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ATTACHMENT capy -3- assurance/quality control if the soils are used to construct a liner or cap. The density of tests per area and per lift must be specified. In addition, some of these tests have been previously performed using on-site soils and can be found in the "Report of Supplemental Monitoring Well Installation and Laboratory Testing" by SNR. Page 40: The risk assessment is based only on exposure to trace metals which occur in surface soils or in near surface soils and does not include an exposure scenario for drinking water where the source is the ground water contaminated by volatile organic constituents (VOCs) . Page 45: Four closure alternatives have been proposed which are soil excavation and off-site disposal , a clay cap, a RCRA cell , and site grading. The facility should also consider alternative technologies such as solidification or fixation. Page 45: None of the four closure alternatives included plans for abandonment of the dry well near Pond 1. Page 45-46: The closure alternatives requiring excavation did not include plans for verification sampling for concentrations of waste constituents to be left in-place. Page 46: Post closure monitoring is to include quarterly sampling and analyses for VOCs and selected trace metals from ten shallow monitoring wells. Because the results from the ground water assessment plan have not ben completed, it is unknown which wells have been selected and if this is an adequate number. Additionally, intermediate and deep monitor wells may need to be included in post closure monitoring. Quarterly ground water monitoring may not be necessary for the duration of the post closure period. Monitoring could be reduced to biannually (representative of the dry and wet seasons) after a specified period of time. Page 47: Closure Alternative 4 includes leaving hazardous wastes in place and grading the area for drainage. This alternative would not be acreptable, as it would be in violation of Section 25208.4(a) of the Toxic Pits Cleanup Act which prohibits the discharge of liquid hazardous wastes or hazardous wastes containing free liquids into a surface impoundment after 30 June 1988. Page 48: Post-closure activities should include ground water monitoring regardless of the chosen closure alternative because of ground water contamination from VOCs. Ground water treatment may be required at the site, therefore, ground water monitoring would continue after closure activities. Page 49: The Hargis Ground Water Assessment Plan states that wells will be sampled and analyzed annually for routine constituents (page 61) . Plans for post-closure monitoring do not include sampling and analyses for routine constituents. This discrepancy should be clarified.