Document JvxjE5B9RrBE53MGnR0vxq0mK

Region 2 Caribbean Environmental Protection Division Multimedia Permits and Compliance Branch Air Protection Team CAA Inspection Report Inspection Date: May 2, 2024 Facility Name: Municipality of Toa Baja Landfill Facility Address: PR-866 Km 1.5 Sec. Candelaria, Toa Baja Puerto Rico EPA Lead Inspector: Alex Rivera, 787-977-5845, rivera.alex@epa.gov EPA Asst. Inspector(s):Gloria Daz-Galarza, 787-977-5882, diaz-galarza.gloria@epa.gov Daniel Heins, 202-565-0070, heins.daniel@epa.gov Steven Rapp, 202-250-8961, rapp.steve@epa.gov Victor Tu, 212-637-3476, tu.victor@epa.gov Katherine Marmanides, 212-637-4063, marmanides.katherine@epa.gov Facility Contact(s): Cynthia B. Otero, Conwaste Environmental Compliance Division, (787) 366-6776, cotero@conwastepr.com; Miguel Sosa, Operations Manager, msosa@conwastepr.com This report is a summary of observations and information gathered from the facility at the time of the inspection. The information provided does not constitute a final decision on compliance with Clean Air Act ("CAA") regulations or applicable permits, nor is it meant to be a comprehensive summary of all activities and processes conducted at the facility. Summary of Onsite Observations A. Opening Conference The representatives of the United States Environmental Protection Agency (USEPA), Alex Rivera, Gloria Diaz-Galarza, Victor Tu, Katherine Marmanides, Steven Rapp, and Daniel Heins arrived at the Municipality of Toa Baja Landfill ("MTL" or "facility") located in PR-866, Km 1.5, Candelaria Sector in Toa Baja, PR. at approximately 9:30 am. The inspectors contacted Ms. Cynthia B. Otero, Conwaste's Environmental Compliance Division via phone. Ms. Otero agreed on joining the inspection at a later time during the day and asked the inspectors to meet Mr. Miguel Sosa, Operations Manager, who was assigned to assist EPA representatives ("the inspectors") during the inspection. The EPA inspectors met with Mr. Sosa, showed credentials and explained the main purpose of the inspection was to conduct surface emission monitoring ("SEM"). The inspectors proceeded with the inspection opening conference, which consisted of a general Page 1 of 5 discussion with Mr. Sosa about the facility operations. The following is a summary of the conversation with Mr. Sosa: 1. Gas collection and control system (GCCS) - Mr. Sosa informed that the facility has 100 landfill gas monitoring regulatory wells, all vertical. Mr. Sosa stated that at the time of the inspection there were eight (8) disconnected landfill gas monitoring wells, all located in the northwest portion of the landfill, which is being used as active area. Mr. Sosa also added that three (3) landfill gas monitoring wells are out for repairs and that all of these wells were disconnected around a week before EPA's inspection and should be placed back in service in approximately a week. 2. Leachate collection - Mr. Sosa indicated that the facility has leachate collection infrastructure located in the southwest portion of the landfill. 3. SEM - Mr. Sosa informed that the facility conducts SEM with in-house personnel and that normally finds three (3) to four (4) leaks per SEM event. EPA informed Mr. Sosa that two (2) Inficon Irwin devices will be used for conducting the SEM inspection and asked about the facility SEM technician availability to join the inspection. Mr. Sosa informed that Mr. Jekser Dvila, GCCS operator/SEM technician, was available to join the inspection. The inspectors also informed Mr. Sosa, that they would capture digital images of the facility wells and any other operation using a digital point and shoot camera and forward-looking infrared camera. 4. Gas to Energy Units - Mr. Sosa informed that the facility has two (2) engines that uses landfill gas to produce the facility power demand. The facility has two (2) flares, two burn the residual landfill gas, each of same capacity. One (1) of the flares is kept in stand-by mode. Mr. Sosa added that the landfill normally produces around 1,000 scfm, but that at the time of the inspection it was producing around 900 scfm due to the series of disconnected wells in the active area. 5. Cover material - Mr. Sosa stated that the facility uses dirt (clay) as daily cover and that approximately 8-12 inches of dirt are applied. Mr. Sosa also informed that no areas within the landfill has final cover. 6. Mr. Sosa also stated that the landfill does not have any closed areas, and that all landfill areas have liner. 7. Safety - Mr. Sosa instructed the inspectors to be wary of heavy trucks transit and slippery conditions during the SEM survey. B. Walkthrough/SEM After completing the opening conference, the inspectors agreed with Mr. Sosa and Mr. Dvila to split in two (2) survey teams, A Survey (Mr. Dvila, Victor Tu, Steven Rapp, Katherine Marmanides and Gloria Diaz-Galarza) and B Survey (Mr. Sosa, Daniel Heins and Alex Rivera). The inspectors agreed with Mr. Sosa on providing a detailed summary of the SEM inspection observations during the inspection closing meeting. The SEM inspection started around 10:15 AM. During the SEM, both survey teams found areas with significant vegetation growth affecting the proper implementation of SEM and cover integrity issues such as exposed waste and erosion gullies creating avenues for gases to migrate through the landfill surface into the atmosphere. Also, both survey teams found 44 locations with surface concentrations of methane over 500 ppm, two (2) greater than 50,000 ppm. The inspectors observed several of the high Page 2 of 5 concentrations measured were from wells that were offline and capped but from which the gas was not being collected. The facility representatives confirmed that their SEM activities rarely find locations with surface concentrations of methane over 500 ppm. The inspectors noted multiple wells bent over with adjacent surface emissions, indicating potential well damage from landfill settlement which could adversely impact gas collection. The inspectors surveyed approximately 32 acres of the eastern of half of the landfill, out of approximately 88 acres of total waste area. After returning to the office/flare station, the inspectors then drove to the leachate riser and tank on the western edge of the landfill. Thick vegetation prevented effective monitoring of the waste area on the west. The inspectors concluded the SEM inspection around 1:50 PM. See Appendix A (SEM Data), Appendix B (SEM Map), Appendix C (Photo Log), Appendix D (Instrument & Calibration Data) and closing meeting discussion summary for further details about the SEM findings and observations. Closing Meeting At approximately 2:00 PM, the inspectors returned to the facility office trailer for a closing conference with Mr. Sosa and Ms. Cynthia Otero, who joined the inspection around noon. As agreed during the inspection opening meeting, the inspectors discussed with Mr. Sosa and Ms. Otero the main findings and observations during the SEM inspection, the following is a summary of the conversation: 1. As confirmed by the facility representatives, its SEM quarterly reports rarely contain SEM methane results over 500 ppm. Although the monitoring activity did not cover the entire extent of the facility SEM plan, the inspectors were able to find 44 different locations with surface concentrations of methane over 500 ppm, some greater than 50,000 ppm. 2. The inspectors informed Mr. Sosa and Ms. Otero that the SEM data along with a map of the survey locations will be shared with them either towards the end of the day or the day after the inspection. The inspectors also indicated that the next facility SEM quarterly report should include the SEM inspection findings and the required corrective actions and that the corrective actions clock will start from the date when EPA shares the SEM data. 3. The inspectors noted that gas collection could be improved, and emphasized on the areas with offline wells, which resulted in elevated surface methane readings, some greater than 50,000 ppm. 4. Mr. Sosa confirmed that the landfill receives around 30,000 tons of waste in a monthly basis and that it has been in operation since the 1980s. 5. Mr. Sosa and Ms. Otero confirmed that the landfill property covers around 213 acres, and that 81 acres are impacted with waste. 6. Cover integrity issues generating avenues for gases to migrate through the landfill surface into the atmosphere. Mr. Sosa indicated that heavy rain events affected their ability to maintain proper coverage. The inspectors further indicated that exposed waste, erosion gullies and unmanaged vegetation observed during the SEM inspection show that not all issues found were a result of the recent rain events. Page 3 of 5 7. SEM inspection findings and walkthrough conversations showed potential lack of SEM training. The inspectors mentioned the lack of sampling all around wells as an example of inadequate SEM implementation. 8. Significant vegetation growth in certain areas of the landfill presents a challenge to properly conduct SEM. 9. The inspectors encouraged the used of practices such as using tarps to cover areas for keeping water from infiltrating the waste, reducing leachate breakouts, and minimizing erosion issues. 10. The coverage conditions observed during the SEM inspection showed that eight (8) inches of daily cover material could not be enough, leaving areas too vulnerable to erosion. Mr. Sosa stated that the facility main challenge has been to obtain consistent quantity and quality of cover material. 11. Mr. Sosa confirmed that the facility has 20 wells with dewatering pumps. 12. Mr. Sosa stated that the facility wells have boot skirts to reduce penetrations leaks and air intrusion. 13. The inspectors recommended to conduct SEM at leachate risers. 14. M. Otero confirmed that Conwaste operates the Fajardo, Mayagez and Carolina municipal landfills. The Carolina and Fajardo Landfills are equipped with GCCS and Mayagez Landfill will have GCCS soon. 15. The inspectors informed about EPA's climate change initiatives focused on landfills methane emissions reduction. 16. Ms. Otero asked the inspectors about the use of drones for conducting SEM. The inspectors confirmed that it could be a good option, but recommended to keep in mind that drones alternative will be limited in vegetated areas such as the ones observed in the landfill. 17. The inspectors also informed Mr. Sosa and Ms. Otero that an inspection report will be prepared and shared with them within approximately 60 days. The inspectors expressed gratitude for all the assistance provided during the inspection and all the cooperation to provide the information needed to complete the inspection. The inspectors concluded the inspection at 2:30 PM. Appendices Appendix A - SEM Data Appendix B - SEM Map Appendix C - Photo Log Appendix D - Instrument & Calibration Data Page 4 of 5 End of Report Lead Inspector's Name: Alex Rivera ALEX RIVERA Digitally signed by ALEX RIVERA Date: 2024.06.14 11:29:14 -04'00' Supervisor's Name: Nancy Rodrguez NANCY Digitally signed by NANCY RODRIGUEZ RODRIGUEZ Date: 2024.06.14 11:41:11 -04'00' Page 5 of 5 Appendix A: SEM Data SEM Exceedances ID Description B1 Exposed waste B2 WH2 B3 Well B4 Erosion rill/exposed waste B5 Slanted well B6 Cushion (exposed waste) Well 48 + Header B7 penetration nearby B8 WH14+exposed waste B9 WH53 B10 Well B11 Well 51 Well 55 header + exposed B12 waste B13 WH71 B14 Exposed waste B15 Exposed waste B16 WH57 B17 WH4? + exposed waste B18 WH46 B19 Tire B20 Cushion (exposed waste) B21 Shallow pit B22 Exposed waste B23 Well by haul road B24 WH33 B25 WH31 B26 WH29 B27 Foam block (exposed waste) B28 WH19 From concrete stormwater conveyance and nearby B29 exposed waste A1 WH1 Leachate breakout with A2 bubbles A3 WH5 A4 WH11 A5 Exposed waste in mud A6 WH50 (capped) A7 Disconnected well Reading (ppm) 1489 2463 773 3000 9401 2280 3200 at header 1383 at wellhead 7206 2263 7087 7716 12727 15748 1474 1017 3330 74713 16863 951 9011 1073 2165 4443 6748 24551 30000 2512 3848 2620 26000 1300 1271 22107 1422 20644 1007 Time 10:31 10:33 10:38 10:42 10:44 10:50 10:52 10:58 11:02 11:04 11:08 11:14 11:27 11:34 11:37 11:39 11:43 11:49 11:55 12:03 12:05 12:07 12:09 12:23 12:27 12:33 12:34 12:36 12:48 10:24 10:40 10:44 10:51 10:55 10:57 11:01 Latitude 18.42239 18.42248 18.42243 18.42215 18.42203 18.42156 18.42179 18.42220 18.42127 18.42138 18.42106 18.42022 18.41958 18.42058 18.42080 18.42100 18.42153 18.42215 18.42186 18.42150 18.42097 18.42071 18.42053 18.42264 18.42310 18.42322 18.42336 18.42358 18.42330 18.42218 18.42182 18.42211 18.42133 18.42094 18.42072 18.42044 Longitude -66.20230 -66.20243 -66.20289 -66.20289 -66.20301 -66.20317 -66.20353 -66.20354 -66.20346 -66.20312 -66.20303 -66.20336 -66.20333 -66.20349 -66.20366 -66.20404 -66.20421 -66.20402 -66.20447 -66.20443 -66.20423 -66.20409 -66.20403 -66.20499 -66.20518 -66.20456 -66.20449 -66.20447 -66.20307 -66.20220 -66.20260 -66.20260 -66.20260 -66.20254 -66.20260 -66.20290 ID Description White capped pipe, at cap A8 and bottom A9 WH75 A10 Pipe into concrete A11 WH79 Capped pipe / exposed A12 waste A14 WH30 hole by well base A15 WH28 A16 WH16 Reading (ppm) 59000 at cap; 38500 at base 8686 3684 850 17952 29578 2141 44254 Time Latitude Longitude 11:05 11:10 11:13 11:22 18.41993 18.41928 18.41882 18.41866 -66.20290 -66.20300 -66.20260 -66.20370 11:30 12:21 12:34 12:39 18.41921 18.42262 18.42320 18.42313 -66.20359 -66.20430 -66.20406 -66.20366 Exceedances in the B survey were detected using the R2 IRwin by Dan Heins and Alex Rivera. Exceedances in the A survey were detected using the AED IRwin by Steven Rapp, Victor Tu, Katherine Marmanides and Gloria Diaz-Galarza. Probe tips were fixed on hiking poles 8 cm from the base of the pole, all readings taken from 8 to 10 cm from the ground with the exception of the secondary reading at A8 measuring gas leaking from the pipe cap. Background readings: Upwind: 0 ppm Downwind: 0 ppm 44 exceedances total: 500 - 1,000 ppm: 3 1,000 - 5,000: 21 5,000 - 10,000: 7 10,000 - 50,000: 11 50,000 - 100,000: 2 Appendix B: SEM Map Blue and red lines trace each team's monitoring path. Exceedances are plotted and labeled as described in Appendix B. The primary surveys covered approximately 32 acres on the eastern half of the landfill (with some gaps in that area, as depicted), in addition to approximately 175 meters on the western perimeter, including the leachate riser, with minimal survey over the waste mass on that side. Appendix C: Photo Log for Municipality of Toa Baja Landfill, Toa Baja, PR Facility Address: PR-866, Km. 1.5, Candelaria Sector, Toa Baja PR EPA Inspectors: Alex Rivera, Gloria Diaz-Galarza, Daniel Heins, Steven Rapp, Katherine Marmanides, and Victor Tu Image numbers: P5020001 through P5020035 (B Survey Team) and P5020065 through P5020084 (A Survey Team) Camera(s) Used: Olympus TG-6 Digital Cameras Image Number 1 File Name P5020001.JPG Descripon Date Taken 5/2/2024 Time taken 1032 Exposed waste 2 P5020002.JPG 5/2/2024 1035 Landfill gas monitoring well #2 Appendix C Municipality of Toa Baja Landfill Inspecon Report 1 3 P5020003.JPG 5/2/2024 1036 Exposed waste 4 P5020004.JPG 5/2/2024 1044 Exposed waste Appendix C Municipality of Toa Baja Landfill Inspecon Report 2 5 P5020005.JPG 5/2/2024 1046 Slanted unidenfied landfill gas monitoring well 6 P5020006.JPG 5/2/2024 1051 Exposed waste Appendix C Municipality of Toa Baja Landfill Inspecon Report 3 7 P5020007.JPG 5/2/2024 1053 Landfill gas monitoring well #48 header pipe penetraon 8 P5020008.JPG 5/2/2024 1056 Exposed waste Appendix C Municipality of Toa Baja Landfill Inspecon Report 4 9 P5020009.JPG 5/2/2024 1100 Landfill gas monitoring well #14 10 P5020010.JPG 5/2/2024 1104 Landfill gas monitoring well #53 Appendix C Municipality of Toa Baja Landfill Inspecon Report 5 11 P5020011.JPG 5/2/2024 1106 Slanted unidenfied landfill gas monitoring well 12 P5020012.JPG 5/2/2024 1109 Landfill gas monitoring well #51 Appendix C Municipality of Toa Baja Landfill Inspecon Report 6 13 P5020013.JPG 5/2/2024 1110 Exposed waste 14 P5020014.JPG 5/2/2024 1115 Exposed waste Appendix C Municipality of Toa Baja Landfill Inspecon Report 7 15 P5020015.JPG 5/2/2024 1116 Leachate breakout 16 P5020016.JPG 5/2/2024 1129 Landfill gas monitoring well #71 Appendix C Municipality of Toa Baja Landfill Inspecon Report 8 17 P5020017.JPG 5/2/2024 1136 Exposed waste 18 P5020018.JPG 5/2/2024 1138 Exposed waste Appendix C Municipality of Toa Baja Landfill Inspecon Report 9 19 P5020019.JPG 5/2/2024 1140 Landfill gas monitoring well #57 20 P5020020.JPG 5/2/2024 1142 Exposed waste Appendix C Municipality of Toa Baja Landfill Inspecon Report 10 21 P5020021.JPG 5/2/2024 1145 Landfill gas monitoring well #40 22 P5020022.JPG 5/2/2024 1150 Landfill gas monitoring well #46 Appendix C Municipality of Toa Baja Landfill Inspecon Report 11 23 P5020023.JPG 5/2/2024 1159 Exposed waste 24 P5020024.JPG 5/2/2024 1204 Exposed waste Appendix C Municipality of Toa Baja Landfill Inspecon Report 12 25 P5020025.JPG 5/2/2024 1206 Exposed waste 26 P5020026.JPG 5/2/2024 1208 Exposed waste Appendix C Municipality of Toa Baja Landfill Inspecon Report 13 27 P5020027.JPG 5/2/2024 1210 Unidentified landfill gas monitoring well by active area haul pad 28 P5020028.JPG 5/2/2024 1224 Landfill gas monitoring well #33 Appendix C Municipality of Toa Baja Landfill Inspecon Report 14 29 P5020029.JPG 5/2/2024 1228 Landfill gas monitoring well #31 30 P5020030.JPG 5/2/2024 1233 Landfill gas monitoring well #29 Appendix C Municipality of Toa Baja Landfill Inspecon Report 15 31 P5020031.JPG Exposed waste 32 P5020032.JPG 5/2/2024 1235 5/2/2024 1237 Landfill gas monitoring well #19 Appendix C Municipality of Toa Baja Landfill Inspecon Report 16 33 P5020033.JPG 5/2/2024 1249 Exposed waste by stormwater collection concrete culvert 34 P5020034.JPG 5/2/2024 1251 Leachate breakouts Appendix C Municipality of Toa Baja Landfill Inspecon Report 17 35 P5020035.JPG Leachate breakouts 36 P5020065.JPG 5/2/2024 1252 5/2/2024 1028 Landfill gas monitoring well #1 Appendix C Municipality of Toa Baja Landfill Inspecon Report 18 37 P5020066.JPG 5/2/2024 1035 Exposed waste 38 P5020067.JPG 5/2/2024 1040 Leachate breakout/waterfall with bubbles Appendix C Municipality of Toa Baja Landfill Inspecon Report 19 39 P5020068.JPG 5/2/2024 10:46 Landfill gas monitoring well #5 40 P5020069.JPG 5/2/2024 1049 Exposed waste (apparent electronic waste) Appendix C Municipality of Toa Baja Landfill Inspecon Report 20 41 P5020070.JPG Landfill gas monitoring well #11 42 P5020071.JPG 5/2/2024 1053 5/2/2024 1055 Exposed waste (northeast portion) Appendix C Municipality of Toa Baja Landfill Inspecon Report 21 43 P5020072.JPG 5/2/2024 1057 Landfill gas monitoring well #50 (capped) 44 P5020073.JPG 5/2/2024 1102 Unidentified landfill gas monitoring well Appendix C Municipality of Toa Baja Landfill Inspecon Report 22 45 P5020074.JPG 5/2/2024 1106 Unidentified landfill gas monitoring well (capped) 46 P5020075.JPG 5/2/2024 1110 Landfill gas monitoring well #75 Appendix C Municipality of Toa Baja Landfill Inspecon Report 23 47 P5020076.JPG 5/2/2024 1110 Landfill gas monitoring well #75 48 P5020077.JPG 5/2/2024 1113 Landfill gas collection pipeline (side of access road) Appendix C Municipality of Toa Baja Landfill Inspecon Report 24 49 P5020078.JPG 5/2/2024 1123 Landfill gas monitoring well #79 50 P5020079.JPG 5/2/2024 1130 Unidentified landfill gas monitoring well (capped) Appendix C Municipality of Toa Baja Landfill Inspecon Report 25 51 P5020080.JPG 5/2/2024 1135 Landfill gas monitoring well #68 52 P5020081.JPG 5/2/2024 1216 Landfill gas monitoring well #46 Appendix C Municipality of Toa Baja Landfill Inspecon Report 26 53 P5020082.JPG 5/2/2024 1223 Landfill gas monitoring well #30 54 P5020083.JPG 5/2/2024 1234 Landfill gas monitoring well #28 Appendix C Municipality of Toa Baja Landfill Inspecon Report 27 55 P5020084.JPG 5/2/2024 1239 Landfill gas monitoring well #16 Appendix C Municipality of Toa Baja Landfill Inspecon Report 28 Appendix D: Instrument and Calibration Data The survey was conducted using two Inficon IRwin devices using the Elkins Earthworks software. They are referred to throughout this report as the "AED IRwin" and the "R2 IRwin" Instrument Information Instrument Type AED IRwin Inficon IRwin R2 IRwin Inficon IRwin Formal Identifier SX # 580-01092006439 SX # 580-01092005497 Calibration Checks Date/Time 2024-05-02 08:55 2024-05-02 15:15 Gas Concentration (ppm) 500 500 R2 IRwin Reading (ppm) 500 400 AED IRwin Reading (ppm) 500 450 Both instruments were calibrated according to Method 21 and manufacturer instructions with zero gas and 500 ppm methane. Bump checks were conducted before and after the survey. Pre-survey bump checks show successful calibration. Post-survey bump check shows downward drift, possibly resulting in false negatives (ie, missed exceedances) and potential underestimation of the severity of measured exceedances. Response Time and Precision Check R2 IRwin Trial Calibration Gas ppm Reading (ppm) 1 500 500 2 500 500 3 500 490 Time (s) 5 5 4 AED IRwin Reading (ppm) 500 500 500 Time (s) 5 4 5 Both instruments were calibrated and checked for response time and precision on April 30, 2024 at 10:00 AM using zero air and 500 ppm methane. All readings are within 10% of the known calibration value. Response times are approximately 4-5 seconds, under the maximum of 30 seconds. Calibration Gas Composition Zero air <1 ppm total hydrocarbon 500 ppm methane in air Manufacturer Airgas Airgas Lot Number 304-402941563-1 304-402960982-1 Expiration Date 2/23/2028 2/2/2028 These were used for the calibration and bump checks on May 2, 2024 for the inspection and during the response time and precision checks on April 30, 2024.