Laserfiche WebLink
)o • <br />San Joaquin County <br />Environmental Health Department <br />600 East Main Street <br />Stockton, California 95202-3029 <br />PETER & MINH BUI <br />4004 MADDIE CIRCLE <br />STOCKTON CA 95209 <br />RE: Ralph's Square <br />2122 S. Airport Way <br />Stockton CA 95206 <br />Website: www-sjgov.org/ehd <br />Phone: (209) 468-3420 <br />Fax: (209) 464-0138 <br />OCT 2 2 2007 <br />DIRECTOR <br />Donna Heran, REHS <br />ASSISTANT DIRECTOR <br />Laurie Cotulla, REHS <br />PROGRAM COORDINATORS <br />Carl Borgman, REHS <br />Mike Huggins, REHS, RDI <br />Margaret Lagorio, REHS <br />Robert McClellon, REHS <br />Jeff Carruesco, REHS, RDI <br />Kasey Foley, REHS <br />RALPH LEE WHITE <br />2230 S AIRPORT WAY <br />STOCKTON CA 95206 <br />SITE CODE: 1004 <br />San Joaquin County Environmental Health Department (SJC/EHD) has reviewed Additional Site <br />Assessment Report (Report) dated October 5, 2007, submitted on your behalf by Advanced <br />GeoEnvironmental, Inc. (AGE) and has the following comments. <br />The Report documents the onsite installation of three groundwater monitoring wells (MW -4, MW -5 & <br />MW -6) and a cone penetration test boring (CPT -1). Soil samples for analysis were collected from the <br />boreholes of the monitoring wells; soil and grab groundwater samples were collected from CPT -1. <br />Analytical results of the soil samples reported 710 milligrams per kilogram (mg/kg) total petroleum <br />hydrocarbons as gasoline (TPHg) at 15 feet below surface grade (bsg), and a few minor detections of <br />toluene, xylenes and methyl tertiary butyl ether (MtBE) to depths as great as 90 feet bsg in the CPT <br />boring. Laboratory analysis of the grab groundwater samples collected from CPT -1 detected TPHg, <br />MtBE, benzene, toluene, ethylbenzene and xylenes from 62 to 100 feet bsg, with the highest <br />concentrations reported at 90 feet bsg. <br />The new monitoring wells were first sampled on July 6, 2007 during the third quarter 2007 quarterly <br />groundwater monitoring and sampling event. Petroleum hydrocarbon contamination was reported in each <br />well; the highest concentrations were reported in well MW -5. <br />The Report recommends installation of additional soil borings and groundwater monitoring wells to <br />assess the vertical extent of the impacted soil and groundwater, and the lateral extent north and south of <br />the former underground tank pit area. SJC/EHD agrees further assessment work needs to be completed, <br />but does not recommend additional CPT work near the source area at this time. The contamination <br />reported in the grab groundwater samples collected from CPT -1 needs to be verified with a deep, <br />discretely screened groundwater monitoring well. <br />Please prepare a work plan to define the lateral and vertical extent, in all directions, of the contamination <br />at your site. The work plan is due for submittal no later than December 28, 2007. If you have any <br />questions please call Lori Duncan at (209) 468-0337. <br />Donna Heran, REHS, Director <br />Environmental Health Department <br />Lori Duncan, Senior REHS <br />LOP/Site Mitigation Unit IV <br />cc: James Barton, PG, CVRWQCB <br />Rebecca Natal, AGE <br />Nuel C. Henderson Jr., PG <br />LOP/Site Mitigation Unit IV <br />