relative position of the butterfly (well isolation) valves were noted. Adjustments were made to landfill gas flow as required based on landfill gas concentrations. Routine maintenance to the landfill gas collection and control system have been performed based on inspection findings. Additionally, WCDEF personnel implemented vegetative management controls to include removal of woody growth that typically accumulates along access roadways and on the landfill cap, as well as adding aggregate to repair ruts in the access roadways. X:\PROJECTS\WCDEF\190446 - Croton LF Periodic Review Report\2019 PPR Report\2019 PRR rpt 2019-06-14.docx 12 3.8 FLARE/BLOWER STATION SERVICE AND MAINTENANCE On February 23, 2016 and October 25, 2017, preventative maintenance was performed and completed on the enclosed flare by LFG Specialties, LLC. While on site, the service technician observed and determined the enclosed flare system has been adequately maintained and is in good condition. The following recommendations for repairs/modifications to the enclosed flare station based on LFG Specialties observations: • The propane tank needs a 15 PSI regulator at the tank. • The propane regulator at the flare should be set to 3 PSI. • The Thermal Instrument flow meter should be rescaled to 0-450 SCFM and calibrated to current gas readings. Corrective action to the enclosed flare deficiencies that were addressed by WCDEF personnel are as follows: • Purchase and installation of 15 PSI regulator. • Adjustment of propane regulator at the flare. • Recalibration and rescaling of flow meter. Additional activities completed by LFG Specialties, LLC while on-site included: • Check of all safety shutdowns. • Verification of flow meter. • Replacement of pilot gauge. • Replacement of grease for blowers. • Replacement of CPU unit. 3.9 LEACHATE COLLECTION AND CONVEYANCE The leachate system consists of five pump stations and nearly two and a half miles of force mains and gravity sewers. In addition to leachate collection from the Croton Point and Railroad I Landfills, the system also collects and conveys sewage from several sanitary lines connected into the system throughout the park and the Metro North railroad yards. The pump stations were monitored every day and any unusual observations were reported. It should be noted that all of the pumping facilities are tied into a central alarm system, which sends an alarm via telephone to the North Yonkers Pump Station. The central station X:\PROJECTS\WCDEF\190446 - Croton LF Periodic Review Report\2019 PPR Report\2019 PRR rpt 2019-06-14.docx 13 is monitored 24 hours per day, 7 days per week, and is tested weekly. WCDEF Personnel are dispatched in response to any alarm conditions. During the reporting period, WCDEF continued its program of daily pump station inspections (including weekends and holidays) assuring that any unfavorable condition is addressed promptly. All of the stations have an elapsed time meter for each pump, which monitors the pump running time. The elapsed time meter readings are recorded each day and a daily, weekly, and monthly summary is prepared. The daily log report is set up to calculate flows discharged from each station. The daily and monthly Pump Station logs, as described above, are provided (CD-1). Table 1: Total Leachate Flow and Table 2: Daily Average Leachate Flow summarize the monthly total and average flows discharged from this facility, and received at the Ossining Wastewater Treatment Facility, from 2014 through 2018. Table 3: Annual Leachate Flow, summarizes the annual leachate flows over the reporting period. TABLE 1: TOTAL LEACHATE FLOW January 2014 2,806,242 Total Leachate Flow (Gallons) 2015 2016 2017 2,556,300 695 2,996,379 February 1,830,708 1,163,160 March 2,750,448 April 2,575,506 May Month 2018 10,296,381 42,900 2,790,565 4,759,072 2,013,234 93,600 3,380,127 3,820,228 2,725,356 171,063 3,927,210 3,639,962 3,118,266 2,286,336 212,097 5,722,146 3,484,850 June 2,016,192 2,942,004 150,972 4,589,839 2,818,588 July 2,697,426 2,494,278 1,849,800 5,268,927 3,303,699 August 2,123,700 2,215,122 2,669,889 4,444,506 4,790,333 September 1,553,448 3,008,418 2,201,361 4,367,942 3,136,680 October 1,798,842 3,115,398 2,114,175 3,921,294 4,613,669 November 2,113,422 1,890,372 3,639,375 4,252,424 5,544,121 December 3,066,108 2,511,060 3,515,489 4,078,760 4,237,773 X:\PROJECTS\WCDEF\190446 - Croton LF Periodic Review Report\2019 PPR Report\2019 PRR rpt 2019-06-14.docx 14 TABLE 2: DAILY AVERAGE LEACHATE FLOW 2014 Daily Average Leachate Flow (gal/day) 2015 2016 2017 2018 91,963 65,382 88,724 85,850 100,589 67,206 87,014 68,506 51,782 58,027 70,447 98,907 82,461 41,541 64,943 90,845 73,753 98,067 80,461 71,456 100,281 100,497 63,012 81,002 332,141 169,967 123,233 121,332 112,415 93,953 106,571 154,527 104,556 148,828 184,804 136,702 Month January February March April May June July August September October November December 22 1,479 3,019 5,702 6,842 5,032 59,671 86,125 73,379 68,199 121,313 113,403 96,657 99,663 109,036 130,907 184,585 152,995 169,965 143,371 145,598 126,493 141,747 131,573 TABLE 3: ANNUAL LEACHATE FLOW Year 2014 2015 2016 2017 2018 Total Leachate Flow 28,450,308 28,921,038 16,661,417 49,740,120 54,445,356 Daily Average Leachate Flow (gal/day) 77,867 79,027 45,349 136,049 149,086 The total sewage/leachate discharged to the Ossining Wastewater Treatment Facility for the 5-year reporting period was 178,218,239 gallons, which results in a monthly average flow of