IMPACT OF TURBIDITY ON TCE AND DEGRADATION PRODUCTS IN-GROUND WATER

Elevated particulate concentrations in ground water samples can bias c ontaminant concentration data. This has been particularly problematic for metal analyses where artificially increased turbidity levels can a ffect metals concentrations and confound interpretation of the data. H owever, few studies have been conducted to determine the impact of par ticulates on trichloroethylene (TCE), cis-dichloroethylene (c-DCE), an d vinyl chloride concentrations. Laboratory batch studies and field in vestigations were conducted to evaluate the effects of suspended solid s on VOC concentrations in ground water samples analyzed by purge-and- trap gas chromatography. Three different solids were used to assess th e effects of suspended particulates. The solids were aquifer material from a field site in North Carolina and two reference clay minerals (k aolinite and Namontmorillonite). During the laboratory portion of this study, the solids were used to determine effects on TCE concentration s under controlled laboratory conditions. The same solids were used in a field study to compare the laboratory results with field results. S olids were added to the sample vials prior to sample collection to int entionally increase turbidity levels in the water samples. Results of the study indicate essentially no decrease in TCE, c-DCE, or vinyl chl oride concentrations due to increased turbidity levels.