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• Horizon Environmental, Inc. FIELD METHODS AND PROCEDURES The following section describes field procedures utilized by Horizon Environmental Inc. (Horizon) personnel in performance of the tasks involved with this project. 1.0 HEALTH AND SAFETY PLAN Field work performed by Horizon and subcontractors at the site will be conducted according to guidelines established in a Site Health and Safety Plan (SHSP). The SHSP is a document that describes the hazards that may be encountered in the field and specifies protective equipment, work procedures, and emergency information. A copy of the SHSP will be at the site and available for reference by appropriate parties during work at the site. 2.0 GROUNDWATER DEPTH EVALUATION Each monitoring well is opened and allowed to equilibrate to atmospheric pressure prior to measuring depth to groundwater. Depth to groundwater will be measured to the nearest 0.01 foot using an electronic hand held water level indicator. Depth to groundwater will be measured from the surveyed point on the top of the well casing. The tip of the probe will be examined to evaluate whether a product sheen is present. 3.0 AQUIFER PUMPING TESTS Aquifer pumping tests will be conducted at the site to evaluate aquifer characteristics of the shallow water-bearing zone beneath the site. The pumping tests will be performed by using a 4-inch diameter submersible pump to extract groundwater from the selected pumping well, and drawdown will be measured in selected observation wells. Automated data loggers will be used to continuously record water level data in the observation wells. Additionally, electronic water level indicators will be used to measure water levels to the nearest 0.01 foot in the observation wells and the pumping well. The pumped groundwater will be routed from the pumping well to a flowmeter, and then into a 200-pound carbon canister prior to discharge. Groundwater will be discharged to the City of Stockton sanitary sewer system under a Municipal Utilities Department Special Permit for Wastewater Discharge dated September 1, 1995, and effective until August 30, 2000. 4.0 MONITORING WELL SAMPLING Prior to sampling, a clean transparent bailer is lowered into the well and a sample of the groundwater is brought to the surface and inspected for the presence or evidence of product on the top of the groundwater. Groundwater sampling is conducted with a . dedicated, clean, disposable plastic bailer. The groundwater samples will be collected without prior well purging because of the on-going aquifer pumping test. Samples will be contained in air-tight vials and then packed on ice and sent to the laboratory for analysis.