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CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD CENTRAL VALLEY REGION MONITORING AND REPORTING PROGRAM NO. R5-2003-XXXX FOR PACIFIC GAS AND ELECTRIC COMPANY McMULLIN NATURAL GAS DEHYDRATOR STATION SAN JOAQUIN COUNTY Pacific Gas and Electric Company's (Discharger) California Gas Transmission Division has operated a natural gas gathering system since the 1940s. The gas gathering system receives wellhead gas from nearby natural gas producers. PG&E then treats the natural gas prior to delivering it into the gas transmission system. The treatment processes may include dehydration, odorization, and compression. The McMullin Dehydrator Station is at Airport Way and Perrin Road, about two miles south of Manteca. Soil and groundwater are contaminated with benzene, toluene, ethylbenzene and xylene, and total petroleum hydrocarbons(TPH). Shallow groundwater, which is first found between nine and 13 feet bgs, contains up to 250 µg11 of benzene and 6,000 µg/l of TPH as gasoline and 2,500 µg/l of TPH as diesel. In late 2002 the Discharger excavated contaminated soil that was leaching pollution into the groundwater. This Monitoring and Reporting Program (MRP) is issued pursuant to Section 13267 of the California Water Code and is necessary to delineate groundwater pollutant plumes and determine whether remediation efforts are effective. Existing data and information about the site show the presence of various chemicals, including benzene,toluene, ethylbenzene and xylenes, and TPH as gasoline and as diesel emanating from the property and resulting from the Discharger's past operation. The Discharger shall not implement any changes to this MRP unless and until a revised MRP is issued by the Executive Officer. This MRP replaces the requirements listed in MRP No. 5-01-857, which was issued on 20 July 2001. Prior to construction of any new groundwater monitoring or extraction wells, and prior to abandonment of any groundwater monitoring or extraction wells, the Discharger shall submit plans and specifications to the Board for review and approval. Once installed, all new wells shall be added to the monitoring program and shall be sampled and analyzed according to the schedule below. GROUNDWATER MONITORING As shown on Figure 1, there are two monitoring-wells and three'piezometers. The groundwater monitoring program is for MW-1,MW-2R and PZ-1, 3 and 4, and any wells installed subsequent to the issuance of this MRP. Monitoring shall follow the schedule below. Monitoring wells with free phase petroleum product or visible sheen shall be monitored for product thickness and depth to water only. Sample collection and analysis shall follow standard EPA protocol.