SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

• Dry Wells Remedial Investigation Lawrence Livermore National Laboratory Site 300 San Joaquin County -2- 21 September 1990 Please note that the State Action Levels listed in RI Table 4 and Addendum Table 2 for the halogenated volatile organic compounds should be in ug/l , not in mg/l . Cleanup Levels LLNL inappropriately persists in using the Title 22 Soluble Threshold Limit Concentrations (STLC) as pollutant cleanup levels in soils. On the contrary, the STLC and the Total Threshold Limit Concentrations (TTLC) establish the line between nonhazardous and hazardous wastes for disposal purposes; for example, hazardous wastes require disposal in a Class I landfill , while nonhazardous waste may be disposed of less restrictively. Cleanup levels should be established via site-specific environmental fate analyses and risk assessments outlined in the Department of Health Services' Decision Tree Manual , Marshack 's staff report, and other sources. Additionally, the STLC should not be used as a cleanup criterion because it provides insufficient information on constituent distribution between the adsorbed, dissolved, and fixed phases in the polluted soils. The leachable constituent concentrations are measured, via the Waste Extraction Test (WET) specified in §66700, for comparison to the STLC criteria listed in Title 22 §66699. The constituent fraction leached into the test extract provides no information regarding the phase distribution mentioned above. An adequate environmental fate analysis should be able to consider this distribution to estimate the extent a constituent may migrate or react in the soil . Finally, the WET extractant (citric acid - citrate buffer solution) can cause major changes in the soil environment of the sample, rendering the results of the test unrepresentative. For metals, in particular, "These gross alterations result from the fact that the extractants can (a) selectively dissolve soil minerals, (b) impede crystallization and formation of aluminum hydroxides and other soil minerals while causing structural distortions in newly formed minerals , (c) perturb hydrolytic reactions of aluminum, and (d) desorb, via mass action, elements and organics from soil adsorption sites which may not normally be desorbed. Because the extractants cause gross alterations in the chemical properties of soil systems, the data derived from these test methods, when the soil is utilized as the solid phase, cannot be extrapolated to actual field conditions. Therefore, they should not be used as soil cleanup criteria [for] spills of hazardous materials. " [James Dragun, The Soil Chemistry of Hazardous Materials, Hazardous Materials Control Research Institute, 1988] Altering the soil chemistry with the extractant may also affect the phase distribution in the soil of the halogenated volatile and other organic compounds further invalidating use of the STLC as cleanup levels for these compounds. Sources of Drinking Water In both the reports reviewed, LLNL states "the nearest water body to be protected is the regional water-bearing zone, which lies at least 100 feet beneath the dry wells". In 1988, the State Water Resources Control Board adopted Resolution No. 88-63