COMPLIANCE INFO_FILE 1 2003-2006

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Mr. Jerry Lile(DISC) Page 5 of 7 have been affected by the operations at Marina West Marine Services and may reflect copper deposition from general public use such as boat storage. The estimated limits of the impacted areas are depicted on Figure 3. As shown, the total affected area would be about 1,000 square feet or less. The eastern edge of impact outside the work area,however,has not been defined. Elevated concentrations of water-soluble copper are also present in the areas with elevated total copper. These concentrations range from 0.05 ppm to 0.12 ppm in extract or 0.5-1.2 ppm in soil. Evaluation of Threat to Surface Water The promulgated freshwater aquatic life protection standards (NTR, CTR) and related policies, while not directly applicable to the contaminated soil at the site, may be relevant requirements. The continuous concentration standard for delta surface water would range between approximately 0.004 and 0.012 ppm, depending upon hardness. The fact that the DI-WET extract of certain soil samples exceeds these criteria creates a presumption that surface waters may be threatened. However, we conclude that the material does not have significant potential to threaten surface water quality or aquatic life. This is based on site-specific conditions and several lines of reasoning which are summarized below: • Runoff from the affected areas would not be expected to contain dissolved copper concentrations at the levels reported in the DI-WET extract. The DI-WET extraction procedure consists of pulverizing the soil sample and vigorously agitating it in water continuously for a period of 48 hours. This is a poor approximation of natural conditions at this site and would be expected to overestimate the concentration in runoff. Rainfall in excess of the penetration capacity of the soil may runoff, but will be in contact with only the immediate ground surface and only for a short period of time. Runoff water should not be capable of leaching more than a small percentage of the soluble copper from the affected soil. • The total mass of water-soluble copper in the affected soil is miniscule and should be incapable of creating an excursion of surface water above the aquatic life protection standard. The total mass of water-soluble copper contained within 1,000 square feet of impacted area is only 0.03 (3 E-02) pounds or less (1000 ft2 x 0.25 ft x 100 lbs/ft3 x 1.2 ppm x 1E-06). This is the mass of 5.4 pennies (United States Mint). As an example, if a particular rainfall event resulted in 2 inches of runoff from 1,000 affected square feet, and the runoff was at the maximum DI-WET leachate concentration (0.12 ppm, unlikely), the runoff would contain 0.00125 lbs of copper(1,000 ft2 x 0.167 ft x 62.4 lbs/ft3 x .12 ppm x 1 E-06). This could elevate the copper concentration of approximately 0.09 acre-feet of water 0.005 ppm. The boat basin at the Marina contains an estimated 75 acre-feet and the portion of Fourteenmile Slough to the south of the Marina contains an estimated 10-15 acre feet. The potential elevation of copper in these G:\GROUNDZE\MARINA\VfllageWest\Aquatoxrpt.doc