Laserfiche WebLink
<br /> <br />Central Valley Regional Water Quality Control Board <br />11 May 2022 <br />Ms. Karen Taylor <br />Joseph L. and Dorothy Nomellini Trust <br />P.O. Box 144 <br />Linden, CA 95236 <br />CONE PENETRATION TESTING REPORT, LOPEZ PROPERTY (T0607717976), <br />1601 TURNPIKE ROAD, STOCKTON, SAN JOAQUIN COUNTY <br />Dear Ms. Taylor, <br />Central Valley Regional Water Quality Control Board (Central Valley Water Board) staff <br />reviewed the Cone Penetration Testing Report (CPT Report) dated 10 December 2021, <br />submitted on your behalf by AdvancedGeo, Inc. (AGI). The Lopez Property is located at <br />1601 Turnpike Road in Stockton (Site). <br />In October 2021, AGI advance 3 cone penetration testing (CPT) borings, CP-3 through <br />CPT-5, and collected depth discrete grab groundwater samples. AGI collected depth <br />discrete samples from 61 to 65 feet below ground surface (ft bgs) from CPT-3, from 57 <br />to 61 ft bgs and 98 to 102 ft bgs from CPT-4, and from 61 to 65 ft bgs and 103 to 107 ft <br />bgs from CPT-5. Grab groundwater samples collected between 57 and 65 ft bgs were <br />collected from the intermediate zone while samples collected between 98 and 107 ft bgs <br />were collected from the deep zone. <br />Central Valley Water Board staff has the following comments: <br />1. Petroleum hydrocarbons were not detected in deep groundwater samples <br />collected from CPT-4 and CPT-5. Based on this data, staff concurs with AGI that <br />the Site has been vertically delineated to the east. <br />2. AGI did not collect a deep grab groundwater sample from CPT-3 due to refusal <br />between 75 and 78 ft bgs. In the work plan approval letter dated 13 June 2021, <br />staff stated that collection of both intermediate and deep grab groundwater <br />samples is needed to compete plume delineation and that if the CPT drill rig is <br />unable to reach the necessary sampling depths, a different drill rig would need to <br />be utilized to collect the needed data. Vertical delineation of petroleum impacts <br />to groundwater are not defined to the northeast of the source area. The closest <br />identified water supply well is located approximately 800 feet to the northeast of