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CH2M HILL <br /> � 155 Grand Avenue <br /> Suite 1000 <br /> Oakland,CA 94612 <br /> l'U <br /> C® 1 HN LL P.O.Box 12681 <br /> eilaw Oakland,CA 94604-2681 <br /> Tel 510.251.2426 <br /> Fax 510.893.8205 <br /> August 10,2004 <br /> Ms. Mary Serra <br /> Water Resources Control Engineer <br /> California Regional Water Quality Control Board <br /> Central Valley Region <br /> 3443 Routier Road,Suite A <br /> Sacramento,CA 95827 <br /> Subject: Request for No Further Action at the McMullin Dehydrator Station <br /> Dear Ms. Serra: <br /> On the behalf of Pacific Gas and Electric Company(PG&E),we are requesting No Further <br /> Action (NFA) at the McMullin Dehydrator Station(site) in San Joaquin County,California. <br /> We sampled the McMullin wells on July 12,2004 pending your rescission of the Draft <br /> Monitoring and Report Program for this site. Remedial soil excavation was performed at the <br /> site in 2002 to remove petroleum hydrocarbons from soil and groundwater and all <br /> equipment has been removed from the station.There are no sources remaining at the site to <br /> cause future releases of petroleum hydrocarbons. <br /> Post-remediation groundwater monitoring has shown no detectable amounts of BTEX in <br /> groundwater over four continuous quarters with the exception of upgradient,off-site well <br /> MW-1. October 2003 results for MW-1 indicated low concentrations of BTEX. Results from <br /> the subsequent three sampling events(January,May,and July 2004)showed no detectable <br /> levels of BTEX in any of the wells. <br /> Post-remediation groundwater monitoring for petroleum hydrocarbons have shown no <br /> detectable levels of TPH over four continuous quarters with the exception of MW-1 and <br /> piezometer PZ-3. Results from October 23,2003 samples for MW-1 detected TPH in the <br /> gasoline range(TPH-g) at 101 µg/L.Three subsequent sampling events(January,May,and <br /> July 2004)showed no detectable levels of petroleum hydrocarbons in the gasoline,diesel,or <br /> motor oil ranges. Analytical results from October 23,2003 samples for PZ-3 detected TPH in <br /> the diesel range (TPH-d) at 400µg/L and TPH-g at 140 µg/L. Results for sampling in <br /> January,May and July showed no detectable levels of TPH-g,and TPH-d (at PZ-3)at 220 <br /> µg/L. <br /> The NFA request is based on the following rationale: <br /> • Concentrations of BTEX in groundwater samples from wells MW-2R,PZ-1,PZ-3,and <br /> PZ-4 in or adjacent to the excavation are non-detect for at least four quarters(see <br /> Tables 1 and 2). <br />