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12 June 2006 • AGE-NC Project No 04-1214 Page 2 of 3 Included in Appendix A and Appendix B All purged ground water was containerized in properly labeled DOT-approved 55-gallon drums and stored on-site Following purging of all wells, and after allowing the wells to achieve a minimum 80% recovery of the pre-purge water volume, ground water samples were collected using a dedicated and disposable bailer or Waterra inertial pump and dedicated tubing,and placed into 500 milliliter(ml), unpreserved plastic containers Each sample container was properly labeled, stored in a chilled container and transported under chain-of-custody to McCampbell Analytical Inc (MAI)in Pacheco, California MAI is certified for nitrate analysis by the California Department of Health Services (DHS) - ELAB Number 1644 All ground water samples were analyzed for nitrate as nitrogen(NO3 as N) by EPA method 300 1 Additionally, samples from MW-101 through MW-104 were analyzed for ammonia as nitrogen (NH4 as N) by EPA method SM450-0 and nitrite as nitrogen (NO2 as N) by EPA method 300 1 A summary of the ground water depth and elevation data are presented in Table 1 3.0. FINDINGS Ground water elevation, flow direction, and gradient were determined from field data The contaminant impact to ground water was quantified by laboratory analytical data 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION Depths to ground water during the May 2006 monitoring event ranged from 20 58 feet(MW-103) to 24 20 feet(MW-101)below the tops of the well casings The calculated groundwater elevations ranged from 36 60 feet (MW-101) to 36 53 feet (MW-103) above mean sea level (MSL) The ground water flow direction was inferred to be west, at a ground water gradient of 0 0005 foot/foot (Rift) west of MW-102 and 0 0002 to 0 0003 ft/ft west of well MW-103 The ground water flow direction and gradient are depicted in Figure 3 32 ANALYTICAL RESULTS OF GROUND WATER SAMPLES The results of analysis for ammonia(NH4), nitrate (NO3) and nitrite (NO2) are summarized below and in Table 2 Ammonia was detected in samples from MW-101 through MW-104,at concentrations ranging from 8 5 milligrams per liter (mg/1) (MW-103) to 157 mg/l (MW-101) Nitrate as N was detected in all eight samples, nitrate was detected at concentrations between 7 0 mg/l (MW-10) and 486 mg/l • (MW-101) Nitrites as N were detected in the ground water samples from MW-101 through Advanced GeoEnvtronmentai,Inc