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3.5.3 Well Development and Sampling The monitoring wells will be developed at least 72 hours after their installation. The depth to water and product thickness (if present) will be measured in each monitoring well to the nearest 0.01 foot, using an electronic oil/water interface probe. Development will consist of surging the screened interval of the monitoring well with a vented surge block of the same diameter as the casing for approximately 10 minutes. The monitoring well will be purged using one of the following methods: • A vacuum truck equipped with a dedicated PVC stinger or disposable tubing; • An inertial pump; • A submersible electric pump; • A centrifugal pump; • An air-lift pump; or • A bailer. As part of the development, each monitoring well will be purged until at least 10 casing volumes of groundwater have been removed, the water is free of silt and apparent turbidity, and water quality parameters (including temperature, pH, specific conductance, dissolved oxygen, and oxidation-reduction potential)have stabilized. A record of the purging methods, water quality parameters, and volumes of water purged will be maintained. All purge water will be contained at the Site in properly labeled 55-gallon drums and transported to an appropriate treatment or disposal facility. All reusable sampling equipment will be washed with a Liqui-Nox solution, rinsed with tap water, and rinsed with distilled water. Following at least 48 hours after development, each monitoring well will be purged and groundwater samples will be collected in clean bottles supplied by the analytical laboratory. Sample bottles will be sealed, labeled, placed in resealable plastic bags and immediately placed on ice in a thermally-insulated cooler, and transported to a state-certified analytical laboratory under chain-of-custody protocol. The groundwater samples will be analyzed for TPH-g, BTEX, five fuel oxygenates (DIPE, ETBE, MTBE, TAME, and TBA), and fuel additives (1,2-DCA and EDB) by EPA Method 8260B. Following the initial sampling, the newly-installed wells will be incorporated into the quarterly groundwater monitoring schedule for the existing wells at the Site. 3.6 MONITORING WELL SURVEYING In accordance with the State of California Geotracker requirements, the locations and elevations of all monitoring wells at the subject site must be surveyed. The survey will be performed by a California-licensed Professional Land Surveyor and include latitude, longitude, 10