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by our landfill. In addition,there was a slight exceedence for turbidity in newly installed wells G-2A and G-5A observed during the 4d'Quarter sampling event. Groundwater elevations for the 4th quarter 2013 show similar results (Table 4). We expect that the turbidity in these newly-installed wells will subside over time. Monitoring Parameter Concentration Limits Interwell concentration limits were established from background monitoring well G-1. No concentration limits were exceeded this semester in any wells,with the exception of well G-1 where a slight exceedence for calcium and EC was reported. In addition, there was a slight exceedence for turbidity in newly installed wells G-2A and G-5A. However, since there is an indication of possible changes in the background water quality, it is possible that higher levels of constituents may begin to be reported in the downgradient wells at the site. Future monitoring results will be carefully reviewed to distinguish the influence to increasing background conditions from influences from the landfill, if any. VOCs VOCs were not reported in any wells during this semester. With the exception of G-1, all wells have been free of VOCs since January 2003. At G-1, Acetone, Chloroform, and Toluene were occasionally observed when the well was first installed in 2010 and reported during the 2nd Semester 2010,but have not been reported since that time. This confirms our conclusion that these detections were due to slight contamination of that well during construction. We expect that this well will remain"non-detect" in the future. With the exception of the short-term detections at G-1 in 2003, VOCs have not been confirmed at the North County Sanitary Landfill since January 2003, over ten years ago. Storm Water Storm water was sampled from discharge point SW-4 at the north west corner of the Unit in April 2013 (Appendix C). Results were unremarkable. Surface Water Surface water was not available for sampling this semester due to lack of rain. Surface water samples were last collected January 31, 2011. Samples are taken if sufficient water is flowing at sampling points during the wet season. Unsaturated Zone (Lysimeters) During the second semester, the Lysimeters did not yield enough water for sampling, indicating no detectable leaks from the liner in those areas. Unsaturated zone monitoring will continue in accordance with the WDRs. Soil Gas Soil gas samples were collected on August 2, 2013. Methane was not detected in any samples. North County RC&SL Public Works/Solid Waste 2"d Semester and Annual 2013 Groundwater Monitoring 7 County of San Joaquin—January 25,2014