Laserfiche WebLink
C A L I IF O N N I A <br />Water Boards <br />Central Valley Regional Water Quality Control Board <br />19 April 2019 <br />Mr. Joshua Hernandez Zavala <br />General Services Department <br />San Joaquin County <br />44 North San Joaquin Street, Suite 590 <br />Stockton, CA 95202 <br />CI VIN NI wBOM <br />t f AY) HNf)H <br />JAHI n 81 UM h Nit1 I) <br />.'Y01—1 1 <br />NYiVt()NMI !11 AI 1'N01 hC 11l)k <br />2136 <br />EPIVIRONMErITAI_ HEALTH <br />Pt RMIRSERVICES <br />San Joaquin County Records Center, 630 North California Street, Stockton, San Joaquin <br />County <br />Central Valley Regional Water Quality Control Board (Central Valley Water Board) staff <br />reviewed the Addendum to Subsurface Investigation Work Plan dated June 21, 2018 (Work <br />Plan Addendum) dated 22 February 2019, and the Semiannual Groundwater Monitoring Report <br />Period Ending December 31, 2018 (3Q2018 Report) dated 8 November 2018, both submitted <br />on your behalf by Condor Earth (Condor). The San Joaquin County Records Center is located <br />at 630 North California Street in Stockton (Site). <br />In the Work Plan Addendum, Condor reported that they attempted to collect shallow soil <br />samples near the UST on 17 December 2018. The borings could not be advanced by hand <br />auger due to refusal within the upper 2 feet of the ground surface. Condor proposes to advance <br />two soil borings, HA2 and HA3, using a direct push rig to collect shallow soil samples, and to <br />collect a down -gradient groundwater sample (GW1). Condor will collect one soil sample from <br />each boring from 4.5 to 5 feet below ground surface (ft bgs). Boring GW1 will be advanced to a <br />depth of approximately 25 to 30 ft bgs. Continuous soil cores will be collected for lithologic, and <br />based on field evidence for laboratory analytical analysis. A grab groundwater sample will be <br />collected from boring GW -1 for laboratory analysis. <br />Condor will analyze soil samples for total petroleum hydrocarbons as gasoline (TPH-G), TPH as <br />diesel (TPH-D), benzene, toluene, ethylbenzene, total xylenes (collectively BTEX), <br />1,2-dichloroethane (1,2 -DCA), naphthalene, and methyl tert butyl ether (MTBE) - <br />Central Valley Water Board staff concur with the scope of work presented in the Work Plan <br />Addendum. Please submit a Results Report by 1 August 2019. Additional work may be <br />required based on the results of this phase of investigation. Please provide me with at least 3 <br />working days notice to allow me the opportunity to observe. <br />KARL E. LONGLEY SCD, P.E.. CHAIR I PATRICK PULUPA. ESO., EXECUTIVE OFFICER <br />11020 Sun Center Drive #200, Rancho Cordova, CA 95670 1 www.waterboards.ca.gov/centralvalley <br />Li HECYCLEO PAPEP <br />