ARCHIVED REPORTS_ANNUAL 2014 GRAOUNDWATER MONITORING AND SAMPLING REPORT

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i Mr.C.Dean Hubbard—Central Valley RWQCB Annual 2014 Groundwater Monitoring and Sampling Report April 29,2014 Alden Park Page 4 of 7 quarterly basis. Depth to groundwater was measured in MW-4, MW-7 through MW-12, and MW-14 on March 28,2014. Cumulative depth-to-groundwater measurements and groundwater elevations are provided in Table 1. A potentiometric map showing groundwater elevation contours and flow direction is shown on Figure 3. Field data sheets are provided as Attachment B. • Site Wells in Program: MW-1, MW-3 through MW-12, MW-14 through MW-16,MW-18, MW-20, and MW-21. A summary of well construction details is included in Table 2. • Wells Containing SPO: MW-1, MW-3,MW-5,MW-6, MW-15, MW-16, MW-18, MW-20, and MW-21 have historically contained SPO. An oil-absorbent (oleophilic) sock is installed in MW-21 and is monitored on a quarterly basis. Vacuum extraction of SPO from the remaining wells is also performed on a quarterly basis. • Depth to Groundwater at the Site: Ranged from 11.30 feet below top of casing (btoc) in MW-8 to 14.14 feet btoc in MW-11. Depth-to-groundwater measurements collected to date from wells indicate that the average depth to groundwater at the Site is 11.29 feet btoc. • Calculated Groundwater Elevation: Ranged from 38.48 feet above mean sea level(MSL) in MW-7 to 41.30 feet above MSL in MW-12. Groundwater elevation measurements collected to date from these wells indicate that the average groundwater elevation at the Site is 41.49 feet above MSL. ' • Approximate Groundwater Flow Direction/Gradient: Predominantly toward the north-northwest at 0.003 ft/ft,which is consistent with historical groundwater flow-gradient site data. A summary of groundwater flow direction/gradient is ' included in Table 3. SAMPLING Following depth-to-groundwater measurements, Leidos installed polyethylene HydraSleeve no-purge sampling devices in groundwater monitoring wells MW-4, MW-7 through MW-12, and MW-14. The HydraSleeves were retrieved, and the groundwater ' samples were decanted into laboratory-provided bottles, which were labeled, sealed, and placed immediately into an ice-cooled container for delivery to Calscience Environmental Laboratories, Inc. (Calscience)2 under Leidos chain-of-custody protocol. ' from MW-1, MW-3, MW-5, MW-6, MW-15,MW-16, Samples were not collected MW-18, MW-20, and MW-21 due to the presence of SPO or hydrocarbon sheen. GROUNDWATER ANALYTICAL RESULTS , Groundwater samples collected March 28, 2014 from MW-4, MW-7 through MW-12, and MW-14 were analyzed for the following constituents: , 2. Calscience is a California-certified laboratory(ELAP#2803).