SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

California Re o Water Quality AtA Board Central Valley Region 'Winston H.Hickox Gray Davis Secretaryfor Governor Environmental Sacramento Main Office Protection Internet Address:http://w .sw b.ca.gov/r gcb5 3443 Routier Road,Suite A,Sacramento,California 95827-3003 Phone(916)255.3000 FAX(916)255-3015 15 December 2000 Fi> Mr. Daniel Decker c.r. ContiGroup Companies, Inc. 277 Park Avenue New York,NY 10172 SITE CHARACTERIZATION,MONITORING AND REPORTING PROGRAM NO. 5-00-858, CONTIGR0UP COMPANIES,INC., FRENCH CAMP, SAN JOA QUIN COUNTY We have reviewed the 13 and 15 September 2000 letters submitted by Ogden Environmental and Energy Services (Ogden) for the ContiGroup Companies, Inc. (CGCI)French Camp Elevator facility(site) at 9504 S. Harlan Road. These letters responded to our 25 August letter that requested amendments to the 23 June Work Plan for Additional Site Characterization (work plan)prepared by Metcalf&Eddy and our 29 June letter that requested CGCI sample five nearby,private wells and a municipal well. The 13 September letter, submitted in lieu of the amended work plan, contained the following statements regarding our request for an alternative,reconnaissance soil investigation: "To our knowledge, all likely locations of spills have been investigated. As you can see from Figure 1, the site has been blanketed by soil borings and there is no evidence of significant contamination in shallow soils." the relatively shallow groundwater and heterogeneous lithology would limit the utility of this technique(soil vapor survey)." As stated in our 25 August letter, adequate soil data have not yet been collected. We do not concur with your opinion that the site has been"blanketed by soil borings." According to Figure 1, CGCI has obtained discrete soil samples for chemical analysis at 14 locations on the approximately 10-acre site. Additionally, and as noted in the Ogden letter, the physical characteristics of carbon tetrachloride (i.e., low soil sorption and high vapor pressure)mean it is generally more readily detected in soil vapor samples than discrete soil samples. Neither groundwater,which is about 20 feet below the ground surface,nor the sedimentology will inhibit collection of soil vapor samples from the vadose zone. Soil vapor migration of contaminants is a significant pathway for groundwater contamination. Therefore, since a source for the contaminants to groundwater has not been identified and the only method of soil investigation to date has been collecting discrete soil samples at a limited number of locations, CGCI needs to conduct an alternative, reconnaissance soil investigation that may have a higher likelihood of identifying the source area than discrete soil sampling.'This may include, but is not limited to, an active or passive soil vapor survey. California Environmental Protection Agency A Recycled Paper