Laserfiche WebLink
San Joaquin County <br /> ;,a.WN .� Environmental Health Department DIRECTOR <br /> % 600 East Main Street Donna Her< REHS <br /> a. :{ Stockton, California 95202-3029 PROGRAM COORDINATORS <br /> Robert McClellon, REHS <br /> - Jeff Carruesco, RENS,RDI <br /> c <br /> Website: www.sjgov.org/ehd Kasey Foley, REHS <br /> Phone: (209) 468-3420 Linda Turkatte, REHS <br /> Fax: (209) 464-0138 <br /> November 2, 2010 <br /> Carl Knowles <br /> PO Box 640 <br /> Woodbridge, CA 95258 <br /> Subject: 1140W. Hammer Lane SITE CODE: 1124 <br /> Stockton, CA 95209 <br /> The San Joaquin County Environmental Health Department (EHD) has received and <br /> reviewed Ground Water Monitoring and Sampling Report-Winter/Spring 2010, dated <br /> June 2, 2010, prepared by your consultant Ground Zero Analysis, Inc. (GZAI). In the <br /> report, GZAI recommends continued semi-annual ground water monitoring by collecting <br /> and analyzing samples from selected on-site and off-site monitoring wells (MWs). <br /> EHD notes the following: <br /> 1. The depths to water in the MWs remain similar to measurements recorded during <br /> recent years and an easterly ground water flow direction remains consistent with <br /> historic data. Ground water has risen approximately 30 feet since the ground <br /> water investigation began in 1987. <br /> 2. MW-11,which replaced the destroyed well MW-5 in 2008, has been sampled five <br /> quarters since it was installed. Ground water sample results from MW-11 have <br /> remained extremely high over the past 5 sampling events with no decline of <br /> contaminant concentrations. Ground water results for 2n`' Quarter 2010 were: <br /> 200,000 micrograms per Liter (ug/L) total petroleum hydrocarbon-gasoline, <br /> 49,000 ug/L benzene, 19,000 ug/L toluene, 2,000 ug/L ethylbenzene, 19,000 <br /> ug/L xylenes, and 510 ug/L 1,2-DCA. <br /> 3. Ground water contaminant concentrations in the area of MW-11 are extremely <br /> high and concentrations need to be reduced to achieve water quality objectives <br /> (WQOs) in a more timely manner. Until ground water contaminants in the area of <br /> MW-11 have been reduced to an acceptable concentration or it can be <br /> demonstrated that ground water will reach an acceptable concentration in a <br /> reasonable amount of time, this site can not be closed without further <br /> remediation. <br /> 4. The State Water Resources Control Board 5-Year Review Summary Report <br /> dated April 15, 2010, for your site recommended that you assess remedial <br /> technologies and implement active remediation to achieve WQOs in a timely <br /> min r <br />