Loading...
HomeMy WebLinkAbout2015 2nd Qtr August 20, 2015 LKB #1439-01 Guy Wheaton, PE Environmental Engineer 1 NYSDEC Region 1 Headquarters Division of Materials Management SUNY at Stony Brook 50 Circle Road Stony Brook, NY 11790-3409 Re: Town of Southold Landfill, 6155 Cox Lane, Cutchogue, NY 11944 Dear Mr. Wheaton, The Second Quarter 2015 Ground Water-Monitoring Report for the Town of Southold Landfill is hereby submitted to the Department per 6NYCRR Part 360 requirements. Sincerely, LOCKWOOD, KESSLER & BARTLETT, INC. John B. Gerlach, CGWP, LEP Director of Environmental Sciences C.c. J. Bunchuck, Town of Southold P. Lappano, Lockwood, Kessler & Bartlett, Inc. Lockwood, Kessler & Bartlett, Inc. One Aerial Way, Syosset, NY 11791 Phone: 516.938.0600 Fax: 516.931.6344 SECOND QUARTER 2015 GROUND WATER-MONITORING REPORT FOR THE TOWN OF SOUTHOLD LANDFILL 6155 COX LANE CUTCHOGUE, NY 11944 Prepared for: Southold Town Solid Waste Management District 6155 Cox Lane Cutchogue, NY 11944 Prepared by: Lockwood, Kessler & Bartlett, Inc. 1 Aerial Way Syosset, NY 11791 Submitted to: New York State Department of Environmental Conservation Region 1 Headquarters SUNY at Stony Brook 50 Circle Road Stony Brook, NY 11790 August 20, 2015 Second Quarter 2015 Ground Water-Monitoring Report Town of Southold Landfill, Cutchoque, NY TABLE OF CONTENTS Section Number and Title Page Number 1.0 INTRODUCTION 1 2.0 METHODS AND PROCEDURES 1 3.0 DISCUSSION OF RESULTS 2 3.1 Water-Level Results 2 3.2 Field Parameter Results 2 3.3 Leachate Indicator Results 3 3.4 Inorganic Parameter Results 5 3.5 Additional Baseline Parameter Results 7 4.0 CONCLUSIONS AND RECOMMENDATIONS 7 Figure Number and Title Follows Page Number 1. Site Location Map 1 2. Well Location Map 1 Table Number and Title Follows Page Number 1. Summary of Part 360 Routine Parameter Results 2 for Second Quarter 2015 Monitoring Round 2. Summary of Part 360 Additional Baseline Parameter Results 2 for Second Quarter 2015 Monitoring Round Appendices A. Sample Results Lockwood, Kessler & Bartlett, Inc. i Second Quarter 2015 Ground Water-Monitoring Report Town of Southold Landfill, Cutchogue, NY 1.0 INTRODUCTION The Town of Southold has retained Lockwood, Kessler & Bartlett, Inc. (LKB) to perform post-closure ground-water monitoring and reporting for its closed and capped MSW landfill in Cutchogue, NY (Site). The location of the Site is shown in Figure 1. th This report is for the second quarter 2015 monitoring round, conducted on June 24, and describes the work performed and the results obtained. Section 2.0 (Methods and Procedures) details the project requirements and the specific work performed. Section 3.0 (Discussion of Results) summarizes the key findings from this monitoring round, including comparison of the laboratory results to standards and guidance values. Section 4.0 (Conclusions and Recommendations) provides conclusions based on this quarter’s results, and recommendations for upcoming quarters. Each report section is supported by figures and/or tables, as appropriate, which follow the page on which they are first referenced. The laboratory results for this monitoring round are provided in Appendix A. 2.0 METHODS AND PROCEDURES Water-level measurements and ground-water samples were collected from each of the Site’s 12 monitoring wells, as listed below. A site plan showing the locations of the wells is provided in Figure 2. MW-1S MW-5S MW-1D MW-5D MW-3S MW-6S MW-3D MW-6D MW-4S MW-8S MW-4D MW-8D Prior to sampling, the water-level in each well was measured to the nearest 0.01-feet from the top of the well casing utilizing a decontaminated water-level meter. Ground- water samples were collected utilizing a Grundfos RediFlo2 variable-speed electric submersible pump connected to 160 feet of ¾-inch diameter polyethylene hose on a Keck Reel. Utilizing the well construction records, the pump was placed at the mid-point of each well’s screen. Each well was then purged at a low flow rate until the turbidity of the ground water was less than 5 NTUs (Nephelometric Turbidity Units), and the field water chemistry parameters were stable. The ground-water samples were collected directly from the pump discharge hose into new laboratory-supplied bottles of the type required for each specific analysis. Field notes were recorded in a bound field notebook. Each sample was labeled with the well o number, time and date, etc., placed in a cooler with ice to keep it at 4C, and shipped to the laboratory the same day. Lockwood, Kessler & Bartlett, Inc. 1 N SITE FIGURE 1 SITE LOCATION MAP TOWN OF SOUTHOLD LANDFILL, CUTCHOGUE, NY FIGURE 2 WELL LOCATION PLAN ANDFILL, CUTCHOGUE, NY TOWN OF SOUTHOLD L : Base map provided by Town of Southold Note Second Quarter 2015 Ground Water-Monitoring Report Town of Southold Landfill, Cutchogue, NY The samples were analyzed for the 6NYCRR Part 360 Baseline Parameters. The field parameters were monitored by LKB. Laboratory analyses were performed by Pace Analytical, Inc. in Melville, NY. This laboratory is certified by the New York State Department of Health’s Environmental Laboratory Approval Program in all required analytical categories, and employs the required internal QA/QC procedures, including analysis of matrix spikes, matrix spike duplicates, method blanks and continuing calibration samples. They also participate in the required biennial proficiency testing. The field data and laboratory results were reviewed by LKB per QA/QC Plan requirements and determined to be useable. 3.0 DISCUSSION OF RESULTS The field and laboratory results for the second quarter 2015 ground water-monitoring round are summarized and compared to the New York State Department of Environmental Conservation Ambient Water Quality Standards and Guidance Values for Class GA (Potable) ground water, as applicable, in Tables 1 and 2. Table 1 summarizes the results for the Part 360 Routine Parameters, which are the parameters typically analyzed for during quarterly monitoring. Table 2 summarizes the results for the additional Part 360 Baseline Parameters analyzed for during this monitoring round. A review of the results for the water-level measurements and each analytical parameter group is provided below. 3.1 Water-Level Results As shown in Table 1, water-table elevations in the shallow (“S”) wells at the Site ranged from 6.98 feet above mean sea level (MSL) in Well MW-1S, located on the south end of the Site, to 4.86 feet above MSL in Well MW-8S, located on the west side of the Site. These water-table elevations are consistent with ground-water flow information published by the United States Geological Survey in Scientific Investigations Map 3066, Water Table – Sheet 1 of 4, which indicates a relatively low horizontal hydraulic gradient and a northerly horizontal ground water-flow direction. Based on these elevations, Well Cluster MW-1 is located upgradient of the Site, and the other wells are located along the downgradient boundary of the Site. Potentiometric surface elevations in the deep (“D”) wells at the Site are consistent with the shallow well results, except for the anomalously high result for Well MW-8D, and indicate flat or downward vertical hydraulic gradients. 3.2 Field Parameter Results Review of the field parameter results in Table 1 indicates the following key findings: Ground-water conductivity values are higher relative to the main area of Long Island. This may be at least partly due to the Site’s North Fork location, where naturally higher ground-water salinities may occur due to the proximity to saline surface-water bodies. Conductivity values are highest in the deep wells located Lockwood, Kessler & Bartlett, Inc. 2 No OdorNo OdorNo OdorNo OdorNo OdorNo OdorNo OdorNo OdorNo OdorNo OdorNo OdorNo Odor MW-8DMW-8DCalciumug/LNo Standard7,22021,40029,70030,80058,800153,0009,51066,70014,00034,10065,50052,5006,61030,6004,980 J18,60017,90027,700Potassiumug/LNo Standard3,510 J830 J19,50062,20039,00056,400 2,680 J117,0004,050 J2,320 B42,50050,100 26,80065,200 Field ObservationsN/ANo StandardClear,Clear,Clear,Clear,Clear,Clear,Clear,Clear,Clear,Clear,Clear,Clear, Cadmiumug/L50.20 J0.40 J5.82.1 J<0.10<0.10<0.10<0.100.30 J0.30 J2.6 J0.60 J N/A44.8344.8849.5049.1963.0362.9268.1467.6455.7755.7154.1655.29N/A37.8537.9043.5243.2257.5457.4662.6862.2549.6949.6649.3048.16 48,9009,56010,6002,3101,0401,1801,470 Floaters or SinkersN/ANoneNoneNoneNoneNoneNoneNoneNoneNoneNoneNoneNoneNone ORPmVNo Standard154164NM-44.814252.385.6105115109-65.6-51.9 7.576.726.90 20.620.7<0.102.57<0.101.6410.8<0.10<0.10 N/A6.986.985.985.975.495.465.465.396.086.054.867.13 ConductivitymS/cmNo Standard0.1940.3030.8501.390.5952.180.1932.030.1720.4420.9101.06 TemperatureoCNo Standard14.613.417.316.616.116.414.615.112.913 .516.715.7 EhpHmVNo Standard10061.9NM46.934.124.687.330.972.910.342.632.0 Dissolved Oxygenmg/LNo Standard0.012.90NM0.520.730.124.530.200.010.010.380.26 TurbidityNTU<52.934.011.431.382.274.514.643.213 .714.622.551.69<0.50<0.50<0.50<0.50<0.501.98<0.500.99<0.50<0.50<0.500.53CODmg/LNo Standard<10.0<10.064.743.117.352.5<10.063.822.3<10.036.125.5TKNmg/LNo Standard<0.10<0.1010.257.1<0.1021.90.1978.20.61 <0.1015.818.1 33.0 Alkalinity mg/LNo Standard5.3532.218.142216667018.568446.615.429828928.82098.6945.642.2104Sulfatemg/L25017.481.028.144.538.811220.244.916.211239.0108105280386496 Hardnessmg/LNo Standard601001502002206005232056160260320 Phenolsug/L1<5.00<5.0<5.0<5.0<5.0<5.0<5.0<5.0<5.0<5.0<5.0<5.0Total Organic Carbonmg/LNo Standard<1.0<1.08.615.35.617.21.825.38.0<1.012.48.8 BODmg/LNo Standard<2<2<2<2<2<2<2<2<2<2<2<2 MW-6SMW-8SMW-5DMW-6SMW-6DMW-8S ORP= Oxygen Reduction Potential.pHmV= pH in milliVolts.N/A= Not Applicable. exceed Class GA Standard or Guidance Value. Leadug/L253.24.02.9 J4.21.8 J2.4 J<1.62.6 J2.8 J3.0 J2.1 J T.O.C.= Top of Casing.COD= Chemical Oxygen Demand.mV= milliVolts.NM= Not Measured (due to probe malfunction). = Degrees Celsius.ug/L= micrograms per Liter.Results in bold font and highlighted in yellow 7,63016,000 MW-6D 12712484.2 J66.4 J 0.170.15 6.16 Summary of Part 360 Routine Parameter Results for Second Quarter 2015 Monitoring Round 132,000 MW-5SMW-5D 6.92 91.9 828 Well Number and Result 13,500 J MW-5S 5.93 0.2938.1 112 MSL= Mean Sea Level.TKN= Total Kjeldahl Nitrogen.mg/L= milligrams per Liter. Town of Southold Landfill, Cutchogue, NY 208,000 63,800 MW-1SMW-1DMW-3SMW-3DMW-4SMW-4DMW-4D BOD= Biological Oxygen Demand.NTU= Nephelometric Turbidity Units.GV = Guidance Value. 1,1605,1602,0202,3003,730 NM6.616.887.03 25.5 284410 4,840 J9,97017,60021,50017,40012,400 MW-1SMW-1DMW-3SMW-3DMW-4S 39.6 J 0.11 Chloridemg/L25043.023.650.011815.2 17.2 Total Dissolved Solidsmg/L500111176293464347 Table 1 103,00036,20030,60087,200 12.062.7 Nitratemg/L101.983.28<0.10<0.10 Sodiumug/L20,00019,10018,400 Manganeseug/L30012.2 J6.0 J 5.726.34 Ammoniamg/L20.200.35 Ironug/L30059.3 J150 C o mS/cm= milliSiemens per centimeter. NYSDEC Part 360Class GA Routine ParametersStandard GV pHUnits6.5-8.5 35000 GV 2 Feet MSLFeet MSL Feet Units Bromidemg/L Magnesiumug/L : Notes Inorganic Parameters: Water-Level Elevation Leachate Indicators: : Field Parameters: Water-Level Data T.O.C. Elevation Depth to Water MW-8D Aluminumug/LNo Std.80.5 J110 J71.8 J128 J58.0 J128 J89.0 J81.6 J91.5 J72.6 J49.4 J68.7 JBariumug/L1,00073.4 J29.4 J206269111 J167 J57.7 J190 J70.4 J25.9 J24965.4 J Chromium, Totalug/L503.7 J1.5 J44.116.40.90 B1.1 B1.5 J1.2 J1.6 J<0.7021.44.7 JCobaltug/LNo Std.<0.200.40 J32.6 J40.3 J0.30 J14.5 J<0.2025.2 J5.3 J1.4 J2.9 J4.8 JCopperug/L200<1.8<1.832.011.9 J2.2 J3.6 J<1.812.7 J10.2 J2.4 J66.84.4 JNickelug/L1003.7 J<0.900.70 J28.0 J11.6 J36.8 J5.0 J37.0 J14.0 J13.5 J<0.604.7 J 65.070.0<0.200.40 J<0.20<0.20<0.20<0.20<0.20<0.20<0.20<0.20<0.20<0.2016.9 J18.0 J28.110.1 J17.3 J16.4 J20.69.2 J9.4 B14.4 J17.5 J43.5 Cyanideug/L200<10.0<10.0<10.0<10.0<10.0<10.0<10.0<10.0<10.0<10.0<10.0<10.0Vanadiumug/LNo Std.0.50 J2.5 J<0.50<0.50<0.50<0.500.50 J<0.50<0.50<0.502.4 J<0.50 Boronug/L1,00021.6 J13.5 J10144510761715.1 J66929.6 J31.1 J199316 <5<54 J4 JAntimonyug/L3<1.8<1.8<1.8<1.8<1.8<1.8<1.8<1.8<1.8<1.8<1.8<1.8Arsenicug/L10<1.4<1.4<1.41.6 J<1.4<1.4<1.4<1.4<1.4<1.42.3 J<1.4Mercuryug/L0.7<0.1<0.1<0.1<0.1<0.1<0.1<0.1<0.1<0.1<0.1<0.1<0.1Sel eniumug/L103.4 J5.7<2.9<2.9<2.9<2.93.1 J<2.9<2.93.0 J3.9 J<2.9Silverug/L50<1.8<1.811.94.3 J<1.8<1.8<1.8<1.8<1.8<1.86.1 J<1.8<2.3<2.3<2.3<2.3<2.3<2.3<2.3<2.3<2.3<2.3<2.3<2.3 1 J2 J 3<5<5<5<5<5<5<52 J<5<5<5<55<5<5<52 J<5<5<53 J<5<5<5<55<5<5<51 J<5<5<5<5<5<5<5<5 <5<52 J2 J<52 J<5<5<5<5<5<5 exceed Class GA Standard or Guidance Value. MW-4DMW-5SMW-5DMW-6SMW-6DMW-8S Results in bold font and highlighted in yellow <5<5<5<5<5<5<5<5 <5.00 Summary of Part 360 Additonal Baseline Parameter Results for Second Quarter 2015 Monitoring Round 30.045.0 4 J 10 Well Number and Result <5.00 5<5<5<53 J<52 J<5<5 Town of Southold Landfill, Cutchogue, NY 20.0 4 J 9 MW-1SMW-1DMW-3SMW-3DMW-4S 5.00 0.6<5<5<5<5<51<5<5<5<5<5 Table 2 70.065.0 <5.00 J= Estmated concentration. ug/L= Micrograms per Liter. 15.0 GV= Guidance Value. NYSDEC Part 360Class GA Baseline ParametersStandard GV GV GV 2,000 ColorUnits5 0.5 50 3 GV Units Berylliumug/LThalliumug/LZincug/L ug/Lug/Lug/Lug/Lug/Lug/Lug/L : Notes : Detected Target VOCs Inorganic Parameters: cis-1,2-Dichloroethene Leachate Indicators: 1,4-Dichlorobenzene 1,2-Dichloropropane 1,2-Dichloroethane Trichloroethene Chlorobenzene Acetone Second Quarter 2015 Ground Water-Monitoring Report Town of Southold Landfill, Cutchogue, NY directly downgradient of the Site (e.g., Wells MW-3D, MW-4D and MW-5D). These highest values appear to be Site-related. There is no Class GA standard or guidance value for conductivity. Ground-water temperatures are approximately 1 to 2 degrees Celsius higher in six of the 10 downgradient wells relative to the upgradient wells. The highest temperatures occurred in Well Clusters MW-3, MW-4 and Well MW-8S. There is no Class GA standard or guidance value for temperature. No floaters or sinkers were noted during this monitoring round. Ground-water pH is slightly acidic in nine of the 11 wells measured, and is lower than the minimum Class GA standard of 6.5 Standard Units in both upgradient wells and two of the 10 downgradient wells. The results are consistent with the naturally low pH of Long Island ground water. Ground-water pH is higher in the deep well at all five well clusters where both wells were measured. Eh is noticeably lower in two of the four shallow downgradient wells measured relative to the shallow upgradient well, and is lower in the deep well at all six Site well clusters. There is no Class GA standard or guidance value for Eh. DO (Dissolved Oxygen) concentrations are lower in eight of the nine downgradient wells measured relative to deep upgradient well, but dissolved oxygen is present in all 11 Site monitoring wells measured. There is no Class GA standard or guidance value for DO. The ground water in all 12 Site monitoring wells was observed to be clear, and did not have noticeable odor. The ORP (Oxidation-Reduction Potential) of ground water is positive in both upgradient wells, and in Well Clusters MW-4, MW-5 and MW-6; and negative in Well MW-3D and Well Cluster MW-8 this quarter. There is no Class GA standard or guidance value for ORP. Overall, the field parameter results obtained this quarter are consistent with the Site’s usage and its North Fork setting. Potential Site-related impacts are relatively minor in magnitude and limited to higher conductivity and temperature, and lower Eh, DO and ORP in certain downgradient wells. 3.3 Leachate Parameter Results Review of the leachate parameter results in Table 1 indicates the following key findings: Ground-water alkalinity is significantly higher in six of the 10 downgradient wells relative to the upgradient wells. The highest alkalinity concentrations were detected in Wells MW-3D, MW-4D and MW-5D, and Well Cluster MW-8D. There is no Class GA ground-water standard or guidance value for alkalinity. Ammonia was detected in both upgradient wells and in all 10 downgradient monitoring wells. Ammonia concentrations are low in the upgradient wells and Downgradient Wells MW-4S, MW-5S, MW-6S and MW-6D. Ammonia Lockwood, Kessler & Bartlett, Inc. 3 Second Quarter 2015 Ground Water-Monitoring Report Town of Southold Landfill, Cutchogue, NY concentrations in the other six downgradient wells exceed the 2-mg/L Class GA ground-water standard. The highest ammonia concentrations occurred in Wells MW-3D and MW-5D. BOD (Biological Oxygen Demand) was not detected in any of the 12 Site monitoring wells this quarter. Bromide was detected in three of the deep downgradient wells (Wells MW-4D, MW-5D and MW-8D) at concentrations lower than the 2-mg/L Class GA ground- water guidance value. The highest concentration occurred in Well MW-4D. Chloride levels are noticeably higher in four of the five deep downgradient wells (Wells MW-3D, MW-4D, MW-5D and MW-8D) relative to the upgradient wells, but with the exception of Well MW-4D are lower higher than the 250-mg/L Class GA ground-water standard. The fact that the highest chloride concentrations occur only in deep wells suggests that they may be due in part to naturally saline ground-water conditions. COD (Chemical Oxygen Demand) was detected in eight of the 10 downgradient wells. The highest COD concentrations were detected in Wells MW-3S, MW-4D and MW-5D. There is no Class GA ground-water standard or guidance value for COD. Ground-water hardness values are higher in eight of the 10 downgradient wells relative to the upgradient wells. Hardness was higher in the deep well at each of the six Site well clusters, suggesting that it may be partly associated with saline ground-water conditions. The highest hardness values occurred in Wells MW-4D, MW-5D and MW-8D. There is no Class GA ground-water standard for guidance value or hardness. Nitrate is present in both upgradient wells and four of the 10 downgradient wells this quarter. Concentrations are lower than the 10-ug/L Class GA ground-water standard in every well except Well MW-4S. Phenols were not detected in any of the Site monitoring wells this quarter. Sulfate is present in all 12 Site monitoring wells, at relatively similar concentrations in the upgradient and downgradient wells. All concentrations are lower than the 250-ug/L Class GA ground-water standard. Sulfate concentrations are higher in the deep well at all six Site well clusters, which suggests that they may be partly associated with saline ground-water conditions. TDS (total dissolved solids) results are noticeably higher in eight of the 10 downgradient wells relative to the upgradient wells, and exceed the 500-mg/L Federal MCL in Wells MW-4D and MW-5D. The highest TDS concentration at each well cluster occurs in the deep well, which suggests that they may be partly associated with naturally saline ground-water conditions. TKN (total Kjeldahl nitrogen) was detected in eight of the 10 downgradient wells this quarter. The highest TKN concentrations occurred in Wells MW-3D, MW-4D and MW-5D. There is no Class GA ground-water standard or guidance value for TKN. Lockwood, Kessler & Bartlett, Inc. 4 Second Quarter 2015 Ground Water-Monitoring Report Town of Southold Landfill, Cutchogue, NY TOC (total organic carbon) was present in nine of the 10 downgradient wells. The highest concentrations occurred in Wells MW-3D, MW-4D and MW-5D. There is no Class GA ground-water standard or guidance value for TOC. Overall, the leachate parameter results obtained this quarter are also consistent with the Site’s usage and its North Fork setting. Potential Site-related impacts indicated by these results include downgradient increases in most of the detected parameters, primarily in the deep wells. However, it is important to note that 1) the there are no Class GA ground-water standards or guidance values for six of the parameters; and 2) the downgradient increases occur in a limited number of wells. Moreover, ground water beneath the Site is naturally saline at depth, and ultimately discharges to a saline surface-water body (Long Island Sound). Therefore, the exceedances for ammonia, bromide, chloride, nitrate and TDS, which occur naturally in saline ground water and seawater, are not a significant concern with respect to public health or the environment. 3.4 Inorganic Parameter Results Review of the inorganic parameter results in Table 1 indicates the following key findings: Cadmium was detected at low, primarily estimated concentrations in both upgradient wells and six of the 10 downgradient monitoring wells this quarter, but all concentrations are much lower than the Class GA ground-water standard for cadmium. The highest concentration occurred in Well MW-3S. Calcium was detected in all 12 Site monitoring wells this quarter. Calcium concentrations are noticeable higher in five of the 10 downgradient wells (Wells MW-4S, MW-4D, MW-5D, MW-8S and MW-8D) relative to the upgradient wells. There is no Class GA ground-water standard or guidance value for calcium. Iron was detected in all 12 Site monitoring wells this quarter. The iron concentrations in Wells MW-3S, MW-3D, MW-4D and Well Cluster MW-8 exceed the 300-ug/L Class GA ground-water standard. The highest iron concentrations occurred in Wells MW-3S and MW-8S. The fact that these highest iron concentrations occurred in the shallow wells at these clusters suggests that they are Site-related. Lead was detected in both upgradient wells and in nine of the 10 downgradient wells this quarter. However, except for Well MW-8D, lead was present at very low, primarily estimated concentrations. The concentration in Well MW-8D is slightly higher than the 25-ug/L Class GA ground-water standard. Magnesium was detected in all 12 Site monitoring wells this quarter, and the concentrations in eight of the 10 downgradient wells are noticeably higher relative to the upgradient wells. The magnesium concentration in Well MW-4D is higher than the 35,000-ug/L Class GA guidance value. At each well cluster, Lockwood, Kessler & Bartlett, Inc. 5 Second Quarter 2015 Ground Water-Monitoring Report Town of Southold Landfill, Cutchogue, NY magnesium concentrations are higher in the deep well, which suggests that they may be partly associated with saline ground-water conditions. Manganese was detected in both upgradient wells at low, estimated concentrations, and at higher concentration in all 10 downgradient wells. The manganese concentrations in nine of the 10 downgradient wells exceed the 300- ug/L Class GA ground-water standard. The highest manganese concentrations occurred in Wells MW-3S and MW-5D. Some of the highest manganese concentrations in the downgradient wells occurred in the shallow wells and therefore appear to be Site-related. Potassium was detected in all 12 Site monitoring wells this quarter. Potassium concentrations in seven of the 10 downgradient wells are noticeably higher relative to the upgradient wells. At each well cluster, the highest potassium concentration occurs in the deep well, which suggests that the potassium results are partly associated with naturally saline ground-water conditions. The highest concentrations occurred in Wells MW-4D and MW-5D. There is no Class GA ground-water standard or guidance value for potassium. Sodium was also detected in all 12 Site monitoring wells. Sodium concentrations in six downgradient wells (Wells MW-3S, MW-3D, MW-4D, MW-5D, MW-8S and MW-8D) are noticeably higher relative to the upgradient wells, and exceed the 20,000-ug/L Class GA ground-water standard. At each well cluster, the highest sodium concentration occurs in the deep well, which suggests that the sodium results are partly associated with naturally saline ground-water conditions. Overall, the inorganic parameter results obtained this quarter are also consistent with the Site’s usage and its North Fork setting. Potential Site-related impacts indicated by these results include downgradient increases in calcium, iron, lead (in one well only) magnesium, manganese, potassium and sodium. However, it is important to note that 1) many of these increases are relatively minor in magnitude, sporadic, and/or do not result in exceedances of the Class GA ground-water standards or guidance values; 2) there are no Class GA ground-water standards or guidance values for calcium or potassium; 3) the Class GA ground-water standards for iron and manganese are aesthetics-based; 4) the limit for magnesium is based on a guidance value rather than an actual standard, and was exceeded in only one well; and 5) sodium is not considered to be particularly hazardous. Moreover, since ground water on the North Fork is naturally saline at depth and ultimately discharges to Long Island Sound, the exceedances for magnesium and sodium, which occur naturally in saline ground water and seawater, are not a concern with respect to public health or the environment. Lockwood, Kessler & Bartlett, Inc. 6 Second Quarter 2015 Ground Water-Monitoring Report Town of Southold Landfill, Cutchogue, NY 3.5 Additional Baseline Parameter Results Review of the Part 360 additional baseline parameter results in Table 2 indicates the following key findings: The majority of the VOCs (volatile organic compounds) analyzed for were not detected in any of the wells sampled. VOC detections were limited to relatively low concentrations of seven aromatic hydrocarbons and solvents in six of the ten downgradient wells, primarily in the deep wells. Low-magnitude exceedances for one or two VOCs occurred in Wells MW-4D, MW-5D and MW-8D. Except for the low, estimated concentrations of acetone in Well MW-3S and chlorobenzene in Well MW-8S, VOCs were not detected in the shallow downgradient wells. VOCs were not detected in the upgradient wells. Boron was detected in all 12 Site monitoring wells, and concentrations are noticeably higher in seven of the 10 downgradient wells (MW-3S, MW-3D, MW- 4S, MW-4D, MW-5D, MW-8S and MW-8D) relative to the upgradient wells. All boron detections are lower than the 1,000-ug/L Class GA ground-water standard. Color exceeded the aesthetics-based 5-CU (Color Units) Class GA ground-water standard in Upgradient Well MW-1S and Downgradient Wells MW-3S, MW-3D, MW-4D, MW-5D, MW-6S, MW-8S and MW-8D. Regarding the baseline inorganic parameters, the concentrations of the parameters for which Class GA ground-water standards or guidance values exist were lower than their standard or guidance value in all 12 Site monitoring wells. Antimony, cyanide, mercury and thallium were not detected. Aluminum, arsenic, beryllium, selenium, silver, vanadium and zinc were detected at similar concentrations in upgradient and downgradient wells and/or only detected sporadically at low, estimated concentrations. Barium, chromium, cobalt, copper and nickel concentrations, while low in all wells, were noticeably higher in at least one downgradient well relative to the upgradient wells. The above results indicate that the Site is not a significant source of releases of the additional Part 360 baseline parameters to ground water. Moreover, the fact that VOC detections are limited to a few compounds at relatively low concentrations, primarily in the deeper wells, suggests that they reflect regional ground water-quality conditions. 4.0 CONCLUSIONS AND RECOMMENDATIONS Based on the results of the second quarter 2015 monitoring round, LKB concludes the following: Water-level elevations, horizontal and vertical hydraulic gradients, and ground water-flow directions are consistent with local/regional hydrogeologic conditions. Lockwood, Kessler & Bartlett, Inc. 7 Second Quarter 2015 Ground Water-Monitoring Report Town of Southold Landfill, Cutchogue, NY In general, ground water-quality conditions are consistent with the Site’s North Fork setting near saline surface-water bodies. Comparison of upgradient and downgradient results indicates potential Site- related impacts consistent with an old MSW landfill, however further assessment indicates that the impacts are not a significant concern with respect to public health or the environment. The NYSDEC has approved the Town of Southold’s petition to reduce the scope and frequency of post-closure monitoring to biannually for Part 360 Baseline Parameters. Therefore, the next monitoring round should be performed during the fourth quarter of 2015, for Part 360 Baseline Parameters. Lockwood, Kessler & Bartlett, Inc. 8 APPENDIX A Sample Results LKB011 S21 of 235 LKB011 S22 of 235 LKB011 S23 of 235 LKB011 S24 of 235 LKB011 S25 of 235 LKB011 S26 of 235 LKB011 S27 of 235 LKB011 S28 of 235 LKB011 S29 of 235 LKB011 S30 of 235 LKB011 S31 of 235 LKB011 S32 of 235 LKB011 S33 of 235 LKB011 S34 of 235 LKB011 S35 of 235 LKB011 S36 of 235 LKB011 S37 of 235 LKB011 S38 of 235 LKB011 S39 of 235 LKB011 S40 of 235 LKB011 S41 of 235 LKB011 S42 of 235 LKB011 S43 of 235 LKB011 S44 of 235 LKB011 S45 of 235 LKB011 S46 of 235 LKB011 S47 of 235 LKB011 S48 of 235 LKB011 S49 of 235 LKB011 S50 of 235 LKB011 S51 of 235 LKB011 S52 of 235 LKB011 S53 of 235 LKB011 S54 of 235 LKB011 S55 of 235 LKB011 S56 of 235 LKB011 S57 of 235 LKB011 S58 of 235 LKB011 S59 of 235 LKB011 S60 of 235 LKB011 S61 of 235 LKB011 S62 of 235 LKB011 S63 of 235 LKB011 S64 of 235 LKB011 S65 of 235 LKB011 S66 of 235 LKB011 S67 of 235 LKB011 S68 of 235 LKB011 S69 of 235 LKB011 S70 of 235 LKB011 S71 of 235 LKB011 S72 of 235 LKB011 S73 of 235 LKB011 S74 of 235 LKB011 S75 of 235 LKB011 S76 of 235 LKB011 S77 of 235 LKB011 S78 of 235 LKB011 S79 of 235 LKB011 S80 of 235 LKB011 S81 of 235 LKB011 S82 of 235 LKB011 S83 of 235 LKB011 S84 of 235 LKB011 S85 of 235 LKB011 S86 of 235 LKB011 S87 of 235 LKB011 S88 of 235 LKB011 S89 of 235 LKB011 S90 of 235 LKB011 S91 of 235 LKB011 S92 of 235 LKB011 S93 of 235 LKB011 S94 of 235 LKB011 S95 of 235 LKB011 S96 of 235 LKB011 S97 of 235 LKB011 S98 of 235 LKB011 S99 of 235 LKB011 S100 of 235 LKB011 S101 of 235 LKB011 S102 of 235 LKB011 S103 of 235 LKB011 S104 of 235 LKB011 S105 of 235 LKB011 S106 of 235