(6.3(b)2.ii.) ▪ • CD-ROM Sampling and Well Locations (6.3(b)5.i.) ▪ • Section 3.4; Appendix B Field Data (6.3(b)4.viii.) ▪ • CD – 1; CD-3 Optimization and Performance Problem Resolution (6.3(b)4.vi. and vii.) ▪ • Sections 3.4 through 3.9 Performance Monitoring (6.3(b)4.v.) ▪ • Section 3.8 Routine Maintenance and Inspection (6.3(b)4.iii and iv.) ▪ • Section 3.6 Contaminant Removal (6.3(b)4.ii.) ▪ • Section 3.10 Recommendations for Change (6.3(b)2.iii.) ▪ • Sections 3.2, 3.3, 3.5, 3.6, and 3.8 Figure 2 Change of Use Documentation (6.3(b)6.) X:\PROJECTS\WCDEF\190446 - Croton LF Periodic Review Report\2019 PPR Report\2019 PRR rpt 2019-06-14.docx 10 ▪ • Recommendations for Modification of ECs or ICs (6.3(b)7.) ▪ • Section 3.10 Cumulative Data Summary Contaminants (6.3(b)8.) ▪ • No change of use during this reporting period Tables and/or Graphical Representations of Section 3.3 Inspection Reports (6.3(b)10.) ▪ CD-5 3.2 POST CLOSURE OPERATION PROGRAM The Program covers record keeping relative to the Leachate, Seeps and Landfill Gas Condensate Collection System, as well as the Landfill Gas Collection and Control System. Operating records for the five (5) leachate and condensate pump stations are reflected in the individual Daily Discharge Logs (CD-1), and Summary Monthly Discharge Logs (CD-2). Operating records for the flare are shown in the Flare Data Logs (CD-3). Data for the pump stations and flare are not complied until the end of each year, as such, information for 2019 has not been provided in this Report. 3.3 POST CLOSURE MONITORING AND SAMPLING PROGRAM The Post Closure Monitoring and Sampling Program, in response to the New York State Department of Environmental Conservation (NYSDEC), Record of Decision, provides for a periodic monitoring program designed to detect any changes in the effectiveness of the remedial program. The sampling program examines changes in surface waters, leachate, landfill gases, marsh sediments and stormwater discharges. Results from the sampling program will be used to assess the long-term performance and effectiveness of the closure systems. Details of the requirements of the monitoring and sampling program are described in the Post Closure Care and O&M Manual. 3.4 WORK AND ACTIVITY PERFORMED The most significant work performed for this reporting period includes the addition of the RR1 header near EW-23 to remediate a water collection issue (April 2014) and a new horizontal gas collection well, EW-13A, to assist with the collection of migrating gas (November 2015). These are shown on the site plan, Figure 2. Actions from 2014 through 2018 are included in Appendix B – Work and Activity Performed. X:\PROJECTS\WCDEF\190446 - Croton LF Periodic Review Report\2019 PPR Report\2019 PRR rpt 2019-06-14.docx 11 3.5 GROUNDWATER AND SURFACE WATER MONITORING WCDEF has made a request for a reduction in groundwater sampling from quarterly to once every fifth quarter for the Croton Point Sanitary Landfill. In a letter dated March 31, 2004, the NYSDEC accepted the proposal. In addition, in a letter dated October 29, 2012, the NYSDEC has reduced the sampling frequency for the Railroad I Landfill to once every fifth quarter, and it is to coincide and be performed at the same time as the Croton Point Landfill Sampling. The individual quarterly reports for the above mentioned sampling periods are not included herewith. Each Quarterly Sampling Report was submitted to NYSDEC following each of the specific sampling events. Quarterly sampling was last performed in December 2018, and the next sampling event is scheduled to be conducted in the first quarter of 2020. 3.6 WORK AND ACTIVITY PERFORMED The most significant work performed for this reporting period includes the addition of the RR1 header near EW-23 to remediate a water collection issue (April 2014) and a new horizontal gas collection well, EW-13A, to assist with the collection of migrating gas (November 2015). These are shown on the site plan, Figure 2. Actions from 2014 through 2018 are included in Appendix B – Work and Activity Performed. 3.7 LANDFILL GAS WELL FIELD During the reporting period of May 18, 2014 through May 18, 2019, WCDEF personnel performed landfill site inspections and conducted wellfield monitoring. The landfill gas wells were inspected and observations with respect to the site conditions, groundhog holes, gas leakage and landfill gas control valve box condition. Vacuum pressure readings, methane quality, carbon dioxide and oxygen levels were recorded, and 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