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k4 KLEINIFELf? ER • 4 RESULTS 4.1. GROUNDWATER DEPTH ELEVATION AND GRADIENT Water level measurements were made in the monitoring wells during drilling, development, and prior to sampling. The depth to water levels during the groundwater sampling event were converted to elevations in reference to the survey conducted. The top of each monitoring well was chosen as the water level and survey measuring point. The depth to groundwater at the site ranged from 78.86 bgs feet to 90.17 feet bgs. The corresponding groundwater elevations ranged from 33.02 feet MSL to 38.86 feet MSL. Based on the SJCFCWCD maps, the groundwater flow direction is estimated to be towards the north/northeast. Three groundwater depressions are located north, east, and west of the site and likely influence the localized groundwater flow direction. 4.2. WATER TABLE GROUNDWATER SAMPLING RESULTS • The water table (or uppermost regional aquifer) sampling results showed the following concentrations of specific analytes, which exceeded applicable water quality goals as stipulated by the State of California EPA: • Nitrate was detected in groundwater samples collected from MW-2 and MW-4 with concentrations of 63.4 and 51.5 mg/L, respectively; exceeding the California PMCL of 45 mg/L. • Atrizine, a common pesticide, was detected in the MW-2 groundwater sample at a concentration of 1.9 µg/L using EPA Method 507. The California PMCL for this pesticide is 1 .0 µg/L. • Diuron, a common herbicide, was detected in the MW-6 groundwater sample with a concentration of 0.2 µg/L using EPA Method 632. The water quality standard for Diuron is 10 µg/l- as a SNARL. • Total coliform bacteria concentrations were reported in each of the monitoring well samples with concentrations ranging from 12 MPN/100ml to more than 23 MPN/100ml. Fecal coliform bacteria were reported in the MW-6 groundwater sample with a concentration of 16.1 MPN/100ml. The water quality goal for coliform bacteria is zero MPN/100m1. • Iron was detected in groundwater samples collected from MW-3, MW-4, MW-7, and MW-9 with concentrations exceeding the SMCL of 300 micrograms per liter 63138.HO1/ST06R312/JDZ:ly Page 12 of 20 ©2006 Kleinfelder, Inc. April 7,2006