Document bBwBy8wwMYEpXr4J5e727MJjD

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 10 1200 6TH AVENUE SEATTLE, WASHINGTON 98101 DATE: SUBJECT: FROM: THRU: TO: See date of Section Chief signature CLEAN AIR ACT INSPECTION REPORT Republic Services Coffin Butte Landfill, Corvallis, OR Daniel Heins, Environmental Scientist Air Toxics Enforcement Section, EPA Region 10 Derrick Terada, Acting Section Chief Air Toxics Enforcement Section, EPA Region 10 File BASIC INFORMATION Facility Name: Republic Services Coffin Butte Landfill Facility Location: 28972 Coffin Butte Road, Corvallis, OR 97330 Date of Inspection: On Site Inspection: June 23, 2022 Virtual Conference: July 11, 2022 EPA Inspector(s): 1. Daniel Heins, Environmental Scientist a,b Other Attendees: 1. Ian MacNab, Environmental Manager - Republic Services a,c 2. Phil Caruso, Environmental Specialist - Republic Services a,b 3. Brock Kienholz, Operations Manager - Republic Services c 4. Nikki Wuestenberg, Operations Support (Nationwide) - Republic Services a 5. Melissa Green, Environmental Consultant - Weaver Consultants a 6. Yuki Puram, Air Inspector & Permit Engineer - Oregon Department of Environmental Quality a,b a Attended virtual conference b Present for all of on-site, including SEM c Present during on site conferences but not during SEM Contact Email Address: imacnab@republicservices.com Page 1 of 14 Facility Type: Muncipal solid waste (MSW) landfill Purpose of Inspection: Surface emissions monitoring (SEM) and evaluating compliance with landfill air rules. Regulations Central to Inspection: 40 C.F.R. Part 60, Subpart WWW; Oregon State Plan for 40 C.F.R. Part 60, Subpart Cf; 40 C.F.R. Part 63, Subpart AAAA On Site (6/23) Arrival Time: 09:00 On Site (6/23) Departure Time: 17:50 Virtual Conference (7/11) Start Time: 13:00 Virtual Conference (7/11) End Time: 15:00 Inspection Type: Unannounced Inspection Announced Inspection SITE OVERVIEW The following information was obtained verbally from Republic Services representatives, including their consultants, during the virtual conference, unless otherwise stated. Operations Overview: The Coffin Butte Landfill (the "Landfill") is owned and operated by Republic Services ("Republic"). Republic acquired the Landfill in 2008. Republic representatives were uncertain of exactly how old the Landfill is, stating that they believed it began as a military dump site in the 1940s. Daniel Heins confirmed this via information online from DEQ, which stated that landfilling began in the 1940s in association with Camp Adair. The areas that predate the Resource Conservation and Recovery Act of 1976 (RCRA) have a clay foundation. Some historic waste that predates the 1970s has been re-located from these unlined sections to the postRCRA lined areas to facilitate construction of future lined cells in those areas. The Landfill is permitted for 178 acres and has a permitted capacity of 35,514,471 according to the Landfill's 2020 Part 98 Greenhouse Gas Report. The Facility receives approximately 3,500 to 4,500 tons per day of waste. Wastes received include MSW, petroleum contaminated soils, construction and demolition (C&D) waste, C&D material recovery facility (MRF) residuals, and other industrial wastes. Based on current waste acceptance rate, the Landfill has approximately 20 years left under its current permit. Republic has room to expand the site on its property beyond the current permitted footprint. Final cover on the Landfill is compacted soils with a synthetic membrane, with penetrations booted and plastic welded. Interim cover is at least 24 inches of soils. Much of the interim cover area is covered in tarps or, in areas without work planned for a few years, a thicker layer of EPDM. In both cases, this is with the primarily goal of reducing water infiltration into the Page 2 of 14 Landfill. Daily cover is 6 inches of soil or approved alternative daily cover (ADC). Republic uses C&D MRF shaker fines, MSW incinerator ash, and tarps as ADC at the Landfill. Leachate flows by gravity to sumps and is pumped to covered storage ponds. Leachate collected varies by year based on the weather but typically is around 25 to 30 million gallons. Condensate is routed to the leachate system. Leachate is trucked to local publicly owned treatment works (POTWs). No leachate is recirculated, and no liquid wastes are added to the Landfill. The gas collection and control system (GCCS) contains over 300 landfill gas (LFG) collection points, including horizontal wells, vertical wells, and parts of the leachate system with gas collection. Collected landfill gas partially routed to a separately owned/operated gas to energy plant run by PNGC Power. The energy plant has five Caterpillar gas engines - three 3516s and two 3520s. Excess gas not routed to the energy plant is controlled via flares at the Landfill. The landfill has two open flares, with capacities of 1000 standard cubic feet per minute (scfm) and 2000 scfm. Recently the Landfill has been collecting 2600 scfm for the full site, with 1600 scfm going to the energy plant and 1000 scfm to the flares. SITE TOUR -- JUNE 23, 2022 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 Data Collected and Observations: Daniel Heins arrived on site and met with the site staff for introductions and a brief site orientation/safety briefing at the Landfill's office. During this meeting, Ian MacNab stated that while there was a Method 21 instrument available and that Phil Caruso is their monitoring technician, that he would not take the opportunity to check EPA readings / provide confirmation readings, as a matter of Republic Services corporate policy. Daniel Heins explained that facilities typically prefer to check and confirm EPA readings and he gave advance notice to provide Republic the opportunity to confirm his TVA readings. Ian MacNab re-iterated that as a corporate policy that they would not provide confirmation readings. After that brief meeting, Daniel Heins began the SEM. Phil Caruso accompanied EPA for the Surface Emission Monitoring (SEM). EPA showed all readings to Phil Caruso for visual confirmation of the readings and instructed him to state if he had any concerns with EPA's monitoring methods at any point. EPA used a ThermoFisher Toxic Vapor Analyzer 2020 (TVA) to perform EPA Reference Method 21 for the SEM. In the morning (9:50 - 12:45), Daniel Heins conducted the monitoring with the TVA, covering a loop on the western portion of the Landfill. In the afternoon (13:30 - 17:15), he continued monitoring with the TVA, covering a loop on the eastern portion of the Landfill. Over the course of the day, Daniel Heins identified 61 points in exceedance of 500 parts per million (ppm), exhausting his supply of marking flags. Of these, 21 flagged exceedances were above 10,000 Page 3 of 14 ppm. Many flagged exceedances represented clusters of exceedances at multiple points or broad areas of exceedances. Of the flagged exceedances, 26 were at or partially at gas collection wells (including both active and abandoned or decommissioned). Eight exceedances were at leachate cleanouts. Daniel Heins focused monitoring on areas under intermediate cover, though the first six exceedances were in final cover areas. During the afternoon monitoring, Daniel Heins measured multiple exceedances that continued to be above 500 ppm multiple feet in the air, with multiple feet lateral distance from the emission source, indicating substantial landfill gas plumes (flag #26, 46, and 51). Flag #51 was by a broad area where the tarp was visibly inflated with gas. The tarp was not moving in the wind, it looked to be being pushed out steadily over a wide area towards the top of the south slope on the central area of the landfill, being held down by straps, cover anchors, and sandbags. Neither Daniel Heins nor Phil Caruso could identify any place where the wind could be lifting under the tarps, as the tarp edges were sandbagged and staked down. Daniel Heins measured a concentration of 2% at flag #51 before pulling away to avoid maxing out his instrument. He measured the methane concentration to be 2000 ppm at 3' in the air at this location, indicating a plume of gas coming out from the inflated tarp area. Along the top of this section of tarp, from flag #52 to #54, every post or tarp hole Daniel Heins monitored exceeded the surface methane standard, with readings of up to 7% shown before the instrument maxed out. Phil Caruso did not dispute any of the readings, though noted that he would not have checked many of the exceedance locations, that he would have spent less time monitoring, or that he would have considered a higher location to be "the ground" when placing his probe 5 to 10 centimeters (cm) above the ground per the SEM regulations. At an exceedance (flag #1) with a hole in the ground from an animal burrow, Phil Caruso stated that he would have considered the "ground" to be where the ground would have been if an animal didn't dig a hole into it at that location, rather than the ground at the base of the hole, and thus measured from a significantly higher location than Daniel Heins. At an exceedance (flag #2) between overlapped tarp material, with one piece of tarp raised above the other with a gap of air in between, Phil Caruso stated that he would have monitored with his probe above the upper tarp, rather than measuring the 5 to 10 cm from the tarp against the ground. When Daniel Heins was monitoring a cluster of decommissioned wells with a patch of distressed soil (flag #3), Phil Caruso stated that he would have moved on after not directly getting above 500 ppm within twice his instrument response time even if there was an increase in reading, rather than moving around the penetration points slowly to find maximum reading point and then waiting twice the response time at this maximum reading location. When Daniel Heins was monitoring at leachate cleanouts, Phil Caruso stated that he does not monitor at these and that they are not fully penetrating the cover. Daniel Heins responded that it was likely that many of these ultimately did penetrate the cover, especially in areas of thinner intermediate cover, and that regardless he recommended checking these as they were proving to be repeated sources of extremely elevated emissions, many over an order of magnitude above the surface methane standard. Phil Caruso stated that he was not required to monitor these. Daniel Heins and Phil Caruso had a similar discussion at the valve box dug into the cover with a reading Page 4 of 14 of 4% methane (flag #37), with Phil Caruso stating that this was not a penetration and thus he did not have to monitor this. When Daniel Heins was monitoring at a horizontal penetration of the cover associated with a well (flag #16), Phil Caruso stated that he would not have monitored this as a penetration. Phil Caruso stated that he would not have monitored the Cell 5 leachate riser that Daniel Heins measured multiple exceedances at, as it was outside of the waste mass. Photos and/or Videos: were taken during the inspection. See Appendix A. Field Measurements: were taken during this inspection. See Appendix B. INSPECTION CONFERENCE -- JULY 11, 2022 Provided U.S. EPA point of contact to the facility Provided CBI warning to facility Staff Interview: The Landfill is subject to the Oregon State Plan implementing the Part 60 Subpart Cf Emission Guidelines, having previously been subject to Part 60 Subpart WWW. The Landfill is also subject to Part 63, Subpart AAAA, and has opted-in to demonstrating compliance with the Oregon State Plan through the Subpart AAAA requirements where allowed. Republic stated that they were unsure if they were excluding non-degradable waste from their maximum gas generation rate calculations in their Design Plan or any other gas modeling runs they have done to size their GCCS. Republic stated that as the operations personnel were not present, they were unable to speak to what types of industrial wastes are received in any further detail. The Landfill does not accept refrigerants. The Landfill receives asbestos. It packages asbestos waste and deposits it in a dedicated asbestos mono-fill that is the only area excluded from the GCCS. Leachate system components are connected for LFG collection on a case-by-case basis per recommendations of the engineer(s) involved in designing the GCCS. Republic is aware of a one-off test of the sulfur content of the LFG requested by DEQ and stated that it read at non-detectable levels. The Landfill has an alternative monitoring plan (AMP) approved by DEQ dating to when the Landfill operated under Subpart WWW. The AMP has allowances for positive pressure, temperatures above 145 degrees Fahrenheit, and elevated oxygen readings. No wells currently are above 145 degrees Fahrenheit. Republic does make use of the positive pressure allowances for wells with high oxygen levels. Republic stated that they do not consistently check water levels in wells but has done so in the past. All new (at least since 10 years ago) wells are constructed with dewatering pumps, as a best Page 5 of 14 practice for a landfill in a wet climate. Republic does not typically add pumps to old wells. As wells are typically constructed with steel casings at the Landfill, redrills are rarely needed. The Landfill has gas migration probes placed outside the area without synthetic liner but has typically seen readings at gas non-detect levels. For cover integrity monitoring, Republic stated that they look for holes and cracks in the soils and wind damage on the tarps, but that there was no set answer for what degree of tarp damage would necessitate repair. For surface emissions monitoring, Republic only excludes active filling areas and other areas with active heavy equipment as "dangerous." When Daniel Heins noted that the drawn paths in the submitted SEM reports went straight through the drawn "dangerous areas," Republic stated that the paths on the maps are general and do not reflect the actual walked paths. Republic monitors penetration points during its serpentine path. Phil Caruso stated that in addition to penetrations, he would go off the serpentine path if he saw distressed vegetation or cracks in the cover, and that those were the only examples of places where visual observations indicate elevated concentrations of landfill gas that he considered. Republic was unable to speak to the what the historic SEM exceedance rate had been in past surveys. Daniel Heins asked if the GCCS was operational on the day of the SEM inspection or if there was anything different from standard operations that could have impacted the results of the monitoring. Republic stated that nothing was operating differently than normal, with all wells in operation and collection running. Republic did note that construction above exceedance flags #48 through 58 would have impacted the cover in the construction area. Daniel Heins asked if Republic viewed the inflated tarps as a concern or something to acted on. Republic disputed that the tarps were inflated with landfill gas, claiming that the wind has blown them up. Daniel Heins noted the extremely elevated methane concentrations detected by the inflated tarps and that the tarps appeared to be in a static inflated state without any steady wind or apparent way for the wind to lift the tarps. Republic noted that construction of additional gas collection on the top of the Landfill is in progress and will be completed this summer. Requested documents: The following documents were requested and supplied ahead of the inspection: Two most recent semi-annual NSPS reports Results of any cover integrity reports and quarterly SEM monitoring events that have been occurred since the most recent semi-annual GCCS map Map of cover by type in place (final vs intermediate vs daily cover) Page 6 of 14 The following documents were requested during the conference and confirmed via subsequent email: Constructed acres and acreages by cover type Past 5 years of flare monitoring data Flare/blower design specs and any performance tests on file for it Past year of migration probe data and a map of the probe locations Current GCCS Design Plan, along with any versions that have been active in the past 5 years and them most recent LandGEM run used for GCCS sizing (if not in the Design Plan) A map of the GCCS showing extent of any horizontal collectors if these are utilized to demonstrate a sufficient density of gas collection Landfill cell map and year of first waste placement for each cell 2021 Part 98 Greenhouse Gas Report Annual waste deposited tonnages by type from 2016 to present o Include a list of the primary sources of industrial wastes and a description for any special wastes listed o Outline of what wastes (if any) are classified as non-degradable for LandGEM maximum expected gas generation (Design Plan) along with the basis for this classification o Outline of what wastes are classified as "inert" for Part 98 reporting along with the basis for this classification Rest of the past 5 years of Annual/Semi-Annual Reports o Include all NSPS/NESHAP/EG reports, SSM reports, and air permit reports as applicable o If the full SEM reports are not included in the above, please include those for the past 5 years o Include the most recent SEM reports, or at least as much of it as has been completed by the end of July, even if they are not a part of any final semi-annual Any versions of the SSM plan that have been in place in the past 5 years Past 5 years of wellhead parameter monitoring Past 5 years of gas flow to the energy plant Any H2S or sulfur gas testing results from the past 5 years, or most recent if not within the past 5 years Map of wells being added this summer since the inspection The Alternative Monitoring Plan and approval letter Identification of which wells have dewatering pumps General description of final cover construction Page 7 of 14 Concerns: Daniel Heins expressed potential concerns with Republic's SEM/Method 21 procedures. Despite Republic having seen no more than 6 exceedances in the recent SEM reports supplied ahead of the inspection that included penetration monitoring, including reports with 0 exceedances, he identified 61 points in exceedance of 500 ppm, including 21 points above 10,000 ppm, with 26 exceedances at gas collection wells that Republic should have specifically been monitoring on a quarterly basis since the Oregon State Plan became effective in November 2020. Daniel Heins expressed concerns with the areas of tarp that were inflated with and leaking out landfill gas, as detected during the SEM, noting that in additions to compliance concerns with the surface methane standard that such an accumulation of flammable gas creates a potential safety concern. DIGITAL SIGNATURES DANIEL Digitally signed by DANIEL HEINS HEINS Date: 2022.09.19 14:26:56 -07'00' _________________________________ Daniel Heins, Report Author DERRICK Digitally signed by DERRICK TERADA T__E_R_A__D_A______1_4:5_1_:00_-_07_'0_0' ______________ Date: 2022.09.19 Derrick Terada, Acting Section Chief Page 8 of 14 APPENDICES AND ATTACHMENTS Appendix A: Digital Image Log Appendix B: Field Measurement APPENDIX A: DIGITAL IMAGE LOG Inspector Name: Daniel Heins Archival Record Location: US EPA SharePoint 2022-06-23 Images Image Time Flag # File Name (PDT) # Description 1 20220623_100838.jpg 10:08:38 1 Animal burrow by cleanout 2 20220623_101327.jpg 10:13:27 2 Overlapping tarps Discolored soil/distressed vegetation by INE9, multiple 3 20220623_101816.jpg 10:18:16 3 decommissioned wells Discolored soil/distressed vegetation by INE9, multiple 4 20220623_102219.jpg 10:22:19 3 decommissioned wells Discolored soil/distressed vegetation by INE9, multiple 5 20220623_102231.jpg 10:22:31 3 decommissioned wells 6 20220623_102717.jpg 10:27:17 4 Cleanout Decommissioned well and surrounding wells by RE8 7 20220623_103235.jpg 10:32:35 5 manifold Decommissioned well and surrounding wells by RE8 8 20220623_103515.jpg 10:35:15 5 manifold 9 20220623_104050.jpg 10:40:50 6 Decommissioned PVC well (W9?) 10 20220623_105243.jpg 10:52:43 7 Hole in liner 11 20220623_110338.jpg 11:03:38 8 cleanout with gap in liner Unmarked well with gap in liner and gap between well and 12 20220623_111123.jpg 11:11:23 9 dirt, plus nearby holes 13 20220623_111129.jpg 11:11:29 9 Close up on gap on liner and in dirt 14 20220623_111216.jpg 11:12:16 9 Hole in liner near unmarked well 15 20220623_111452.jpg 11:14:52 10 Liner tear and adjacent hole 3V91 Manifold, both at tarp edge and at multiple 16 20220623_112408.jpg 11:24:08 11 penetrations 17 20220623_113216.jpg 11:32:16 12 Hole in liner 18 20220623_113733.jpg 11:37:33 13 3V92 wells with tarp gap 19 20220623_114521.jpg 11:45:21 14 3B0V0351 bad liner seal at base 20 20220623_115250.jpg 11:52:50 15 Decommissioned well with tarp tear/gap 21 20220623_115912.jpg 11:59:12 16 3H94 where horizontal intersects tarp 22 20220623_120314.jpg 12:03:14 16 3H94 penetration cluster 23 20220623_120746.jpg 12:07:46 17 Cleanout by unknown well out of liner Liner that had been pulled back from unknown well by 24 20220623_121307.jpg 12:13:07 18 chopped off pipe segment on ground 25 20220623_122009.jpg 12:20:09 19 Unknown well at liner seam Page 9 of 14 2022-06-23 Images, continued Image Time Flag # File Name (PDT) # Description 26 20220623_122332.jpg 12:23:32 20 Riser with bad liner seal 27 20220623_123220.jpg 12:32:20 21 Well 3COV3 with liner gap 28 20220623_140422.jpg 14:04:22 22 Cell 5 leachate riser complex 29 20220623_140538.jpg 14:05:38 22 Cell 5 leachate riser complex 30 20220623_140921.jpg 14:09:21 22 Cell 5 leachate riser complex - pipe connector 31 20220623_140924.jpg 14:09:24 22 Cell 5 leachate riser complex - pipe connector 32 20220623_140927.jpg 14:09:27 22 Cell 5 leachate riser complex 33 20220623_141045.jpg 14:10:45 22 Cell 5 leachate riser complex 34 20220623_142020.jpg 14:20:20 23 Well 5V40 in liner 35 20220623_143317.jpg 14:33:17 24 Tarp anchor 36 20220623_143735.jpg 14:37:35 25 Tarp anchor 37 20220623_144405.jpg 14:44:05 26 4B55 well cluster 38 20220623_144407.jpg 14:44:07 26 Mystery pipe with improvised cap with folded plastic wrap 39 20220623_144923.jpg 14:49:23 27 2V114 at base in dirt 40 20220623_145332.jpg 14:53:32 28 Hole near edge of liner, and in neighboring hole 41 20220623_145705.jpg 14:57:05 29 Tarp edge 42 20220623_150256.jpg 15:02:56 30 Tarp hole and neighboring holes 43 20220623_150616.jpg 15:06:16 31 Hole at tarp anchor 44 20220623_150954.jpg 15:09:54 32 Abandoned well 45 20220623_150957.jpg 15:09:57 32 Liner hole near abandoned well 46 20220623_151520.jpg 15:15:20 33 4V53 - well surrounded by sandbags in lined area 47 20220623_151822.jpg 15:18:22 34 Anchor and nearby liner hole 48 20220623_154015.jpg 15:40:15 35 Cleanout coming out of dirt 49 20220623_154916.jpg 15:49:16 36 Vertical cleanout in dirt 50 20220623_155053.jpg 15:50:53 37 Circular valve box 51 20220623_155522.jpg 15:55:22 38 Hole in liner 52 20220623_160008.jpg 16:00:08 39 Cleanout / hole in liner 53 20220623_160336.jpg 16:03:36 40 Tarp hole and neighboring holes 54 20220623_160711.jpg 16:07:11 41 PH2101, 2H101 - whole cluster of wells (some tarp gaps) 55 20220623_160900.jpg 16:09:00 41 PH2101, 2H101 - whole cluster of wells (some tarp gaps) 56 20220623_161111.jpg 16:11:11 42 3AV68 and nearby hole in liner 57 20220623_161551.jpg 16:15:51 43 2V100 well in tarp area 58 20220623_161847.jpg 16:18:47 44 3V73 well in tarp gap 59 20220623_162101.jpg 16:21:01 45 Tarp stake 60 20220623_162525.jpg 16:25:25 46 Hole in tarp 61 20220623_162743.jpg 16:27:43 47 Tarp edge 62 20220623_163203.jpg 16:32:03 49 tarp edge 63 20220623_163313.jpg 16:33:13 50 2H86 cluster in tarp 64 20220623_163646.jpg 16:36:45 51 Series of tarp tears near inflated tarp area Tarped slope showing buildup of gas inflating tarps over 65 20220623_163710.jpg 16:37:10 - slope Tarped slope showing buildup of gas inflating tarps over 66 20220623_163718.jpg 16:37:18 - slope Page 10 of 14 2022-06-23 Images, continued Image Time Flag # File Name (PDT) # Description 67 20220623_163934.jpg 16:39:34 52 Tarp stake 68 20220623_164213.jpg 16:42:13 53 Tarp stake in area of continuously elevated readings Tarped slope showing buildup of gas inflating tarps over 69 20220623_164217.jpg 16:42:17 - slope Tarped slope showing buildup of gas inflating tarps over 70 20220623_164219.jpg 16:42:19 - slope Tarped slope showing buildup of gas inflating tarps over 71 20220623_164221.jpg 16:42:21 - slope 72 20220623_164521.jpg 16:45:21 54 Tarp stake in area of continuously elevated readings 73 20220623_164718.jpg 16:47:18 55 Tarp edge, inflated tarps visible 74 20220623_164914.jpg 16:49:14 56 Broad area of dirt/waste uphill of tarp area 75 20220623_164917.jpg 16:49:17 56 Broad area of dirt/waste uphill of tarp area 76 20220623_165102.jpg 16:51:02 57 2H94 well cluster - all 77 20220623_165319.jpg 16:53:19 58 Tarp edge 78 20220623_165637.jpg 16:56:37 59 3V89 well cluster in dirt 81 20220623_170040.jpg 17:00:40 60 2V113 - well with some tarp wrapped in dirt area 82 20220623_170947.jpg 17:09:47 61 Valve with well at haul road above cell 5 Page 11 of 14 APPENDIX B: FIELD MEASUREMENT DATA Measured Exceedances Flag # Reading Description 1 1% Animal burrow by cleanout 2 1000 F/O Overlapping tarps 3 1000 Discolored soil/distressed vegetation by INE9, multiple exceedances including multiple decommissioned wells 4 2000 Cleanout 5 1% Decommissioned well and surrounding wells by RE8 manifold 6 700 Decommissioned PVC well (W9?) 7 1500 Hole in liner 8 1.20% cleanout with gap in liner Unmarked well with gap in liner weld and gap between 9 1.20% well and dirt, plus nearby holes 10 2.70% Liner tear and adjacent hole 11 3700 3V91 Manifold, both at tarp edge and at multiple penetrations 12 2.20% Hole in liner 13 5000 3V92 wells with tarp gap 14 1200 3B0V0351 bad liner seal at base 15 1200 Decommissioned well with tarp tear/gap 16 9000 3H94 where horizontal intersects tarp, and multiple penetrations in cluster 17 4700 Cleanout by unknown well out of liner 18 5500 Liner that had been pulled back from unknown well by chopped off pipe segment on ground 19 2000 Unknown well at liner seam 20 8000 Riser with bad liner seal 21 1220 Well 3COV3 with liner gap 22 2400 Cell 5 leachate riser complex - multiple risers and at pipe connection 23 800 Well 5V40 in liner 24 3000 Tarp anchor 25 600 Tarp anchor 26 1% 4B55 at base of cluster as well as top of mystery pipe with improvised cap with folded plastic wrap 27 4000 2V114 at base in dirt 1% F/O, 28 3% Hole near edge of liner, and in neighboring hole 29 4500 Tarp edge 30 1% Tarp hole and neighboring holes 31 1500 Hole at tarp anchor Latitude 44.69737457 44.69745665 44.69766687 44.69775127 44.69786105 44.69782839 44.69865701 44.69790548 44.69829911 44.69842096 44.69885999 44.69830399 44.69837287 44.69822886 44.69836899 44.698248 44.69812972 44.69811411 44.69804442 44.69804447 44.69784857 44.70181118 44.70167582 44.70101596 44.70114084 44.70115072 44.70111214 44.70103128 44.70082423 44.70072043 44.70068672 Longitude -123.2356198 -123.2357082 -123.2360485 -123.2362152 -123.236267 -123.2365858 -123.2365257 -123.2358232 -123.2354937 -123.23558 -123.2350488 -123.2350079 -123.2347328 -123.2340741 -123.2337448 -123.2334448 -123.2337702 -123.2338379 -123.2344811 -123.2345951 -123.2333245 -123.2257475 -123.2273125 -123.2273626 -123.2274474 -123.2275846 -123.2278246 -123.2276965 -123.2275253 -123.2273274 -123.227044 Page 12 of 14 Measured Exceedances Flag # Reading Description 32 3200 At abandoned well and nearby hole in liner 33 1200 4V53 - well surrounded by sandbags in lined area 34 1100 Anchor and nearby liner hole 35 1% Cleanout coming out of dirt 36 1200 Vertical cleanout in dirt 37 4% Circular valve box 38 1500 Hole in liner 39 1200 Cleanout / hole in liner 40 1600 Tarp hole and neighboring holes 41 1% PH2101, 2H101 - whole cluster of wells (some tarp gaps) 42 2% 3AV68 and nearby hole in liner 43 3% F/O 2V100 well in tarp area 44 1200 3V73 well in tarp gap 45 2% Tarp stake 46 2% Hole in tarp 47 2500 Tarp edge 48 6000 3V74 - whole well cluster 49 5000 tarp edge 50 7000 2H86 cluster in tarp 51 2% Series of tarp tears near inflated tarp area 52 2000 Tarp stake 53 2% Tarp stake (and every tarp stake between 52 and 53) 54 7% Tarp stake (and every tarp stake between 53 and 54) 55 3% Tarp edge 56 800 Broad area of dirt/waste uphill of tarp area 57 8000 2H94 well cluster - all 58 2000 Tarp edge 59 4000 3V89 well cluster in dirt 60 4000 2V113 - well with some tarp wrapped in dirt area 61 800 Valve with well at haul road above cell 5 Latitude 44.70068362 44.70057706 44.7005098 44.69962827 44.69926032 44.69922726 44.69923732 44.69906809 44.69912191 44.69926451 44.69929347 44.69920828 44.69913826 44.6990841 44.69927783 44.69937083 44.69942123 44.69944725 44.69950461 44.69964525 44.69970317 44.69985738 44.69994174 44.70001207 44.70011566 44.7001631 44.70021131 44.7005688 44.70062987 44.70159276 Longitude -123.2267606 -123.2263945 -123.2261782 -123.2287076 -123.2301237 -123.2302603 -123.2303614 -123.2308424 -123.2309496 -123.230824 -123.2310994 -123.2314229 -123.2316593 -123.2318812 -123.2319267 -123.2319 -123.2320147 -123.2316747 -123.2315035 -123.2311715 -123.2309795 -123.2307325 -123.2304609 -123.2302193 -123.2300539 -123.2301332 -123.2296507 -123.2284677 -123.2276513 -123.2253808 All readings are given as methane parts per million, except for readings above 10,000 ppm which are given as percent methane. "F/O" refers to instrument flame out, indicating readings above 5% that have exceeded the TVA measurement range. Page 13 of 14 Calibration and Instrument Information Daniel Heins used a ThermoFisher Toxic Vapor Analyzer 2020 (TVA2020), designated as TVA A95732. The EPA TVA2020 response time is approximately 4.5 seconds. 9:15 calibration check 13:30 drift check 17:50 drift check Calibration gas ppm 500 500 500 A95732 ppm 500 464 462 EPA calibration gases Composition Air zero grade THC <1 ppm Methane in air 500 ppm Lot # DBJ-1-24 1-167-64 Expiration March 2023 June 2024 Background readings: Upwind: 0 ppm Downwind: 3 ppm Map of Detected Exceedances SEM exceedance locations plotted over Google Maps satellite imagery. Approximate monitoring paths included, derived from GPS data. Morning path shown in white, afternoon in black. Line of continuous exceedance at every tarp hole between flags 52 and 54 is highlighted in red. Page 14 of 14