Laserfiche WebLink
N r/ <br /> San Joaquin County <br /> " . Environmental Health Department DIRECTOR <br /> O Donna Heran,REHS <br /> m » f iSiG` 1868 East Hazelton Avenue PROGRAM COORDINATORS <br /> Stockton, California 95205-6232 Robert McClellon,REHS <br /> Jeff Carruesco,REHS,RDI <br /> Website: www.sjgov.org/ehd Kasey Foley,RENS <br /> c4 � R�. Linda Turkatte,REHS <br /> FO <br /> Phone: (209)468-3420 Rodney Estrada,REHS <br /> Fax: (209) 464-0138 Adrienne Ellsaesser,REHS <br /> April 3, 2014 <br /> Charanjit S. & Davinder K. Jutla <br /> 3940 N. Tracy Boulevard Site Code: 0001953 <br /> Tracy, CA 95304 <br /> Subject: Tracy Truck& Auto <br /> 3940 N. Tracy Boulevard <br /> Tracy, CA 95304 <br /> The San Joaquin County Environmental Health Department (EHD) has received and reviewed <br /> Summary of Supplemental Subsurface Investigation (Report) dated 22 December 2009, prepared <br /> and submitted by ATC Associates, Inc. (ATC) on your behalf. In the Report, ATC documented <br /> methods and results from advancing three soil borings east of the dispenser area borings that had <br /> encountered soil impacted by total petroleum hydrocarbons quantified as diesel (TPHd) in samples <br /> collected at 5 feet below surface grade (bsg). TPHd was detected in six out of seven soil samples, <br /> with four samples impacted at concentrations between 1,900 and 6,300 milligrams per kilogram <br /> (mg/kg). The depth to groundwater on your site is estimated to be approximately ten feet bsg, <br /> leading to the possibility that groundwater may have been impacted by the unauthorized release <br /> (UAR) from your underground storage tank (UST) system. The supplemental investigation reported <br /> in the Report was conducted to determine the vertical extent of impacted soil and to assess the <br /> impact on groundwater. <br /> Due to obstructions in the immediate dispenser areas, three soil borings (SB1, SB2 and S63) were <br /> advanced approximately 25 to 27 feet east of a center line through the dispensers to assess the <br /> impacted to groundwater and vertical extent of impacted soil. An earlier report by Advanced <br /> GeoEnviron mental, Inc (AGE) indicates the original soil samples were collected on the west side of <br /> the dispensers, so the distance between the actual initial soil sampling points and the tops of the <br /> three borings may be greater than the 25 to 27 feet. The three borings were advanced inclined at <br /> 30 degrees from vertical toward the dispensers to close the distance a bit; ATC estimates the <br /> boring bottoms to have been about 10 feet closer to the dispensers than the borings tops at a <br /> depth of 17 feet bsg. According to the Report, soil samples were collected from each boring at <br /> approximately 14.5 to 15 feet bsg and the grab groundwater samples were collected from <br /> approximately 15 feet bsg at the base of each of the three borings for laboratory analysis. TPHd <br /> was not detected in any of the three soil samples or the three grab groundwater samples, leading <br /> ACT to request case closure for your site. <br /> While reviewing your site for closure consideration, the EHD found that the groundwater flow <br /> direction on your site may not be predominantly toward the northeast as was modeled by ATC <br /> based on monitoring data from the active service station sites south of your site on Tracy <br /> Boulevard. Monitoring data from a site east of yours (425 Larch Road) has the predominant <br /> groundwater gradient direction (inferred to be the groundwater flow direction) toward the southwest <br /> to northwest. A closed site directly south of your site (3788 N. Tracy Blvd.) had a predominant <br /> groundwater gradient direction varying from northeast to northwest; the predominant gradient at <br /> Directive Letter 0414 <br />