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A Mann-Kendall trend analysis of all monitoring parameters for MW-2 is conducted semiannually in accordance with WDR Order No. R5-2009-0049. The results of a statistical analysis of trends in VOC concentrations in well MW-2 are shown on Table 1. Surface!Nater tConcentration limits for surface water constituents are determined by the inter-well tolerance limit method using Sanitas software. Analytical results from the upstream monitoring point S-1 provide the background data for this analysis. Compliance is verified if current test result from monitoring point S-2 (downstream) is within the tolerance limit. Tolerance limits are updated when surface water analyses are available. Note that surface water samples are no longer being collected because the landfill is separated from Waters of the State by drainage system and a retention pond. Samples will be taken from the pond discharge if it were to occur. Pond discharge requires manual operation of discharge pumps. MONITORING RESULTS Groundwater The groundwater at all monitoring wells meet drinking water standards. The first semiannual sampling event was conducted on January 16, 2014. Quarterly groundwater elevations were measured at all groundwater monitoring wells on January 16, 2014 and April 22, 2014. Volatile compounds associated with landfill gas were detected at well MW-2, well MW-3A, MW- 4A and well MW-5. All concentrations were below 1.0 ppb with the exception of Trans-1,2- Dichloroethene in MW-4A. Note that MW-5 is upgradient from the landfill, but downgradient from the wastewater treatment ponds. Significant improvement in VOC concentration has been observed in well MW-2 with the non- detection of two chlorinated VOCs (CFC-12 and 1, 2-Dichloropropane) that indicated LFG impact. This is a significant improvement since 2007, when three compounds were consistently reported at well MW-2. No concentration limits were exceeded in any wells during this sampling period, where concentration limits could be determined. MWA (Up-gradient) No general water quality parameter concentration limits were exceeded and no VOCs were q Y , detected in MWA during this period. The trend analysis by Sanitas software indicates increasing trends for EC, TDS, Bicarbonate Alkalinity and Chloride, and a decreasing trend for Turbidity. However, since MWA is the upgradient well, the increasing trends in EC, TDS, Bicarbonate Alkalintiy and Chloride are unlikely to have arisen from the landfill, and are likely due to changes in background water quality conditions. Harney Lane Sanitary Landfill 4 Department of Public Works/Solid Waste 1"Semiannual 2014 Groundwater Monitoring Report County of San Joaquin—July 31,2014