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KLEINFELDER level was measured in approximate 30-minute intervals for four hours, refilling as necessary to maintain the prescribed amount of water over the gravel (SJCEHD Procedure #2). Under the observation of a representative from the SJCEHD, the last r 30-minute readings of the four-hour period were used to calculate the percolation rate in minutes per inch. The SJCEHD representative approved the test results for both percolation test holes. A copy of our field percolation test result is attached on Plate 7. w On September 6, 2007, samples of groundw er were obtained using clean procedures from the tap in the kitchen sink. A permit the onsite well was found on file with SJCEHD, and a copy is provided on Plate 12. The water samples obtained from the well were delivered to a laboratory on is hat same day using chain-of- custody procedures for DBCP and nitrate (N) testing. The boring and percolation test holes were located in the field by visual sighting and/or pacing from existing site features; therefore, the locations shown on Plate 1 should be considered approximate. 6. GROUNDWATER _ Groundwater was first encountered at a de� of 6 feet elow ground surface in the y soil profile boring drilled for this investigation. A er 24 urs, groundwater had risen to a depth of 5'/a feet below ground surface. Gr dwater levels published on the California Department of Water Resources website (1970 to 1996) show groundwater levels in the project area ranging from about 6 to 18 feet below ground surce. We understand the ell on the property will be used to supply water fo, the office, facility. No new wells re planned. The resuftg of-the -g-foundwa r a to determine the concentrations of nitrate , (NO3)_in th�watef sampled r , the o ite well indicated a concentration 9� 68.2 -mg/l. I nitrate con atio Js above , e state drinking water standard of 4'5 mg// ;) �DBCP v ashresent in de table-, ounts with a reporting limit of 0.01 µg/I. Copies of the test results and th , of-custody are presented on Plate 8. We understand a dairy is located adjacent to the project site which could be a source of the nitrates in the groundwater. We do not know of any other existing and/or potential groundwater contamination issues in the project vicinity. There are no gas stations adjacent to the property. Other than the dairy, seasonal fertilization of the off- ` site agricultural land, if performed, and other septic tank/leach field systems in the project area are probably the largest contributor of nitrates to groundwater in the project vicinity. I� 4 http://wdL water.ca.gov/gw/ r 86892.G01/ST07R953 November 21,2007 O 2007 Kleinfelder Page 3 of 7