Laserfiche WebLink
California RecFional Water Quality Control Board : <br /> Central Vallev Region <br /> Steven T.Butler.Cktair Gray Davis <br /> Stan H Hickox Gmernor <br /> � <br /> +rrararyjor Sacramento Jam <br /> Office r <br /> tiirofurcroal kttrnet Address b;[�1rwwls sw�c'� gay!-trtigt:5 <br /> Pro'evion �3 R:aer Road,Suitt�,SacTat&rco,Gal Aotna SSe?7- G03 <br /> { phon-(916)355-3000•FAXtS1S)=55-3015 <br /> • I <br /> TO. Gordon L.Boggs FROM: Marty Hartzell <br /> LAST Program Manager Associate Engineering Geologist <br /> I SIGNATURE: -^ ' �• / <br /> D 4TE: 1/ July_000 E <br /> SUBJECT. <br /> NONCONCURRENCE WITH SAN JOAQttLN COriNWY S NO FURTHER <br /> ACTION REQUIRED DETERN ATION,REGAL#603, 6425 PACIFIC AVEti'C�E <br /> STOCKTON, SAIL JOAQIJnq COUNTY <br /> I reviewed San Joaquin CounYt s (County) 6 June 2000 Case Closure Summary and the following <br /> documents in respomse to allo Further Action Required(N-YAR)request for the qub}ect site. <br /> • The 18 January 1999 Update Status Report#55,January 1999 Quarterly Groundwater Report <br /> prepared by Western Geo-Engmeers (WEGE), <br /> • The 5 February 1999 Request for Closure(Closure)prepared by Blakely Environmental <br /> Investigations(Blakely); <br /> • The 2: March 2000 Gasoline Dispensing System Removal Documentation SamF -Dort <br /> prepared by VfHGE; and <br /> o The 6 April 2000 Over-excavatron of Gasoline C`ontar:��nated Soils Associated v► <br /> Dispensing System prepared by WEGE <br /> My review shows. <br /> 1 The off-site TPHg plume has riot been laterally or veeically defined, <br /> 2 The concentrations of TPHS in off-site irmonytoring well'_VIW-12 are increasing, while TPHg in <br /> on-site wells are decreasing; <br /> 3 The status of a domestic water supply well southeast of the site has not been determined; <br /> 4 The groundwater has not been monitored for all fuel oxygenates and fuel additives; and <br /> 5 The quarterly groundwater monitoring has not been conducted sauce January 1999 <br /> Background <br /> The Regal#603 service station(Regal) operated until December 1988 when three 10,000 gasoline <br /> -gallon <br /> underground storage tanks (USTs) were removed and replaced- The new USTs were operated by Exxon <br /> from December 1988 to July 1998 Soil contamination was identified in the tank pits during UST <br /> replacement, and a soil and groundwater mvestigation was completed Figure 1 presents a site map from <br /> wEGE's January 1999 quarterly monitoring report- <br /> On-site Xnvestigatio>a <br /> Multiple soil borings were completed on-site, and contammated soils were identified from 25 feet to a <br /> total depth of 65 feet At the time of the initial investigation iii 1988 and 1989, the depth to water ranged <br /> S fr50 to 60 feet The current depth to water is approximately 33 feet. `TY e hig}iest soil co <br /> ntai:iinatiom <br /> om <br /> r'nlrfn,+nrn F'r,virnr,ntvintal protect on Aeena <br />