SITE INFORMATION AND CORRESPONDENCE

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San Joaquin County DIRECTOR o U. i N Donna Heran, REHS Environmental Health Department f" ASSISTANT DIRECTOR ` 2� 600 East Main Street Laurie Cotulla, REHS W Stockton , California 95202 -3029 PROGRAM COORDINATORS - Carl Borgman, REHS o . . , p • Mike Huggins, REHS, RDI 0 . ORS) Website: www. sjgov. org/ehd Margaret Lagorio, REHS Phone : (209) 468-3420 Robert McClellon, REHS Fax : (209) 464-0138 Jeff Carruesco, REHS, RDI ,JULhA 11 B 3 2007 Kasey Foley, REHS FOPPIANO INVESTMENTS ERNEST FOPPIANO JERI FOPPIANO 372 PARAGON AVE 2386 PHEASANT RUN CIRCLE STOCKTON CA 95210 STOCKTON CA 95207 RE : Stockton City Taxi Service SITE CODE : 1117 2085 Fremont Street Stockton CA 95320 San Joaquin County, Environmental Health Department (SJC/EHD) has reviewed "Subsurface Investigation Report" (Report) dated December 20, 2006 and "Comparative Site Study" (Study) dated March 19 , 2007 submitted on your behalf by ATC Associates Inc. (ATC) and has the following comments. The Report documents the installation of two offsite shallow groundwater monitoring wells (MW-13 & MW-14) to define the lateral extent of the shallow groundwater contamination to the east and northeast of your site, and one deep groundwater monitoring well (MW- 15) to define the vertical extent of the groundwater contamination onsite. The Report concludes that the groundwater contamination is laterally defined in the shallow zones in all directions except to the south , and is vertically defined onsite to between 90 and 116 feet below surface grade (bsg). The lateral extent of the groundwater contamination in the intermediate (90 feet bsg) zone is not well defined . In the Study ATC compares your site to the contaminated underground storage tank site located at 2050 Fremont Street, (Apache Plastics), south across Fremont Street in the apparent down gradient direction from your site. ATC has proposed using wells at the Apache Plastics site as part of your site investigation . In comparing the shallow zone monitoring wells at the two sites, ATC concluded that Apache Plastics well A-MW-2, which is screened similar to your onsite shallow monitoring wells, could provide groundwater quality data from southeast of your site. This well does provide groundwater quality data, and does appear to connect with the sandy interval that has been logged on both sites at approximately 60 feet below surface grade (bsg). However, A-MW-2 has reported concentrations of 1 ,2-dichloroethane (1 ,2-DCA), occasionally at high concentrations, and therefore does not define the lateral extent of your contamination . Apache well A-MW-6 , screened shallow and located southeast of A-MW-2, also has reported concentrations of 1 ,2-DCA. Therefore, the shallow plume of 1 ,2-DCA is not defined . In comparing the intermediate zone monitoring wells, ATC notes that Apache wells A-MW-8 and A-MW-9, screened from approximately 95-105 feet bsg, and A-MW-11 , screened from 99 .5-109. 5 feet bsg , are screened deeper than the intermediate wells at your site, which are all screened from 85-90 feet bsg . ATC concludes that these Apache Plastics wells will serve to evaluate the intermediate plume to the southeast and southwest. It should be noted that A-MW- 11 is located on the north side of Fremont Street, at the corner of Laurel; it is not down gradient from your site. SJC/EHD does not consider that enough information has been provided on the subsurface at these two depth intervals to conclude that they are connected . Additionally, both A-MW-8 and A-MW-9 are impacted wells and therefore do not provide lateral definition of the contamination in the intermediate zone, if that is the zone in which they are screened , and if the groundwater plume at your site has indeed traveled to that extent.