SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

San Joaquin County DIRECTOR o u M Donna Heran,REHS Environmental Health Department h ASSISTANT DIRECTOR "G 600 East Main Street Laurie Cotulla, REHS N: Stockton, California 95202-3029 PROGRAM COORDINATORS Carl Borgman,REHS r•' Mike Huggins, REHS, RDI 0.•- :a�P Website: v+rww.sjgov.org/ehd Margaret Lagorio, REHS i F O R Phone: (209) 468-3420 Robert McClellan,REHS Fax: (209)464-0138 Jeff Carruesco,REHS, RDI Kasey Foley, REHS March 6, 2009 John Cervantes PO Box 6008 Stockton, CA 95206 Subject: JC Trucking Site Code: 2571 1207 Aurora Street Stockton, CA 95206 The San Joaquin County Environmental Health Department (EHD) has reviewed Quarterly Groundwater Monitoring and Sampling Report, Fourth Quarter 2008 Sampling Event (Report) dated February 2009, submitted on your behalf by JJW Geosciences, Inc. (JJW) and has the following comments. The Report documents a routine quarterly groundwater monitoring and sampling event that was conducted at the above subject contaminated underground storage tank (UST) site. The site has been in active groundwater remediation by ozone infusion since December 2004, and reported concentrations of contamination in the groundwater continue to decline. In the Report JJW recommends putting ozone sparge point SP-4, which is screened at a depth of approximately 124 feet below surface grade (bsg), online to address the reported detections of 1,2-dichloroethane (1,2-DCA) in groundwater monitoring well MW-11. The EHD agrees with this recommendation. In the Report JJW also recommends adding analysis for 1,2-DCA to the analytical suite for MW-1, but according to the submitted laboratory analytical report this has already been implemented; the EHD does approve the analysis. The EHD also approves further reductions in the sampling regimen at the site. Monitoring wells MW-1, MW-2, MW-5, MW-7 MW-8 and MW-11 may be changed to a semi-annual schedule; and wells MW-4, MW-6, MW-9, MW-10 and MW-12 may be changed to an annual schedule. In May 2008 the State Water Resources Control Board Cleanup Fund completed a 5-year review of your site. Their recommendation to the EHD was that the site be considered for closure providing the potential for soil vapor migration is assessed and determined safe for prescribed site activities. The EHD agrees that this site is a likely candidate for closure this year, but there was significant petroleum hydrocarbon impact to the shallow soil in both of the former tank pit areas. This remaining source area contamination presents a threat to both the groundwater as it continues to leach from the soil in to the water, and as soil vapor migrating to the surface. No structures currently are located over this area but nothing is to preclude that some day a structure may be constructed here.