SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Mr. Kirk Moon -2- 16 July 1990 U. S. Chemical Company The four locations numbered 5, 6, 7, and 8 may be composited if indeed the sludge is no more than a few inches thick, however, the complete suite of tests need to be performed. We think it likely that the two stratified samples from two locations near the discharge pipe probably contain the highest concentrations of metals, minerals and organics. 4. The detection limit must be sufficiently low enough to identify the potential constituents. Costly sampling and analysis yielding non-detect values higher than water quality criteria are not useful to the Board and should be avoided. Also, sufficient sample volume should be taken to allow the laboratory room for additional runs if matrix interference is projected and allow analysis at acceptable detection levels. 5. The workplan indicates that the samples will not be taken beyond 2 inches of the clay liner. If the liner is 'clean' , assurance that the waste will not be diluted with liner material is necessary. If the clay liner with ten years of use has become completely saturated with waste constituents it then it becomes a waste itself and needs characterization. 6. The 13 chemical groups listed and the group of dyes and scents are possible wastewater constituents. The proposed wastewater sampling includes two samples form the surface impoundment and five samples from the sump on five consecutive days. The sump sampling needs to be scheduled when the waste stream is representative of the processing schedule that would include the chemical groups that have been historically impounded. 7. A chemical comparison of wastewater collected in the sump and the wastewater within the surface impoundment should be tabulated and compared to allow evaluation of volatilization. The aquatic toxicity testing the California Department of Health Services (DHS) performed on the liquids and sludge from the surface impoundment indicate that the sludge within the surface impoundment exceeds the hazardous criteria. The identification of what specific constituent or combination of constituents makes the sludge/wastewater fail the toxicity criteria for hazardous wastes is not addressed in the present work plan. If a hazardous/non-hazardous waste re- determination is desired the Waste Evaluation Unit within the California State Department of Health Services must be contacted, and may require more stringent analysis than that proposed in the 2 July 1990 work plan. It is anticipated that the technical report that will be generated by sampling of the waste stream and surface impoundment will satisfy the waste characterization requirements of the TPCA Hydrogeological Assessment Report. In addition, please submit for our review the preliminary laboratory data when the laboratory supplies the results of the testing.