The URL can be used to link to this page

Home My WebLink AboutFinal September 2017 Quarterly Gas Monitoring Rpt - Nantucket Landfill REPORT Summary of Landfill Gas Sampling Results Nantucket Landfill Nantucket, Massachusetts September 2017 75 State Street, Suite 701 Boston, Massachusetts 02109 tel: 617 452-6000 May 2, 2018 Mr. Mark Dakers Massachusetts Department of Environmental Protection Southeast Regional Office 20 Riverside Drive Lakeville, Massachusetts 02347 Subject:Summary of Landfill Gas Sampling September 2017 Nantucket Landfill Nantucket, Massachusetts Dear Mr. Dakers: On September 27, 2017, CDM Smith Inc. (CDM Smith) personnel field analyzed landfill gas samples at the Nantucket Landfill in Nantucket, Massachusetts. The sampling was performed in accordance with the Massachusetts Solid Waste Management Regulations (310 CMR 19.132) and the approved Environmental Monitoring Plan, prepared by SECOR International Inc., in July 1999 for the landfill. Post-closure landfill gas monitoring consisted of sampling 13 landfill gas wells, including LGW-1 through LGW-13 and four landfill gas probes, Probes #1, #2, #3 and #4 as shown on the attached site plan. Each well and location was sampled for methane (CH4) in percent volume and lower explosive limit (LEL), carbon dioxide (CO2), oxygen (O2), using a Landtec GEM 2000 Gas Analyzer; volatile organics using an organic vapor meter (OVM), lamp eV 10.6; and hydrogen sulfide (H2S) using an Interscan1000 Meter. The following summarizes the results of the gas sampling: Methane was detected above the regulatory limit of 25% of the LEL in wells LGW-7 and LGW-9 during this round. The final concentration in LGW-9 was 21.2% by volume, equivalent to 424% of the LEL. Probe #1, Probe #2 and Probe #3 were installed this round since methane was detected in LGW-9. Methane was detected in Probe #1 with a final concentration of 4.8% by volume equivalent to 96% of the LEL. Probe #2 and Probe #3 were both non-detect for methane. Methane was also detected in well LGW-7 this round. The final concentration was 35.9 % by volume equivalent to 718% of the LEL. Probe #4 was installed approximately 80 ft. east of LGW-7 at the property boundary and was non-detect for methane. The regulatory limit is 25% of the LEL at the property boundary or beyond. LGW-7 is located within the property boundary and thus it is not necessary to report exceedances at this monitoring location to MassDEP within the 24-hour notification time frame. Probe #1 Probe #2, Probe #3 and Probe #4 results indicate that methane is not migrating beyond the property boundary. The methane exceedance at LGW-9 was reported Mr. Mark Dakers May 2, 2018 Page 2 within the required 24-hour time period. Appendix D contains a copy of the notification made to MassDEP on September 27, 2017. Carbon dioxide was detected in all monitoring locations with final concentrations ranging from 0.2% to 17.1%. Oxygen was detected in all but two monitoring locations at final concentrations between 3.7% and 20.4%. Hydrogen sulfide was not detected at any monitoring locations. VOCs were not detected at any of the monitoring locations. Prior to the October 2013 sampling round, landfill gas had been consistently detected in monitoring well LGW-9, located on the south side of the site near the compost pad. Subsequently, an adjacent compost pile to LGW-9 was removed which resulted in no landfill gas detected at LGW-9 in sampling rounds conducted during October and December 2013. Since then, the compost pile has increased in size and current sampling results for LGW-9 are generally consistent with pre-2013 concentrations. LGW-7 Gas well is located on the Northeast side of the landfill behind the compost facility. The area to the east of LGW-7 has been mined for sand for use in a new landfill cell. The replacement material was a mixture of cover material and raw compost material. The compost material may be contributing to the methane exceedance at LGW-7. LGW-6 had a small detection of methane. The concentration was 0.4% equivalent to 8% of the LEL. This is within the regulatory 25% in the LEL so it was not reported. This well is also located on the Northeast side on the access road in front of the composting facility. Air monitoring was conducted in the compost facility building in the floor drains, office and bathroom to confirm that gas was not migrating inside. Methane was not detected inside the building. Mr. Mark Dakers May 2, 2018 Page 3 The next sampling round was completed in March 2018. Please do not hesitate to call me at (617) 452-6635 if you have any questions or require additional information. Very truly yours, Mary Mancini, P.E., BCEE Senior Project Manager CDM Smith Inc. Attachments c: Robert D. McNeil, Nantucket Public Works Director Kaitlyn Shaw, Nantucket Whitney Hall, Waste Options File: 1910/78240/03/05/01/2016/September 2017 Appendix A Site Plan Appendix B Sampling Results Summary Tables Table 1 Nantucket LandfillNantucket, MassachusettsLandfill Gas Sampling Summary - September 2017 LEL (%)Initial Final Initial Final Initial Final Initial Final Initial Final Initial FinalLGW-1 Well 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.1 2.0 18.8 18.7 29.77LGW-2 Well 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.4 1.7 19.6 19.1 29.77LGW-3 Well 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 2.0 18.6 18.5 29.77LGW-4 Well 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.2 2.0 18.4 18.6 29.77LGW-5 Well 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 8.9 9.1 3.83.7 29.79LGW-6 Well 9/27/2017 0.0 0.0 0.0 0.0 0.4 0.4 8.0 8.0 16.8 16.7 0.1 0.0 29.79LGW-7 Well 9/27/2017 0.0 0.0 0.0 0.0 35.9 35.9 718.0 718.0 15.2 15.2 0.0 0.0 29.79LGW-8 Well 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.2 18.3 19.8 29.85LGW-9 Well 9/27/2017 0.0 0.0 0.0 0.0 42.8 21.2 856.0 424.0 34.2 17.1 3.3 12.0 29.85Probe-1 Probe 9/27/2017 0.0 0.0 0.0 0.0 5.3 4.8 106.0 96.0 9.38.3 12.5 13.3 29.85Probe-2 Probe 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 6.7 6.88.6 8.0 29.85Probe-3 Probe 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 4.0 2.611.2 15.6 29.85Probe-4 Probe 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.3 0.819.9 20.4 29.79LGW-10 Well 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 1.0 19.6 19.7 29.77LGW-11 Well 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.1 0.9 18.9 19.4 29.77LGW-12 Well 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 2.1 18.8 18.6 29.77LGW-13 Well 9/27/2017 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4 0.4 20.4 20.2 29.85Notes: (1) Probes and wells were purged for approximately 10 minutes before final readings were recorded. (2) Methane, oxygen and carbon dioxide, measured with GEM-2000 combustible gas meter. (3) Volatile Organic Compounds (VOCs) measured with an Organic Vapor Meter (OVM), lamp eV 10.6. (4) Hydrogen Sulfide measured with an Interscan1000 meter. (5) Probe-4 was conducted 80 ft beyond LGW-7 at the property line. (6) Compost Building behind LGW-6 was monitored for gas. No methane was detected inside the building. Gas Monitoring LocationsH2S (ppm)CH4 (% by Vol.)CO2 (%)Barometric Pressure (In. Hg)O2 (%)VOCs (ppmv)Type Date 1910-78240-05-01 Appendix C Landfill Gas Notification to MassDEP 1 Dudley, Emily From:Dudley, Emily Sent:Thursday, September 28, 2017 10:00 AM To:'Mark.Dakers@State.MA.US' Cc:Mancini, Mary; rmcneil@nantucket-ma.gov; Santoro Jr, Frederic; Dolan, Michael Subject:24-hour Landfill Gas Notification - Nantucket Landfill, Nantucket Attachments:Nantucket Landfill Environmental Monitoring Plan 3-13-13.pdf Mark, In accordance with 310 CMR 19.132 (5) (h), CDM Smith on behalf of the Town of Nantucket notifies MassDEP that during landfill gas sampling on September 27, 2017, the concentration of methane gas exceeded 25% of the Lower Explosive Limit (LEL) at one landfill gas well and one probe located to the south-east of the landfill site. The percent of the LEL by volume detected at these locations are as follows: LGW-9 424 % LEL Probe #1 96 % LEL Landfill gas well LGW-9 is located adjacent to Massasoit Bridge Road which is an unpaved narrow path in the southeast corner of the site. An additional probe, Probe #1 was conducted closer to the road and fence line, approximately 6-8 feet away from LGW-9. Gas was detected at 96% of the LEL in Probe #1. Two additional probes were conducted at 10-15 foot intervals away from Probe #1; no gas was detected in these additional probes. These results are consistent with previous sampling rounds. Because the well is so close to the composting pile and approximately several hundred feet from the active landfill, we do not believe the methane detected is from the landfill cell. There are no houses or utilities in this area; it is open land with dense vegetation. Attached is a site plan showing the landfill gas monitoring locations. A report summarizing all the sampling results will be submitted in the next few weeks. Please feel free to call Mary Mancini at 617-452-6635 or me at 617-452-6616 if you have any questions or require any additional information. Emily P. Dudley, P.E. | CDM Smith | 75 State Street, Suite 701 | Boston, MA 02109 | T/F: 617.452.6616 | cdmsmith.com