The URL can be used to link to this page

Home My WebLink About2017 1st FIRST SEMIANNUAL REPORT OF 2017 TOWN OF SOUTHOLD LANDFILL POST CLOSURE GROUNDWATER MONITORING PROGRAM Prepared for: TOWN OF SOUTHOLD SOLID WASTE MANAGEMENT DISTRICT CUTCHOGUE, SUFFOLK COUNTY, NEW YORK Prepared by: D&B ENGINEERS AND ARCHITECTS, P.C WOODBURY, NEW YORK JULY 2017 3753\\NN07191701_SoutholdGWrpt FIRST SEMIANNUAL REPORT OF 2017 TOWN OF SOUTHOLD LANDFILL POST CLOSURE GROUNDWATER MONITORING PROGRAM TABLE OF CONTENTS Section Title Page 1.0 INTRODUCTION....................................................................................................... 1-1 2.0 SAMPLING PROCEDURES AND ANALYSES .................................................... 2-1 2.1 Groundwater Level Measurement Procedures .................................................. 2-1 2.2 Groundwater Sampling Procedures .................................................................. 2-1 2.3 Sample Analyses ............................................................................................... 2-3 3.0 GROUNDWATER LEVEL MEASUREMENTS .................................................... 3-1 4.0 DISCUSSION OF RESULTS .................................................................................... 4-1 4.1 Data Validation ................................................................................................. 4-1 4.2 Groundwater Results ......................................................................................... 4-2 4.2.1 Field Parameters ................................................................................... 4-2 4.2.2 Volatile Organic Compounds ............................................................... 4-3 4.2.3 Inorganic Parameters (Metals) .............................................................. 4-4 4.2.4 Leachate Indicators ............................................................................... 4-5 5.0 CONCLUSIONS AND RECOMMENDATIONS ................................................... 5-1 List of Appendices Groundwater Analytical Results ...................................................................................A Groundwater Sampling Logs ........................................................................................B Chain of Custody Forms ...............................................................................................C Data Validation Check List ..........................................................................................D 3753\\NN07191701_SoutholdGWrpt i TABLE OF CONTENTS (continued) List of Figures 1-1 Site Location Map .............................................................................................1-2 2-1 Groundwater Monitoring Well Location Map ..................................................2-2 List of Tables 3-1 Groundwater Level Data June 11, 2017 .......................................................3-2 3753\\NN07191701_SoutholdGWrpt ii 1.0 INTRODUCTION The Town of Southold has retained D&B Engineers and Architects, P.C. (D&B) to perform post-closure groundwater monitoring and reporting for the closed and capped municipal solid waste (MSW) landfill in Cutchogue, New York (i.e. the Site). The location of the Site is shown in Figure 1-1. This report is for the First Semiannual 2017 groundwater monitoring event, conducted on June 11, 2017 and describes the work performed and the results obtained. The groundwater monitoring wells were sampled in strict conformance with the Quality Assurance/Quality Control (QA/QC) Plan, which is part of the Post Closure Monitoring and Maintenance Manual, dated August 2003. In the past, groundwater sampling was performed quarterly with three rounds analyzed for New York Codes, Rules and Regulations (NYCRR) Part 360 Routine Parameters and one round analyzed for 6NYCRR Part 360 Baseline Parameters on a rotating basis. In the Spring of 2015, on behalf of the Town of Southold, D&B proposed modifications to the New York State Department of Environmental Conservation (NYSDEC) pertaining to the sampling frequency and analyses for the Post-Closure Groundwater Monitoring Program for the Site. The request for these modifications was approved by the NYSDEC on July 2, 2015. Commencing with the Second Semiannual 2015 groundwater monitoring event, modifications to the Post-Closure Groundwater Monitoring Program included: A reduction in sampling frequency from quarterly to semiannually for all well clusters (MW-1, MW-3, MW-4, MW-5, MW-6 and MW-8); and Groundwater analysis for 6NYCRR Part 360 Baseline Parameters for both semiannual sampling events. This report is organized into the following sections: Section 2.0 (Sampling Procedures and Analyses) describes the water level measurements and groundwater sampling procedures, as well as the groundwater analyses. Section 3.0 (Groundwater Level Measurements) summarizes 3753\\NN07191701_SoutholdGWrpt 1-1 Long Island NN Sound Southold 48 25 Great Peconic Bay SOUTHOLD LANDFILL CUTCHOGUE, NEW YORK SITE LOCATION MAP Figure 1-1 3753 -Site Location Map.indd (04/29/16 - 2:54 PM) the groundwater level measurements and groundwater elevations. Section 4.0 (Discussion of Results) summarizes the key findings from this groundwater monitoring event, including comparison of the laboratory results to NYSDEC Class GA Groundwater Standards and Guidance Values. Section 5.0 (Conclusions and Recommendations) provides conclusions and recommendations based on the first semiannual 2017 results. 3753\\NN07191701_SoutholdGWrpt 1-3 2.0 SAMPLING PROCEDURES AND ANALYSES monitoring wells (MW-1S, MW-1D, MW-3S, MW-3D, MW-4S, MW-4D, MW-5S, MW-5D, MW-6S, MW-6D, MW-8S and MW-8D) on June 11, 2017 as part of the First Semiannual 2017 groundwater monitoring event. A site plan showing the locations of the monitoring wells is provided in Figure 2-1. The following sections provide a brief discussion of the procedures used during groundwater level measurements, groundwater sampling and sample analysis. 2.1 Groundwater Level Measurement Procedures Prior to sampling, water level measurements were obtained from the 12 monitoring wells to determine the volume of standing water in the well for purposes of purging, as well as for determination of groundwater elevations and flow direction. Groundwater level measurements were obtained from a surveyed measuring point on each well utilizing a decontaminated electronic water level indicator to an accuracy of 0.01 foot. A discussion regarding groundwater level measurements and groundwater flow direction is provided in Section 3.0. 2.2 Groundwater Sampling Procedures Sampling procedures for the collection of the groundwater samples were implemented in accordance with the protocol described in the Quality Assurance/Quality Control (QA/QC) Plan, which is part of the Post Closure Monitoring and Maintenance Manual, dated August 2003. Field decontamination was performed between sampling locations for non-disposable equipment. Prior to collecting groundwater samples, the 12 monitoring wells were purged to remove the standing water in the well. Well purging was accomplished by first measuring the static water level in the well and calculating the volume of standing water. A decontaminated submersible pump was used to purge the water from the well. Decontamination of the submersible pump used for well purging was performed in accordance with the procedure described in the QA/QC Plan. 3753\\NN07191701_SoutholdGWrpt 2-1 During the purging process, groundwater was monitored and recorded for the following field parameters: pH, temperature, specific conductance, oxidation reduction potential (ORP), dissolved oxygen and turbidity. When the values of the field parameters stabilized within 10% based on the last two readings, the turbidity of the groundwater was less than 50 Nephelometric Turbidity Units (NTUs) and at least three well volumes had been removed, well purging was considered complete. In accordance with the QA/QC Plan, groundwater samples were collected using new, dedicated, disposable polyethylene bailers and polypropylene rope. Samples for VOC analysis were collected first, followed by inorganic parameters and leachate indicators. Each sample was labeled with the well number, time and date, and stored in an ice-filled cooler with the chain of custody forms and shipped to the laboratory (ALS Environmental). Appropriate quality assurance/quality control (QA/QC) samples, which included matrix spike and matrix spike duplicate (MS/MSD) sets and a trip blank were collected in accordance with the QA/QC Plan. Tables summarizing the analytical results are provided in Appendix A and discussed in Section 4.0. Groundwater sampling logs for the First Semiannual 2017 groundwater monitoring event are provided in Appendix B, and the chain of custody forms are provided in Appendix C. 2.3 Sample Analyses Groundwater samples collected during the First Semiannual 2017 groundwater monitoring event from the 12 monitoring wells were analyzed for 6NYCRR Part 360 Baseline Parameters. Laboratory analyses were performed by ALS Environmental, located in Rochester, New York. This laboratory is approved under the New York State Department of Health Environmental Laboratory Approval Program (ELAP) for the analyses performed. 3753\\NN07191701_SoutholdGWrpt 2-3 3.0 GROUNDWATER LEVEL MEASUREMENTS Groundwater level measurements were collected by D&B on June 11, 2017, from the 12 groundwater monitoring wells as part of the First Semiannual 2017 groundwater monitoring event. The groundwater level measurements from the monitoring wells are summarized in Table 3-1. As shown in Table 3-1, water ranged from 7.06 feet above mean sea level (MSL) in well MW-1S, located on the south end of the Site, to 4.91 feet above MSL in well MW-8S, located on the west side of the Site. Well MW-8S exhibits a lower water table elevation in comparison to the closest shallow wells MW-4S and MW-6S. The lower water table elevation at well MW-8S may be due to reduced groundwater recharge in close proximity to the capped landfill. Based upon the June 11, 2017 groundwater level measurements and calculated water table elevations, groundwater flow direction was determined to be in a north-northwesterly direction. Therefore, well cluster MW-1 is located upgradient of the Site, and the other wells are located along the downgradient boundary of the Site. the shallow well water table elevations, except for well MW-8D, and indicate virtually no vertical hydraulic gradient throughout the landfill site. An upward vertical hydraulic gradient is indicated at well cluster MW-8, due to the lower water table elevation. 3753\\NN07191701_SoutholdGWrpt 3-1 Table 3-1 SOUTHOLD LANDFILL FIRST SEMIANNUAL 2017 GROUNDWATER MONITORING EVENT MONITORING WELL GROUNDWATER ELEVATION MEASUREMENTS JUNE 11, 2017 Measuring Point Depth to Water from Elevation Measuring Point Groundwater Elevation Well Designation (feet above msl) (feet) (feet above msl) 37.77 7.06 MW-1S 44.83 MW-1D 37.70 7.18 44.88 MW-3S 43.45 6.05 49.50 MW-3D 43.13 6.06 49.19 MW-4S 57.45 5.58 63.03 MW-4D 57.35 5.57 62.92 MW-5S 62.55 5.59 68.14 MW-5D 62.10 5.54 67.64 MW-6S 49.65 6.12 55.77 49.61 6.10 MW-6D 55.71 49.25 4.91 MW-8S 54.16 48.01 7.28 MW-8D 55.29 3753\\NN07191701_SoutholdGWrpt 3-2 4.0 DISCUSSION OF RESULTS 4.1 Data Validation Twelve groundwater samples and one trip blank were collected on June 11, 2017 as part of the First Semiannual 2017 groundwater monitoring event performed at the Town of Southold Landfill. All samples were analyzed for the 6NYCRR Part 360 Baseline Parameters, including volatile organic compounds (VOCs), inorganic parameters (metals) and leachate indicators. Sample analysis was performed in accordance with SW-846 methods. The laboratory analyses were performed by ALS Environmental, located in Rochester, New York and reported in data package R1705362. The data package submitted by the analytical laboratory was validated in accordance with NYSDEC quality assurance/quality control (QA/QC) requirements, the contract requirements and Part 360. All samples were analyzed within the method specified holding times except where noted below. The following requirements were outside limits and required qualification of the data: Acetone was detected in the trip blank and was qualified as non-detect (UB) in all groundwater samples. Biochemical oxygen demand and hexavalent chromium were analyzed outside holding times in all groundwater samples, and were qualified as estimated (J/UJ). Nitrate was analyzed outside holding time in groundwater samples MW-3S, MW-3D and MW-6D. Color was analyzed outside holding time in groundwater samples MW- 3S, MW-3D, MW-6S, MW-6D, MW-8S and MW-8D. Nitrate and color were qualified as estimated (J/UJ) for these samples. The percent recovery (%R) was below the QC limit for hexavalent chromium and chemical oxygen demand in the matrix spike (MS) and matrix spike duplicate (MSD) associated with all groundwater samples. These compounds were qualified as estimated (J/UJ) for all samples. The %R was above the QC limit for nitrate in the MS and MSD associated with all groundwater samples. Nitrate was qualified as estimated (J) where detected. 3753\\NN07191701_SoutholdGWrpt 4-1 No other issues were found with the sample results and all results are deemed valid and usable for environmental assessment purposes as qualified above. Data validation checklists completed for the First Semiannual 2017 groundwater monitoring event conducted on June 11, 2017 are provided in Appendix D. 4.2 Groundwater Results The laboratory results for the First Semiannual 2017 groundwater monitoring event are summarized on Table A-1 through Table A-3 in Appendix A and compared to the New York State Department of Environmental Conservation Ambient Water Quality Standards and Guidance Values for Class GA groundwater (herein referred to as the Class GA groundwater standards and guidance values). Table A-1 provides the volatile organic compound (VOC) results, Table A-2 the inorganic parameters (metals) results and Table A-3 the leachate indicator results. Field parameters measured during the groundwater purging process are presented on the groundwater sampling logs in Appendix B. A discussion of the field parameters and each analytical parameter group is provided below. 4.2.1 Field Parameters A review of the field parameters for the groundwater samples collected from each well, provided on the groundwater sampling logs in Appendix B, indicates the following key findings: Conductivity values were highest in deep wells located downgradient of the Site, including wells MW-3D, MW-4D, MW-5D and MW-8D. The high conductivity values appear to be Site-related. There is no Class GA standard or guidance value for conductivity. Groundwater temperatures were approximately 1 to 2 degrees Celsius higher in 7 of the 10 downgradient wells relative to the upgradient wells. The highest temperatures were recorded in well clusters MW-3, MW-4 and MW-8. There is no Class GA standard or guidance value for temperature. pH was lower than the minimum Class GA groundwater standard of 6.5 in upgradient well MW-1S and in 6 of the 10 downgradient wells. The results are consistent with the naturally low pH of Long Island groundwater. Groundwater pH was typically higher in the deep well at each well cluster, including the upgradient deep well. 3753\\NN07191701_SoutholdGWrpt 4-2 Dissolved Oxygen (DO) concentrations were generally lower in the downgradient wells relative to upgradient wells. DO concentrations in the downgradient wells ranged between 0.61 mg/l at deep well MW-4D to a maximum of 6.47 mg/l at shallow well MW-5S. The concentrations in upgradient wells MW-1S and MW-1D were 8.70 mg/l and 2.47 mg/l, respectively. There is no Class GA standard or guidance value for DO. The Oxidation-Reduction Potential (ORP) of groundwater was positive in both upgradient wells and well clusters MW-4, MW-5 and MW-6 indicating oxidizing conditions; and negative in well clusters MW-3 and MW-8 indicating reducing conditions. There is no Class GA standard or guidance value for ORP. In general, the groundwater samples collected from the 12 Site monitoring wells were observed to be clear, and did not have a noticeable odor. A slight sulfur odor was noted in deep well MW-3D. Light non-aqueous phase liquid (LNAPL) or dense non-aqueous phase liquid (DNAPL) was not noted in any of the groundwater samples collected from the 12 Site monitoring wells. Overall, the field parameter results obtained during the First Semiannual 2017 groundwater monitoring event are consistent with previous sampling events indicating some leachate impacts typical of a closed municipal solid waste (MSW) landfill. The leachate-related impacts are relatively minor in magnitude and limited to higher conductivity and temperature, and lower DO and ORP in certain downgradient wells. 4.2.2 Volatile Organic Compounds Review of the VOC results provided on Table A-1 in Appendix A indicates the following key findings: VOCs were not detected in upgradient well cluster MW-1. Four out of the ten downgradient monitoring wells (shallow well MW-3S and deep wells MW-4D, MW-5D and MW-8D) exhibited several VOCs at concentrations marginally above Class GA groundwater standards, including: 1,2,3-trichloropropane in MW-3S; 1,2-dichloroethane (1,2-DCA) and 1,2-dichloropropane in MW-4D and MW-8D; and 1,2-dichloropropane and chlorobenzene in MW-5D. 3753\\NN07191701_SoutholdGWrpt 4-3 The highest detected VOC concentration was chlorobenzene in MW-5D at a concentration of 9.5 ug/l, above the Class GA groundwater standard of 5 ug/l. In general, the VOC results for the First Semiannual 2017 groundwater monitoring event are consistent with previous sampling events. Based on these results, the Site is not a significant source of VOC contaminants to the groundwater. 4.2.3 Inorganic Parameters (Metals) Review of the inorganic parameter (metals) results provided on Table A-2 in Appendix A indicates the following key findings: Iron, magnesium, manganese and sodium were detected above Class GA groundwater standards/guidance values in one or more downgradient wells. Inorganic parameters were not detected above Class GA groundwater standards/guidance values in upgradient wells. Iron was detected above the Class GA groundwater standard of 300 ug/l in 5 downgradient wells (MW-3S, MW-3D, MW-4D, MW-8S and MW-8D). These iron concentrations ranged from 309 ug/l at MW-4D to a maximum of 104,000 ug/l detected in shallow well MW-3S. Magnesium was detected above the Class GA guidance value of 35,000 ug/l in downgradient deep well MW-4D at a concentration of 60,700 ug/l. At each well cluster, higher magnesium concentrations occurred in the deep well, which suggests that the detected magnesium concentrations may be partly associated with naturally saline groundwater conditions at depth. Manganese was detected above the Class GA groundwater standard of 300 ug/l in 9 of the 10 downgradient wells (MW-3S, MW-3D, MW-4S, MW-4D, MW-5D, MW- 6S, MW-6D, MW-8S and MW-8D). Manganese concentrations in these wells ranged between 522 ug/l at MW-8S to a maximum of 11,100 ug/l at deep well MW-5D. Sodium was detected above the Class GA groundwater standard of 20,000 ug/l in 6 downgradient wells (MW-3S, MW-3D, MW-4D, MW-5D, MW-8S and MW-8D). Sodium concentrations in these wells ranged between 20,900 ug/l at MW-8S to a maximum of 188,000 ug/l at deep well MW-4D. At each well cluster, higher sodium concentrations occurred in the deep well, which suggests that the detected sodium concentrations may be partly associated with naturally saline groundwater conditions at depth. 3753\\NN07191701_SoutholdGWrpt 4-4 In general, the inorganic parameter results for the First Semiannual 2017 groundwater monitoring event are consistent with previous sampling events indicating some leachate impacts typical of a closed MSW landfill. Groundwater in the North Fork of Long Island is also naturally saline at depth, which may contribute to the higher concentrations of some inorganic parameters observed in the deep wells. 4.2.4 Leachate Indicators Review of the leachate indicator results provided on Table A-3 in Appendix A indicates the following key findings: Ammonia, chloride, nitrate and phenols were detected above Class GA groundwater standards in one or more downgradient wells. Leachate indicators were not detected above Class GA groundwater standards/guidance values in upgradient wells. Ammonia was detected above the Class GA groundwater standard of 2 mg/l in 6 downgradient monitoring wells (MW-3S, MW-3D, MW-4D, MW-5D, MW-8S and MW-8D). Ammonia concentrations in these wells ranged between 7.39 mg/l at MW-3S to a maximum of 78.8 mg/l at deep well MW-5D. Chloride was detected above the Class GA groundwater standard of 250 mg/l in downgradient deep well MW-4D at a concentration of 282 mg/l. The higher chloride concentrations in the deep wells may be due in part to naturally saline groundwater conditions at depth. Nitrate was detected above the Class GA groundwater standard of 10 mg/l in downgradient shallow well MW-4S at a concentration of 22.4 mg/l. Phenols were detected above the Class GA groundwater standard of 0.001 mg/l in downgradient deep wells MW-3D (0.0062 mg/l), MW-4D (0.0073 mg/l) and MW-5D (0.0073 mg/l). In general, the leachate indicator results for the First Semiannual 2017 groundwater monitoring event are consistent with previous sampling events indicating some leachate impacts typical of a closed MSW landfill. Groundwater in the North Fork of Long Island is also naturally saline at depth, which may contribute to the higher concentrations of some leachate indicators observed in the deep wells. 3753\\NN07191701_SoutholdGWrpt 4-5 5.0 CONCLUSIONS AND RECOMMENDATIONS Based on the results of the First Semiannual 2017 groundwater monitoring event, D&B concludes the following: Water level elevations, horizontal and vertical hydraulic gradients, and groundwater flow directions are consistent with previous results and local/regional hydrogeologic conditions. In general, groundwater quality is consistent with previous results indicating some downgradient leachate impacts typical of a closed MSW landfill. Some of the elevated concentrations detected in downgradient deep wells may be related in part to naturally saline groundwater conditions at depth. The NYSDEC has previously scope and frequency of post-closure monitoring to semiannually for Part 360 Baseline Parameters. The First Semiannual 2017 results discussed in this report are generally consistent with previous sampling events and do not indicate any significant changes or deterioration in groundwater quality that would warrant a change in the scope of the monitoring program. Therefore, the monitoring reduction approved by NYSDEC should be continued. The next monitoring round (Second Semiannual 2017 groundwater monitoring event) is scheduled to be conducted in December 2017 for Part 360 Baseline Parameters. 3753\\NN07191701_SoutholdGWrpt 5-1 APPENDIX A GROUNDWATER ANALYTICAL RESULTS 3753\\NN07191701_SoutholdGWrpt 2/4!K 4/5!K 7/8 Fydffet!Dmbtt!HB!Tuboebse0Hvjebodf!Wbmvf \\\\dbfs1\\Jobs\\_HazWaste\\3753 (Southold Landfill)\\1st 2017 GW Report\\1ST_2017 2/2!K 3/6!K2/3!K :/6 Fydffet!Dmbtt!HB!Tuboebse0Hvjebodf!Wbmvf \\\\dbfs1\\Jobs\\_HazWaste\\3753 (Southold Landfill)\\1st 2017 GW Report\\1ST_2017 2151113791141:3:61122211 71811 3751264124714:7122211322125516332831 36:118881129911122711131:1171711 Fydffet!Dmbtt!HB!Tuboebse0Hvjebodf!Wbmvf \\\\dbfs1\\Jobs\\_HazWaste\\3753 (Southold Landfill)\\1st 2017 GW Report\\1ST_2017 393 8/4:66/72:/889/928/:26/5 33/5!K 1/11731/11841/1184 Fydffet!Dmbtt!HB!Tuboebse0Hvjebodf!Wbmvf \\\\dbfs1\\Jobs\\_HazWaste\\3753 (Southold Landfill)\\1st 2017 GW Report\\1ST_2017 APPENDIX B GROUNDWATER SAMPLING LOGS 3753\\NN07191701_SoutholdGWrpt APPENDIX C CHAIN OF CUSTODY FORMS 3753\\NN07191701_SoutholdGWrpt 0 z 10 10 10 10 10 10 10 10 10 10 t-jYG-(JJL /) R17053625 Qbhf!24!pg!2965 10 Jd 10 0C )N\\.10 10 10 R17053625 Qbhf!25!pg!2965 APPENDIX D DATA VALIDATION CHECK LIST 3753\\NN07191701_SoutholdGWrpt »may D&B ENGINEERS AND .. .. "", ARCH 1-110"S, P.C. DATA VALIDATION AND QUALIFICATION SUMMARY Laboratory Numbers:R1 705362 Sample ID Analyte sualifier Reason s VOCs All samples Acetone UB Detected in the Tiip Blank Metals No qualification of the data was necessary. General Chemistry All samples BOD and hexavalent chromium MW-31),MW-3S,MW-6D and Nitrate Analyzed outside of holding Blind Du -1 J/UJ times MW-31),MW-3S,MW-61), MW-6S,MW-8S,MW-8D and Color Blind Du -1 All samples Hexavalent chromium and The%Rs were below QC chemical oxygen demand J/iTJ limits in the MS and MSD MW-1S, MW-11), MW-4S, The%R was above the QC MW-5S,MW-6S and MW-6D Nitrate J limits in the MS and MSD VALIDATION PERFORMED BY&DATE: Donna M.Brown 7/10/2017 VALIDATION PERFORMED BY SIGNATURE: Pages \\dbfsl\Jobs\HazWaste\3753(Southold Landfill)Alst 2017 GW Report\R1705362_Jun2017.docx 6/6