Laserfiche WebLink
Oct. <br /> ENSR International <br /> 10411 Old Placerville Road <br /> Suite 210 <br /> July 30, 2004 Sacramento, GA 95827 2508 <br /> ' (916)362 7100 <br /> FAX (916)362-8100 <br /> www ensr cam <br /> ' Mr James Barton j� <br /> Regional Water Quality Control Board W � �� J� <br />' Central Valley Region <br /> 11020 Sun Center Drive, Suite 200 AUG 0 3 2004 <br /> Rancho Cordova, CA 95670 ENVIRO <br /> NMEN 1'HEALTH <br />' <br /> RE- Monitoring Well Installation Report PFRMITISERVICES <br /> and Summary of Efforts to Cease Plume Movement <br /> Former Unocal Facility No. 5098 <br />' 5400 and 5606 Pacific Avenue, Stockton, California <br /> Dear Mr Barton <br />' ENSR Corporation ENSR was authorized b Union Oil Company of California Unocal to <br /> P (ENSR) Y P Y (Unocal), <br />' conduct an additional hydrogeologic investigation at the subject site (Figure 1) The <br /> investigation was conducted in response to the Regional Water Quality Control Board, Central <br /> Valley Region (RWQCB) request for additional work to further assess the extent of groundwater <br /> impacts and to undertake remedial efforts to cease migration of the dissolved petroleum <br /> hydrocarbon plume This investigation was conducted on July 6 and July 7, 2004 to define the <br /> lateral extent of the dissolved petroleum hydrocarbon plume extent to the east, southeast, and <br /> south of existing wells within the B-zone (Figure 2) A summary of efforts taken to cease plume <br />' movement and the results of those efforts is also provided The work was conducted in <br /> accordance with ENSR's Workplan and Schedule to Cease Plume Movement and Define Limits <br /> Within the B-zone dated June 14, 2004 The RWQCB approved the workplan to install the <br /> t proposed monitoring wells, with conditions, as specified in RWQCB letter dated June 18, 2004, <br /> a copy of the RWQCB letter is included in Attachment A <br />' Site Background and History <br /> The site is located in a commercial business and retail shopping district The site currently has <br />' an active air sparge remediation system and an inactive soil vapor extraction remediation <br /> system Montgomery Wards (Wards) and Unocal are named jointly responsible for actions <br /> necessary to abate the effects of contamination In the vicinity of the sites, in Cleanup and <br /> Abatement Order No 5-00-707 dated, September 8, 2000 In August 2000, Wards and Unocal <br /> executed an agreement for coordinated corrective action for Underground Storage Tank (UST) <br /> Fund Claim No 1760 and UST Fund Claim No 6864 On November 2, 2001, unocal was <br /> named as the appointed representative for the Pacific/Robinhood commingled plume <br />' Wards formerly operated an auto service center at 5400 Pacific Avenue, Stockton, California <br /> Between 1986 and 1988, Wards removed one waste oil UST, four bulk oil USTs, and two <br /> gasoline USTs from the site Numerous soil and groundwater investigations of the Wards site <br /> were conducted and a remedial system (air sparging with vapor extraction) was installed to <br /> address the remediation of petroleum hydrocarbons present in soil and groundwater beneath <br /> J 1Proiect0694015098 293final\Reports15098 Well Results Report doc <br />