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A LI California Regional Water Quality Control Board 15365 January 30, 2003 Page 5 probe through the aluminum seal. PID and sheen screening will not be conducted at locations where visual observations clearly indicate the presence of product. Following field screening for the presence of separate phase product, the soil will be returned to the test pit*. Locations of the test pits will be surveyed with a hand-held GPS and field measured for documentation on the site map. Field notes will be maintained describing the lithology encountered and the results of the field screening at each test pit. Groundwater Monitoring. Groundwater samples will be collected from wells PS/P-10, PS/P-11, and PS/P-12. These wells are all screened in the shallow"A"water-bearing zone and are located downgradient of the ST Services facility. Groundwater levels and the thickness of separate phase product(if any) will be measured in the wells prior to sampling. Groundwater samples will not be collected from wells that contain separate phase product. Wells that do not contain separate phase product will be purged using a peristaltic or two-stage electric pump. At least three casing volumes of groundwater will be removed. Groundwater field parameters (e.g., groundwater pH, electrical conductivity, temperature, and dissolved oxygen) will be measured for each casing volume removed to assess the effectiveness of purging. Purge water will be drummed pending disposal. Observations made during purging will be documented in field notes. Groundwater samples will be obtained from the wells using a new disposable bailer. If the well pumps dry during purging, the well will be allowed to recover to at least 50 percent of its original volume before sampling is performed. If the well does not recover to within 50 percent within 24 hours, a sample of the recovered volume will be collected no longer than 24 hours after purging. Sample containers (including any necessary sample preservation) will be provided by the laboratory. QA/QC and Decontamination. For QA/QC purposes, one duplicate groundwater sample will be collected. All sample containers will be marked with a sample number, date of collection, project number, and sampler's initials. Groundwater samples will be stored in a cooler with ice for transport to the analytical laboratory. Sampling equipment will be disposable or cleaned before each well sampling location. Disposable items will be replaced between each sampling event. Cleaning of non-disposable items will consist of washing in a detergent (Alconox®) solution, rinsing with tap water, followed with a deionized water rinse. Rinsate water will be collected and handled as described below. Groundwater Sample Analysis. The groundwater samples will be analyzed for total petroleum hydrocarbons in the gasoline carbon range (TPHg) , benzene, toluene, Approved by Margaret Lagorio of the SJCEHD in a telephone conversation on January 29, 2003.