SITE INFORMATION AND CORRESPONDENCE

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RE-MANUFACTURING LTD. -3- 19 February 1991 SOIL AND GROUND WATER ASSESSMENT REPORT The water sample the Board collected from MW-1 contained four metals in concentrations above detection limits: chromium, copper, nickel , and selenium in concentrations of 0.011, 0.002, 0.005, and 0.002 mg/L, respectively. This does not conflict with Kleinfelder's results, because their detection limits were at or above these levels for those four metals. Appendix E contains Piper and Stiff diagrams for the three wells. The diagrams indicate the water chemistry in MW-3 is different from MW-1 and 2. The TDS in wells MW-1, 2 and 3 were 919, 625, and 1,500 mg/L, respectively. These exceeded the recommended secondary MCL of 500 mg/L. Nitrate was above the MCL of 10 mg/L in MW-1 at a concentration of 23.4 mg/L. In comparison, samples from wells MW-2 and 3 contained levels of 4.2 and 5. 1 mg/L, respectively. Chloride and sulfate concentrations in MW-3 exceeded the secondary MCLS of 250 mg/L with concentrations of 254 and 441 mg/L, respectively. Kleinfelder attributes the elevated nitrate concentration in MW-1 to the influence of agricultural runoff in Mormon Slough. However, no water quality data for Mormon Slough was presented to support this claim. One round of sampling was included in the report. Low levels of VOC's were found in MW-1 only. The VOC's found in MW-1 could be from other sources on Moore Industrial property and may not be from the SI, since no VOC's were found in the soil borings drilled in the SI. Ground water contamination does not appear to be significant. However, we cannot determine whether or not further ground water investigations are necessary from a single sampling event. Additional sampling is needed for quality assurance and seasonal variation determination. 3. Initiate a monthly ground water level measurement program. This shall be continued for a minimum of 12 consecutive months to determine seasonal variations. Monthly water level measurements were collected 9 October, 5 November, and 5 December 1990. According to the ground water gradients determined for October through December 1990, the gradient is to the northeast. Monthly ground water level measurements should continue for 12 consecutive months. 4. Determine the transmissivity (T), permeability (k), and storage coefficient (Sc) of soils beneath the SI. This data shall be used to calculate the rate of ground water flow and predict the movement of contaminants in the subsurface, if they are detected. A lab permeability test was run on one soil sample collected from the water bearing zone in each of the three well borings. The results are included on page 8 of the SGWA report, as well as velocity estimates. An estimate of the transmissivity and storage coefficient must also be calculated as required by section 25208.8(f)(3). 5. Determine background ground water quality from an upgradient well that has not been affected by any other waste disposal practices such as septic tanks, leach fields, or other waste management units.