on container size of incoming waste. Therefore, the equation found in 40 CFR 60.754(a)(ii) was used to determine NMOC emission rates for the Annual Tier 1 NMOC Emission Rate Report. kl MNMoc=2LoR(ekc -t; )(CNmoc)(3,6 x 10-g) NMOC Emission Rate - 20091 Mass methane generation potential, Ma/Mg MNMOC Lo = Refuse methane generation potential, ma/Mg = 170.00 R - = Average annual -acceptance rate; Mg/yr - - - - = 122,160.83 k Methane generation rate constant, 1/yr = 0.02 c = Years since closure, yrs = 0.00 (c = 0 for active and/or new landfills) t = Age of landfill, yrs = 17.66 CNM0C = Concentration of NMOC, ppm as hexane = 153.00 Conversion factor = 3.6 x 10'g MNMoc=2(170)(73,002.26)(ein.02)(6) e�0.02)116.661 (153.00)(3.6 x 10"6) = 6.53 2009 Information used to determine annual average acceptance rate The average annual acceptance rate (R) is based on waste in place as of 10/31/09 divided by 17.66 years (age of site at time of volume measurement) less inert materials. Waste in place is tracked monthly on the North Weld Sanitary Landfill Title V Log by compiling monthly waste received and subtracting inert material volumes. Waste in place (Mg) thru 10/31/09 4,070,491.00 Waste in place less inert and soil (Mg) 2,157;360.23 Percent inert 0.47 Age of site at volume measurement 17.66 Annual average acceptance rate (Mg/yr) 122,160.83 2 For regulatory purposes, the EPA default values for Lo and CNNoc must be used to calculate Tier 1 NMOC emission rates unless actual values have been obtained during Tier 2 sampling. NWLF conducted Tier 2 site specific sampling for CNMoc in 2008 (using Method 25C) with a resulting concentration of 153 ppmV as hexane. - " Inert material includes inert wastes that are disposed in the landfill as well as intermediate and final cover soil used as part of routine landfill cell development. NOTE: These calculations are made for NSPS purposes only. EPA has specifically stated as follows: "It is recommended that these default values not be used for estimating landfill emissions for purposes other than NSPS and EG (61 FR 9905, 9912, March 12, 1996). Consequently, these emissions calculations grossly overestimate actual and potential emissions and reviewers of this document ere specifically cautioned against Improper and irresponsible uses of these calculations. 3.; 0.5P8q5 STATE OF COLORADO Bill Ritter, Jr., Governor James B. Martin, Executive Director Deldicated to protecting and improving the health and environment of the people of Colorado 4300 Cherry Creek Dr. S. Denver, Colorado 80246-1530 Phone (303) 692-2000 TDD Line (303) 691-7700 Located in Glendale, Colorado http://www.cdphe.state.co.us November 20, 2009 Laboratory Services Division Weld County Planning Department 8100 Lowry Blvd. GREELEY OFFICE Denver, Colorado 80230-6928 (303) 692-3090 Mr. Tom Schweitzer, Engineering Manager Waste Management of Colorado 5500 South Quebec Street, Suite 250. Greenwood Village, CO 80111 NOV 25 711f1.9 RECEIVED ED Colorado Department of Public Health and Environment RE: Approval with Modifications of Landfill Gas Remediation Plan Revision Dated September 19, 2009 North Weld Landfill Weld County, Colorado SW WLD NWC 4.1 Dear Mr. Schweitzer: The Colorado Department of Public Health and Environment Hazardous Materials and Waste Management Division ("the HMWMD") reviewed the above referenced document. ("the Plan"), received in this office on September 18, 2009, for compliance with Section 2.3 of the Regulations Pertaining to - Solid Waste Sites and Facilities, 6 CCR 1007-2 ("the Regulations"). Methane regulatory exceedances (greater than 5% by volume in air) were initially observed at GPI, GP10 and GP11 on July 22, 2009. GP10 and GPI I are facility property boundary gas probes whereas GPI is an interior probe that serves to identify potential fgas migration to the buildings on site. The plan notes elevated concentrations above the regulatory level in all three gas probes during the August 2009 monitoring event as well. Per my phone conversation with you on October 26, 2009 and the Fourth Quarter Gas Monitoring Report, we learned that the level has since fallen below the regulatory threshold of 5% by volume in air at GP11 and GP 1. Sections 2.1 and 3.2 of the Plan, as well as Figure 3, shed light on subsurface conditions in the vicinity of the affected probes. Some key points are as follows: • No lithologic record of the installation of GP10 and GP11 can be located. Based on site wide geology, "the assumption can be made that thin sandstone layers could be present.... Such layers could provide a pathway along which landfill gas could migrate." • Gravelly alluvium and consolidated sandstone layers could form migration pathways, the alluvium ranges in depth from 15 to 30 feet in the area represented by the cross section in Figure 3. • Figure 3 shows layers of sandstone or sand and gravel alluvium that could be a migration pathway. Figure 3 shows thinning of these transmissive layers in a southward direction. Mr. Tom Schweitzer November 13, 2009 Page 2 of 3 • An undeveloped residential area lies within 1,000 feet of the site boundary in a southwesterly direction. Gas monitoring probes in a direct line from the landfill mass to these offsite areas do not show any concentrations of methane. • Specific data regarding these transmissive strata west of the site boundary either do not exist, or were not provided in the Plan. Section 3.3 of the Plan details the remedial measure being proposed. A bulleted summary follows:. • Six passive landfill gas vent wells would be installed in the vicinity of gas probes GPI, GPI0 and GP11 • The vent wells would be 36 inches in diameter and terminate 10-15 feet above the as built elevation of the liner and leachate collection system. • Although not specified in the plan, the design concept (as articulated by you during the October 26, 2009 phone call) is to locate the wells near where the toe of the sideslope meets the base grade elevation, in order to maximize the depth of trash vented by the wells white keeping the vent wells in proximity to the affected gas probes. • The Plan states. "no protective posts are proposed because no traffic is expected in the area." However, Figure 4 shows some of the vent wells to be in proximity to haul roads. • While the Plan is silent on the distance or direction to the nearest structure, the original notice of exceedance reported a residential dwelling at a distance of 1,200 feet west of the site. Per review of the aerial photographs on the Weld County Assessors website, the nearest structure west of the site and north of Highway 14 appears tobe at a distance of 2,200 to 2,400 feet. • There is a residential area under development to the southwest of the site. This area was not referenced in the Plan, but is evident from the Weld County Assessors webpage. The nearest lots appear to lie within,a 750 to 1,000 foot radius of the affected gas probes. Per phone message from Mr. Bill Hedberg of WMC dated October 28, 2009, the area most proximal to the landfill is slated for later development. • On November 10, 2009, the facility submitted to the Division the Fourth Quarter 2009 Gas Monitoring Report. It shows methane levels having reduced to nondetect in GP -1 and GP -11, and having reduced from 30% methane to 8% methane in GP -10. GP -2, another well in the southwest corner of the site, remained at nondetect levels for methane. In consultation with the Weld County Department_ofB_ublic"Health and .Environment(by_way-of phone_ conversation with Mr. Troy Swain on October 27, 2009), the Division approves the plan with the following modifications. 1. The Plan shall be modified to include the requirement for warning signage in the vicinity of the affected gas probes. 2. The Plan shall be modified to include the requirement for barriers to protect the vent wells, as the southwest portion of the landfill has the potential for vehicular traffic. 3. The Plan shall be modified to include provision for monthly monitoring of the utility corridor at practicable access points along WCR 25 along the west side of the landfill. Mr. Tom Schweitzer November 13, 2009 Page 3of3 4. Monthly monitoring of gas probes GP1, GP 10 and GP11 shall continue until methane concentrations in these wells are below the regulatory concentration for three consecutive months. 5. The Plan shall be modified to include provision for continuous monitoring for explosive gas within onsite buildings in proximity to GPI. 6. Based on the thinning of the transmissive layers in a southward direction and the recent nondetect levels in GP -1, the Division does not require at this time offsite investigation and monitoring. However, should construction in the offsite areas commence sooner than expected, or should the passive venting remedial action not prove successful in reducing the methane concentrations within six months of implementation; the Division reserves the right to require additional investigation and/or remedial action. The lack of nearby structures (i.e. within 1,500 feet of the affected wells), particularly in a southwest direction where there is an area to be - developed, shall be confirmed by -site personnel and verified in each monthly monitoring report: In closing, the Hazardous Materials and Waste Management Division is authorized to bill for its review of technical submittals, pursuant to Section 1.7 of the solid waste regulations 6 CCR 1007-2 An invoice for the Division's review of the referenced Report will be transmitted to you under separate cover. Should you have any questions, please feel free to contact me at 303-692-3455. Sincerely, enderson Solid Waste and Material Management Unit Solid and Hazardous Waste Program cc: Bill Hedberg, WMC K ztt'_Qgle'WCDPSl ' Troy Swain, WCDPHE 4 WASTE MANAGEMENT Weld County Planning Departme4 GREELEY OFFICE luny 122009 RECEWED November 4, 2009 Mr. Jerry Henderson Colorado Department of Public Health and :Environment Hazardous Materials and Waste Management Division HMWMD-SWIM-B2 -- — " 4300 Cherry Creek Drive South Denver, CO 80246-1530 Mr. Troy Swain. Weld County Department of Public Health and Environment 1555 N. 17th Avenue Greeley, CO 80631 5500 South Quebec Street Suite 250 Greenwood Village, CO 80111 303.486-6045 (Phone) 303.486-6146 (Fax) SUBJECT: NORTH WELD LANDFILL FOURTH QUARTER 2009 GAS MONITORING REPORT Dear Mr. Henderson and Mr. Swain: Enclosed for your information is the Fourth Quarter 2009, Gas .Monitoring Report for North Weld Landfill (NWLF). The gas monitoring and corresponding report was completed by Waste Management of Colorado, Inc. (WMC). The gas report contains monitoring results obtained on October 6 and 7, 2009 from the Phase 1 and 2. perimeter soil gas probes (GP) GP -06, GP -07, GP - 10 through GP -20, •and -structure probes* GP -01- and GP -02, inside -the shop and office, and :.confined,spaces.inithevicinity-of,the•.western:boundaryqf,:the site.;,A-map shoyyng thg,gas,probe.„, . . locations, the scale house and maintenance shop is included as Figure 1. Section 2.3.1 of the Regulations Pertaining to Solid Waste Sites and Facilities, 6 CCR 1007 -2; -Part 1 (Regulations) requires that the concentration of explosive gases shall not exceed (A) 25% of the lower explosive limit (LEL) (1% by volume in air for methane) with facility structures, .and (B)' the LEL (5% by volume in air for methane - i.e., percent methane) at the facility boundary. During this monitoring event, methane was detected in perimeter probe GP -10 at a concentration of 8.0%, which is down from the third quarter:2009 measurement.of 30.6%. GP -01 and GP -11, which were measured during the third quarter 2009 event with methane concentrations of 20.9% and 24.9%, respectively, did not register for methane for the fourth quarter 2009 event. Combustible gas above regulatory limits was not detected in any of the other probes, shop, office or• confined spaces. GP -1O is located to the west of Phase 2 along the perimeter fence approximately 25 feet within the property boundary. Barhole probe monitoring performed at a 1O - foot lateral interval adjacent to perimeter probe GP -10 showed that combustible gas was 'not detected at this interval. _4 Letter Jerry Henderson and Troy Swain November 4, 2009 Page 2 Following the provisions of Section 2.3.3 of the Regulations, the facility notified the Colorado Department of Public Health and Environment (CDPHE) and Weld County Department of Public Health and Environment (WCDPHE) of the third quarter 2009 elevated methane concentrations on July 29, 2009 and submitted a remediation plan on September 15, 2009. The remediation plan, which includes the installation of six passive gas vents west side of the landfill in the Phase 2 disposal area,. is currently being reviewed by CDPHE and WCDPHE. It'is our understanding that approval should be issued shortly. Pending your approval of the remediation plan, vents during the week of November 16, 2006. If you have any questions -regarding this -report: or me at (303) 486-6045. Sincerely, On behalf of North Weld Landfill Tom Schweitzer • Engineering Manager cc: Kim Ogle, WCDPS, w/o enc{ Bill Hedberg, NWLF Alan Scheere, Waste Management we are tentatively planning to install the passive' please call Alan Scheere at (303) 644-4335 Ext. 1' (44, Weld County Planning Department GREELEY OFFICE OCT 2 7 MINI REC M ED October 19, 2009 Ms. Marley Shoaf Colorado Department of Public Health and Environment, Air Pollution Control Division APCD-SS-BI 4300 Cherry Creek Drive South Denver, CO 80246-1530 SUBJECT: NORTH WELD SANITARY LANDFILL (NWSL) TITLE V OPERATING PERMIT # 97OPWE181 2009 SEMI-ANNUAL MONITORING REPORTS Dear Ms. Shoaf: WELD LANDFILL A WASTE MANAGEMENT COMPANY 40,000 Weld County Road 25 Ault, Colorado 8061O.9748 (970) 686-2800 (970) 686-1031 Fax CERTIFIED MAIL In accordance with the NWSL Title V Operating Permit -# 97OPWE181, attached are the following reports covering the monitoring period of April 1; 2009 - September 30, 2009. • Monitoring and Permit Deviation Reports, Part I • Monitoring and Permit Deviation Reports, Part II • Monitoring and Permit Deviation Reports, Part III These reports reflect a minor deviation in the waste acceptance limit as a result of NWSL providing emergency solid waste disposal services to the citizens of Town of Windsor and other surrounding areas, following the tornado disaster in the spring of 2008. The receipt of tornado related waste caused a minor deviation in the waste acceptance limit during the current and previous reporting periods. This minor deviation occurred subsequent to the disaster recovery period and did not impact the rolling twelve- month average until the calculation at the end ofFebruary 2009 semi-annual reporting period and - - ... continued to impact the;twelve-month rolling averages during the months of March, April,and May, . . 2009. During the previous reporting period, NWSL submitted the initial Air Pollution emissions Notice '(APEN) renewal and permit modification prepared by Golder.AssOciates, Inc. dated February 18, 2009: Subsequently, NWSL has been working diligently with CDPHE during the current reporting period and submitted. additional information included in the August 17, 2009 letter prepared by Golder and an amended APEN on August 31, 2009. NWSL also submitted a revised Title V semi-annual report and annual compliance certification on August 31, 2009. In addition, based oh further discussions with CDPHE, NWSL submitted an updated APEN dated October 9, 2009 requesting an additional increase in the waste acceptance limit and revising particulate emission limits to provide operational flexibility and margin of compliance. C:\AiANWSIANWSL Semi Annual Cert 0909 Cover.doc F: Operating Record 1.4 (2009). Marley Shoaf October 19, 2009 Page 2 Should you have any questions regarding these reports, please contact Alan Scheere at (303) 644-4335 ext. 1 or Bill Hedberg at (970) 686-2800 ext. 23. Sincerely, Bill Hedberg Sr. District Manager /attachments cc: Dana Podell, CDPHE APCD, w/enc. Jim King, CDPHE APCD, w/enc. Jerry Henderson, CDPHE, w/enc. Troy Swain, WCDPHE, w/enc. flCunlOgle P.Sww/,oiene,� C: /Air/NWSUNWSL Semi -Annual Cat 0909 Cover doc. F: Operating Record 1.4 (2009) ar4 COLORADO MEMORANDUM Weld County Planning Department GREELEY OFFICE OCT 15 ?nn9 RECEIVED TO: Kim Ogle, Planning Services DATE: October 15, 2009 FROM: Clay Kimmi, P.E., C.F.M, Public Works VG< SUBJECT` USR-895 Waste Management N Weld Landfill Grading Permit Weld County Public Works received a grading permit submittal from AGProfessionals, LLC concerning USR-1675 Rusco Land & Cattle Producer Feedlot. The grading permit application was not complete. Comments made during this stage of the Peview process will not be all inclusive, as revised materials are submitted other concerns or issues may arise. All issues of concern and critical issues during further review must be resolved with the Public Works Department. 1. A grading permit application form was not submitted with the packet. Please complete the grading permit application and provide all supplemental information. The grading permit application can be downloaded at http://www.co.weld.co.us/departments/planning/Building/build comm.html. Please provide the appropriate fee and application to the Planning Department 2. Please submit a copy of the approved SWMP for the landfill site. Please reference the SWMP on the drawing sheet. 3. Please label all sheets with the correct USR number. 4. Please label all proposed contours. 5. Please revise the tracking pad to show that 3 inch angular rock will be used. It has been Weld County's experience that the tracking pad show on the drawing sheet is not adequate to prevent the tracking of mud and debris onto Weld County roads. 6. Please include installation and maintenance notes for all BMPs. 7. Please specify the seed mix that will be used to reclaim the site. S. Please specify the type and quantity of mulch to be used for those areas to be protected with mulch. 9. Please include a detail for the low tail water basin. 10. Please include a detail for the swales that will be protected with straw bales. 11. Please provide a drawing or a note that shows the straw bales extending down the sides of the swale and across the bottom of the swale. 12. Please include a complete legend on the drawing. Comments made during this stage of the review process will not be all inclusive, as revised materials are submitted other concerns or issues may arise. All issues of concern and critical issues during further review must be resolved with the Public Works Department. Original & Email: PC: CC: Kim Ogle, Planning Services USR-895 Brian Moss, Calibre Page - 1 - of 1 August 7, 2009 M:\PLANNING— DEVELOPMENT REVIEW\USR-Use by Special Review\USR-895 Waste Management\USR-895 Grading Permit Comments 10-15-09.DOC US/L Vi5 WASTE MANAGEMENT September 15, 2009 Weld County Planning Department GREELEY OFFICE y',�y, tyS�SE�Po 18 7f109ENE Mr. Jerry Henderson Colorado Department of Public Health and Environment Hazardous Materials and Waste Management Division HMWMD-SWIM-B2 4300 Cherry Creek Drive South Denver, CO 80246-1530 Mr. Troy Swain Weld County Department of Public Health and Environment 1555 N. 17th Avenue Greeley, CO 80631 5500 South Quebec Street Suite 250 Greenwood Village, CO 80111 303-486-6045 (Phone) 303.486-6146 (Fax) Sent by Email Hard Copy to be Mailed SUBJECT: NORTH WELD LANDFILL REMEDIATION PLAN FOR ELEVATED METHANE CONCENTRATIONS Dear Mr. Henderson and Mr. Swain: • Enclosed for approval is the document titled, "Remediation Plan for Landfill Gas Occurrence" (Plan) prepared by AquAeTer and dated September 2009. This Plan is submitted pursuant to Section 2.3.3 (C) of 6 CCR 1.007-2, Part 1, Regulations Pertaining to Solid Waste Sites and Facilities (Regulations) and our notification letter to the Department and Weld County dated July 29, 2009 regarding elevated methane concentrations that were observed in gas migration probes GP -1, GP -10 and GP -11 at North Weld Landfill. The enclosed Plan provides a general description of the facility design and construction, landfill gas probe monitoring system, summary of monitoring results at GP -1, GP -10 and GP -11, and a description of our remediation plan that includes the placement of several passive vents within the waste mass in the vicinity of the three -subject -gas -probes. We look forward to your approval of the enclosed plan. If you have any questions regarding the plan, please contact Alan Scheere at (303) 644-4335 or me at (303) 486-6045. Sincerely, On behalf of North Weld Landfill Tom Schweitzer Engineering iManager cc: ! m Ogle, WCDPS, w/o enc. ' William Hedberg, NWLF Alan Scheere, Waste Management August 26, 2009 Ms. Marley Shoaf Colorado Department of Public Health and Environment Air Pollution Control Division APCD-SS-B 1 4300 Cherry Creek Drive South Denver, CO 80246-1530 WELD LANDFILL A WASTE MANAOIMGNY COMPANY 40,000 Weld County Road 25 Ault, Colorado 80610.9748. (970) 686-2800 (970) 686-1031 Fax CERTIFIED MAIL 7004, asp 0004 4`4"? 4'197[, • SUBJECT: ---NORTH WELD LANDFILL (NWLF) TITLE V OPERATING PERMIT # 97OPWE1•81 AMENDED 2009 SEMI-ANNUAL MONITORING REPORTS Dear Ms.. Shoat: The Colorado Department of Public Health and Environment, (CDPHE) requested NWLF amend the following reports covering the monitoring period of October 1, 2008 - March 31, 2009. • Monitoring and Permit Deviation Reports, Part I • Monitoring and Permit Deviation Reports, Part II • Monitoring and Permit Deviation Reports, Part III These reports were amended to reflect a minor deviation in the waste acceptance limit as a result of NWLF providing emergency solid waste disposal services to the citizens of Town of Windsor and other surrounding areas, following the tornado disaster in the spring of 2008. The receipt of tornado related waste caused a minor deviation in the waste acceptance limit. This deviation occurred subsequent to the ' disaster recovery period and did not impact the rolling twelve-month average until the calculation at the end of February, 2009 period. Prior to this time, NWLF submitted the revised APEN renewal and permit modification prepared by Golder Associates Inc. (Golder) to the CDPHE on February 18, 2009 requesting an increase in the waste acceptance limit. Nevertheless, NWLF believed it was following appropriate protocol by requesting the permit modification and APEN renewal to provide for the increase in waste volume prior to the waste acceptance limit deviation. Should you have any questionsregarding these reports, please contact -Alan Scheere at (303) 644-4335 ext. 1 or Bill Hedberg at (970) 686-2800 ext. 23. Sincerely, Bill Hedberg Sr. District Manager /attachments C: Air W WLFNWLF semi Annual Cert 0409 Cover.doc F: Operating Record 1.4 (2009) ' Marley Shoaf August 26, 2009 Page 2 cc: Dana Podell, CDPHE APCD, w/enc. Jim King, CDPHE APCD, w/enc. Douglas Ikenberry, CDPHE, w/enc. Troy Swain, WCDPHE, w/enc. ItcunWOgle' iri7.€ll1PS tiy&enc.,. C: /Air/NWLF/NWLF Annual Cert 0809 Cover doc. F: Operating Record 1.4 (2009) WtI4 C..:Tyty Planning Department cii;_;:zLEY OFFICE Weld County Planning Department GREELEY OFFICE SEP 01 7110g RECEWED WELD LANDFILL A WASTE MANAGEMENT COMPANY August 26, 2009 Ms. Cindy Beeler, Environmental Engineer. Office of Enforcement, Compliance and Environmental Justice Mail Code 8.ENF-T U.S. Environmental Protection Agency, Region VIII 1595 Wynkoop Street Denver, CO 80202-1129 SUBJECT: NORTH WELD LANDFILL (NWLF) TITLE V OPERATING PERMIT NUMBER 97OPWE1S1 2009 ANNUAL COMPLIANCE CERTIFICATION REPORT 40,000 Weld County Road 25 Ault, Colorado 80610-9748 (970) 686-2800 (970) 686-1031 Fax CERTIN'tt,D MAIL 7D04 4-9/5-O 0004- 46-4-r flip 9 Dear Ms. Beeler: The Colorado Department of Public Health and Environment (CDPHE) requested NWLF amend the Annual Compliance Certification. Report which covers the period April 1, 2008 through March 31, 2009. This report was amended to reflect a minor deviation in the waste acceptance limit'as a result of NWLF providing emergency solid waste disposal services to the citizens of Town of Windsor and other surrounding areas, following the tornado disaster in the fall of 2008. The receipt of tornado related waste caused a minor deviation in the waste acceptance limit. This deviation occurred subsequent to the disaster recovery period and did not impact the rolling twelve-month average until the calculation at the end of February, 2009 period. Prior to this time, NWLF submitted the revised APEN renewal and permit modification prepared by Golder Associates Inc. (Golder) to the CDPHE on February 18, 2009 requesting an increase in the waste acceptance limit. Nevertheless, NWLF believed it was following appropriate protocol for requesting the permit modification and MEN renewal to provide for the increase in waste volume prior to the waste acceptance limit deviation. Should you ve any questions regarding this-report,please-contact Alan-Scheere-at-(303)-644-4335.or-- Bill Hedberg at (970) 686-2800 ext. 23. Sincerely, . Bill Hedberg Sr. District Manager /attachment cc: Douglas Ikenbeny, CDPHE, w/enc. Troy Swain, WCDPHE, w/enc. t1Cim'Og`le; WCDPS WLo enc. Dana Podell, CDPHE, w/o enc. .C:\Afr)NWLF Annual Cert 0408 EPA Cover.doc F: Operating Record 1.4 (2009) eta)gq5 July 29, 2009 Weld County Planning Deperiniadf GREELEY OFFICE AUG 072009 RECEIVED Mr. Douglas Ikenberry, P.E. Colorado Department of Public Health and Environment Hazardous Materials and Waste Management Division HMWMD-SWIM-B2 4300 Cherry Creek Drive South Denver, CO 80246-1530 Mr. Troy Swain. Weld County Department of Public Health and Environment 1555 N. 17th Avenue Greeley, CO 80631 NORTH WELD LANDFILL A WASTE MANAGEMENT COMPANY 40,000 Weld County Road 25 Ault, Colorado 80610.9748 (970) 686-2800 (970) 686-1031 Fax SUBJECT: NORTH WELD LANDFILL THIRD QUARTER 2009 GAS MONITORING REPORT AND NOTIFICATION OF ELEVATED METHANE CONCENTRATIONS Dear Mr. Ikenberry and Mr. Swain: - Enclosed for your information is the Third Quarter 2009, Gas Monitoring Report for North Weld Landfill (NWLF). The gas monitoring and corresponding report was completed by Waste Management of Colorado, Inc. (WMC). The gas report contains monitoring results obtained on July 22 and 23, 2009 from the Phase 1 and 2 perimeter soil gas probes (GP) GP -06, GP -07, GP -10 through GP -20, and structure probes GP -01 and GP -02 and inside the shop and office. Section 2.3.1 of the Regulations Pertaining to Solid Waste Sites and Facilities, 6 CCR 1007-2, Part 1 (Regulations) requires that the concentration of explosive gases shall not exceed (A) 25% of the lower explosive limit (LEL) (1% by volume in air for methane) with facility structures, and (B) the LEL (5% by volume in air for methane - i.e., percent methane) at the facility boundary. During this monitoring event, combustible gas was detected in structure probe GP -0l and perimeter probes GP -10, GP -11, GP -12 and GP -17 at percent methane levels of 20.9, 30.6, 24.9, 0.2 and 0.1, respectively. Combustible gas was not detected in any of the other probes, shop or office. GP -01 is a structure probe internal to the site located northeast of the maintenance shop. GP -10 and GP -11 are located to the west of Phase 2 along the perimeter fence approximately 25 feet within the property boundary. In accordance with the site's landfill gas monitoring plan, barhole probe monitoring was performed at a 10 -foot lateral interval adjacent to structure probe GP -01 and perimeter probes GP -10 and GP- word'letter\nwgsr3 F: nwsl 4.2.5.09 Letter Douglas Ikenbeny and Troy Swain July 29, 2009 Page 2 11, which showed that combustible gas was not detected at this interval. Given the proximity of GPs 10 and 11 to the property boundary, we are hereby following the provisions of Section 2.3.3 and notifying the Colorado Department of Public Health and Environment (CDPHE) and Weld County Department of Public Health and Environment (WCDPHE) of the elevated methane concentrations. Below are additional provisions of Section 2.3.3 followed by our response to each provision: (A) Immediately take all necessary steps to ensure protection of human health; Response to (A): We performed gas monitoringin the gate house and maintenance building and detected no combustible gas in either structure. In addition, both structures are equipped with continuous gas monitors with alarms that sound in the event that combustible gas at, or above, 25% of the LEL is detected. The adjacent land use to the west of the facility is agricultural with the nearest structure (a residence and outbuildings) being approximately 1,200 feet from the property boundary. Since both onsite structures showed no detectable methane, the continuous gas monitors within these structures have not been triggered, and any potential off -site structures to the landfill are 1,200 feet from the property boundary, WMC does not believe landfill gas has migrated off -site or is otherwise creating an adverse risk to human health or the environment. (B) Within seven days of detection, place in the operating record documentation of the explosive gas levels and description of actions taken; Response to (B): This letter, which reports the elevated combustible gas levels observed on July 22nd and 23rd and actions employed to date have been placed in the facility operating record. (C) Within 60 days of detection, implement an approved remediation plan, place an approved copy of the plan in the operating record, and notify the Department and the local governing body having jurisdiction that the plan has been implemented. The plan shall describe the nature and extent of the problem and the proposed remedy. Response to (C): Although our quarterly monitoring events have not previously detected combustible gas at these probe locations, we will perform monthly monitoring of these probes to assess the recent elevated concentrations of methane. Monthly monitoring will continue until elevated methane concentrations subside to historical levels or unless an alternative frequency is requested by the facility and' approved by the Department. In addition, local surface and subsurface conditions will be evaluated to assess the cause of the elevated methane levels and remedial actions will be proposed, as appropriate. Results of additional monitoring will be forwarded to CDPHE and WCDPHE as they become available. Copies of all related correspondence and monitoring results will be placed into the site's operating record. We request CDPHE's approval of this plan, in consultation with WCDPHE, for the increased monitoring of word\letter\nwgsrp3 F: nwlf4.2.5.09 Letter Douglas Ilcenberry and Troy Swain July 29, 2009 Page 3 probes GP -01, GP -10, and GP -11 and the ongoing evaluation of conditions that may be contributing to the elevated methane concentrations. If you have any questions regarding this report and notification, please call Alan Scheere at (303) 644-4335 or Bill Hedberg at (970) 686-2800. Sincerely, Bill Hedberg Sr. District Manager cc: Kim Ogle, WCDPS, w/o enc. Alan Scheere, Waste Management word\letterinwgsrp3 F: nwlf 4.2.5.09 t 0 a. d 0) C 0 Y_ _ C ti C O N 0 m A - O 3a • .c .0 ▪ O a C • z m N a 0 co Gas Probe Readings Field Technician 0 .. SE_3�S88EE88EE88e888888 a 0 s 0 LO LT 0 U)..,, a 0 n 0 U) m 09 U) m a 9 n ccirocc-occcc 0 NN m 0 a 0 y n 0 Y a 0 co m 0 cal m 0 ..t n 0 m 0 m O o o m cc 00 N m 00 m cc LO 4R m C m E— 0000000000000000 0)000)0)000000)0000)00000000 en orr0 or 22 r r 2222222222222222222222 an o al. Nrr at -,-In'- LO a• -•- r MMr.-<n.- o or, -or-,'--,-'- 0 0 0 m �'-. 0) a iP0 r 0) 0 r .Intrument Type o 00000 N WLUJWWLUUJWWWW222222WWW W 00000000000000000000 o N W o N W o N UAW o N a N W 0 N LULU 0 N 0 N W 0 N W 00000000000 N W N W N Ili N W N W N W N W N W N W tV W [ EM -20001 a s N gg2 4I 000 oo N Ill N W Barometric Pressure (Inches ,l Mercury) Or . N NN N 25.07 'J wOO N NNN N N 25.05 t-- N NNpp CNN-CO N N N 25.07 N NNNN�Np LO N N 00 N N 25.04 0 N N 25.09 5-0 N NN N 25.04 O . N N N •;J6t 8 H Di�rrr top tN O• In roo n d'• r r -f00 ry to 0 t(Dootwv CI 00 aN}}N o O 000000). NO' • M OO N 3 N in 42.80 N<m0�0 O M V V Depth to Water (Feet) r o I Not Measured I I Not Measured] Not Measured rrar 0 0 0 0 I Not Measured I Not Measured I Not Measured I E v Not Measured I Not Measured Not Measured rrrrrarr 0 0 0 0 0 0 0 0 Pressure (Inches Water Coin.) N 0 N 0 0 0 o 0'r n o. d 9 N d'' 0 J 0 d 0 d 0 0 0 0 0 d 0 Q 0 0 0 0 0 Q 0 0 0 0 0 Si 0 do r- Carbon Filtering Filtered I Filtered I Filtered I Filtered I • Filtered I Filtered I Filtered Filtered I L Filtered Filtered 2 Il Filtered Filtered I Filtered 1g : iL. Filtered Filtered Filtered Filtered I Filtered I .rg m IL Filtered Filtered ' Oxygen t Concentration) r OOONNICic OO co rower, OOO 000WOOOr(D co rN.O a in co rN to N NN,r-N N O aI or N Carbon Dioxide Concentration) m O tO a r 00r NONN? r �� Q O • NNN to a) N ty O r V r r 00 as •0 00 •tJ •0) 000 •0 a d Methane (% Concentration) 0 r 0 ,_N 0 0 000ONtlmd,_,,_N00000�00000 0 0 0 n r (00>" ( 0 0 N 0 0 0 O r 0 0 0 Reading Timestamp 7/22/09 10:21 7/22/09 11:20 7/23/09 9:49 tl6 �4 A0 or n� 1. 7/23/09 7:47 1 0 a 0 a ^ 7/22/09 10:31 I 6 r A N r 17/13/09 11:14 P7/22/0911:38 R O f� 0 N n 7/22/09 12:09 I O r NilD T n 17/22/09 11:49 I 7/22/09 10:53 7/23/09 8:32 7/22109 10:05 17/22/09 10:28H al O o N n 7/22/09 10:47 I 7/23/09 8:19 I 7/23109 8:06 I 7/23/097:51 Device ID I—NWLFGP01 NWLFGP01 I 0 LL 3 Z LNWLFGP01-BHP10 I NWLFGP02 a LL -I z NWLFGP07 I 00 as LL 32 U. Z NWLFGP10 I NWLFGP10-BHP10 NWLFGP11 I NWLFGP11 r a LL 3 z NWLFGP11-BHP10_ NWLFGPI2 I m a LL 2 z NWLFGP14 NWLFGPI5 NWLFGP16 I NWLFGP17 NWLFGP18 NWLFGP19 NWLFGP20 N O t�) a O a. a) C I- -0.. C = as 2 C 'O N {C 10 r �J W p• 4- d O m 33, C• 'J .c O..o a.C C Z F co m 2 a 0) co CD Structures Readings Field Technician c 8 0 c 0 8 0 C 0 3 0 c 0 3 0 o 0 0 0 00 E c o 0 o 0 E 0 0 0 N 0 2r w w w w — 0 0 0 0 Carbon Filtering 2 2 Filtered 2 0 0) N IL CL ILL 0 . v i 2 O 20.5 to a N 20.3 20.4 3 Carbon Dioxide (5 Concentration) 0 0 0 0 d d o 0 Methane (ss Concentration) O o o O d d d d Reading Timestamp 7/23/09 9:24 7/23/09 9:26 N co r 0)0 0) 0 CO N N N N- Location ID Scalehouse - Outside Scalehouse - Inside Maintenance Building - Inside Maintenance Building - Outside Instrument Calibration Information Field Technician '0 CD re E 0. C 0 to N 0 C 0 0 N a a m CO 0 E ❑ to ,- 2- mEE E 00 0 0 D 0 0 0 E in NN N T ~ C www 00 Barometric Pressure (Inches Mercury) 0 0 t 25.03 I N N Ambient Temp (Degrees F) N- 00 CON. 10 n Balance Gas ( Concentration) N N r tri LO I0 Oxygen Concentration) co co 0 O 0 a Carbon Dioxide Concentration) ro m o to Co co Methane Concentration) L 50.0 t0 A . V Reading Timestamp l 7/22/09 9:38_ r N V' CD O3 Y r t0 0 0 N N- CO n Calibration ID 01 rn 0 0) 0 CO N 0 r J _I J 0 0 0 Weather Information I 00 co Weather Unde round Weather Under round Weather Under round Weather Unde round Sky Conditions Partly Cloudy Cua CO N 0 0 0 Barometric Pressure (Inches Mercury) r r r 0 0 t�) coco d c NNW Calm o CD 0 Wind Speed (MPH) 5 E v 10 o 0 Ambient Temp (Degrees F) 72 • 79 CD CM co Weather Information Timestamp to p) 7/22/09 12:35 7/23/09 7:35] 7/23/09 11:35 O o N A Weather Information Type Pre -Monitoring Post -Monitoring Pre -Monitoring Post -Monitoring X a 8 C c o O e. m 0 ?°' 8E ornw c 8 2 a • 2 c 5 to E. co co 00 3 E N 2 W E ,. 0 2 w y Z0 • m a E c o Y.13 C w to N 0 O rn Co S o m • c v 2 co E.' • 0 gC a u m • w E t Q0a N m 0 = m Z r N co N N 0 as hb a CCC C C C nueece C C C C M1 C C C M1 SR a€x6393 sa _ �9�i[2if8 9 ng AUG n5 rmv Weld GREELEY (OFFICE Department AUG 0570119 A� quriZ - RECEIVED • optimizing cnvamanmml mcwnts I uatcr, air, cash 7340 E. Caley Avenue, Ste 200 ^ Centennial, CO 80111 = Phone (303) 771-9150 ^ Fax (303) 771-8776 July 20, 2009 093180 Mr. Douglas Ikenberry, P.E. Colorado Department of Public Health and Environment Hazardous Materials and Waste Management Division HMWMD-SWIM-B2 4300 Cherry Creek Drive South Denver, Colorado 80246-1530 Mr. Troy Swain Weld County Department of Public Health and Environment 1555 N. 17th Avenue Greeley, Colorado 80631 RE: North Weld Landfill, Ault, Colorado First Half 2009 Groundwater Monitoring Report Dear Mr. Ikenberry and Mr. Swain: On behalf of Waste Management Disposal Services of Colorado, Inc., please find enclosed the results of first half 2009 groundwater monitoring by AquAeTer, Inc., for the North Weld Landfill, in Ault, Colorado. Regular semi-annual detection groundwater monitoring was done on March 17, March 18, and April 6, 2009 at five monitoring wells. We enclose one copy of the report for CDPHE, one copy of the report for WCDPHE, and an electronic file containing laboratory analytical data for CDPHE. This was the 26th detection monitoring event for these wells. There were no volatile organic compound detections and no statistical exceedances during this first half 2009 event. If you have any questions pertaining to the groundwater monitoring, please contact Mr. Alan Scheere by telephone at (303) 644-4335 or Mr. Bill Hedberg at (970) 686-2800. Sincerely, AquAeTer, Inc. Terra Plute, E.I. Project Engineer cc: CGAlMt s\t,-3cvbsc— Cathryn Stewart, P.G. Project Manager IziWCDPSZw/mEnc Mr. Steve Denis, Waste Management, w/o enc. Mr. Bill Hedberg, Waste Management, w/ enc. Mr. Alan Scheere, Waste Management, w/ enc. Mr. Tom Schweitzer, Waste Management, w/o enc. A tS 615 DEPARTMENT OF PLANNING SERVICES Greeley Planning Office 918 Tenth Street Greeley, Colorado 80631 WEBSITE: www.co.weld.co.us E-MAIL: kogle@co.weld.co.us PHONE (970) 353-6100, EXT. 3549 FAX (970) 304-6498 July 10, 2009 Mr. Chip Wertz Manager of. Construction Waste Management Company • 5500 South Quebec Street, Suite 250 Greenwood village, Colorado 80111 Subject: North Weld County Landfill, USR-895 Dear Chip: The Departments of Planning Services and Public Works thanks Bill Hedberg and yourself for meeting with the County to discuss the proposed upgrades to the Waste Management facility north of State Highway 14 and east of County Road 25, permitted under a Special Use Permit, USR 895. The proposed upgrade of weighing the vehicle with materials entering the site and the weight of the vehicle without materials upon exiting appear to be a matter of efficiency and the utilization of new technology to better manage the facility. Given this interpretation of the information presented, the Department of Planning Services does not view this as a substantial modification to the existing permit. An amendment to the existing application will not be required; however, this office will be requesting an updated site plan for the entire facility and specifically the areas with new construction. As indicated in our discussion, the Department of Public Works will be seeking tracking pads on both end of the access drive to and from the scale house area. These pads may be cobbles of sufficient length to accommodate two complete tire rotations, or may be rumble bars (reinforced cattle guards aligned end to end) of similar size. Concerns were raised on the stormwater flows, their direction and if this water was held on site or released. A follow-up conversation with Mr. Clay Kimmi with the Public Works Department (970-356-4000 x 3741) may be warranted. The new scale house structure will require evidence of water and a new septic tank and field will be required. With limited information of the existing conditions, it is suggested that Lauren Light with Environmental Health (970-356-4000 x2211) be contacted to ascertain the requirements of the new structure. Building Permits, including a grading permit will be required at a minimum, to commence with the project. Plan check of building plans and associated documents takes up to 20 business days to complete for the building, while the grading permit may be several days less for approval. Please contact Clay Kimmi with the Public Works Department to obtain the requirements for the grading permit submittal. Given that this is an upgrade to your current operations, the County will not require collateral to be posted for the improvements. Should you have additional questions or require clarification on any of the points presented herein, please contact this office. Thank you. Sincerely, Ki T.T. le Planning Services pc: D. Carroll, Public Works C. Kimmi, Public Works L. Light, Environmental Health L. Dodge, Building File: USR-895 Property research COUNTG SCALES CHECKW'EIGHERS lEdE'd� i IIJi'a LiUXL �sGN L r' u�ts�i? j Legendary reliability and precision with the exclusive Weigh Bar° and rugged weighbridge design backed by an industry -leading warranty. Avery Weigh-Tronix Innovative design features Exclusive design features are what make Avery Weigh-Tronix truck scales #1 in the industry. These features add up to a truck scale of remarkable quality and value. for reliable and precise vehicle weighing THE LEGENDARY WEIGH BAR® A patented and proven weight sensor Reliable For over 30 years, the exclusive Avery Weigh-Tronix Weigh Bar has enjoyed a reputation for precision and reliability — something no other load cell can match. The Weigh Bar's long service life is a big reason why Avery Weigh-Tronix truck scales offer the lowest cost of ownership, with fewer service calls and costly load cell replacements. Rugged The Weigh Bar contains 3 to 10 times more steel content than shear beams or compression cells. Unlike other load cells, it easily absorbs impact to minimize peak forces and is virtually fatigue -proof. The Weigh Bar is proven to resist electrical surges and is protected by a 5 -year warranty that includes coverage against lightning damage. Consistent Each Weigh Bar is precision machined by Avery Weigh-Tronix from aircraft -quality, alloy steel for excellent repeatability and long-term durability. The entire process is controlled by strict quality standards that are certified by ISO. The Weigh Bar's massive size makes its reputation for reliability readily apparent. 2 Accurate The sensor's design automatically cancels the effects of side loading, end loading and twisting, resulting in quick, accurate readings. Only vertical forces are measured regardless of vibration, and shock loads on the scale. Weigh Bars ignore the effects of weighbridge expansion/contraction due to temperature change. Sealed The Weigh Bar is well protected against harsh environments by an exclusive 5 -layer, sealing process. It is approved by Factory Mutual as intrinsically safe for hazardous locations. Annual Load Cell Failure Rate 0% 1% 2% 3% 4% Art • Weigh Bar • Other Models 5% 6% 1 WEIGHBRIDGE SUSPENSIONS Rugged, precise and easy to install Easi-Post and Pin & Link suspension systems are proven designs that offer a high degree of performance, efficiency, and durability while absorbing the energy applied to the weighbridge during braking and acceleration. Checking Checking systems are internal and self -aligning. They allow for deck expansion/contraction and self -check against the weighbridge end box plates. EASI-POST" An innovative, patent pending suspension system that greatly simplifies the job of leveling a scale with the foundation and offers long-lasting performance. Ideal for those "less than perfect"foundations. Each module may be raised or lowered by 1" with a simple turn of the adjustment bolt. Eosi-Post self -checking points Adjustment Bolt Easi-Post Suspension Weigh Bar Truck Scales Dampening Dampening features quickly stabilize rocking motion as trucks stop and go, for fast and stable weight readings. Installation Base plates are anchored directly to pier tops. No grouting is necessary for proper alignment. Pin & Link self -checking points Pin Link Weigh Bar PIN & LINKS" The traditional Avery Weigh-Tronix suspension system with heavy-duty components for long-lasting performance. Installs quickly and minimizes weighbridge movement for consistent accuracy and low maintenance. Height adjustment is achieved by using shim plates. Design features continued on page 4 > 3 Innovative design features RUGGED WEIGHBRIDGE DESIGN High -quality construction ensures long-lasting integrity Convenient, top -side maintenance Removable section covers allow convenient top access for maintenance and service. Exceptional rust & corrosion protection 3 -step coating process seals out the elements. Surfaces are shot -blasted and cleaned, primed with epoxy, and finished with a tough, acrylic polyurethane top coat. Entirely galvanized units are available as well for maximum corrosion protection. No exposed wiring Cables are sheathed with a stainless steel jacket and routed through steel conduit for extra protection. Professional foundation plans Foundations are professionally designed by Avery Weigh-Tronix engineers to meet specific site requirements. Nothing is left to chance, for an efficient, reliable, and long- lasting scale installation. Choose from slab, pier, or pit construction. High -strength steel construction Only the highest quality structural steel is used. Automated continuous welding provides extra strength — no lower strength spot or intermittent welds. Finite Element Analysis Advanced engineering ensures all weighbridge components meet design specifications for long-term structural integrity. Fully assembled Quick, easy installation with no hidden labor or material costs. Steel or concrete Choose the easy installation of a steel deck, or the enhanced durability of a concrete surface. Closed underside Bottom plates are important stress - carrying members that increase strength and rigidity by joining the bottom I-beam flanges together. 100% welding ensures maximum strength and corrosion prevention. No check rods or bumper bolts Internal checking system at each section is self -aligning. Safely prevents excessive scale movement during acceleration and braking. INTEGRATED COMMUNICATIONS impressive communication abilities connect all the components of a powerful truck scale system Create a truck scale system to fit specific needs by choosing from a variety of integrated components. Avery Weigh-Tronix components utilize industry -standard protocols such as Ethernet, which merge with existing computer networks for precise data management. SensorComm, Traxle, Indicators and Software give you the ability to communicate in the language of your business; convey operational status in a meaningful form; diagnose and isolate potential problems. SensorCommTM SensorComm is a digital Junction Box that converts analog load cell inputs into digital outputs. It features remote diagnostics and optical or serial data transmission. SensorComm is the basis for advanced truck scale connectivity. 4 Concrete reinforcement Factory welded studs bond the concrete to the steel structure, eliminating the need for costly and time- consuming rebar. Composite design Only the top half (5") of the deck is poured, allowing the concrete to stay in compression. Tension forces are handled by the high -strength steel structure below the concrete. Fiber -mesh concrete is specified to increase strength and resist cracking. Traxle' Traxle is a patented system that provides both total truck and axle weights on a standard truck scale. This is accomplished by obtaining weighments at two scale positions (shown below). Second Weigh Point First Weigh Point Low profile 14" height from baseplate to driving surface. Indicators Avery Weigh-Tronix offers a range of easy -to -use digital indicators that meet the exact needs of any truck scale application, from basic weighing to advanced transactions and data handling. No -bolt module connections Simple hook & notch design allows quick, easy joining of the modules. Overall scale length is easily increased by adding modules. PC Software MI Payload provides powerful yet flexible truck scale management, supply chain function and business intelligence capabilities. Steel Bridge XT truck scale installation at Ambassador Bridge Customs — Detroit, Mich. Take the time to compare. You'll hnd Avery Weigh-Tronix offers the best selection, features, options and value in the industry - not to mention knowledgeable distributor support and an exceptional warranty. to suit any type of vehicle or location SELECTION GUIDE Standard Profile SteelBridge XT Extreme Duty 14" BridgeMont Heavy Duty 14" BridgeMont XL Heavy Duty 14" BridgeMont Standard Duty 14" Gross Capacity 50,000 to 270,000 lb 40,000 to 270,000 lb 40,000 to 270,000 lb 35,000 to 270,000 lb CLC/DTA 45 tons 45 tons 45 tons 35 tons NTEP Approved ✓ ✓ ✓ ✓ Standard Module Lengths Standard Total Scale Lengths Custom Lengths 10,12; 20; 23.5' up to 150' 'e' 10', 12', 20', 23.5' up to 150' a 25' up to 150' $' 10',12', 20', 23.5' up to 120' $' Standard Module Widths Custom Widths 10,11',12' up to 15' 10',11',12' up to 15' 10', 11', 12' up to 15' 10',11' s Weight Sensor Weight Sensor Warranty Weigh Bar 5 -years Weigh Bar 5 -years Weigh Bar 5 -years Weigh Bar 5 -years Weighbridge Structure Warranty 15 years 10 years 10 years 5 years Suspension System Pin & Link Easi-Post or Pin & Link Easi-Post or Pin & Link Easi-Post or Pin & Link Deck Surface Steel or Concrete Steel or Concrete Steel or Concrete Steel Finish Paint or Galvanize Paint or Galvanize Paint or Galvanize Paint or Galvanize Stainless Steel Sheathed Cable ✓ ✓ ✓ 3 Stainless Steel Analog J -Box SensorComm Digital J -Box 0 0 0 0 Guide Rails 0 O 0 7 Manholes 0 0 0 .3 Dump Modules 0 O 0 D Pre -Fab Foundation U r O 0 LEGEND: ✓ STANDARD ) OPTIONAL t' CONSULT FACTORY - NOT AVAILABLE OUTSTANDING WARRANTY PROGRAMS Makes the cost of ownership even lower No lifetime" warranties that really aren't lifetime. No pro- rating that erodes coverage, year after year. No hidden exclusions about lightning. These warranties are the real deal. 5 YEARS Internal scale components on BridgeMont & SteelBridge XT models. BridgeMont Standard Duty weighbridge structure. 10 YEARS BridgeMont Heavy Duty weighbridge structure, BridgePort Portable. 15 YEARS Steel Bridge XT weighbridge structure. Truck Scales ENVIRONMENTAL PROTECTION Dependable even in the worst conditions Environmental seals, stainless steel sheathed cable, surge protection, heavy-duty coatings and rugged construction help Avery Weigh-Tronix scales defend against Mother Nature's worst. LIGHTNING & SURGES MOISTURE DUST & DIRT SteelBridge XT BridgeMont Portable Heavy Duty Portable BridgePort BPV Portable Off -Road Combo -Weigh 19" 19" 19" a '$ 50,000 to 270,000 lb 40,000 to 270,000 lb 50,000 to 270,000 lb Up to 270,000 lb Vehicle: 270,000 lb Rail: 400,000 lb 45 tons 40 tons 40 tons 80 tons Vehicle: 40 tons Rail: 180 ton section ✓ ✓ ✓ ✓ ✓ 20', 23.5', 25' up to 100' a 20', 23.5', 25' up to 100' a 20', 25', 30, 35' up to 105' S" — a Tr — up to 100' 8 10', 11' g 10', 11' a 10',11',12' a 11'6" to 16' 8 10',11 Tr Weigh Bar 5 -years Weigh Bar 5 -years Weigh Bar 5 -years Load Cell Manuf. Warranty Load Cell Manuf. Warranty 15 years 10 years 10 years 5 years 10 years Pin & Link Easi-Post or Pin & Link Pin & Link Pin & Link Rocker Assembly Steel Steel Steel Steel or Concrete Steel or Concrete Paint or Galvanize Paint or Galvanize Paint or Galvanize Paint or Galvanize Paint or Galvanize ✓ ✓ O O O ✓ o ✓ O ✓ O ✓ O ✓ O p ) O O O — — — O O LEGEND: V STANDARD ) OPTIONAL Tr CONSULT FACTORY -- NOT AVAILABLE Models continued on page 8 > 7 A wide variety of models STEELBRIDGE XT Long-lasting performance for extreme traffic and axle loads SteelBridge XT is a true heavyweight in the industry. It is a premium scale engineered to thrive on heavy, frequent, day-to-day use. The XT is often used in aggregate, logging, and recycling operations as well as for high traffic, over -the -road weighing. The extra rugged design and construction means structural integrity will be maintained, even after many years of heavy use. With a 15 -year weighbridge warranty, you can be sure SteelBridge XT will still be in operation long after the competitor's scale has worn out. SteelBridge XT is virtually unstoppable! ► Fully Assembled — Scales arrive on -site fully assembled and are easily installed in a pit, or above ground on a slab or piers. Available with a steel or concrete deck surface. ► Low Profile — SteelBridge XT features a low 14" profile that saves real estate and construction costs by using a shorter approach area. Higher profile for additional clearance is easily accomplished with affordable base plate options. ► Standard to Custom — A wide range of standard lengths and widths or built to customer specifications. Also available as a portable unit. MULTI -PLATFORM SCALE One -stop, legal -for -trade axle weighing Choose any combination of SteelBridge XT or BridgeMont scale sections to create a legal -for -trade, one stop axle weighing system. ► Fast axle weighing — Individual scale sections trim minutes off traditional axle weighing methods, substantially increasing productivity. i _ TRAILER AXLE SECTION DRIVE AXLE SECTION 1 I 1 7) STEERING AXLE SECTION 8 BRIDGEMONT® Long-lasting performance for heavy to moderate traffic and axle loads The versatile BridgeMont series truck scales are designed for the majority of users - those that require a dependable, long-lasting scale, but don't need the extreme traffic or axle load capacity of a SteelBridge XT. The BridgeMont series offers an unbeatable combination of structural integrity and cost effectiveness. With many sizes and capacities to choose from, BridgeMont fits virtually any application. ► Fully Assembled — Scales arrive on -site fully assembled and are easily installed in a pit, or above ground on a slab or piers. Available with a steel or concrete deck surface. ► Low Profile — Features a low 14" profile that saves real estate and construction costs by using a shorter approach area. Higher profile for additional clearance is easily accomplished with affordable base plate options. ► Standard to Custom — A wide range of standard lengths and widths or custom built to customer specifications. OFF -ROAD Built for extreme trucks carrying extreme loads Truck Scales BRIDGEMONT HEAVY DUTY The BridgeMont Heavy Duty is a rugged scale that can easily handle heavy traffic and axle loads beyond legal highway limits. It has quickly become one of North America's favorite truck scales over the last 5 years and is preferred by several major corporations in a variety of industries. Available as a portable unit. The Low -Pro 8 version of the BridgeMont Heavy Duty comes in special lengths of 15'and 17.5'with an extra low profile down to 11" to serve as a replacement for other brands of scales. BRIDGEMONT XL This extra -long version of the BridgeMont Heavy Duty is a 75' scale that can handle any legal -length truck in 48 states. As trucks get longer, a standard 70'truck scale may not be the best choice. The 75' BrideMont XL consists of only 3 modules which significantly reduces initial investment and overall ownership costs. Because of their limited module lengths, other manufacturers only offer more costly 80' scales. BRIDGEMONT STANDARD DUTY The BridgeMont Standard Duty provides an economical solution for those applications with moderate traffic and axle loads up to highway limits. It utilizes the same sandwich steel construction and Weigh Bars as the heavier models for outstanding strength and reliability. Avery Weigh-Tronix Off -Road truck scales are designed to meet the tough requirements of industries such as mining and excavating. Widths range from 11'6" to a full 16'with bolt -on outriggers. Lengths up to 100'are available. Custom designs are available. Specify the vehicles to be weighed and let Avery Weigh Tronix take care of the rest. Models continued on page 10 > 9 A wide variety of models PORTABLE TRUCK SCALES Quick set-up for weighing almost anywhere Avery Weigh-Tronix portable truck scales go anywhere there is an immediate need for on -site vehicle weighing — timber operations, road construction, asphalt facilities, quarries, or construction and clean-up sites. They quickly fill temporary needs when other scales fail or there are delays with foundation construction. The self-contained modular sections eliminate costly site preparation and allow for fast setup. Supported by a high - strength frame, our portable scales can be installed on any stable surface in just 2 to 4 hours. They can be readily converted for installation as permanent, low -profile scales. With 3 models to choose from, there's a model available to fit almost any application. Also available as rental units. BRIDGEPORT BPV A rugged deck design and sub -frame of high -strength, tubular steel increases durability for frequent moves. Arrives completely pre -wired with quick -connectors between modules. Individual module lengths of 20', 25', 30', and 35'can be combined to create just the right scale. COMBOWEIGH Weigh trucks & railcars with one scale Comboweigh is a legal -for -trade pit -type scale which does double duty. It weighs both trucks and railcars on the same surface. The structure of the Comboweigh Truck /Track Scale allows users to fit it exactly to location and to specific processes. ► Dual function — One scale, one installation, weighs both rail cars and trucks. ► Factory assembled modules — Scale package includes the weighbridge, load cells, load cell mountings and grout plates, anti -creep angles and summing boxes with surge protection. ► Heavy duty construction — Heavy, wide flange steel beams assure structural integrity. ► Rigid checking system — Critical for track scale systems. Stabilizes the scale quickly for fast weighments. ► Versatile — Optional equipment and designs let you order the scale configuration that fits new or existing loading and unloading systems. Dump grating is available. Avery Weigh-Tronix Truck Scales Above: Portable truck scale installation with temporary gravel ramps. Left: Detail of sub -frame. BRIDGEMONT HEAVY DUTY Same scale used for permanent installations with the addition a high -strength, tubular steel frame and a pair of"C"channel bulkheads. STEELBRIDGE XT Same scale used for permanent installations with the addition a high -strength, tubular steel frame and a pair of"C"channel bulkheads. 10 Avery Weigh-Tronix Options Select from a wide range of options and accessories to create a powerful and versatile vehicle weighing system. Create a complete truck scale system Q GUIDE RAILS AND POSTS: Extreme -duty guide rails are welded in place to provide a strong, attractive barrier against accidental drive -offs. Tubing is gentle on truck wheels and is offset to allow full use of deck. O STOP & GO LIGHTS: Help direct vehicle movement and provide added safety on the premises. Rugged design withstands all types of weather and environments. Q INDICATORS: A range of digital indicators meet the exact needs of any truck scale application, from basic weighing to advanced transactions and data handling. Manufactured to rigid quality standards to provide the fastest, most accurate weight processing available. O PRINTERS: Several printers are available, including the dot-matrix TM - U590, which prints a wide range of slips and documents. Prints 88 columns wide on up to four copies. © REMOTE DISPLAYS: Allow clear, comfortable viewing of scale information at considerable distances, indoors and outdoors. They provide outstanding value with a long list of standard features and are engineered for many years of reliable performance. O v Options continued on page 12 > 11 o UNATTENDED SYSTEMS: Allows 24/7 scale availability. Can be customized with several hardware options such as loop detectors, ID readers, video surveillance, traffic lights, and wireless communication. Q PRE-FAB FOUNDATIONS: Removes most of the complexities of truck scale installation. The scale and foundation can arrive on the same truck shipment to be set-up in just a few hours. If the scale needs to be relocated, the foundation can be reused. • GRAIN DUMP MODULE: An easy -flow grate allows trucks to weigh and dump over a BridgeMont truck scale. Available in 10'or 11' widths. 43 MANHOLE: Provides easy access in pit installations. Reinforced 2'x 2' manhole includes a heavy-duty cover to maintain weighbridge integrity. • GALVANIZING: Steel deck scales can be completely hot -dip zinc galvanized, for enhanced corrosion protection. MI PAYLOAD SOFTWARE: The solution for those companies that use the weight of commodities and products carried by vehicles as a key input to their supply chain processes. The software uses a Microsoft® SQL Servers 2005 database and runs under Windows® XP or Windows Vista*. It may be installed on a single PC and linked to a single weighbridge, or may be configured to run easily and securely across networks within a sophisticated IT environment alongside other supply chain and customer relationship management solutions, supporting many different types of users and interfacing with multiple scales. 12 LOCALIZED SALES AND SERVICE SUPPORT Your local Avery Weigh-Tronix representative has extensive application experience and can help determine which truck scale model is best suited for your needs. Avery Weigh-Tronix sales offices are valuable resources that are readily available to you. They are complete support centers, providing needs assessment, technical information, product sales and service. Avery Weigh-Tronix Avery Weigh-Tronix - USA 1000 Armstrong Drive, Fairmont, MN 56031-1439 USA usinfo@awtxglobal.com Toll -Free: (800) 533-0456 Phone: (507) 238-4461 Avery Weigh-Tronix - UK Foundry Lane, Smethwick, West Midlands B66 2LP UK info@awtxglobal.com Phone: +44 (0) 8453 66 77 88 Fax: +44 (0) 121 224 8183 Please call us or visit www.averyweigh-tronix.com for your nearest Avery Weigh-Tronix distributor *Avery Weigh-imna group of companies 2008. All nghb reserved. Aver/Weigh-trona n a registered hademarb ofthe AmyWeigh-lronu groupof companies. Ns publication is issued to p, de outline infatuation only which. unless agreed byan AreryWeigh-lronb group company in wrong. may rot be regarded as a representation relating tothe products or services concerned this pubbsaton was tornt al the tare of gong no own howeveu Avery Weigh-Lona'nerses the rght N. alter wtlhoot nonce Me specdr,atnin, desgn, puce or cenddins or supply of any pedal a service al any time Weigh Bar• and BridgeMonr• are registered trademarks of Avery Weigh-4=AM Macrosnrt'.Wmdws•,WmdnwsYnta• and SQL SeW• ale wintered trademarks of Microsoft (reparation 12/08 Truckhcale_L_ 099940-0012.indd (C&O) PN099940-0012E el Printed in USA FILE CONTAINS OVERSIZED MAP Please See Original File MIA June 8, 2009 Mr. Douglas Ikenberry, P.E. Colorado Department of Public Health and Environment Hazardous Materials and Waste Management Division HMWMD-SWIM-B2 4300 Cherry Creek Drive South Denver, Co 80246-1530 Mr. Troy Swain Weld County Department of Public Health and Environment 1555 N. 17th Avenue Greeley, Co 80631 N WELD LANDFILL A WASTE MANAGEMENT COMPANY 40,000 Weld County Road 25 Ault, Colorado 80610-9748 (970) 6862800 (970) 6861031 Fax Weld County Planning Department GREELEY OFFICE Subject: North Weld Landfill (NWLF) 2009 Groundwater Monitoring Plan Update Dear Mr. Ikenberry and Mr. Swain: JUN 12pnpg ECEIVE Enclosed is an updated text and corresponding pages to the Groundwater Monitoring Plan (GWMP) for NWLF. This plan was updated pursuant to Development Standard #8 of the Weld County Certificate of Designation. This Development Standard requires the plan to be reviewed at least once every two years. The NWLF Groundwater Monitoring Plan was previously reviewed, updated and submitted to the Colorado Department of Public Health and Environment (CDPHE) and Weld County Department of Public Health and Environment (WCDPHE) on May 30, 2007. Another update was submitted by Earthtech on May 1, 2008 which updated Table 7-1 of the GWMP. The NWLF GWMP was reviewed and modified by NWLF and only minor plan updates/revisions were required since the previous plan submittal. These plan updates/revisions are described below: 1. Changed the front cover page of the Updated Groundwater Monitoring Plan to reflect the plan update; 2. Updated the Revision Summary page to document the plan updates; 3. General Text Edits • Updated information in Section 5.1.2 regarding sample collection. c:\data\letter\nwsl\upgrwp1n2009 File: 4.1.6 Letter Douglas Ikenberry and Troy Swain June 5, 2009 Page 2 • 'Updated information in Section 7.3 regarding the EPA Method Update Rule • Updated Section 7.4 to include additional information which will be provided as part of future groundwater reports. • Updated the information in Appendix 4 (Directory). Please replace the existing text which has been revised as described above, with the enclosed text and corresponding pages. If you have any questions concerning these revisions, please contact either of us (303- 644-4355 for Alan Scheere or 970- 686-2800 ext. 23 for Bill Hedberg). Sincerely, Alan Scheere Bill Hedberg Environmental Specialist Sr. District Manager Enclosure AS/as cc: Kim Ogle, WCDPS, w/o enc. c:\data\letter\nwsl\upgrwpin2009 File: 4.1.6 Groundwater Monitoring Plan WASTE MANAGEMENT GROUND WATER MONITORING PROGRAM NORTH WELD LANDFILL WELD COUNTY, COLORADO Prepared December 1992 by: ATEC Associates, Inc. Deliver, Colorado For Waste Management Disposal Services of Colorado, Inc. 40,000 Weld County Road 25 Ault, Colorado 80610 Revised March 1994, October 1996, November 1997, May 1999, May 2001, May 2003, May 2005 May 2007 May 2009 by: Waste Management Disposal Services of Colorado, Inc. Groundwater Monitoring Plan REVISIONS TO NORTH WELD LANDFILL GROUND WATER MONITORING PLAN Version # Date , "Description of Revision #1 3/16/94 Revised Tables 5-1, 5-2 and 7-1 3/16/94 Corrected typographical error on Page 14 3/16/94 Corrected typographical error on Table 6-1 3/16/94 Sentence deletion on Page 32 3/16/94 Sentence change on Page 39 3/16/94 Reference deleted from Page 44 #2 8/7/96 Revised Groundwater Monitoring Plan #3 11/25/97 Revised Groundwater Monitoring Plan* #4 5/4/1999 General Plan review and update** #5 5/30/01 General Plan review and update*** #6 5/29/03 General Plan review and update**** #7 5/25/05 General Plan review and update***** #8 5/30/07 General Plan review and update ****** #9 5/2009 General Plan review and update****** See letters (Appendix 6) dated 3/16/94, 8/7/96 and 2/26/97 CDPHE for more information concerning the above revisions. *See letter dated 11/25/97 for more information concerning the November 1997 plan revision. ** See letter dated 5/4/99 for more information concerning the May 1999 plan revision. *** See letter dated 5/30/01 for more information concerning the May 2001 plan revision. **** See letter dated 5/29/03 for more information concerning the May 2003 plan revision. ***** See letter dated 5/25/05 for more information concerning the May 2005 plan revision. ****** See letter dated 5/30/07 for more information concerning the May 2007 plan revision. ****** See letter dated June 5, 2009 for more information concerning the May 2009 plan revision. i Groundwater Monitoring Plan NORTH WELD LANDFILL GROUND WATER MONITORING PLAN TABLE OF CONTENTS Page 1.0 INTRODUCTION 1 1.1 PURPOSE 1 1.2 LOCATION 1 1.3 OPERATIONAL HISTORY 1 1.4 STATUS OF MONITORING PROGRAM 2 1.4.1 Regulatory Requirements 2 1.4.2 Site Specific Program Details 3 2:0 PHYSICAL SETTING 3 2.1 TOPOGRAPHY 3 2.1.1 Regional Topography 3 2.1.2 Site Topography 3 2.2 GEOLOGY 4 2.2.1 Regional Geologic Setting 4 2.2.2 Site Geology 5 2.3 HYDROGEOLOGY 6 2.3.1 Regional Hydrogeology 6 2.3.2 Hydrogeology 7 2.3.3 Groundwater Movement _ 9 2.3.4 Surface Water Hydrology 10 2.3.5 Local Water Use 11 3.0 GROUNDWATER MONITORING SYSTEM 12 3.1 WELL PLACEMENT 12 3.2 WELL CONSTRUCTION 13 3.3 WELL DEVELOPMENT 14 3.4 MONITORING WELL INSPECTION PROGRAM 14 3.4.1 Surface Survey 14 3.4.2 External Protective Casing Observations 15 3.4.3 Internal Casing Observations 15 4.0 LEACHATE AND SURFACE WATER MONITORING SYSTEMS 15 4.1 LEACHATE SYSTEM 15 ii Groundwater Monitoring Plan 4.2 SURFACE WATER SYSTEM 15 5.0 SAMPLING PLAN 16 5.1 SAMPLING PLAN SUMMARY 16 5.1.1 Procedures Prior to Sampling 16 5.1.2 -Sample Collection 17 5.1.3 Field Analysis 18 5.1.4 Sample Filtering, Preseivation and Shipment 18 5.1.5 Chain -of -Custody Control 18 5.1.6 Field QA/QC 19 5.2 SAMPLE TECHNICIAN CONTACT 19 6.0 SAMPLE ANALYTES AND SCHEDULE 20 7.0 ANALYSIS PLAN 21 7.1 LABORATORY QUALITY CONTROL PROCEDURES 21 7.2 DETECTION LIMITS 21 7.3 ANALYTICAL METHODOLOGIES 21 7.4 DATA REPORTING AND RECORDKEEPING 21 7.4.1 Reporting Requirements 21 7.4.2 Recordkeeping Requirements 22 7.5 LABORATORY CONTACTS 22 DATA EVALUATION 22 8.1 STATISTICAL PROGRAM 22 9.0 REFERENCES 23 iii Groundwater Monitoring Plan NORTH WELD LANDFILL GROUND WATER MONITORING PLAN List of Tables Table 1-1 Table 2-1 Table 2-2 Table 2-3 Table 2-4 Table 2-5 Table 3-1 Table 3-2 Table 3-3 Table 3-4 Table 5-1 Table 7-1 Monitoring Well Network Previous Hydrogeological Investigation Summary of Packer Test Hydraulic Conductivities Summary of Slug Test Hydraulic Conductivities HELP Model Water Balance Data Permitted Wells Within One and Two Miles Groundwater Monitoring Well Construction Summaries Groundwater Depths and Elevations (deleted) Groundwater Conductivities and Temperature (deleted) Summary of Water Quality Results (deleted) Sample Analytes and Schedule Laboratory Analytical Methods and Reporting Limits iv Groundwater Monitoring Plan NORTH WELD LANDFILL GROUNDWATER MONITORING PLAN List of Drawings Drawing 1-1 Site Vicinity Map Drawing 1-2 Facility Arrangement, Limits of Fill and Phases of Development Drawing 2-1 Site Location Map Drawing 2-2 Regional Geologic Map Drawing 2-3 Bedrock Geology Map Drawing 2-4 Geologic Cross Section A -A' Drawing 2-5 Surficial Geology Drawing 2-6 Generalized Stratigraphic Column Drawing 2-7 Coal Bearing Stratigraphic Section of the Laramie Formation Drawing 2-8 Locations of Test Holes and Monitoring Wells Drawing 2-9 Locations of Geologic Cross Sections Drawing 2-10 Hydrogeologic Cross Section B -B' Drawing 2-11 Hydrogeologic Cross Section C -C' Drawing 2-12 Hydrogeologic Cross Section D -D' Drawing 2-13 Hydrogeologic Cross Section E -E' Drawing 2=14 Regional Chemical Quality of Groundwater Aquifers Map Drawing 2-15 Site Piezometric Contour Map Drawing 2-16 Graphic Summary of Packer Test Results Drawing 2-17 Phreatic Surface of Perched Groundwater Drawing 2-18 Registered Wells Located Within a One -Mile Radius Drawing 2-19 Regional Surface Water Features and Flood Prone Areas Map Drawing 2-20 Surface Water Flow Patterns Drawing 3-1 Locations of Groundwater Monitoring Wells Drawing 3-2 Typical Monitoring Well Construction Details Drawing 3-3 Monitoring Well Integrity Field Survey Form Drawing 5-1 Field Information Form Drawing 5-2 Chain -of -Custody Form r Grounthvater Monitoring Plan NORTH WELD LANDFILL GROUND WATER MONITORING PLAN List of Appendices Appendix 1- Well Location Map Appendix 2- Logs of Drill Holes Appendix 3- Monitoring Well Construction Summaries Appendix 4- Directory Appendix 5- Data Reporting Forms Appendix 6- Regulatory Approvals Appendix 7- Well Permit Applications and Permits Appendix 8- State of Colorado Well Records vi Groundwater Monitoring Plan GROUNDWATER MONITORING PLAN NORTH WELD LANDFILL WELD COUNTY, COLORADO 1.0 INTRODUCTION 1.1 PURPOSE Waste Management Disposal Services of Colorado, Inc. (WMDSC) operates a 119 -acre landfill on a 170 -acre site known as the North Weld Landfill (NWLF). The landfill currently accepts household, commercial, and industrial solid waste. No regulated hazardous, radioactive, or bulk liquid wastes are accepted by the facility. This document presents the groundwater monitoring program for the NWLF. The groundwater monitoring program is designed to monitor the potential impacts of the facility on groundwater beneath the site, and was developed to meet the requirements of the Colorado Department of Public Health and Environment (CDPI-IE), the Weld County Certificate of Designation (CD), and WMDSC policies. This document is updated as needed to reflect any changes in the monitoring system, regulations and/or company policies. Interim addenda will also be added to the plan as appropriate between updates. The site location, operational history, and monitoring plan status are presented in the remainder of this section. Section 2.0 presents the physical setting of the site, including topography, geology, and hydrogeology. Section 3.0 summarizes the ground water monitoring system. The leachate and surface water monitoring systems are described in Section 4.0. Sections 5.0 through 8.0 present the sampling, analytical methodologies and evaluation plan and process. Section 9.0 presents the references used to prepare this document. 1.2 LOCATION The NWLF is located approximately five miles west of the town of Ault and 14 miles east of Fort Collins on Colorado State Highway 14, in northern Weld County, Colorado, as shown on Drawing No. 1-1. The facility address is 40,000 Weld County Road 25, Ault, Colorado 80610. The NWLF occupies approximately 170 acres in the southwest portion of Section 7, Township 7 North, Range 56 West of the Sixth Principal Meridian. The site is owned and operated by WMDSC. In addition, WMDSC owns 320 acres of adjacent buffer property. 1.3 OPERATIONAL HISTORY The NWLF is located on land which was primarily undeveloped agricultural land used for dry -land fanning prior to the development of the current landfill operation. In 1989, 1 Groundwater Monitoring Plan WMDSC, known at that time as Waste Services Corporation (WSC), conducted geological and geotechnical investigations (IC, 1989) to evaluate the property for potential development as a municipal solid waste disposal site. The NWLF received its CD from the Weld County Board of County Commissioners on June 28, 1990 (Weld County, 1990). After receipt of the CD, construction of site civil improvements (entrance road, gatehouse, and maintenance shop, above ground fuel tank containment area, water, sewer, fencing and landscaping) began. On July 12, 1991, WSC merged with Waste Management, Inc. Construction of the first disposal cell was completed December 1991. Site civil improvements were completed in January 1992, and the NWLF opened,to the public for the first receipt of municipal solid waste on February 3, 1992. The landfill property boundary and limits of landfill disposal area are shown on Drawing No. 1-2. 1.4 STATUS OF MONITORING PROGRAM Presently, there are 6 groundwater monitoring wells on -site that comprise the monitoring network at NWLF. These wells are listed in Table 1-1. Of these wells (MW -3 through MW -5, MW -10 and MW -12) are completed in the upper portion of the regional aquifer, and one well (MW -9) is completed in a shallow perched groundwater zone. The eight quarters of background data were completed during the first quarter of 1996. Logs of the drill holes for these monitoring wells are presented in Appendix 2, and well construction summaries are presented in Appendix 3. Locations of these monitoring wells are presented on the Well Location Map presented in Appendix 1. 1.4.1 Regulatory Requirements As a solid waste disposal facility, NWLF is regulated by the State of Colorado "Regulations Pertaining to Solid Waste Disposal Sites and Facilities" Title 30, Article 20, Part 1, Colorado Revised Statutes (CRS), as amended. The CD for NWLF (Weld County Board of Commissioners, June 27, 1990) requires groundwater monitoring in accordance with the facility Development Standards. Section 8 of the Development Standards states: "The facility shall be operated in a manner, which protects against surface and groundwater contamination. A groundwater monitoring plan, including leachate detection and groundwater monitoring wells, periodic sampling, and monitoring shall be implemented by the facility operator. This plan shall be reviewed and approved by the Colorado Department of Health and the Weld County Health Department. The plan shall be reviewed at least every two years by the State and County Health Departments. Changes and updates to the plan shall be facilitated by the reviewing agencies." 2 Groundwater Monitoring Plan The name, title, addresses, and phone number of the agency individual(s) who receives the monitoring data are presented in the NWLF Directory contained in Appendix 4. 1.4.2 Site Specific Program Details Quarterly groundwater monitoring at NWLF started in January 1992. The current groundwater monitoring program as approved by the CDPHE and WCDPHE consists of semi-annual monitoring of MWs 3, 4, 5, 10, and 12. The monitoring of MW -9 has been temporarily suspended as discussed in Section 6.0. Based on previous additional hydrogeologic site investigations, an enhanced groundwater monitoring program was implemented as discussed in Section 3.0. This enhanced program consists of monitoring five deep regional groundwater wells for groundwater level and quality. One well in shallow, perched groundwater will be monitored for groundwater level and quality when landfilling commences over the perched area. Locations of the monitoring wells and their construction details are discussed in Section 3.0. 2.0 PHYSICAL SETTING 2.1 TOPOGRAPHY 2.1.1 Regional Topography The site is located within the Colorado Piedmont section of the Great Plains physiographic province. The mountainous Front Range lies'approximately 20 miles west of the site. The site is located approximately nine miles north of the Cache la Poudre River Valley, a tributary to the South Platte River, on a broad upland area consisting of gently rolling hills. Elevations in the area decrease very gradually to the southeast. The highest local elevation is 5,232 feet above mean sea level (MSL) at a point approximately two miles to the northwest of the site. This upland surface is scored by closely spaced, shallow valleys that trend southeastward with long, low dune ridges of silt and sand, which are aligned northwest -southeast. Deflation basins are present, and many are used as water reservoirs. Natural landforms and drainage courses have been modified by irrigation systems and agricultural activities in the area (Crosby, 1978). The location of the site and adjacent topography are shown on Drawing No. 2-1, which also shows the northwest -southeast trends in topography. 2.1.2 Site Topography The site is situated near a topographic high and experiences very little surface water run-on. The natural topography of the site is gently rolling ridges and swales. Natural topographic elevations at the site range from a high of approximately 5,160 feet MSL in the 3 Groundwater Monitoring Plan northwestern portion of the site to a low of 5,080 feet MSL in the southeastern portion of the site. A small unnamed drainage runs from the west central portion of the site to the southeastern perimeter and eventually joins Coalbank Creek approximately two miles southeast of the site. The site was previously used for dryland farming, and this practice continues on portions of the buffer property only. Elongated soil stockpiles are present along the north and east perimeters of the site. A borrow area is open in the southeast portion of the site and provides a collection sump for surface water run-off. Details of the on -site topography are presented in Drawing No.1-2. Constructed and proposed base grades for the fill area range from 5,130 feet MSL in the northwest corner to 5,055 feet MSL in the southeast corner. The CD limits the maximum elevation of the fill to 5,210 feet MSL. 2.2 GEOLOGY 2.2.1 Regional Geologic Setting The site is located on the northwestern flank of the Denver Basin, which extends to the north and east into southeastern Wyoming, southwestern Nebraska and eastern Kansas. The Front Range Uplift structure lies west of the Denver Basin and approximately 20 miles west of the site. The site lies on sedimentary bedrock strata, which dips gently southeasterly in the site vicinity. Further to the west, the bedrock dip increases as the distance to the uplifted Front Range decreases. The Front Range Mountains to the west are composed of highly complex igneous and metamorphic rock systems.The general arrangement of geologic bedrock units in the region, including the Front Range Uplift, are shown on a Regional Geologic Map presented as Drawing No. 2-2 and are described on. subsequent pages. A more detailed map of bedrock units in the area is presented in Drawing No. 2-3. A generalized cross-section along axis A -A' is presented in Drawing No. 2-4. This cross-section line is also shown on Drawing No. 2-5, a Surficial Geology Map, which shows the location of the site with respect to exposures of the uppermost bedrock units and surficial soil deposits along with descriptions of these units. The site and surrounding area are underlain by unconsolidated surficial deposits, which lie unconformably over sedimentary bedrock. These surficial deposits include alluvial and eolian deposits. The alluvium consists of interbedded sands and gravels representing glacial and interglacial sediment deposits. Minor amounts of clay and varying amounts of silt are interspersed within the sand and gravel. Eolian deposits generally blanket the region and consist of very fine to fine grained silty sand, which represents erosion of rock in glaciers at higher elevations to the west. Sandy and gravelly alluvium underlie flood plains of streams in the area. 4 Groundivater Monitoring Plan The bedrock underlying the site and surrounding area contains strata consisting of a varied mixture of claystone, siltstone, limestone, sandstone, shale and conglomerates, which comprise several thousand vertical feet. The bedrock strata of interest from upper to lower include the Laramie Formation, Fox Hills Sandstone, and the Pierre Shale. A generalized stratigraphic column for the site area is presented as Drawing 2-6. The Laramie varies from 400-1200 feet thick in the Denver Basin; however, at the site location it has been eroded to a thickness of about 100 feet. On a regional basis, the lower part pf the Laramie contains numerous coal beds up to 14 feet thick, as shown in Drawing No. 2-7, which characterizes the lower Laramie Formation and its coal bearing stratigraphy. 2.2.2 Site Geology Information regarding geologic conditions at the site were obtained from available U.S.G.S. maps, Colorado Geologic Survey maps, a thesis paper by Harry J. Briscoe, Jr. (1972), investigations conducted by Industrial Compliance (IC, 1989), site geologic reconnaissance and extensive subsurface exploratory drilling and coring during the Hydrogeologic Site Characterization investigation in 1992 (ATEC, 1992). A summary of the geologic/hydrogeologic investigations and environmental monitoring plans containing geologic/hydrogeologic information are presented in Table 2-1. During the ATEC Hydrogeologic Site Characterization, a total of 43 exploratory holes were drilled to evaluate subsurface conditions and to install groundwater monitoring wells and piezometers. An additional 13 drill holes were advanced for the construction of gas monitoring probes at the site. The locations of these exploratory holes are shown on Drawing No. 2-8 along with exploratory drill holes conducted by IC in 1989 and 1991. The logs of the drill holes used to construct groundwater monitoring wells and piezometers are presented in Appendix 2 of this plan. The logs of the other on -site drill holes and gas probe installations .are presented separately in the Hydrogeologic Site Characterization Report (ATEC, 1992) along with a more detailed description of the site geologic and hydrogeologic conditions. Geologic surface conditions in the vicinity of the site are also illustrated in Drawing Nos. 2-3, 2-4, and 2-5. Five geologic cross -sections were developed along the cross-section axes shown on Drawing No. 2-9. These cross sections A -A', B -B', C -C', D- D' and E -E', are presented on Drawing Nos. 2-4, 2-10, 2-11, 2-12 and 2-13. Locations of test holes in monitoring wells sampled for this study are shown on these sections. The site is situated in an upland area, which is underlain by glacial outwash and eolian deposits underlain by sandstones, claystones and lignitic shales of the Laramie Formation. The geologic units present at the site which are significant to this groundwater monitoring plan, in descending order of occurrence are: • Eolian deposits • , Alluvial deposits 5 Groundwater Monitoring Plan • The Laramie Formation • The Fox Hills Formation • The Pierre Shale The eolian deposits blanket the site to depths ranging from 14 to 17 feet except where they have been removed by excavation activities. The deposits are mainly sandy silt with varying amounts of clay. The alluvial deposits underlie the eolian silt and overlie the weathered Laramie Formation under much of the site. These deposits range from absent up to 29 feet in the thickness. The alluvium consists mainly of gravelly, silty, sand with varying amounts of clay. The entire site is underlain by deposits of the Laramie Formation. The Laramie Formation underlies the site at depths below the natural ground surface ranging from 10 to 40 feet and ranges from about 75 to over 100 feet in thickness. The Laramie Formation consists of interbedded claystone, shale, siltstone, sandstone, and coal strata of highly variable thickness and lateral extent. The Fox Hills Formation underlies the Laramie Formation below the site at depths of 95 to over 138 feet below natural grades. The Fox Hill Formation is about 190 feet thick under the site and consists mainly of sandstone with some shale interbeds. The Pierre Formation consists of a thick sequence of shale with thin interbeds of siltstone and sandstone. The Pierre Shale underlies the Fox Hills Formation and is several thousand feet thick. 2.3 HYDROGEOLOGY 2.3.1 Regional Hydrogeology Groundwater occurrences in the vicinity of the site are controlled by a variety of liydrogeologic conditions, climatic conditions and geographic controls. The area receives an average annual precipitation of about 12.5 inches and is considered semi -arid. The region is quite dry in the upland areas, but does support dryland farming. Occurrences of ground water identified in the site vicinity are primarily of four types: • Saturated alluvial deposits along low-lying streams or drainages. • Thin localized zones of perched groundwater within surficial deposits. • Localized zones of perched groundwater within permeable or semi -permeable bedrock strata. This occurrence will normally be fed through a localized recharge 6 Grounfivater Monitoring Plan mechanism. These may involve sandstone strata or fractured zones of less - permeable, near -surface bedrock. • A regional zone of saturation within bedrock units of the Laramie and Fox Hills Formations. Groundwater production in the area is generally from the saturated alluvial deposits along the larger streams and is of low quality as shown in Drawing No. 2-14. 2.3.2 Hydrogeology The hydrogeology of the site has been interpreted from regional groundwater patterns, regional surface water occurrences, the stratigraphy and geologic structure of the site subsurface exploratory drilling, and observation of groundwater in the groundwater monitoring wells. As discussed in detail in the following sections, two zones of saturation have been identified at the site and targeted for groundwater monitoring. These zones are: • A deep regional zone of saturation within the bedrock units of the Laramie and Fox Hills Formations (uppermost aquifer and primary target zone for groundwater monitoring); and • Localized perched shallow bedrock saturation within the Laramie Formation (secondary target zone for groundwater monitoring). The uppermost aquifer andprimary target zone for groundwater monitoring is a deep regional zone of saturation within the sedimentary bedrock of the upper portion of the Fox Hills Formation and, under the eastern one-half of the site, the lowermost strata of the Laramie Formation. This saturated zone is laterally continuous under the site and is in communication with the regional groundwater flow system. Monitoring wells indicate the deep groundwater system underlies the site with depths below ground surface (bgs) and elevations of the piezometric surface of approximately: • 140 feet bgs (elevation 5,010 feet MSL) under the northwest corner • 70 feet bgs (elevation 5,022 feet MSL) under the northeast corner • 135 feet bgs (elevation 4,989 feet MSL) under the southwest corner • 80 feet bgs (elevation 5,001 feet MSL) under the southeast corner • 125 feet bgs (elevation 5,003 feet MSL) under the center of the site The slope of this piezometric surface is to the southwest at a gradient of about 0.010 foot/foot. A map showing contours of the piezometric surface is presented on Drawing No. 2-15. 7 Groundwater Monitoring Plan Under the western portion of the site the phreatic surface lies within the Fox Hills sandstone, and the Laramie Formation is unsaturated. However, the bedrock strata dip to the east and southeast steeper than the groundwater gradient and the lower most strata of the Laramie Formation is saturated under the eastern portion of the site. The dipping claystone of the Laramie Formation creates a confined and artesian aquifer under the eastern portion of the site. Borings for MW -3 and MW -4 revealed the Fox Hills sandstone is about 190 feet in total thickness under the site and that this formation may be separated by a shale aquitard into an upper and lower aquifer unit. The upper unit is a sandstone unit roughly 40 to 100 feet thick separated by a 16 to 18 foot thick shale unit from a lower unit of sandstone with shale interbeds totaling about 100 to 130 feet in thickness. These units are seen in the logs of core holes MW -3 and MW -4. At MW -3, the lower 52 feet of this upper aquifer unit of the Fox Hills is saturated and unconfined, while at MW -4, the full 42 foot thickness of this upper Fox Hills unit is saturated, confined, and artesian. In MW -4, the saturated zone of the deep groundwater system extends approximately 25 feet into the overlying Laramie Formation. Two packer tests were conducted in the Laramie Formation with results of 7.3x10 5 cm/s and 2.4x105 cm/s with a geometric mean value of 4.2x10-5 cm/s. Seven tests conducted in the Fox Hills sandstone yielded hydraulic conductivities ranging from 4.1x104 cm/s to 8.7 x 104 cm/s with a geometric mean of 5.7x104 cm/s. Results of the packer tests are summarized in Table 2-2 and Drawing No. 2-16. Slug testing results as presented in Table 2-3 indicates hydraulic conductivities in the Fox Hills sandstone ranging from 5.8x10-5 to 4.4x104 cm/sec (a geometric mean of 1.4x104 cm/sec). Slug testing in the Laramie Formation aquifer as presented in Table 2-3 yielded hydraulic conductivities ranging from 4.9x104 cm/sec in shale to 9.7x10-5 cm/sec in various interbedded sandstone, siltstone, shale, and lignite strata. The values for the Laramie Formation interbedded strata range from 3.0x10"5 cm/sec to 9.7x10-5 cm/sec with a geometric mean of 5.4x10-5 cm/sec. A second localized occurrence of groundwater and secondary target zone for groundwater monitoring is a perched zone located within the shallow weathered bedrock of the Laramie Formation in the extreme southeast corner of the site. This saturated zone is only a few feet in thickness and slopes to the southeast at depths of 26 to about 50 feet below the ground surface of the clay borrow area as present in 1992. One slug test conducted in the perched shallow ground water zone of MW -9 yielded a hydraulic conductivity of 3.0x10"5 cm/sec. MW -9 was screened in interbedded clay lignite and sandstone with a 2 foot thick sandstone bed in the saturated zone. 8 Groundwater Monitoring Plan Perched shallow groundwater was found in former monitoring wells MW -1, MW -2, MW -9 and piezometer PZ-1. Two other piezometers (PZ-2 and PZ-3) installed to evaluate the lateral extent of this perched groundwater did not encounter groundwater and have remained dry. Based on drill logs, well and piezometer construction information, stratigraphic intervals and the general dip of bedrock at the site, it appears that the shallow groundwater occurs in the sandstone interbeds of the Laramie Formation. This is depicted in the cross-section on Drawing No. 2-10, which also shows the relative level of the deeper regional zone of saturation represented by groundwater levels in MW -4 and MW -5. Phreatic surface contours of the perched water are presented in Drawing No. 2-17. The perched shallow groundwater exhibits a gradient of approximately 0.095 foot/foot to the southeast. With a bedrock dip of about 1 to 2 degrees to the east, the low to moderate permeability sandstone interbeds containing the perched groundwater rise to the west and may be receiving surface water from on -site infiltration via one or more drainage swales or from direct infiltration. Water in the sandstone interbeds is believed to be moving down dip by flowing along pervious strata on a lower claystone interface. The down -dip extent is not known; the sandstone beds may pinch out in claystone or continue downward to the regional bedrock saturation level. 2.3.3 Groundwater Movement Groundwater levels measured at the site indicate groundwater movement in the uppermost aquifer under the site is from the northeast toward the southwest. The uppermost aquifer occurs in strata of the Fox Hills sandstone and to a very limited extent in the lowermost strata of the Laramie Formation. The vast majority of the flow is through the more permeable sandstone of the Fox Hills with a small component of flow in the less permeable interbedded and discontinuous sandstone/siltstone/claystone strata of the Laramie Formation. On a regional basis, groundwater flow through the saturated bedrock probably follow a somewhat convoluted, southwesterly route through the southeast to northeast dipping permeable strata and bedrock joints. Due to the low average annual rainfall of about 12.5 inches and surface soils of low to moderate hydraulic conductivity, direct precipitation infiltration is probably low over most of the surface area. A water balance conducted by IC (1989) indicates no infiltration. However, the site stratigraphy and the groundwater detected under the southeast corner of the site indicate localized infiltration of precipitation into permeable strata does occur. This infiltrating water probably migrates directly down -dip until it reaches a pinch -out of the permeable layer or until it reaches the level of the regionally saturated bedrock. Although leachate migration is unlikely, potential leachate migration pathways from the landfill to the upper aquifer would tend to be downward along northeast dipping strata or 9 Groundwater Monitoring Plan more vertically downward through joints, or a combination of the two until the regional zone of saturation is reached. This potential leachate movement would primarily be along sandstone strata. Migration below the regional zone of saturation would be very slow and in a generally southerly direction. Based on the geometric mean horizontal hydraulic conductivity of the Fox Hills sandstone of 5.7x1O cm/s as obtained by packer testing, the average hydraulic gradient under the site of 0.0010, and an estimated effective porosity of 0.20, the average flow velocity in the Fox Hills is estimated at approximately 30 feet per year. The on -site groundwater gradient is to the south-southwest while the regional gradient is to the southeast. The nearest known off -site water well lies 0.9 miles southeast of the site in Section 18 as shown on Drawing No. 2-18. Using conservative straight line distance as the shortest flow path and a velocity of groundwater in the Fox Hills of 30 feet per year, the estimated minimum travel time to the nearest off -site water well is 160 years. This estimate does not include travel time for vertical infiltration of leachate through the unsaturated Laramie Formation underlying the base grades of the landfill. 2.3.4 Surface Water Hydrology Surface water features located in the site vicinity include shallow lakes and reservoirs, irrigation ditches, creeks, rivers and flood plains as shown in Drawing N. 2-19. The largest controlling surface water feature in the vicinity is the South Platte River, which is located at its closest point to the site approximately 16 miles to the southeast, near Greeley. The Cache la Poudre River, a major tributary to the Platte, drains the site vicinity approximately 9 miles southwest of the site. The confluence of the Platte and Cache la Poudre is located approximately three miles east of Greeley, approximately 16 miles southeast of the site. Small creeks in the vicinity flow to the southeast toward the Cache la Poudre River and many feed small reservoirs in the area. This drainage pattern is controlled by the physiographic nature and prevailing southerly topographic gradient of the upland area on which the site is located. Numerous irrigation ditches flow easterly through the vicinity and may be linked to the reservoirs in the area. In addition, there are numerous small shallow ponds and lakes in the vicinity. Many of these features are located in deflation basins on the upland complex and may be ephemeral containing water in spring and early summer months. Flood -prone areas include small creeks and associated low-lying areas, shallow ephemeral ponds and lakes. Drawing No. 2-19 shows the 100 -year flood plain as mapped by the U. S. Corps of Engineers and U. S. Geological Survey. The closest major flood plain is along the Cache la Poudre River, located approximately 9 miles southwest and south of the site 10 Groundwater Monitoring Plan (McCain & Hotchkiss, 1975). The site lies on an upland area and is not crossed by a stream or flood plain. Natural surface drainage on the site is generally to the southeast toward the Pierce Lateral Canal, Collins Lateral Canal and Coalbank Creek. Virtually all of the surface water flow originates on site due to a topographic high in the northwest corner of the property. Therefore, there is minimal run-on surface flow to control. The landfill clay borrow area located in the southeast portion of the site created a surface water run-off sump. Although a segment of this sump area has since been backfilled with soil, it continues to capture a portion of surface run-off from the undeveloped planned fill area of the site. The surface water collected in this sump area is pumped out and used for dust abatement applications. Surface water control is augmented by the existing soil stock piles and screening berms constructed at the site. No running or standing water, phreatophytes or wetlands are present on the site or in the immediate vicinity other than the run-off collection sumps. In addition, no springs or seepage areas were observed in the immediate site vicinity. Regional surface water features are shown on Drawing No. 2-19. Site specific features and drainage patterns are shown on Drawing No. 2-20. 2.3.5 Local Water Use Surface Water Use — Surface water in the area is collected in small reservoirs and deflation basins for agricultural use. Distribution is through canals. Two canals skirt the low ridge on which the site is situated. • These canals named Pierce and Collins laterals, trend southeast on the west side of the site, east along the south side, and north along the east side as depicted on Drawing No. 2-1. Ground Water Use — Due to the lack of good producing aquifers in the area and sparse population, there are few groundwater production wells in the immediate site vicinity. Consequently, there are few sources of information regarding groundwater quality in the. vicinity of the site and particularly in the bedrock aquifers. Hillier and Schneider (1979) of the USGS, have published a map of groundwater quality in the region based on well water quality data obtained by CDPHE in 1971 and 1977. This map is reproduced in Drawing No. 2-14. Present quality in the area is considered poor, and most groundwater is not fit for human consumption as determined by the U. S. Environmental Protection Agency due to higher than acceptable levels of total dissolved solids (typically 800 to 3,000 mg/I). Potable water at the NWLF is obtained by a rural pipeline supply furnished by the North Weld Water District. Our research indicates that most residents in the area also obtain water from the North Weld Water District pipeline supply system. 11 Groundwater Monitoring Plan Most of the water production wells, which are located in the region, tap unconsolidated alluvial, deposits along the large stream valleys incised between the uplands or buried bedrock valleys of ancient drainages. Drawing No. 2-18 shows the distribution of most of the producing wells in the region. Table 2-5 shows permitted wells within 1 and 2 miles of the facility. During the site characterization conducted by ATEC during 1993, the State Engineer's records of permitted water wells in the vicinity of the site were reviewed. Only one water well other than the on -site monitoring wells has been identified within one mile of the site as shown on Drawing No. 2-18. This well is approximately 0.9 miles southeast of the site in Section 18 and is topographically and hydraulically downgradient of the site. Most groundwater in the area of the site is not considered suitable for human consumption. Furthermore, there are very few locations in the area where either surface or ground water is of a quality suitable for livestock use (Shelton & Rogers, 1975). 3.0 GROUNDWATER MONITORING SYSTEM 3.1 WELL PLACEMENT Wells previously constructed at NWLF for site characterization purposes consisted of 12 monitoring wells (MW), one test hole (TH) and 3 piezometers (PZ). Of the 12 monitoring wells, nine MWs (MW -3 through MW -5, MW -7, MW -8, MW -10 through MW -12) and one test hole (TH-23) were screened in the deep, regional bedrock aquifer, and three MWs (MW -1, MW -2, and MW -9) were screened to monitor the shallow, perched groundwater system. One well, MW -6 was screened in the dry interval above a confined zone of saturation and below the potentiometric level. The three piezometers (PZ-1, PZ-2 and PZ- 3) were screened in the area of the shallow, perched groundwater system, and two of these (PZ-2 and PZ-3) were dry. Of these wells, only MW -3, 4, 5, 9, 10 and 12 are included in the current monitoring program at NWLF. The locations of these wells are shown in Appendix 1. Drill logs and well construction records for these wells and piezometers are presented in Appendices 2 and 3. Based on the hydrogeologic site characterization completed for NWLF in 1992, separate monitoring systems were approved for the deep regional and shallow perched groundwater systems. The monitoring system for the deep regional groundwater system includes two upgradient wells (MW -3 and MW -12) and three downgradient wells (MW -4, MW -5 and MW -10). The shallow perched groundwater is monitored by one downgradient well (MW - 9). Monitoring was suspended at well MW -9 in February 1997, until landfill operations commence near this area of perched groundwater. MW -1 and MW -2 were either within or on the edge of the designed and permitted solid waste fill area and were not suitable for long-term monitoring. Monitoring wells 1, 2, 6, 7, 8, 11 and test hole 23 and piezometers 1, 2 and 3 were decommissioned as part of the implementation of the enhanced groundwater 12 Groundwater Monitoring Plan monitoring program. Decommissioning reports were submitted to the CDPHE and WCDPHE. 3.2 WELL CONSTRUCTION Well construction techniques are designed to maintain the integrity of the borehole, minimize introduction of extraneous materials, provide representative groundwater samples from the monitored aquifers, minimize maintenance, and prevent entry of surface water into the annular space of the well. The materials used for well construction have been selected on the basis of: 1. Strength 2. Corrosion resistance 3. Low interference with parameters to be monitored 4. Cost 5. Compatibility with the drilling method employed Each of the wells consisted of ten to 40 feet of two-inch diameter Schedule 40 slotted flush - joint PVC well screen coupled to two-inch diameter flush joint Schedule 40 riser pipe. The well screen consisted of 0.01 inch slotted pipe to minimize the infiltration of fines into the well. The flush joint pipe sections which were fitted with O-ring seals were twisted together and lowered into the drill hole until the bottom of the well screen was within one to two feet of the bottom of the drill hole. The well screens and casings were centered in the drill hole through the use of PVC and stainless steel centralizers and mechanical centering, including suspending the well screen and casing string about 1 or 2 feet above the bottom of the drill hole. Suspension of the screen and casing string eliminates lateral bending of the string due to compression under its own weight. The annular space between the well and drill hole wall was then filled 10-20 or 20-40 (as shown on the well construction records in Appendix 3 and on Table 3-1) silica sand to a minimum of two feet above the screened interval. A bentonite pellet seal having an approximate thickness of three feet or greater was placed above the sand pack. The pellets were hydrated by in -situ groundwater or one gallon of distilled water. A 1-1/4 inch diameter tremmie pipe was used to place materials in the drill hole. After allowing about 1/2 hour for the pellets to hydrate and swell, the remainder of the drill hole was filled with a 95%/5% cement/bentonite grout mix. The 2 - inch PVC riser pipes were cut off at approximately 2.5 feet above grade and fitted with a PVC slip cap. Each slip cap is vented with one or two 1/8 inch diameter holes. All monitoring wells have protective steel or anodized aluminum surface casings 6 or 10 inches in diameter and 7 to 8 feet in, length set in grout to a depth of about 4 to 5 feet. The above grade annular space between the surface casing and inner casing is filled with pea gravel to about six inches below the riser pipe on all wells. The pea gravel allows free drainage through the weep hole installed in the surface casing at about two inches above grade level. All surface casings are fitted with locks and locking metal covers to prevent unauthorized access. 13 Groundwater Monitoring Plan Each monitoring well in the groundwater monitoring network is fitted with a dedicated pumping device for maintaining sample integrity. A diagram of typical monitoring well construction details is presented in Drawing No. 3-2. The drill logs for these well installations are presented in Appendix 2, and the well construction details are presented in Appendix 3. Locations of these wells are shown on Drawing Nos. 2-8 and 3-1.. Copies of permits for the wells are included in Appendix 7. 3.3 WELL DEVELOPMENT The groundwater monitoring wells selected for groundwater quality monitoring were developed during the period of September 30 through October 5, 1992. Development consisted of a combination of surging and bailing at periodic intervals with a 3 -foot stainless steel bailer to agitate and remove the courser sediment and pumping with a Grundfos 2 -inch stainless steel and Teflon 220 -volt submersible pump to remove fines. Approximately four to six hours were spent on developing each well. MW -3 and MW -4 cleaned up very well. MW -12 remained somewhat murky, but moderately well developed. MW -5 and MW -10 were very silty and sandy and interfered with proper functioning of the pump. These silty wells did not clean up with the methods employed. One of the wells, MW -9, which has a 20 -foot screen in the perched, shallow groundwater zone, did not produce sufficient flows to allow much development cleaning. This well was bailed dry several times and recovered very slowly. 3.4 MONITORING WELL INSPECTION PROGRAM During each sampling event, the existing monitoring wells, including temporarily suspended well MW -9, are inspected for integrity by the sampling technician. The purpose of the, monitoring well inspection program is to ensure that the physical integrity of the monitoring wells is maintained at a level, which ensures that samples obtained from the well are of the highest quality. Drawing 3-3 presents a Monitoring Well Integrity Field Survey form to be completed during sampling events. 3.4.1 Surface Survey Sampling personnel are responsible for assessing the following conditions of the area surrounding the well and noting any problems on a form such as the Monitoring Well Integrity Field Survey: 1. Condition of the surface plug 2. Erosion or ponding of surface water/runoff around the casing 3. Subsidence of the soil materials surrounding the casing 4. Animal or insect activity in or around the casing 5. Obstructions which preclude access to the well 6. Other conditions, which affect access to the well or the ability to obtain samples from the well. 14 Groundwater Monitoring Plan 3.4.2 External Protective Casing Observations The following information pertaining to the external protective casing is to be noted and recorded by sampling personnel on a form such as the Monitoring Well Integrity Field Survey: 1. Condition of the locking cap 2. Bends or cracks in the external casing 3. Whether the external casing is loose 3.4.3 Internal Casing Observations Sampling personnel shall perform a visual survey of the casing and note the following on a form such as the Monitoring Well Integrity Field Survey form: 1. Loose casing; both horizontal and vertical axes will be checked 2. Bent or damaged casing 3. Any obstructions in the casing 4. Missing casing cap 4.0 LEACHATE AND SURFACE WATER MONITORING SYSTEMS 4.1 LEACHATE SYSTEM The NWLF has been designed and permitted with four phases of development, each with its own independent leachate collection systems and sumps. Phase 1 will drain to a sump in the northeastern part of the fill area. Phase 2 will drain to a sump in the southwestern part of the fill area. Phases 3A and 3B will drain to separate sumps in the south/southeastern portion of the fill area. The leachate collection system at NWLF consists of three components: 1) Leachate Collection Drain Lines; 2) A 6" Drainage Blanket overlying the 2 -foot compacted clay liner; and 3) Leachate Collection Sumps. Leachate at NWLF will be sampled and analyzed on an annual basis for the same parameters as used for the ground water monitoring program (Table 5-1) in order to provide an adequate database for the assessment of potential impact to the local groundwater system. Leachate is removed from the sump, when present, and used for dust control within the permitted disposal area in accordance with previous agency approvals. 4.2 SURFACE WATER SYSTEM The site is situated near a topographic high, such that surface water run-on from off -site locations is unlikely. Surface water run-off is managed as discussed in Section 4.3.2 of the 15 Groundwater Monitoring Plan Updated Design and Operations Plan dated January 1996, prepared by Rust Environment and Infrastructure (currently known as Earth Tech, Inc.) and revised November 1997. Any stormwater discharged from the facility is managed in accordance with the Colorado Discharge Permit System (CDPS) Permit No. CDR -0202237 issued by the CDPHE Water Quality Control Division. This permit authorizes NWLF to discharge stormwater associated with heavy industrial activity from the facility. 5.0 SAMPLING PLAN 5.1 SAMPLING PLAN SUMMARY The plan for groundwater sampling at the NWLF facility is described below. The sample parameters and.schedule are listed in Table 5-1 and discussed in Section 6. Section 7 describes the laboratory analysis plan, and Section 8 presents the statistical program. All sampling is conducted pursuant to ASTM protocol or equivalent. The remainder of this section describes the equipment, procedures, and techniques typically used to collect groundwater samples, including: • Procedures Prior to Sampling • Measurements of Ground Water Elevation • Observations Upon Arrival at Well Location (Also Section 3.4) • Sample Collection • Well Purging • Sample Withdrawal • Sample Preservation and Containers • Field Analysis • Decontamination of Field Equipment • Chain of Custody Control • Quality Control Samples • Sample Contact 5.1.1 Procedures Prior to Sampling Upon arrival at the well location, sampling personnel will observe and record the condition of the well, as outlined in Section 3.4„ on a form such as Monitoring Well Integrity Field Survey. Prior to purging and sampling, a static water level measurement will be taken and • recorded to the nearest hundredth of a foot. 16 Groundwater Monitoring Plan 5.1.2 Sample Collection Wells typically will be low -flow purged or a minimum of three standing water volumes will be removed from the monitoring well prior to sampling by bailing or by bladder pump operation. Purging will be conducted in a manner to minimize the potential of dewatering the well. This procedure assures that samples are drawn from the aquifer rather than from stagnant water left in the well between sampling events. Depth to water will be subtracted from total well depth, and the result multiplied by the appropriate conversion factor for well casing size (0.163 for 2.0 -inch I.D. wells). This value will be one well volume, in gallons, and can be used to calculate purge volumes. The actual purge volumes and times will be recorded on a form such as the Field Information Form presented in Appendix 5. If a monitoring well is dewatered and does not recharge within 24 hours, the well will be declared dry for the sampling event, and conditions will be documented on a form such as the Field Information Form. If a well partially recharges within the 24 hour period, then a limited sample will be collected. For this situation, parameter priorities have been developed and are presented in Table 5-1. The priority list has been developed to allow collection of the most important indicator parameters first in order to maximize the amount of information generated from low yield wells. Special procedures will be followed to collect samples for volatile organics. To ensure that the samples will be free of air, sample containers for volatile organics will be slightly overfilled before capping. After capping, the sample containers will be inverted and checked to verify no headspace is present. Containers will generally be filled in order of non -filtered to filtered parameters. Immediately after collection, sample containers will be wiped clean, checked to make sure caps are secure, and stored in dark insulated shuttles with frozen ice packs. Shuttles will be sent to Test America Laboratory (TAL) located in Arvada, Colorado. Signed Field Information Form and Chain -of -Custody forms will be placed inside the sample shipping containers. NWLF may also employ low flow or minimal drawdown purging (i.e., passive sampling procedures) in accordance with ASTM protocol or equivalent. The objective of minimal drawdown purging is to obtain a representative sample, taking into consideration aquifer heterogeneities and site -specific subsurface conditions, without imparting bias due to excessive pump rates. This technique is premised on minimizing drawdown of the aquifer and stabilization of field parameters prior to sample collection. Pump flow rates will be selected to approximate the yield of the well, so that the water is not significantly lowered during purging and sampling (i.e. 10% of the water column). Minimal drawdown procedures will consist of evacuating the total volume of groundwater present in the sampling system to clear the well pump and tubing of any stagnant water left 17 Groundwater Monitoring Plan - from prior sampling events. The maximum flow rate is determined by pumping a rate, which causes no net drawdown of the water level surface within the well. Field measurements, as described in Section 5.1.3, will be initiated at the start of purging and continued at evenly spaced intervals until stabilization. Once stabilization has been achieved, sampling will be conducted at the same, or lower, flow rate. The field parameter turbidity will not be used to indicate stabilization. Periodic turbidity measurements will be made during purging. If turbidity values are not lower than 25 NTUs, a decreasing and stabilized trend in turbidity values will be established prior to sampling. 5.1.3 Field Analysis Specific conductance, turbidity, pH, and temperature measurements are typically, taken during the purging process. Procedures provided with the instruments will be used for calibration and testing. Duplicate field measurements are typically taken at each monitoring location for QA/QC purposes. 5.1.4 Sample Filtering, Presentation and Shipment All samples which require filtering (See Table 5-1) will be field filtered through a 0.45 micron in -line cartridge filter. The filtered sample will be collected directly from the end of the sample filter into the sample bottle. A new filter will be used for each well. If the . sample is not field filtered, the ions and compounds that are naturally present in, or absorbed on, the suspended particles may be released when samples are preserved and analyzed (i.e., heavy metals). This could result in the reporting of false positive data, which are not representative of the constituents actually present in the groundwater (i.e., data can represent the leaching of metals from the sample matrix). Since the groundwater requires multiple laboratory analyses, different types of sample containers and preservatives will be used. TAL Denver will supply properly preserved containers for each sampling point. 5.1.5 Chain -of -Custody Control At the time each sample is taken, a Chain -of -Custody Form will be completed and placed in the sample cooler. Included on these forms will be the name of the site and facility; the sample point; the sample date and time; the number, type and size of sample containers; sample preservatives and filtering, analyses requested, and any pertinent comments or observations. As part of the Chain -of -Custody procedure, each sample container will be labeled with the sample number and the parameter to be analyzed. In addition, the following information will be documented on a form such as the Field Information Form (Drawing 5-1) or Chain - of -Custody Record Form (Drawing 5-2): 18 Groundwater Monitoring Plan • Facility site name, sample point identification number, and other pertinent identifiers • Depth to ground water • Date, start time and elapsed time from purge start to purge finish • Sampling method • Samples filtered • Field test results, including pH, temperature, turbidity and specific conductance • Type of sample and necessary treatment • Field observations (e.g., well condition) • Appearance of sample (i.e., color, turbidity, sediment, or oil on surface) • Sample's identity and signature In order to maintain chain -of -custody control, the samples will be, at all times: • In sight of the assigned custodian; or • Locked in a tamper proof location; or • Sealed with a tamper proof seal. Upon receipt of samples at the laboratory, the Chain -of Custody form will be signed by the person taking custody of the samples and the date and time of arrival will be noted on the Chain -of Custody forms. The laboratory receiver will verify that the seal is intact. In addition, the sample bottle condition and temperature will be noted on the forms. The Chain -of -Custody records will be included in the analytical report prepared by the laboratory. 5.1.6 Field QA/QC At least one trip blank will be prepared by the laboratory for transport to the site by the sampling team. The trip blank is used to document potential sample contamination resulting from environmental conditions during shipment, field sampling, and within laboratory. The trip blank will subsequently be submitted for VOC analysis. 5.2 SAMPLE TECHNICIAN CONTACT Sampling for WMDSC is conducted under the direction of the Environmental Protection Manager/Engineer utilizing both in-house and outside contracted technicians. The Environmental Protection Manager /Engineer for the NWLF facility can be contacted at: NORTH WELD LANDFILL 40,000 WELD COUNTY ROAD 25 AULT, COLORADO 80610 970/686-2800 19 Groundwater Monitoring Plan 6.0 SAMPLE ANALYTES AND SCHEDULE Table 5-1 presents the sample analytes and sampling schedule for each well in accordance with current regulatory requirements of the CD, CDPHE, WCDPHE, this plan and related approvals. Six wells (MW -3 through MW -5, MW -9, MW -10, and MW -12) were monitored quarterly for the background parameters listed in Table 5-1. Background monitoring for these wells were completed during the first quarter of 1996. Upon completion of the background monitoring program, a statistical evaluation was prepared and submitted to CDPHE and WCDPHE on October 25, 1996 (see Section 8.0). Semi-annual detection monitoring including statistical analyses commenced in September 1996, for MWs 3, 4, 5, 9, 10 and 12. NWLF received approvals from CDPHE and WCDPHE to temporarily discontinue monitoring MW -9 until waste disposal begins in areas that overlie the perched water zone in which MW -9 is completed (See Appendix 6). In 1992, Atec Associates, Inc. conducted an expanded hydrogeologic characterization at the NWLF. The results of this characterization were reported in the document titled "Hydrogeologic Site Characterization Report, North Weld Sanitary Landfill, Weld County, Colorado" dated April 21, 1993, which was submitted to CDPHE and WCDPHE on September 3, 1993. At that time, Atec installed three shallow piezometers (PZ-1 through PZ-3) in order to further evaluate and identify the lateral extent and gradient of the perched water zone in the south east portion of the site (see Drawing 2-8). Measurements from these three piezometers following installation in 1992, until their abandonment in December 1995, generally showed PZ-2 and PZ-3 to be dry (with the exception of water measured in June 1993 and June 1995) and PZ-1 showed the presence of water, which generally represented the northern most limit of the perched water. The area previously identified by PZ-1 represents the area that overlies the perched water zone. The coordinates for PZ-1 will be identified and marked in the field prior to filing in this area of Phase 3a/b. This marker will represent the northern most limit of perched water. Semiannual monitoring of MW -9 will resume following the sampling period after filling encroaches on the survey coordinates marked in the field for PZ-1. Although MW -9 will not be sampled until waste disposal begins in areas that overlie the perched water zone, the surface conditions of MW -9 will continue to be inspected and documented as part of our routine monitoring program. Leachate will be analyzed on an annual basis, assuming leachate is present, for parameters included in the groundwater monitoring program. 7.0 ANALYSIS PLAN 7.1 LABORATORY QUALITY CONTROL PROCEDURES A copy of the Test America Laboratories, Inc. — TAL - (formerly STL Denver) Laboratory Quality Manual is available at the site for review. 20 Groundwater Monitoring Plan In addition to strict chain -of -custody procedures, trip blanks are used to assure the integrity of the sampling and shipping process and will be used to detect any volatile contamination introduced while samples are prepared in the laboratory and in transit to the laboratory. A record of laboratory sample receipt, storage, and analysis procedures and copies of the Chain -of -Custody and Field Information forms will be kept for each sample received. 7.2 REPORTING LIMITS The reporting limits for parameters analyzed in the groundwater samples will be those listed on Table 7-1. Limits reported for each parameter will be provided on the analytical reports and are generally listed in Table 7-1. Further description of detection limits is provided in the Laboratory Quality Manual for TAL. 7.3 ANALYTICAL METHODOLOGIES Table 7-1 presents the typical methodologies used for each parameter (or group of parameters) required in the NWLF facility's monitoring program. This table was updated as a result of the U.S. EPA Method Update Rule (MUR) and recognizes new methods numbers and additionally updates laboratory reporting limits associated with those methods. This plan update was submitted to CDPHE and WCDPHE on May 1, 2008. The Laboratory Quality Manual for TAL further describes the methodologies used by TAL. All methods are EPA approved. Considering the recent MUR by the U.S. EPA, it is emphasized that analytical methods used and referenced for meeting environmental testing requirements evolve over time due to changes in technology, updates and additions to published methodology, and when regulations change to require reference to different methods. In many instances there are equivalent methods for the same analyte published by different authorities on method development; e.g. the USEPA Office of Water, USEPA Office of Solid Waste, Standard Methods, and ASTM. Analytical methods listed in this Plan may be substituted provided that the alternate methods are generally approved for use, provide technically defensible data, and are appropriate for the media being tested. The use of alternative approved methods is considered an acceptable deviation from the prescribed methods in this Plan and will not be considered a violation of the requirements of the Plan. 7.4 DATA REPORTING AND RECORDKEEPING 7.4.1 Reporting Requirements Analytical data for the NWLF facility will be accumulated in TAL's computer (LIMS) and run through a quality assurance program. Final reports, which include field forms, a case narrative, summary reports, and analytical results, will be submitted to WMDSC. The laboratory data, after review by the Environmental Protection Manager/Engineer, will be submitted to the CDPHE and WCDPHE. The addresses for these individuals and agencies are presented in the Directory in Appendix 4. 21 Groundwater Monitoring Plan In addition to including the laboratory analytical results and statistical summary, semi- annual groundwater monitoring reports will include a site map with monitor well locations, and a review of groundwater elevations to show groundwater gradient and flow direction. The second -half semi-annual report will include the results of leachate level measurements and sampling. Additional reporting requirements include submission of an application for a well permit to the State Engineer for each new well installed at the NWLF. Such permit applications and permits will be periodically added to Appendix 7. It is also necessary to file an abandonment/closure report following the decommissioning of wells and piezometers, which will not be used (or continue to be used) as permanent monitoring locations. Closure or decommissioning of either permanent or temporary wells will be documented on a closure/decommissioning form and kept on -file at the site. 7.4.2 Recordkeeping Requirements This document, as well as the analytical results for each sampling event, is kept on site at NWLF. The accumulation of these items meets all CD, CDPHE and WCDPHE and recordkeeping requirements. 7.5 LABORATORY CONTACTS The contractor presently providing analytical services is: TestAmerica Laboratories, Inc. 4955 Yarrow Street Arvada, Colorado 80002 303/736-0100 8.0 DATA EVALUATION 8.1 STATISTICAL PROGRAM NWLF submitted the statistical program titled "Statistical Methods for Groundwater Monitoring at The North Weld Sanitary Landfill" prepared by Robert D. Gibbons Ph.D. dated July 20, 1996, to CDPHE and WCDPHE on October 25, 1996. This statistical program was developed in accordance with requirements of the "Regulations Pertaining to Solid Waste Disposal Sites and Facilities" Title 30, Article 20, Part 1, Colorado Revised Statutes (CRS), revised November 30, 1995. Statistical analyses commenced during the September 1996, sampling period utilizing the most recent version of Downgradient Upgradient Monitoring Program Statistics (DUMPStat) as described in the above report to statistically evaluate ground water monitoring data from the NWLF. 22 Groundwater Monitoring Plan 9.0 REFERENCES The list of resources and literature used for preparation of this groundwater monitoring plan are as follows: Aerial Photograph, 10-25-90, scale 1' = 3000' Aerometric Engineering, Inc., (1992), Surface Topography, North Weld Sanitary Landfill, Contour Interval 2 foot, scale 1" - 200', January 1992. ATEC Associates, Inc.,. December, 1992, "Hydrogeology Site Characterization Report, North Weld Sanitary Landfill, Weld County, Colorado", ATEC Project No. 41-17238. ATEC Associates, Inc., November, 1992, "Landfill Gas Migration Monitoring Plan, North Weld Sanitary Landfill, Weld County, Colorado", ATEC Project No. 41- 17238-3. Briscoe, H.J., Jr., (1972), "Stratigraphy of the Fox Hills Sandstone With Some Comments On Its Suitability As An Aquifer, Greeley Area, Weld County, Colorado", Thesis Paper 1456, Colorado School of Mines, 1972. Colorado Division of Water Resources, Location and logs of wells within one mile radius, Office of the State Engineer. Colorado State Climatologist, Summary of Monthly Climatic Data for Greeley, Colorado, 1931 through 1967. Colorado State Climatologist, summary of Monthly Climatic Data, Greeley, Colorado, 1967 through 1990, Colorado. Colorado State Climatologist Summary of Monthly Climatic Data for Fort Collins, Colorado, 1931 - 1990, Colorado. Colorado State Climatologist, Summary of Monthly Climatic Data for Greeley, Colorado, 1931 through 1967. Colorado State Climatologist, Summary of Monthly Climatic Data, Greeley, Colorado, 1967 through 1990, Colorado. 23 Groundwater Monitoring Plan - Colorado State Climatologist Summary of Monthly Climatic Data for Fort Collins, Colorado, 1931 - 1990, Colorado. Colorado State Climatologist, Summary of Monthly Climatic Data for Nunn, Colorado, 1948 - 1990. Colton, B., (1978), "Geologic Map of the Boulder - Ft. Collins - Greeley Area, Colorado", U.S. Geological Survey, Miscellaneous Investigation Series I -855-G, 1:100,000, 1978. Crabb, J.A., (1980), "Soils Survey of North Weld County, Colorado, Southern Part", Soil Conservation Survey. Crosby, J., (1978), "Landforms in the Boulder - Ft. Collins - Greeley Area, Front Range Urban Corridor, Colorado", U.S. Geological Survey Miscellaneous Investigation Series I -855-H, 1978. Hampton, E.R., Clark, G.A., and McNutt, M.H., (1974), "Map Showing Availability of Hydrologic Data, Boulder - Ft. Collins - Greeley Area, Front Range Ureban Corridor", USGS Miscellaneous Investigation Series I -855-C. Hershey, L.A. and Schneider, P.A., (1972), "Geologic Map of the Lower Cache La Poudre River Basin, North-Central Colorado", USGS Miscellaneous Investigation. Series *-687 1:62,500. Hiller, D.E. and Schneider, P.A., Jr., (1979), "Depth to the Water -Table in the Boulder - Ft. Collins - Greeley Area, Front Range Urban Corridor", U.S. Geological Survey, Miscellaneous Investigations I -855-I. Hiller, D.E. and Schneider, P.A., Jr., (1979), "Well Yields and Chemical Quality of Water from Water -Table Aquifers in the Boulder - Ft. Collins - Greeley Area, Front Range Urban Corridor, Colorado", U.S. Geological Survey Miscellaneous Investigation Series I-8tt-J. Industrial Compliance, Inc., (1989), "Surface Topography and Test Hole Locations, North Weld County Sanitary Landfill, 1" = 400', Contour Interval 2 foot, 1989. Industrial Compliance, Inc., (1991.), "Drill Hole Logs and Construction Details for Piezometers PZ-15 through PZ-22 (Gas Probes GP -15 through GP -22)", North Weld County Sanitary Landfill, May 8 and 9, 1991. 24 Groundivater Monitoring Plan Interpex Limited, (1988), "SLUGIX User's Manual", manual May, 1988, software 1991. Kirkham, R.M. and Rogers, W.P., (1981), "Earthquake Potential in Colorado - A Preliminary Evaluation, Colorado Geological Survey Bulletin 43. McCain, J.F., & Hotchkiss, W.R., (1975), "Flood -prone Areas, Boulder, Ft. Collins - Greeley Area, Colorado", USGS Miscellaneous Investigation Series I -855-E, 1:100,000. Romero, J.C. and Hampton, E.R., (1972), "Maps Showing the Approximate Configuration and Depth to the Top of the Laramie -Fox Hills Aquifer, Denver Basin, Colorado", U.S. Geological Survey, Miscellaneous Investigation Series I- 791, 1:500,000. Schroeder, R., et al, "The Hydrologic Evaluation of Landfill Performance (HELP) Model User's Guides and Documentation for Versions 1, 2 and 2.05", and version 2.05 software, U.S. Army Engineer Waterways Experiment Station, 1986 through 1989. Selton, D.C., & Rogers, W.P., (1987), "Environmental and Engineering Geology, Laramie and Weld Counties, Colorado"; Colorado Geological Survey Environmental Geology publication 6. Test America , "Quality Assurance Manual" 1/31/2008. Stewart and Associates, (1989), "Site Plan", North Weld County Sanitary Landfill, Contour Interval 2 foot, Scale 1" = 200', 1989. U.S. Geological Survey, (1971), 7.5 Minute Topographic Map, "Severance Quadrangle", 1:24,000. Waste Management, Inc., (April, 1990), "Example Site Specific Ground Water Monitoring Plan, "Site Name", preparation guide. Waste Management of North America, (1991), "Design Procedures Manual Release No. 2", October 31, 1991. Weld County Board of Commissioners, (June 27, 1990), "Certificate of Designation, Solid Waste Disposal Site and Facility", permit for the North Weld Landfill facility. 25 Groundwater Monitoring Plan 26 Groundivater Monitoring Plan NORTH WELD LANDFILL GROUNDWATER MONITORING PLAN TABLES Groundwater Monitoring Plan TABLE 1-1 North Weld Landfill Monitoring Well Network August, 1997 Well No. Contractor Responsible For Installation Installation Date Groundwater Unit Gradient Location Relative to - Site MW -3 ATEC Associates, Inc. 3/92 Deep, Regional Upgradient . MW -4 ATEC Associates, Inc. 3/92 Deep, Regional Downgradient MW -5 ATEC Associates, Inc. 3/92 Deep, Regional Downgradient MW -9* ATEC Associates, Inc. 3/92 Shallow, Perched Downgradient MW -10 ATEC Associates, Inc. 9/92 Deep, Regional Downgradient MW -12 ATEC Associates, Inc. 9/92 Deep Regional Upgradient * Monitoring suspended 2/97; will be reinstated when landfilling commences over shallow perched groundwater. Groundwater Monitoring Plan NORTH WELD LANDFILL GROUNDWATER MONITORING PLAN DRAWINGS Groundwater Monitoring Plan NORTH WELD LANDFILL GROUNDWATER MONITORING PLAN APPENDIX 2 LOGS OF DRILL HOLES Groundwater Monitoring Plan NORTH WELD LANDFILL GROUNDWATER MONITORING PLAN APPENDIX 3 MONITORING WELL CONSTRUCTION SUMMARIES Groundwater Monitoring Plan NORTH WELD LANDFILL GROUNDWATER MONITORING PLAN APPENDIX 1 WELL LOCATION MAP Groundivater Monitoring Plan NORTH WELD LANDFILL GROUNDWATER MONITORING PLAN APPENDIX 4 DIRECTORY Groundwater Monitoring Plan DIRECTORY NORTH WELD LANDFILL FACILITY OWNER: WM Disposal Services of Colorado Inc. 40,000 Weld County Road 25 Ault, Colorado 80610 Phone (970) 686-2800 Contact: William Hedberg WASTE MANAGEMENT Steve Derus Director of Landfills 5500 South Quebec St Suite 250 Greenwood Village, CO 80111 (303) 486-6040 Alan Scheere Environmental Specialist 41800 E 88th Avenue Bennett, CO 80102 Phone (303) 644-4335 REGULATORY AGENCIES Douglas Ikenberry Colorado Dept. of Public Health & Environment Hazardous Materials & Waste Mgmt. Div. 4300 Cherry Creek Drive South Denver, CO 80246-1530 (303)692-3389 MONITORING CONSULTANT Cathryn Stewart AquAeter 7340 E. Caley Avenue, Ste 200 Centennial, CO 80111 Phone (303) 771-9150 FACILITY OPERATIONS: William Hedberg Sr. District Manager North Weld Landfill 40,000 Weld County Road 25 Ault, Colorado 80610 Phone (970)686-2800 Tom Schweitzer Engineering Manager 5500 South Quebec St. Suite 250 Greenwood Village, CO 80111 (303) 486-6045 Bruce Clabaugh Environmental Protection Manager 5500 South Quebec St. Suite 250 Greenwood Village, CO 80111 (303) 486-6034 Troy Swain Weld County Dept. of Public Health & Environment 1555 N. 17th Avenue Greeley, Colorado 80631 (970) 304-6415 ext.2219 Groundwater Monitoring Plan NORTH WELD LANDFILL GROUNDWATER MONITORING PLAN APPENDIX 5 DATA REPORTING FORMS Groundwater Monitoring Plan NORTH WELD LANDFILL GROUNDWATER MONITORING PLAN APPENDIX 6 REGULATORY APPROVALS Groundwater Monitoring Plan NORTH WELD LANDFILL GROUNDWATER MONITORING PLAN APPENDIX 7 WELL PERMITS Groundivater Monitoring Plan NORTH WELD LANDFILL GROUNDWATER MONITORING PLAN NORTH WELD LANDFILL APPENDIX 8 STATE OF COLORADO WELL RECORDS Groundwater Monitoring Plan Vt-Srl PS WASTE MANAGEMENT April 21, 2009 Weld County Planning Department GREELEY OFFICE APR 24?In Ms. Marley Shoal riRz G E N ED Colorado Department'of Public Health and nvironment Air Pollution Control Division APCD-SS-B1 4300 Cherry Creek Drive South Denver, CO 80246-1530 WASTE MANAGEMENT 5500 S. Quebec St. Suite 250 Greenwood Village, CO 80111 (303)486:-6000 (303) 797.3031 Fax CERTIFIED MAIL: 70033110000523829402 SUBJECT: NORTH WELD LANDFILL (NWLF) TITLE V OPERATING PERMIT 2009 SEMI-ANNUAL MONITORING REPORTS Dear Ms. Shoat: In accordance with the NWSL Title V Operating Permit # 97OPWE181, attached are the following reports covering the monitoring period of October 1, 2008 — March 31, 2009. • Monitoring and Permit Deviation Reports, Part I • Monitoring and Permit Deviation Reports, Part II • Monitoring'and Permit Deviation Reports, Part III In addition, the responsible official has changed from Mr. Tom Buchholz to Mr. Steve Derus as Director of Landfill Operations. Should you have any questionsregarding these reports, please contact Alan Scheere at (303) 644-4335 or Bill Hedberg at (970);686-2800 ext. 23. Environmental Protection /attachments cc: Dana Podell,`CDPHE APCD, w/enc, Jim King, CDPHE APCD, w/enc. Douglas Ikenberry, CDPHE, w/enc. Troy Swain, WCDPHE, W/enc. Kim Ogle, WCDPS, w/o enc. C:V+ir\NWLFINWLF Semi Annual Cert 0409 Cover.doc F: o1Eraiiu aaterpdayze1ljlection to environmental protection; Think Green® Think Waste Management. ® Printed on 700% yuawnmmer recycled ”Per. LA -‘7 WASTE MANAGEMENT . Wald County Planning Department GREELEY OFRCE APR 24 'OOP "EC VE April 14, 2009 Ms: Cindy Beeler, Environmental Engineer Office of Enforcement, Compliance and Environmental Justice Mail Code 8 ENF-T U.S. Environmental Protection Agency; Region VIII 1595 Wynkoop Street Denver, CO 80202-1129 WASTE MANAGEMENT 5500 S. Quebec Sr. Suite 250 Greenwood Village, CO 80111 .293) 486-6000 (303) 797.3031 Fax CERTIFIED MAIL: 70033110000523829396 SUBJECT: NORTH WELD LANDFILL TITLE V OPERATING PERMIT NUMBER 97OPWE181 2009 ANNUAL COMPLIANCE CERTIFICATION REPORT Dear Ms. Beeler: In accordance with the NWSL Title V Operating Permit # 97OPWE181, enclosed is the 2009 Annual Compliance Certification Report, which covers the period April 1, 2008 through March 31, 2009. During the last six months of the reporting period the site submitted a revised APEN within 30 days of the expiration date. A revised APEN was submitted in accordance with requirements nonetheless, within 30 days of the expiration date In addition, the responsible official has changed from Mr. Tom Buchholz to Mr. Steve Derus as Director of Landfill Operations. Should you have any questions regarding this report, please contact Alan Scheere at (720) 977-2107 or Bill Hedberg at (970) 686-2800 ext. 23. Sincerely, Eric Dl sposti Environmental Protection /attachment cc: Douglas Ikenberry, CDPHE, w/enc. Troy Swain, WCDPHE, w/enc. Kim Ogle, WCDPS, w/o enc. Dana Podell, CDPHE, w/o enc. C:\Air\NWLF Annual Cert 0408 EPA Cover.doc ' F: op&iallm d64Srd d4y2 •lection to environmental protection, Think Green® Think Waste Management. ®,.Printed on 1004 post -consumer recycled paper. USC- €GS WASTE MANAGEMENT Weld County Planning Department GREELEY OFFICE APR 15 9nnq RECEIVE April 8, 2009 1z Mr. Charles Johnson Colorado Department of Public Health and Environment Hazardous Materials and Waste Management Division 4300 Cherry Creek Drive South Denver, CO 80246-1530 5500 South Quebec Street Suite 250 Greenwood Village, CO 80111 303-486-6045 (Phone) 303-486-6146 (Fax) Subject: gath` eefdtindfilE(NWLF) Updated Closure and Post -Closure Plan and Financial Assurance Plan Dear Mr. Johnson: A revised closure and post -closure plan and financial assurance plan for NWLF are enclosed. The closure and post -closure plan was revised to reflect current operations at the site. The financial assurance plan and annual cost adjustment were also revised based on the revised closure and post -closure plan. The closure and post -closure plan was revised to reflect a change in the size of the largest area requiring final cover during the active life as well as changes that appropriately respond to the Colorado Department of Public Health and Environment's (CDPHE's) letter dated April 9, 2008 and discussions during our subsequent meeting on June 10, 2008. Section 1.8.3 (C) of the Colorado Regulations Pertaining to Solid Waste Disposal Sites and Facilities, 6CCR-1007-2, requires an annual adjustment to the closure and post - closure financial assurance cost estimate by using the implicit price deflator (IPD) for the gross domestic product. For 2009, the IDP is 1.021 as confirmed with CDPHE. The closure and post -closure cost estimates were adjusted using this value. The enclosed insurance certificate reflects this adjustment to the closure and post - closure financial assurance cost estimate for NWSL and has been placed in the NWSL operating record. Mr. Charles Johnson April 8, 2009 Page 2 Please call me at (303) 486-6045 or Alan Scheere at (303) 644-4335 if you have questions about the enclosures. Sincerely, Torn-chweitzer, P.E. Engineering Manager Enclosures cc: Troy Swain, WCDPHE EKim-Ogte'WCDTSJ Douglas Ikenberry, CDPHE Bill Hedberg/NWLF Operating Record Alan Scheere, Waste Management of Colorado Julie Overmyer, Waste Management of Colorado, w/o enlcosure CLOSURE/POST-CLOSURE PLAN NORTH WELD LANDFILL Weld County, Colorado Prepared by: Waste Management Disposal Services of Colorado, Inc. North Weld Landfill 40,000 Weld County Road 25 Ault, Colorado Reviewed By: pe ° SJ r •. °°pSTIAIne 4 e, L° 011 Thomas S. Schweitzer PEro a • 4 Registered Professional En e' omg G��,` State of Colorado ��Gn NAL V., oil ani0 \ License # 24176 Revised March 2009 CLOSURE/POST-CLOSURE PLAN NORTH WELD LANDFILL TABLE OF CONTENTS Section Page 1.0 INTRODUCTION 1 1.1 PURPOSE 1 1.2 FACILITY INFORMATION 1 2.0 CLOSURE PLAN 2 2.1 INTRODUCTION 2 2.1.1 Description 2 2.1.2 Regulatory Requirements 2 2.2 CLOSURE ACTIVITIES 3 2.3 MAXIMUM EXTENT OF OPERATIONS 4 2.4 FINAL COVER 4 2.4.1 Final Grades 4 2.4.2 Final Cover Description 4 2.5 CONSTRUCTION 5 2.6 CONSTRUCTION QUALITY ASSURANCE (CQA) 5 2.7 CLOSURE SCHEDULE 6 3.0 POST -CLOSURE PLAN 7 3.1 INTRODUCTION 7 3.1.1 Description 7 3.1.2 End Use 7 3.1.3 Regulatory Requirements 7 3.2 POST -CLOSURE ACTIVITIES 8 3.2.1 Facility Management 8 3.2.2 Post -Closure Activities 8 LIST OF FIGURES Figure 1 Site Location Map 2 Closure Area Map 3 Backfill Area Map 4 Post -Closure Drainage Channel 5 Closure Schedule Closure/Post Closure Plan ii March 2007 North Weld Landfill 5 CLOSURE/POST-CLOSURE PLAN NORTH WELD LANDFILL REVISION LOG DATE DESCRIPTION OF REVISION BY 4/97 Update Plan originally submitted to CDPHE 10/93, to reflect operational changes TS/AS 3/01 Update Plan to increase estimate of largest area of the landfill ever requiring final cover during the active life TS/AS 4/03 Update Plan to increase estimate of largest area of the landfill ever requiring final cover during the active life TS/AS 3/05 Update Plan to increase estimate of largest area of the landfill ever requiring final cover during the active life and modify text in Sections 2.4, 2.5 and 2.6 to reflect approval of an alternative final cover design TS/AS 3/06 Updated Plan to decrease estimate of largest area of the landfill requiring final cover during the active life. Miscellaneous text changes were also made to the Plan. TS/AS 3/07 Updated Plan to reflect changes to the corresponding Financial Assurance Plan dated March 2007 specifically replacing cost estimates prepared in 2002 with new cost estimates; updated Plan to adjusf estimate of largest area of the landfill requiring final cover during the active life; update soil backfill quantities. Miscellaneous text changes were also made to the Plan. TS/AS 3/09 Updated Plan to adjust estimate of largest area of the landfill requiring final cover during the active life; update soil backfill quantities; included drawing illustrating surface water control structures that remain to be constructed and areas requiring backfill to achieve 5% slope TS/AS Closure/Post Closure Plan North Weld Landfill March 2007 1.0 INTRODUCTION 1.1 PURPOSE This Closure/Post-Closure Plan (Plan) for the North Weld Landfill (NWLF) reflects the facility's present understanding of closure and post -closure care requirements for this solid waste disposal site. It has been prepared to meet the following objectives: 1. Describe the steps necessary to close the site when the cost of closure would be the greatest. 2. Describe the activities to be conducted during the post -closure care period. This Plan has been prepared in accordance with the provisions of the Colorado "Regulations Pertaining to Solid Waste Disposal Sites and Facilities", 6 CCR 1007-2 (Regulations). Sections 2.5 and 3.5 of the Regulations pertain to closure activities and Sections 2.6 and 3.6 pertain to post - closure activities. This Plan is to be used in conjunction with the Financial Assurance Plan forNWLF revised March 2009. Cost estimates are calculated in the Financial Assurance Plan for the closure and post - closure care activities described in this Plan. 1.2 FACILITY INFORMATION NWLF is located approximately six miles west of Highway 85, on Colorado Highway 14, in the southwest quarter of Section 7, Township 7 North, Range 66 West, as shown on Figure 1. The facility is owned and operated by Waste Management of Colorado (WMC). The site consists of 170 acres, 119 of which are permitted for municipal solid waste disposal, and an approximate disposal capacity of 15 million bank cubic yards. Current operations are in Phase 2, Module 4. The facility accepts non -hazardous municipal, commercial and industrial solid wastes. NWLF will be developed in four phases: 1, 2, 3A and 3B. The site will be closed and monitored as a single unit. Individual phases will not be closed or monitored separately; therefore, this plan addresses the site as a whole. However, operational factors occurring during the life of the site may necessitate closure or monitoring of portions of the site individually. Closure/Post Closure Plan North Weld Landfill 1 March 2009 2.0 CLOSURE PLAN 2.1 INTRODUCTION 2.1.1 Description This closure plan describes the steps necessary to close the facility at any point during its active life. This plan will be reviewed and updated as needed for changing conditions. 2.1.2 Regulatory Requirements This closure plan is prepared in accordance with Section 2.5, "Closure of Solid Waste Disposal Sites and Facilities" and Section 3.5, "Closure" of the Regulations. This plan will be maintained in the facility operating record: The closure requirements call for a closure plan, a description of the closure activities and the closure certification. The requirements are summarized below: Closure Plan 1. Prepare a closure plan for approval by the CDPHE after consultation with the local governing body having jurisdiction. The plan, at a minimum, must include the following: a. The steps necessary to close the landfill at any point during its active life. b. A description of the final cover system and the methods and procedures to be used to install the cover. c. An estimate of the largest area of the landfill ever requiring a final cover during the active life. d. A schedule for completing closure activities. 2. Maintain a copy of the closure plan in the operating record. Closure Activities 1. Close the site in accordance with the Solid Waste Disposal Sites and Facilities Act and the Regulations. 2. Sixty (60) days prior to closure notify the CDPHE and the local governing body in writing that the facility will be closing. 3. Sixty (60) days prior to closure notify the general public of the facility closure by posting clearly visible signs of suitable size at the site entrance. Closure/Post Closure Plan North Weld Landfill 2 March 2009 4. Enact precautions to prevent further use of the site for unauthorized disposal. 5. Prevent water pollution from occurring at or beyond the point of compliance. 6. Prevent nuisance conditions at or beyond the site boundary. 7. Initiate closure activities within thirty (30) days of reaching fmal design grades unless an extension is obtained from CDPHE. 8. Complete closure within 180 days after closure initiation, or if necessary, obtain an extension from the CDPHE. Closure Certification 1. Following closure, submit a report certified by a Colorado professional engineer (RE.) to the CDPHE documenting that closure has been completed in accordance with the closure plan. Place a copy of the report in the facility operating record. 2. Following closure, record a notation on the deed or other title instrument stating that the land was used as a landfill and its use is -restricted. Notify the CDPHE and the local governing authority that the notation has been recorded and place a copy of the notation in the operating record. 2.2 CLOSURE ACTIVITIES The following closure activities will be performed when site closure is necessary: 1. Construction Documents — Closure construction plans will be prepared as needed. 2. Regulatory Agency Notification - Sixty (60) days prior to closure of any landfill phase, a notification of the intent to close will be submitted to the CDPHE and the local governing authority and a copy of the notice will be placed in the operating record. 3. Public Notification - Sixty (60) days in advance of closure date, signs will be placed at entrance to the site notifying the general public of the closure date. 4. Final Cover - Final cover will be placed in accordance with the Regulations. The final cover design is discussed in detail in Section 2.3 of this Plan. 5. Completion of Closure - Closure activities will be completed within 180 days following closure. A request for an extension may be submitted to CDPHE if climatic or operational factors dictate that additional time is required for proper closure. Closure/Post Closure Plan North Weld Landfill 3 March 2009 6. Certification/Documentation - Upon completion of construction, a report will be prepared by a Colorado P.E. certifying that closure was conducted in accordance with the provisions of this plan. The report will be submitted to CDPHE for approval after consultation with the local governing board. The approved report will be placed in the operating record. To complete closure a notation will be made on the title or deed to the land, which notifies prospective buyers that the land was used as a landfill, and that certain land use restrictions apply. Copies of the notation will be submitted to CDPHE and the local governing body and a copy will also be placed in the operating record. 7. Security - During closure activities and after closure, public disposal will be prohibited. Signs will be posted warning of unauthorized entry or waste disposal. The existing fence will be maintained and the front gate will be kept locked when not in use. 2.3 MAXIMUM EXTENT OF OPERATIONS An estimate of the largest area of the landfill currently requiring final cover is about 60.5 acres in Phases 1 and 2 as shown in Figure 2. The estimated closure area is based on the facility's current disposal activities. During 2005 and 2006 approximately 16 acres of final cover was placed in Phase 1 and an additional module (4) was constructed in Phase 2 during 2008. This resulted in approximately 60.5 acres in Phases 1 and 2 that currently require final cover. The estimated closure area is also based on the facility's projected disposal activities over a five year period. Section 1.8.3(D) of the Regulations requires the closure and post -closure cost estimates to be recalculated every five years unless otherwise required by CDPHE. The last recalculation was performed in 2007 and the associated cost estimates are included in the corresponding Financial Assurance Plan, inflation adjusted to 2009 dollars. The next replacement of cost estimates is scheduled for 2012. 2.4 FINAL COVER 2.4.1 Final Grades Final grades have been designed to promote surface water runoff and minimize erosion. Final grade slopes are designed to be a minimum of 5 percent (20 to 1) and a maximum of 25 percent (4 to 1), unless alternative grades have been approved by CDPHE. Prior to placement of final cover, areas of the site that have not been filled to final grades may require placement of backfill to achieve 5% slopes. About 290,200 cubic yards of on - site soils are estimated for achieving minimal slopes prior to placement of final cover. Figure 3 shows the area of backfill needed to achieve 5% slopes. 2.4.2 Final Cover Description NWLF received approval from CDPHE and Weld County Department of Public Health and Closure/Post Closure Plan North Weld Landfill 4 March 2009 Environment (WCDPHE). for an alternative final cover (AFC) design on March 30, 2004 and September 3, 2004 respectively. The AFC components are described below. 1. Alternative Final Cover Layer - The AFC layer will consist of a minimum of 18 inches of slightly compacted soil from on -site sources. AFC thickness on the side slope will be increased to 20 inches in accordance with the AFC design. The AFC components should have no less than 15% fines content and be compacted to between 80% to 90% of maximum density as determined by Standard Proctor (ASTM D 698). Approximately 163,000 cubic yards of soil will be necessary for the AFC layer. This conservatively assumes a 20 -inch AFC layer will be installed over the 60.5 - acre area. 2. Alternative Final Cover Topsoil Layer — The 6 -inch topsoil layer of the AFC will have no less than 30% fines content and be compacted to between 80% and 90% of maximum density as determined by Standard Proctor (ASTM D698). The 6 -inch topsoil layer of the AFC will be material suitable for sustaining vegetation. AFC seedbed preparation, seed mix and fertilizer requirements are specified in the approved "North Weld Landfill Alternative Final Cover Demonstration" prepared by Golder Associates dated December 30, 2003. Approximately 48,800 cubic yards of soil will be required for the topsoil layer over the 60.5 -acre area. 2.5 CONSTRUCTION Construction of the final cover system will be performed by using equipment such as scrapers to excavate, haul and place loose soil lifts for the AFC layer. A motor grader, low ground pressure dozer, or other suitable equipment will be used to spread/shape the cover. The topsoil layer will be placed loosely over the AFC layer with scrapers and then shaped with a motor grader, low ground pressure dozer, or other suitable equipment. The topsoil layer will then be prepared in accordance with specifications provided in the above referenced North Weld Landfill Alternative Final Cover Demonstration. 2.6 CONSTRUCTION QUALITY ASSURANCE (CQA) To ensure proper implementationof the AFC design the following CQA requirements apply. • Performance of grain -size distribution tests every 5,000 cubic yards will be conducted for the AFC layer and the 0.5 foot topsoil layer; • Performance of Standard Proctor tests every 10,000 cubic yards; • In -situ density testing using a nuclear gauge at a frequency of one test per 1,000 cubic yards; Closure/Post Closure Plan North Weld Landfill 5 March 2009 • Oven -thy moisture contents at a frequency of one test every 1,000 cubic yards; • Verification of proper thickness of cover at a grid spacing of approximately 100 feet on -center. A design drawing showing the area of AFC to be built and a detail of the cover cross- section will be supplied to the CDPHE and WCDPHE prior to construction. Also, an as - built construction drawing will be provided with the certification report that shows the survey points used to verify thickness on the approximately 100 feet on -center grid pattern. Upon completion of construction activities, a Colorado P.E. will sign a certification document indicating that the final cover was constructed in substantial conformance with the project specifications and approved closure plan. 2.7 CLOSURE SCHEDULE The schedule for closure is weather dependent. Excessive cold or rainy weather can affect placement of cover materials. The typical available construction window for placing cover materials in this climate is from late April through late September. A typical closure schedule is provided in Figure 5. If necessary, a request for an extension will be submitted to CDPHE to ensure that sufficient time is available to complete closure in accordance with the provisions of this closure plan. Closure/Post Closure Plan North Weld Landfill 6 March 2009 3.0 POST -CLOSURE PLAN 3.1 INTRODUCTION 3.1.1 Description This post -closure plan describes all actions to be taken following closure of the site. Post - closure care begins after the site is closed in accordance with the closure plan. Post -closure care continues for a period of 30 years, unless during the life of the facility or the post - closure period, a demonstration is made to the CDPHE and the local governing body, which shows that a reduced time period is sufficient to protect human health and the environment. If the post -closure period is reduced, this plan will be updated accordingly. 3.1.2 End Use Upon completion of closure, current plans indicate that the site will be zoned for agricultural use. This end use should have minimal impact on the final cover, and the use will not interfere with post -closure monitoring. 3.1.3 Regulatory Requirements This post -closure plan is prepared in accordance with Section 2.6 "Post -Closure Care and Maintenance Standards" and Section 3.6, "Post -Closure Care and Maintenance" of the Regulations. This plan will be maintained in the facility operating record. The regulatory requirements are summarized below: Post -Closure Plan 1. Prepare a post -closure plan for approval by CDPHE in consultation with the local governing body, which includes the provisions to prevent or minimize nuisance conditions, maintain the final cover, monitor groundwater, maintain and monitor the leachate collection system, and monitor landfill gas. 2. Describe the planned end use for the site and identify the name and address of a contact person who is responsible for the facility. 3. Maintain a copy of the post -closure plan in the site's operating record. Post -Closure Activities 1. The post -closure period shall be at least 30 years unless a demonstration is made to CDPHE and the local governing body that a shorter time period is sufficient to protect human health and the environment. 2. Permanent surface water structures remaining after closure shall be designed to manage run-on and run-off from a 100 year, 24 -hour storm event. Figure 4 Closure/Post Closure Plan North Weld Landfill 7 March 2009 shows the general location of permanent stormwater channels anticipated to be constructed as part of closure activities. 3. Enact precautions to prevent water pollution at the point of compliance after closure. 4. Enact precautions to prevent nuisance conditions at or beyond the site boundary after closure. 5. Post -closure monitoring shall be conducted in accordance with the approved post -closure monitoring plan. 6. At the completion of the post -closure care period, a notification will be submitted to CDPHE with a certification signed by an independent Colorado Registered Professional Engineer or approved by the CDPHE and the local governing body having jurisdiction verifying that post -closure care has been completed in accordance with the post -closure plan. The notification will be placed in the operating record. 3.2 POST -CLOSURE ACTIVITIES 3.2.1 Facility Management During the post -closure period, a facility manager will be named and a phone number and address for the manager will be incorporated into this plan. The manager currently responsible for the facility is: Mr. William Hedberg North Weld Sanitary Landfill 40,000 WCR 25 Ault, Colorado (970) 686-2800 3.2.2 Post -Closure Activities The following post -closure activities provide for inspection, maintenance, and monitoring of the design features of the facility during the post -closure period: 1. Inspections - Inspections of the site will be conducted quarterly for the first two years after closure and semi-annually thereafter. The inspector will assess the conditions of the site and recommend corrective actions for any items needing attention. Items to be inspected are further described in the following line items and include nuisance conditions, the final cover system, groundwater monitoring points, leachate monitoring system, gas monitoring system, surface water management Closure/Post Closure Plan North Weld Landfill 8 March 2009 system, and security. 2. Prevent Nuisance Conditions - The placement of final cover provides a bather between the refuse and the environment. Construction of the final cover in substantial conformance with the project specifications should prevent disease vectors, deter birds, minimize odors, reduce blowing litter, and minimize air and water pollution as direct contact with refuse is prevented. Inspections and continued maintenance of the final cover system will ensure the integrity of the final cover so nuisance conditions are prevented throughout the post -closure period. The potential for on -site litter, traffic congestion, and noise pollution will be eliminated once the closure of the facility is complete since refuse will no longer be accepted for disposal and heavy equipment will no longer be operating. 3. Final Cover System - The maintenance of the final cover may involve repair of the AFC layer, the erosion layer and vegetation. It is estimated that 5% of the site per year will require cover maintenance, reseeding and fertilizer. An additional 5% is estimated, which will allow for 10% of the site for the first 2 years of post -closure for cover maintenance, reseeding and fertilizer. Additionally, NWLF will conduct a qualitative vegetation assessment annually during post -closure to ensure the vegetative cover is established and assist in identifying any areas that may require attention. 4. Groundwater Monitoring - The current groundwater monitoring program consists of 5 wells, which will be monitored in accordance with the Site Specific Groundwater Monitoring Plan (GWMP). Depending on the monitoring analytical data obtained during the site operating period, the number of wells and the monitoring frequency may be reduced during the post -closure care period with concurrence by CDPHE and the local governing authority. For this plan it is estimated that groundwater monitoring will be performed semi-annually. Samples will be analyzed for the constituents listed in the Groundwater Management Plan. The results of all analysis will be placed in the site's operating record. Monitoring results will be reviewed and a statistical evaluation performed comparing each event's results to background levels. Detection monitoring will continue as long as results remain below specified levels for each constituent. If the statistical evaluation shows that background levels are exceeded, confirmation sampling, and if necessary, corrective action will be performed in accordance with the GWMP and this plan will be updated as necessary. In addition to sampling, it is estimated that one well will require repair each year and a new pump will be required every five years. The integrity of the monitoring well Closure/Post Closure Plan North Weld Landfill 9 March 2009 system will be inspected during the monitoring events or during the annual site inspections. Any required repairs will be corrected. 5. Leachate Monitoring - The liquid elevation in the leachate collection sump will be monitored semi-annually to verify the levels are 1 ft or less above the base liner. The measurements will be taken concurrent with semi-annual groundwater monitoring or site inspection activities. Leachate samples from the sumps will be taken annually for analysis, if leachate is present. Although leachate is not expected during post -closure, in the event that leachate is removed from a sump, it will be managed in accordance with the analytical data and approved leachate management procedures. Information related to the number of gallons removed, date, time, and location of leachate removal, and the disposal method will be maintained in the facility operating record. Due to the arid climate leachate generation is not expected at closure. Nevertheless, during the post -closure period, an allowance for leachate management is provided for the first 5 years of post -closure in the event of premature closure. A demonstration may be made to the CDPHE showing that the leachate no longer poses a threat to human health and the environment and that monitoring can cease. 6. Gas Monitoring - The facility will continue to monitor gas at the site quarterly in accordance with the Landfill Gas Migration Monitoring Plan (LGMMP). The post - closure cost estimate assumes the 15 gas monitoring probes (currently in the program) will be monitored during post -closure. Based on the monitoring data obtained during the site operating period, the number of probes and the frequency of monitoring may be reduced during the post -closure care period with concurrence by CDPHE and the local governing authority. Results from each gas monitoring event will be placed in the site's operating record. If monitoring results indicate that methane gas is present above the permissible regulatory limits, measures will be taken in accordance with Section 2.3.3 of the Regulations. 7. Surface Water Management System - Maintenance of the surface water management system is expected to be required during the post -closure period. This maintenance consists of regrading or desilting channels and ponds. In addition, semi-annual inspections of the stormwater system will be performed. Inspections of permanent stormwater management structures will be performed following storm events exceeding the 100 year, 24 hour storm event. 8. Waste Disposal - Off -site refuse will not be accepted during the post -closure period. However, if during post -closure repairs, previously placed refuse is Closure/Post Closure Plan North Weld Landfill 10 March 2009 excavated for construction activities, the refuse will be placed within the permitted fill area and final cover will be applied. 9. Security- During post -closure, the perimeter fence will remain in place and the front gate locked when not in use. Signs will be posted warning of unauthorized entry. The integrity of the fence will be monitored and maintenance performed as necessary. 10. Certification - At the completion of the post -closure care period, a notification will be submitted to CDPHE with a certification signed by an independent Colorado Registered Professional Engineer or approved by the CDPHE and the local governing body having jurisdiction verifying that post-closurecare has been completed in accordance with the post -closure plan. The notification will be placed in the operating record. Closure/Post Closure Plan North Weld Landfill 11 March 2009 FIGURES a 3 g rcy • —eZ—GQEo N 050866 N 000L6t 000961 600i/9/I A0Y0 1014 05p• 90/06002 se.'Y ''n"a ea I ,J POOL PIYat\l'n'6° SO 6u! iel!u(P'p 0.440, loOOiaYOO — z 4 'vomits, N 000951 Sines OO0 tole 31111 nnl 'MAYO o >:z 35 is a 6 i s »»»»»»>i os x lPIR.�T \ N 0®SOV N 000150 N 00097e r't INISI/S/P 13150 1010 u0p sae, Jo sate'!0 000a;o,0 8001 p iSoee..e'5'!p peilo,!e N\p, NNeol.0.6,0 ISO 'NANO 7 H a w v z 0 0 W J 7 0 W 2 U N W 0 J U Month 12 Closure acitivities to begin after 60 Notification Period I Month 11 O r L co S Month 9 Month 8 I I2 Month 6 I to ks vt 5 ts Month 3 I Month 2 Month 1 Tasks Contract Preparation Regulatory Agency Notification Public Notification Premature Closure Contractor Mob/Demob Backfill to 5% AFC/Infiltration Layer Placement Erosion Layer Placement Vegetation Completion of Closure Activities QA/QC Certification (Security FINANCIAL ASSURANCE PLAN NORTH WELD LANDFILL Weld County, Colorado Prepared by: Waste Management Disposal Services of Colorado, Inc. North Weld Landfill 40,000 Weld County Road 25 Ault, Colorado Revised March 2009 FINANCIAL ASSURANCE PLAN NORTH WELD LANDFILL TABLE OF CONTENTS Section Page 1.0 INTRODUCTION 1 2.0 REGULATORY REQUIREMENTS 1 2.1 Cost Estimates 1 2.2 Financial Assurance Activities 1 2.3 Financial Assurance Mechanisms 2 3.0 CLOSURE AND POST -CLOSURE COSTS 2 4.0 FINANCIAL ASSURANCE MECHANISM 2 LIST OF APPENDICES Appendix A Closure Costs B Post -Closure Care Costs C Insurance Certificate for Closure and Post -Closure Care Costs Financial Assurance Plan North Weld Landfill March 2009 FINANCIAL ASSURANCE PLAN NORTH WELD LANDFILL REVISION LOG DATE DESCRIPTION OF REVISION BY 4/99 Replaced letter of credit with insurance certificate. TS 3/01 Revise financial assurance costs based on the revised closure and post- closure plan dated March 2001. TS/AS 5/02 Replace original engineering cost estimates of closure and post -closure based on 2002 CDPHE guidance or determined by NWSL TS/AS 4/03 Revise financial assurance costs based on the revised closure and post- closure plan dated April 2003. TS/AS 3/05 Revise financial assurance costs based on the revised closure and post- closure plan dated March 2005 TS/AS 3/06 Revised financial assurance costs based on the revised closure and post- closure plan dated March 2006. TS/AS 3/07 Replace cost estimates of closure and post -closure prepared in 2002 with new cost estimates in accordance with Section 1.8.3 of the Solid Waste Regulations. Miscellaneous text changes were also made to the Plan. TS/AS 3/09 Revised financial assurance costs based on the revised closure and post- closure plan dated March 2009. TS/AS Financial Assurance Plan North Weld Landfill ii March 2009 1.0 INTRODUCTION This revised Financial Assurance Plan (Plan) has been prepared in accordance with Section 1.8 of the Regulations Pertaining to Solid Waste Disposal Sites and Facilities, 6 CCR 1007-2, (Regulations), and sets forth the closure and post -closure care costs for North Weld Landfill (NWLF) in Ault, Colorado. This Plan includes, in Appendices A and B, closure and post -closure cost estimates which are updated from 2008. The Regulations require that cost estimates be replaced every five (5) years or as otherwise required by the Colorado Department of Public Health and Environment (CDPHE) and 2007 marks the most recent year that costs were replaced. The next replacement of cost estimates is scheduled for 2012. Adjustments for 2009 reflect changes in the closure area subsequent to the 2008 Plan. This Plan also describes the financial assurance mechanism in place to ensure payment of all associated closure and post -closure costs. This Plan is to be used in conjunction with the NWLF Closure/Post Closure Plan dated March 2009. 2.0 REGULATORY REQUIREMENTS 2.1 Cost Estimates Sections 1.8 of the Regulations list the specific financial assurance requirements for solid waste disposal sites. These requirements are described below: 1. Maintain cost estimates, in current dollars, for hiring a third party to close the largest area of the facility requiring closure during the active life of the site. The cost estimate must also include costs associated with conducting post -closure care. 2. The facility must establish financial assurance sufficient to ensure payment of the closure and post -closure care costs. 2.2 Financial Assurance Activities The following are the requirements for financial assurance activities as described in Section 1.8 of the Regulations: 1. Notify CDPHE when the required cost estimates have been placed in the operating record; 2. Annually adjust cost estimates to account for inflation using the method prescribed by CDPHE; 3. Replace original cost estimates with new cost estimates every five (5) years, unless otherwise required by CDPHE; Financial Assurance Plan North Weld Landfill 1 March 2009 4. Costs associated with closure, post -closure and corrective actions maybe adjusted, after approval by CDPHE and the local governing authority; 5. Financial assurance must be provided continuously unless a release is granted by CDPHE. 2.3 Financial Assurance Mechanisms Several financial assurance mechanisms are available, and more than one mechanism may be used. For corporate entities, these mechanisms include a trust fund, letter of credit, surety bond and insurance. Waste Management of Colorado, Inc. (WMC) has chosen to use insurance to meet the financial assurance requirements. The insurance certificate was prepared in accordance with the requirements set forth in Section 1.8.9 of the Regulations. 3.0 CLOSURE AND POST -CLOSURE COSTS Closure and post -closure costs are those costs associated with closing the facility and conducting post -closure care activities. These costs are determined by calculating the cost to complete all of the actions in the Closure/Post Closure Plan. The unit cost values for closure and post -closure activities were determined by WMC. Costs for items including earthwork, excavation and soil placement, were taken from recent bids for similar work completed at Waste Management construction projects. The updated closure costs are provided in Appendix A, and the new post -closure costs are provided in Appendix B. The costs are based on 2007 dollars and inflation adjusted to 2009. 4.0 FINANCIAL ASSURANCE MECHANISM WMC has established insurance coverage to assure adequate funds are available for all closure and post closure care costs determined in the Closure/Post-Closure Plan. The insurance meets all requirements set forth in Section 1.8.9 of the Regulations, "Insurance for Closure and Post - Closure". The insurance certificate is provided in Appendix C. Financial Assurance Plan North Weld Landfill 2 March 2009 APPENDIX A CLOSURE COSTS TABLE 1 - CLOSURE COST ESTIMATE Site: NORTH WELD LANDFILL Date: March -09 Page: 1 Item Description Units Quantity Unit Cost (Note 1) Extended COSt L tegory COSt 1 Foundation Layer a Backfill of intermediate grades to achieve minimum 5% slope (on -site source) CY 290,200 1.85 536,870 b Other Foundation Layer Closure Costs 0 Foundation Layer Total Cost 536,870 2 Final Cover Section Closure Area: 60.5 Acres a Compacted Clay Layer (on -site source) CY 0 b Alternative Final Cover (on -site source) CY 163,000 1.85 . 301,550 c Topsoil (on -site source) CY 48,800 1.85 90,280 d Fertilizer/Soil Amendements/material hauling Acre 60.5 834.00 50,457 e Seeding Acre 60.5 620.00 37,510 f Other Final Cover Closure -Related Costs Acre 0 Final Cover Total Cost 479,797 3 Surface Water Controls a Drainage Swales/Berms/Channels LF 3,400 7.45 25,330 b Culverts 0 c Sedimentation/Surface Wtr Control Ponds 0 d Erosion Control 0 e Other Surface Water Closure -Related Costs 0 Surface Water Total Cost 25,330 4 Environmental Monitoring Installations a Grndwtr Mntg Wells w/dedicated pumps EA 0 b Gas Monitoring Probes EA 0 c Other Env. Monitoring Closure Costs 0 Environmental Monitoring Total Cost 0 5 Gas Collection and Control System (GCCS) a Extraction Well Installation 0 b Extraction Well - Well Head Assembly 0 c Extraction Well - Lateral Pipe 0 d GasNapor Collection - Header Pipe 0 e GasNapor Collection - Header Drain 0 f Blower 0 g Blower Enclosure/Building 0 h Flare 0 i Other GCCS Closure -Related Items 0 GCCS Total Cost 0 TABLE 1 - CLOSURE COST ESTIMATE (Continued) Site: NORTH WELD LANDFILL Date: March -09 Page: 2 Item Description P Units QuantityUnit Cost (Note 1) Extended COSt Category Cost 6 7 8 9 10 11 12 Miscellaneous Closure Activities a Access Road Construction 0 b Fencing 0 c Signs EA 2 150.00 300 d Other Miscellaneous Closure -Related Items 0 Miscellaneous Total Cost 300 CLOSURE COST ESTIMATE SUBTOTAL 1,042,297 Engineering & Project Management a Design & Bid Documents (% of Subtotal) 3% 31,269 b CQA, Surveys & Reports (% of Subtotal) 10% 104,230 c Project Mqmt & Admin (% of Subtotal) 2% 20,846 Engineering & Project Mgmt Total Cost 156,345 Contingency (% of Subtotal) 10% 104,230 CLOSURE COST ESTIMATE TOTAL (in 2007 do lars) $1,302,871 Inflation Adjustment Factor for 2008 (1.027) 1.027 Inflation Adjustment Factor for 2009 (1.021) 1.021 CLOSURE COST ESTIMATE TOTAL (adjusted to 2009 dollars - Items 10 x 11 x 12) $1,366,148 Notes: 1 All costs include material and installation unless noted otherwise. APPENDIX B POST -CLOSURE CARE COSTS TABLE 2 - POST -CLOSURE COST ESTIMATE Site: NORTH WELD LANDFILL Date: March -09 Acres at Closure: 76 Item Description Units Unit Quantity Unit Cost Quantity per Year Cost per Year 1a Facility Inspections & Reportinq - 2 per year - EA 1 1,000 . 2 2,000 1 b Facility Inspections & Reporting - 2 addt'l events to allow for qtrly inspections first 2 yrs.of post -closure. .. .. Annual cost for 2 addtl events = 2,000 Total Item cost for 2-yr period = 4,000 Total Item cost annualized over 30 yr PC period = 133 2 Qualitative Vegetative Assessement - annual EA 1 1,500 . 1 1,500 3a Cover Maintenance, Reseeding & Fertilizing - 5% of site per year (Note 1) AC 5% 2,181 3.8 8,288 3b _ ... Cover Maintenance, Reseeding,& Fertilizing- addt'l 5% per year to allow for 10% of the site first 2 yrs of post -closure Annual cost for addrl5%= 8,288 Total Item cost for 2-yr period = 16,576 Total Item cost annualized over 30 yr PC period = 553 4 . Surface Water Controls- Maintenance LS 1,000 . 1 1,000 5 Fence Repair LS , 500 1 500 6 Mowing - Assume annual mowing for first 10 years of post -closure _ AC 1 20 76 507 Annual mowing cost = 1,520 Cost for 10 mowing events = 15,200 Total Item cost annualized over 30 yr PC period = 7 Groundwater Monitoring - Semi-annual events EA 5 1,111 2 . 11,110 8. Groundwater Well Pump Repair / Maintenance LS 300 1 300 9'. Gas Probe Monitoring, Maintenance and Reportinq - 4 Events per Year . . EA 15 92 4 5,520 10 Leachate Monitoring - Annual EA 2 461 1 922 11 Leachate Depth Measurement - Semi-annual EA 2 237 2 946 12' Leachate Management - First 5 years of post- closure (managed on -site) (Note 2) _ Annual cost for leachate mgmt = 5,000 Total Item cost for 5-yr period = 25,000 Total Item cost annualized over 30-yr PC period = _ 833 13 . Gas Collection and Control Syst Maint LS 0 14 Gas Condensate Disposal GAL 0 15 . Subtotal- Items 1 through 14 34,114 16 Administrative Costs (% of Subtotal) Contingency (% of Subtotal) 5% 1,706 17 10% 3,411 18 Total Cost per Year 39,231 19 Post -Closure Care Period: 30 Years 20 Total,Post-Closure Cost (in 2007 dollars) $1,176,921 21 Inflation Adjustment Factor for 2008 (1.027) 1.027 22 Inflation Adjustment Factor for 2009 (1.021) 1.021 Total Post -Closure Cost (adjusted to 2009 dollars - Item 20 x Items 21 & 22) $1,234,081 Notes: 1 Unit cost for Item 3 is based on the Fertilizer, Soil Amendment and Seeding costs of the Closure Cost Estimate (Table 1) Increased by a factor of 1.5 to provide an allowance for cover maintenace in addition to seeding, fertilizer and amendments. 2 Due to and climate, leachate generation is not expected at closure. However, an annual allowance for leachate management is provided for the first 5 years of post -closure in the event of premature closure. Basis for Costs Line to $1,000 based on 9 hrs for site Inspector @ $70/hr and 3 hrs for report preparation @ $120/hr 2 $1,500 vegetation assessement based on actual 2007 3rdparty costs for this service 3a $1,803 based on Table 1, Line 2d and 2e values increased by a factor of 1.5 4 & 5 Estimated values 6 $20/acre mowing cost based on 3rd party bid submitted to DADS 7 Based on actual 3rd party sampling and lab costs 8 Estimated value 9 Based on representative 3rd party costs from other Colorado WM landfills 10. Based on actual 3rdlparty sampling costs 11 Based on actual 3rd party costs APPENDIX C INSURANCE CERTIFICATE FOR CLOSURE AND POST -CLOSURE CARE COSTS ANNUAL ADJUSTMENT TO CLOSURE AND POST -CLOSURE COST ESTIMATES The NWSL Financial Assuarance Plan as revised March 2009 includes a closure cost estimate of $1,366,148 (Appendix A) and a post -closure cost estimate of $1,234,081 (Appendix B) for a combined total estimate of $2,600,229. These estimates are based on the site Closure and Post - Closure Plan revised March 2009. These estimates are based on 2007 dollars, inflation adjusted to 2009 dollars. The accompanying insurance certificate reflects this adjusted amount. ACORD CERTIFICATE OF LIABILITY INSURANCE DO/ 9) 03/23/2009 T. PRODUCER National Guaranty Insurance Company of Vermont 100 - Bank Street, Suite 610 Burlington, Vermont 05401 (802) 864-1715 THIS CERTIFICATE IS ISSUED AS A MATTER OF NFORMATION ONLY AND CONFERS NO RIGHTS UPON THE CERTIFICATE HOLDER. THIS CERTIFICATE DOES NOT AMEND, EXTEND OR ALTER THE COVERAGE AFFORDED BY THE POLICIES BELOW. INSURERS AFFORDING COVERAGE NAIC # INSURED Waste Management of Colorado, Inc. 5500 Quebec Street, Suite 250 Greenwood Village, Colorado 80111 INSURER A: National Guaranty Insurance. Company INSURER B: Of Vermont INSURER C: INSURER D: INSURER Et COVERAGES THE POLICIES OF INSURANCE LISTED BELOW HAVE BEEN ISSUED TO THE INSURED NAMED ABOVE FOR THE POLICY PERIOD INDICATED. NOTWITHSTANDING ANY REQUIREMENT, TERM OR CONDITION OF ANY CONTRACT OR OTHER DOCUMENT WITH RESPECT TO WHICH THIS CERTIFICATE MAY BE ISSUED OR MAY PERTAIN, THE INSURANCE AFFORDED BY THE POLICIES DESCRIBED HEREIN IS SUBJECT TO ALL THE TERMS, EXCLUSIONS AND CONDITIONS OF SUCH POLICIES. AGGREGATE LIMITS SHOWN MAY HAVE BEEN. REDUCED BY PAID CLAIMS. INSR LTR ADD'L NSRC TYPE OFINSURANCE -- POLICY NUMBER POLICY EFFECTIVE DATEIMMIDD/YYI POLICY EXPIRATION PATEIMM/DDIYY) LIMITS GENERAL LIABILITY GENERAL LIABILITY EACH OCCURRENCE $ DAMCOMMERCIAL PREMISES( RENTED PREMISES R NTED ) $ I CLAIMS MADE OCCUR MEDEXP(Any one person) $ PERSONAL BADV INJURY S. GENERAL AGGREGATE S GEN'L AGGREGATE UMITAPPLIES PER: POUCY [ Ca& I LOC PRODUCTS -COMP/OP AGG $ AUTOMOBILEUABIUTY ANY AUTO ALL OWNED AUTOS SCHEDULED AUTOS HIRED AUTOS NON -OWNED AUTOS COMBINED SINGLE OMIT (Ea accident) $ BODILY INJURY (Per person) $ BODILY INJURY (Per accident) PROPERTY DAMAGE. (Per accident) $ GARAGE LIABILITY ANY AUTO AUTO ONLY- EA ACCIDENT $ OTHER THAN EAACC $ AUTO ONLY: AGG $ EXCESS/UMBRELLA LIABILITY EACH OCCURRENCE S I OCCUR CLAIMS MADE AGGREGATE $ DEDUCTIBLE RETENTION $ $ $ $ WORKERS COMPENSATION AND EMPLOYERS' LIABILITY ANY PROPRIETOR/PARTNERIEXECUTIVE OFFICER/MEMBER EXCLUDED? Ryes, Eesonbe under SPECIAL PROVISIONS below I TORYIIMITS I I TN - E.L EACH ACCIDENT $ E.L DISEASE -EA EMPLOYEE $ E.L. DISEASE- POUCY LIMIT $ A OTHER Closure Post -Closure CPCS99-0013 4/09/99 4/09/10 $1,366,148.00 $1,234,081.00 DESCRIPTION OF OPERATIONS/LOCATIONS/VEHICLES/EXCLUSIONS ADDED BY ENDORSEMENT/SPECIAL PROVISIONS North Weld Sanitary Landfill, 40000 Weld County Road 25, Ault, CO 80610 This certificate certifies that the policy to which this certificate applies provides closure and/or post -closure care in connection with the Insured's obligation to demonstrate financial responsibility under Section 1.8M of the regulations pertaining to Solid Waste Disposal Sites and Facilities 6 CCR 1007-2, as amended. CERTIFICATE HOLDER Director Colorado Department of Public Health and Environment Hazardous Materials/Waste Management Division 4300 Cherry Creek Drive South Denver, Colorado 80246-1530 CANCELLATION SHOULD ANY OF THE ABOVE DESCRIBED POLICIES BE CANCELLED BEFORE THE EXPIRATION DATE THEREOF, THE ISSUING INSURER WILL MORO= MAIL 120 DAYS WRITTEN NOTICE TO THE CERTIFICATE HOLDER NAMED TO THE LEFT, DIRIWRIlairDiNKR- AUTHORIZEDREPRESENTATIVE Donna L. Meals, Vice President and Secretary ACORD 25 (2001/08) ©ACORD CORPORATION 1988 4AS2 gq5 vwi WASTE MAIYAGIEM ENT January 30, -2009 Mr Douglas Ikenberry, P.E. Colorado Department of Public Health and Environment Hazardous Materials Waste_'Mana_gement Division HMWMD-SWIM-B2 4300 Cherry Creek Drive South Denver CO 80246-1530 Mr. Troy Swain Weld County Department of Public Health and Environment 1555 17th Avenue Court Greeley, CO 80631 North d fi 40,000 Weld Countll Road 25y Ault, CO Weld 80610Land 970.686.2800 (Phone) 970.686.1031 (Fax) Weld County Planning Department GREELEY OFFICE FEB 115 mnq RECEIVED Subject: North Weld Landfill Supplement to Waste Acceptance Plan to Allow for Managing Asbestos Waste Dear Mr. Ikenberry arid Mr. Swain: The North Weld Landfill is committed to protecting public health and the environment while meeting industry and community needs forintegratedand comprehensive disposal and recycling services. Since 1992, NWLF has provided industry and our community with comprehensive waste management disposal options. We continue to routinely evaluate solid waste disposal needs of northern Colorado. To this end, NWLF has prepared the enclosed Asbestos Waste Acceptance Plan to meet the needs of industry and our community. —The enclosed -plan exemplifies- and -expands -our commitment to -provide industry andour community with an integrated and comprehensive waste management program. This Asbestos Waste Acceptance Plan supplements the NWLF Waste Identification Plan dated December 2005, and sets forth the wasteacceptance, design, and operating provisions for managing. friable asbestos, in addition to the current management of non -friable asbestos waste at NWLF. The Asbestos Waste. Acceptance Plan is a supplement to enhance the currently approved NWLF Waste Identification Plan. The Asbestos Waste Acceptance Plan addresses the requirements of 6 CCR 1007-2, Part B, Section 5 of Colorado's 'Regulations Pertaining to Solid Waste Disposal Sites and Facilities' (Regulations) as they apply to asbestos disposal at NWLF. Section.5 of the Regulations specifically addresses requirements for facilities associated with managing asbestos waste disposal. This plan also addresses United States Department of Transportation (USDOT) and National Emission Standards for Hazardous Air Pollutants (NESHAP) requirements for asbestos as these apply to the asbestos disposal activities at NWLF. r Mr. Doug Ikenberry and Mr. Troy Swain January 30, 2009 Page 2 Accordingly, NWLF requests your review and approval of the enclosed Asbestos Waste Acceptance Plan as a supplemental document to the NWLF Waste Identification Plan. Upon receiving approval from the Colorado Department of Public Health and Environment and the Weld County Department of Public Health and Environment, we will file this modification as a minor change with the Weld County Department of Planning Service in accordance with Condition #34 of the Certificate of Designation Development Standards. Should you have any questions regarding the Asbestos Waste Acceptance Plan for NWLF, please contact either Alan Scheere at 303.644.4335 or Bill Hedberg at 970.686.2800. —Sincerely, — - --- - /J /% /� • f'/ /;.s c .yw.E/7'L7e2 / or. /7 - Alan Scheere Environmental Specialist Enclosure cc: &Kip'0gfMOLI)PS,-w/a-eno.. Tom Schweitzer, WM Steve Derus, WM Bruce Clabaugh, WM Gary Baldwin, WM Bill Hedberg Sr. District Manager Hello