CORRESPONDENCE_2023-2025 - Laserfiche WebLink

Home Browse Search

Mr. Joyesh Chandra April 11, 2023 Page 2 • For probes more than 20 feet deep, turn on sample pump, extract a minimum of one probe volume, observed and record methane, oxygen, and carbon dioxide gas concentrations, when readings have stabilized for 30 seconds. • Close test valve, disconnect sample instruments and secure sample location. SCS monitored structure vent risers as directed by the County. Other required monitoring documentation (e.g., sampling personnel, date, time and meteorological conditions) is shown on the attached testing data tables. Instrument calibration logs are attached to this report. LFG PERIMETER PROBE TESTING In accordance with the approved testing schedule, all LFG perimeter (compliance) probes are to be tested at a minimum, on a quarterly basis. On March 2 and 27, 2023, all perimeter compliance were tested. Results of the probe testing (Table 1) indicated that all probes exhibited methane gas concentrations below the LEL (5 percent by volume) or no methane gas was detected. SCS will continue to monitor all perimeter monitoring probes quarterly as directed by the County. SCS is scheduled to perform second quarter 2023 monitoring (April through June) of all the probes before the end of the month of June 2023. Note that the evaluation probes are tested semi-annually in conjunction with the VOC testing. On March 2, 2023, SCS performed testing of all evaluation probes which indicated compliance. The next semi-annual monitoring event will be performed by December 31, 2023. STRUCTURES In accordance with the approved testing schedule, the on-site structures are to be tested on a quarterly basis. On March 27, 2023, structures were tested for the presence of methane gas. Test results (Table 2) indicated no methane gas was detected at any structure location tested. SCS is scheduled to perform second quarter 2023 monitoring (April through June) of the structures before the end of the month of June 2023. STANDARD PROVISIONS This report addresses conditions at the subject site during the test dates only. Accordingly, we assume no responsibility for any changes that may occur subsequent to our monitoring which could affect the quantity of LFG at the subject site or adjacent properties.