Document B8gQpzE3kbvbN9r61ZN17mOJE

DATE: SUBJECT: FROM: THRU: TO: See date of Branch Manager signature CLEAN AIR ACT INSPECTION REPORT Waste Connections - Front Range Landfill, Erie, CO Enforcement and Compliance Assurance Division, Air and Toxics Enforcement Branch Enforcement and Compliance Assurance Division, Air and Toxics Enforcement Branch File BASIC INFORMATION Facility Name: Front Range Landfill Facility Location: 1830 Weld CR 5, Erie, Colorado 80516 Date of Inspection: October 18, 2023 EPA Inspector(s): 1. , Clean Air Act Inspector, EPA Region 8 2. , Clean Air Act Inspector, EPA Headquarters 3. , Clean Air Act Inspector, EPA NEIC Front Range Landfill Attendees: 1. , District Manager 2. , Assistant District Manager 3. Lead Site Operator 4. Region Engineer 5. , Gas Technician Contact Email Address: ; Page 1 of 7 Purpose of Inspection: To determine Clean Air Act (CAA) compliance and perform a comparative Surface Emissions Monitoring (SEM) survey Facility Type: Municipal solid waste (MSW) landfill Regulations Central to Inspection: 40 C.F.R. Part 60, Subpart Cf (formerly subject to 40 C.F.R. Part 60, Subpart WWW); 40 C.F.R. Part 63, Subpart AAAA; Title V Permit Requirements of Operating Permit 97OPWE188 Date: Arrival Time: Departure Time: 10/18/2023 8:45 MDT 13:30 MDT Inspection Type: Unannounced Inspection Announced Inspection OPENING CONFERENCE Presented Credentials Stated authority and purpose of inspection Provided Small Business Resource Information Sheet Small Business Resource Information Sheet not provided. Reason: Not a small business Provided CBI warning to facility The following information was obtained verbally from Front Range Landfill (FRLF) representatives or through review of facility records. Process Description: Front Range Landfill (FRLF) is a municipal solid waste (MSW) landfill located near Erie, in Weld County, Colorado and is owned and operated by Waste Connections, Inc. FRLF is part of a larger facility which includes Denver Regional Landfill South (DRLS) (Operating Permit 03OPWE254), also owned by Waste Connections; Denver Regional Landfill North (DRLN) (Operating Permit 99OPWE215), owned by Allied Waste; and a landfill gas to energy plant (GTEP) owned by Timberline Energy (Operating Permit 10WE1096). Both Denver Regional Landfill South and Denver Regional Landfill North have stopped accepting waste since December 2020 and April 1992, respectively. The Timberline Energy GTEP receives and processes landfill gas from all three landfills. Only the operations covered under Operating Permit 97OPWE188 and within the boundaries of FRLF were inspected during the EPA inspection. FRLF began accepting waste in 1996 and accepts MSW, construction and demolition debris, non-friable asbestos, and various contaminated soils. Asbestos wastes and PCS are buried at the working face when they are received. The landfill accepts white goods, but does not Page 2 of 7 conduct recycling, open burning, or composting. Its design capacity is approximately 348 million cubic yards or 35,768,342 megagrams (Mg). FRLF is expected to remain open until approximately 2040. By itself, Front Range Landfill does not exceed the emissions thresholds of 34 and 50 Mg/yr of non-methane organic compounds (NMOC) above which emissions must be controlled. However, CDPHE conducted a single source determination in 2009 and determined that FRLF was to be considered a single source with DRLS and DRLN. Once Front Range Landfill became a single source with DRLS and DRLN, total facility emissions on an uncontrolled basis exceeded 50 Mg NMOC/year, and NSPS Subpart WWW required the existing gas collection and control system (GCCS) at DRLS and DRLN be expanded to FRLF. CDPHE informed FRLF of the single source determination and associated control requirements in a letter dated August 25, 2009, and established a deadline of April 1, 2010, for submission of a GCCS design plan, and of October 1, 2011, to install the GCCS. A GCCS and open flare began operation at FRLF on October 1, 2011, as required under the terms of Construction Permit 11WE1680. FLRF receives approximately 7,000 - 9,000 tons of waste per day, a majority of which is MSW. Other wastes, such as construction and demolition waste as well as asbestos waste, are comingled for disposal with MSW. Since there are no dedicated monofils at the landfill, all portions of the landfill with waste-in-place for greater than five years are under active landfill gas (LFG) collection. Condensate and leachate collected at FRLF is recirculated or managed via the leachate management system and/or managed in accordance with FRLF's operating plan. From June 2022 through May 2023, the landfill recirculated 274,100 gallons of leachate. Based on the 2009 single source determination, an initial GCCS design plan was submitted April 1, 2010 and the initial GCCS was subsequently installed and began operation on October 1, 2011. At the time of the inspection, the GCCS consisted of approximately 60 vertical landfill gas extraction wells. The LFG collection system spans all areas where waste has been in place for at least 5 years. FRLF's GCCS control system consists of two control devices rated to accommodate a combined inlet LFG flow of up to 3,200 standard cubic feet per minute (scfm). The control devices include one open (candlestick) flare with a capacity of 2,000 scfm and an on-site landfill GTEP with a rated maximum capacity of 1,200 scfm. The GTEP consists of two reciprocating internal combustion Caterpillar G3520C engines. On August 8, 2023, FRLF submitted a permit modification application to replace the 2,000 scfm flare with a 3450 scfm flare. According to a GCCS design plan prepared by FRLF on March 2, 2023 (2023 Design Plan), EPA Landfill LandGEM modeling predicts LFG generation of 4,165 scfm in 2024, with peak LFG generation in 2031 of 6,861 scfm and declining LFG generation thereafter. FRLF assumes 75% of LFG is captured through the GCCS, with the remaining 25% uncollected and venting directly through the landfill surface. Surface Emission Monitoring: Page 3 of 7  icy, snow covered, and/or extremely muddy slopes; and areas where the landfill cover material has been exposed for the express purpose of installing, expanding, replacing, or repairing components of the GCCS, leachate, or gas condensate collection and removal systems. TOUR INFORMATION EPA Tour of the Facility: Yes Data Collected and Observations: EPA conducted a partial SEM and cover integrity survey of the facility. EPA used two ThermoFisher Toxic Vapor Analyzer 2020s (TVA2020) to perform EPA Reference Method 21 for the SEM survey. EPA confirmed each exceedance with both TVA2020s and also offered FRLF representatives the opportunity to visually confirm each exceedance above 500 ppm measured on the TVA2020s during the SEM survey. and of FRLF visually confirmed all exceedances. See Appendix C for additional instrument and calibration information. The EPA SEM survey covered central and eastern slopes of the landfill, estimated to constitute roughly 30% of the area routinely monitored during quarterly SEM events. EPA did not monitor northern portions of the landfill in order to avoid the working face, which was designated as unsafe to monitor by FRLF staff. Areas monitored during the EPA SEM survey were selected in accordance with regulatory requirements, focusing on locations with visual indicators of elevated landfill gas (e.g., distressed vegetation, cracks, seeps, cover penetrations) and areas with sparse vegetation, which are also prone to elevated emissions. EPA inspectors recorded 6 points on the landfill surface where methane concentrations equaled or exceeded 500 ppm, including 4 exceedances recorded at penetrations and 2 exceedances recorded on the landfill surface. Note that exceedance #8 of Appendix B is labeled as a penetration exceedance, although it does not meet FRLF's definition of a penetration. See Appendix B for more details. On the landfill slope where exceedances #3 - #5 were recorded, EPA observed a large continuous area with little to no vegetation and some erosion rills. These conditions were also noted near exceedances #6 and #7. Aside from these locations, the landfill cover was generally in good condition, with minimal erosion and well-established vegetation. CLOSING CONFERENCE Provided U.S. EPA point of contact to the facility Compliance Assistance: None. Photos and/or Videos: were taken during the inspection. See Appendix A Field Measurements: were taken during this inspection. See Appendix B. Records: were not taken during this inspection. Publicly available records were reviewed as part of the inspection. Page 5 of 7 Concerns: EPA recorded cover integrity and SEM exceedances issues during the inspection which were communicated to FRLF staff during the closing conference. The locations of the methane exceedances were communicated to FRLF personnel during the closing conference. FRLF committed to addressing the methane exceedances in the same way that is required for exceedances identified through quarterly SEM and followed up with EPA to confirm correction of the exceedances and return to appropriate methane levels at the surface. Review of the 2023 Design Plan revealed a few alternative requests that are not supported by EPA: 1) SEM exclusion areas and, 2) FRLF's interpretation of the cover penetration definition. First, areas may be excluded from monitoring only if the act of monitoring an area poses a significant risk of death or injury of the person conducting the monitoring, and/or the act of monitoring an area would violate state or federal occupational safety standards. Consistent with the State Plan and NESHAP AAAA, slopes may be excluded from monitoring only if it is not practically feasible for the area to be monitored safely and legally during the quarter. Final design slopes should not be designed in such a way that prevents surface emissions monitoring (SEM) in applicable areas. The working face (if above applicable waste) should only be excluded if there is active truck traffic and waste deposition on the day of monitoring - areas under daily cover where waste has been in place for greater than 5 years are still otherwise subject to SEM requirements. SEM should be scheduled around large-scale construction projects that would make significant areas of the landfill unsafe to monitor. SEM should be scheduled to avoid or minimize snowy, icy, or muddy surfaces, and within a weather window during the quarterly period that is conducive to monitoring in the preferred conditions. Excluding areas from monitoring that could have been safely and legally monitored during the quarter constitute a violation of the Clean Air Act. SEM reports should include detailed explanations for reasons of excluding any areas subject to the collection and control requirements of the regulations. Finally, the FRLF 2023 Design plan incorrectly interprets the definition of cover penetration by shortening the full definition. Survey stakes, fencing including litter fences, flags, signs, utility posts, and trees would all be considered cover penetrations if they pass through the cover, according to the definition of "cover penetration" at 40 C.F.R. 63.1990. The landfill cover includes that portion which covers the waste, as well as the portion which borders the waste extended to the point where it is sealed with the landfill liner or the surrounding land mass. No other concerns were noted. Page 6 of 7 DIGITAL SIGNATURES , Report Author , Manager Page 7 of 7 Facility Name: Front Range Landfill Facility Location: 1830 Weld CR 5, Erie, Colorado 80516 Date of Inspection: October 18, 2023 APPENDICES AND ATTACHMENTS Appendix A: Digital Image Log Appendix B: Field Measurement Data Appendix C: Calibration Data Appendix D: Maps of SEM Results and Satellite Imagery Appendices Page 1 of 6 Facility Name: Front Range Landfill Facility Location: 1830 Weld CR 5, Erie, Colorado 80516 Date of Inspection: October 18, 2023 APPENDIX D: MAPS OF SEM RESULTS AND SATELLITE IMAGERY SEM hit locations plotted over satellite imagery from September 4, 2023 as depicted on Google Earth. Approximate monitoring path and monitored areas included (green line and green highlight), derived from GPS data. Detail view of exceedances in the central portion of landfill Appendices Page 5 of 6 Facility Name: Front Range Landfill Facility Location: 1830 Weld CR 5, Erie, Colorado 80516 Date of Inspection: October 18, 2023 Google Earth satellite imagery from September 4, 2023, demonstrating extensive erosion rills and sparse vegetation on the central slope of the landfill near exceedances #3 - #5 Google Earth satellite imagery from September 4, 2023, demonstrating erosion rills and sparse vegetation on the western slope of the landfill near exceedances #6 and #7. Appendices Page 6 of 6