Laserfiche WebLink
1 <br /> ENVIRONMENTAL HEALTH DEPARTMENT <br /> SAN JOAQUIN COUNTY <br /> Unit Supervisors <br /> Donna K.Heran,R.E.H.S. P <br /> 304 East Weber Avenue Third Floor Carl Borgman,R.E.H.S. <br /> Director Mike Huggins,R.E.H.S.,R.D.I. <br /> Al Olsen,R.E.H.S. Stockton, California 95202-2708 Douglas W.Wilson,R.E.H.S. <br /> cgC/FOR �P Program Manager <br /> Telephone: (209) 468-3420 Margaret Lagorio,R.E.H.S. <br /> Laurie A.Cotulla,R.E.H.S. <br /> Program Manager Fax: (209)464-0138 Robert McClellon,R.E.H.S. <br /> Mark Barcellos,R.E.H.S. <br /> STEPHEN VALENTINE OCT 2 2 2002 <br /> STEVE & GENES SERVICE <br /> 6232 HEMET AVE <br /> STOCKTON CA 95207 <br /> RE: STEVE & GENES SERVICES SITE CODE: 2080 <br /> 2315 N ELDORADO ST <br /> STOCKTON CA 95204 <br /> San Joaquin County Environmental Health Department(EHD) has reviewed Additional <br /> Characterkation Work Plan(work plan) dated June 27,2002 prepared by Geological Technics,Inc. <br /> (GTI). The work plan proposed installing 19 monitoring wells to assess the vertical and 1.lateral <br /> extent of the impacted groundwater. GTI proposes to: <br /> 1) Install a 2-inch diameter monitoring well,MW-301 at 155 feet below surface grade <br /> (bsg) using mud rotary system and a 6-inch diameter steel conductor casing to 130 <br /> feet bsg to minimize cross-contamination. Total depth of MW-301 would be <br /> determined at the field,and the borehole would be logged from 130 to 170 feet bsg. <br /> 2) Install six clustered shallow/ intermediate/ deep wells for a total of 18 monitoring <br /> wells using hollow stem auger and mud rotary system off site to define the lateral <br /> extent of the contamination. Each well cluster made up of one shallow monitoring <br /> well screened at 25 to 40 feet bsg,an intermediate well screened at 70 to 80 feet bsg, <br /> and a deep monitoring well screened at 120 to 125 feet bsg. <br /> EHD has received 11,Quarter 2002 Groundwater Monitoring Report dated May 15,2002 prepared by <br /> GTI,and fax of the analytical results for the June sampling event received on September 9,2002 <br /> from GTI. Analytical results of the last three groundwater samples collected from the deepest <br /> monitoring well (MW-201) on site are as follows: <br /> Table 1: Anal tical results of groundwater samples from MW-201 <br /> Benzene Toluene Ethyl- Xylenes TPH-gas MTBE <br /> Benzene <br /> 12/11/01 13.8 85.5 24.7 165 1,140 ND<5 <br /> 02/27/02 1.0 1.5 0.8 16 233 ND<5 <br /> 06/14/02 ND<0.04 ND<0.09 0.3 4.8 ND<8 2.4 <br /> All results in micrograms per liter(µg/1) TPH-gas: Total Petroleum Hydrocarbons as gasoline <br /> MTBE: Methyl tert butyl ether ND: Non Detect <br /> Concentrations of petroleum hydrocarbon contamination in the groundwater samples of M%V-201 <br /> have dropped significantly since its installation in October 2001. Additional monitoring wells <br /> screened in the same depth of MW-201 do not appear to be necessary at this time. Installation of <br /> the proposed MW-301 is not approved at this time,but may be necessary in the future depending <br /> on future monitoring results. <br />