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Home My WebLink About2021-03-10 Quarterly LF Gas Monitoring Report - December 2020 REPORT Quarterly Landfill Gas Monitoring – December 2020 Nantucket Landfill Nantucket, Massachusetts March 2021 75 State Street, Suite 701 Boston, Massachusetts 02109 tel: 617 452-6000 March 10, 2021 Mr. Mark Dakers Massachusetts Department of Environmental Protection Southeast Regional Office 20 Riverside Drive Lakeville, Massachusetts 02347 Subject: Quarterly Landfill Gas Monitoring – December 2020 Nantucket Landfill Nantucket, Massachusetts Dear Mr. Dakers: On behalf of the Town of Nantucket, CDM Smith Inc. (CDM Smith) collected field analyzed landfill gas samples on December 9, 2020 at the Nantucket Landfill located on Madaket Road in Nantucket, Massachusetts. The quarterly landfill gas sampling was conducted to satisfy the monitoring requirements of the Massachusetts Solid Waste Management Regulations (310 CMR 19.132) and was conducted in accordance with the Environmental Monitoring Plan (EMP) for the Nantucket Landfill, prepared by SECOR International Inc. in July 1999. This report presents the results of the December 2020 quarterly landfill gas monitoring. Landfill Gas Monitoring On December 9, 2020, CDM Smith sampled thirteen (13) landfill gas monitoring wells identified as LGW- 1 through LGW-13 including two landfill gas probes identified as Probe-1 and Probe-2 for the presence of landfill gas. The landfill gas well and probe locations are shown on the Site Plan. The landfill gas monitoring program is conducted to confirm that landfill gas is not migrating off site. For all landfill gas probes sampled, concentrations of methane (CH4), carbon dioxide (CO2), oxygen (O2), hydrogen sulfide (H2S), and atmospheric pressure were obtained using a Landtec GEM 5000 Gas Analyzer. The lower explosive limit (LEL) for methane was calculated based on the methane concentration reading from the GEM 5000. VOC concentrations were obtained using a photoionization detector (PID). Landfill gas wells and temporary landfill gas probes were purged for 10 minutes with the Landtec Gas Analyzer prior to collection of final readings. The results of the landfill perimeter gas monitoring are summarized in Table 1. Methane was not detected at any landfill gas well except for LGW-9 during the December 2020 landfill gas monitoring round. At the start (initial), methane was detected at 84% of the LEL and upon completion of purging (final), methane was detected at 10% of the LEL. Since methane was detected at Mr. Mark Dakers March 10, 2021 Page 2 LGW-9, landfill gas probe-1 and landfill gas probe-2 were installed and sampled approximately 10 feet to the south of LGW-9 and 20 feet to the south of LGW-9, respectively. Methane was not detected at the two landfill gas probe locations. Hydrogen sulfide and VOCs were not detected at any landfill gas sampling locations during this monitoring round. Carbon dioxide was detected at all landfill gas sampling locations, with concentrations ranging from 0.2 to 9.2 percent volume. The results suggest that landfill gas is not migrating off-site including the area adjacent to Massasoit Road where LWG-9 is located. Conclusions and Recommendations Results of the December 2020 landfill gas monitoring are consistent with historical results. The next quarterly landfill gas monitoring round will be conducted in March 2021. In accordance with 310 CMR 19.011 of the Massachusetts Solid Waste Regulations, please find the attached certification of this report by the appropriate responsible official for the Nantucket Landfill in Nantucket, Massachusetts. Please contact Mary Mancini at (617) 452-6635 or Nicholas Castonguay at (617) 452-6721 if you have any questions or require any additional information. Very truly yours, Mary Mancini, P.E. Nicholas Castonguay, P.G. CDM Smith Inc. CDM Smith Inc. Enclosures cc: Robert D. McNeil, Nantucket Public Works Director (electronic) Table 1 Nantucket LandfillNantucket, MassachusettsLandfill Gas Sampling Summary - December 2020 LEL (%)Initial Final Initial Final Initial Final Initial Final Initial Final Initial FinalLGW-1 Well 12/9/2020 0.0 0.0 0.0 0.0 0.8 1.1 20.1 20.0 0.0 0.0 0.0 0.0 29.82LGW-2 Well 12/9/2020 0.0 0.0 0.0 0.0 0.7 1.7 20.4 19.6 0.0 0.0 0.0 0.0 29.81LGW-3 Well 12/9/2020 0.0 0.0 0.0 0.0 1.4 1.5 19.7 19.6 0.0 0.0 0.0 0.0 29.82LGW-4 Well 12/9/2020 0.0 0.0 0.0 0.0 0.6 0.6 20.3 20.2 0.0 0.0 0.0 0.0 29.82LGW-5 Well 12/9/2020 0.0 0.0 0.0 0.0 6.8 6.9 14.6 12.5 0.0 0.0 0.0 0.0 29.81LGW-6 Well 12/9/2020 0.0 0.0 0.0 0.0 9.1 9.2 8.7 8.3 0.0 0.0 0.0 0.0 29.81LGW-7 Well 12/9/2020 0.0 0.0 0.0 0.0 2.9 3.8 16.6 14.9 0.0 0.0 0.0 0.0 29.78LGW-8 Well 12/9/2020 0.0 0.0 0.0 0.0 0.6 0.2 20.4 20.8 0.0 0.0 0.0 0.0 29.78LGW-9 Well 12/9/2020 4.2 0.5 84.0 10.0 6.2 0.7 16.3 20.4 0.0 0.0 0.0 0.0 29.76LGW-10 Well 12/9/2020 0.0 0.0 0.0 0.0 0.7 0.7 20.3 20.1 0.0 0.0 0.0 0.0 29.82LGW-11 Well 12/9/2020 0.0 0.0 0.0 0.0 0.8 0.3 20.2 20.7 0.0 0.0 0.0 0.0 29.82LGW-12 Well 12/9/2020 0.0 0.0 0.0 0.0 1.7 1.7 19.9 19.7 0.0 0.0 0.0 0.0 29.82LGW-13 Well 12/9/2020 0.0 0.0 0.0 0.0 0.2 0.0 20.8 20.9 0.0 0.0 0.0 0.0 29.78Probe-1 Probe 12/9/2020 0.0 0.0 0.0 0.0 1.3 1.1 19.9 19.9 0.0 0.0 0.0 0.0 29.76Probe-2 Probe 12/9/2020 0.0 0.0 0.0 0.0 3.0 3.0 16.6 16.0 0.0 0.0 0.0 0.0 29.76Notes: (1) Landfill gas well and gas probes were purged for approximately 10 minutes before final readings were recorded. (2) Methane (CH4), carbon dioxide (CO2), oxygen (O2) and hydrogen sulfide (H2S) were measured with GEM-5000 combustible gas meter (3) Volatile Organic Compounds (VOCs) measured with a Photoionization Detector (PID), lamp eV 10.6. (4) Landfill gas probe 1 and probe 2 monitor gas migration at LGW-9; LGP-1 is approx 10 feet away from LGW-9; LGP-2 is approximately 20 feet away from LGW-9. LEL = Lower Explosive LimitHg = MercuryGas Monitoring LocationsH2S (ppm)CH4 (% by Vol.)CO2 (%)Barometric Pressure (In. Hg)O2 (%)VOCs (ppmv)Type Date