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02 January 2009 <br /> AGE-NC Project No . 99-0682 <br /> Page 6 of 7 <br /> will be continued until field parameter (pH, electrical conductivity, and temperature) readings have <br /> stabilized and purged water is visually sediment-free. The proposed well will be surveyed relative <br /> to the closest City of Stockton benchmark by a licensed surveyor. <br /> 3 . 6. GROUNDWATER MONITORING PROCEDURES <br /> Ground water sample collection from the newly installed well (MW- 12) will be performed in <br /> accordance with the EHD ' s Recommended Groundwater Sampling Guidelines, dated 15 February <br /> 1995 . <br /> ii <br /> 3 .6. 1 . Static Water Level Measurements <br /> Before purging and sampling during ground water monitoring events, static water level will be <br /> measured using an electric water level indicator. Water level data will be recorded to the nearest <br /> 0 .01400t from a reference point marked at the top of the PVC well casing. Before and after each use, <br /> the electric oil/water level indicator will be washed in an Alconox solution and rinsed with water. <br /> 3 .6.2. Well Evacuation <br /> Subsequent to measurement of depth to water and prior to sampling, the well will be purged using <br /> an inertia pump or submersible pump to ensure that the ground water sample is representative of the <br /> formation, rather than water standing in the well casing. Each well will be purged until: 1 ) a <br /> minimum of three casing volumes is removed from the well; and/or 2) the field-measured ground <br /> water parameters pH, temperature and electrical conductivity have stabilized. However, if a well is <br /> purged dry prior to evacuating three casing volumes, a ground water sample will be collected <br /> following 80 percent recovery of ground water level within the well or within 8 hours of well <br /> evacuation. <br /> Purge water, free-product, and decontamination water generated during the ground water sampling <br /> activities will be contained in DOT-approved drums which will be appropriately labeled for storage. <br /> Drums containing purge water will be stored on-site pending appropriate removal and disposal. <br /> 3 .6. 3. Sample Withdrawal <br /> Water samples will be collected from the monitoring well using a disposable polyethylene bailer or r <br /> dedicated Teflon tubing used in conjunction with a Waterra inertial pump. The bailers are disposed <br /> F>i <br /> Advanced GeoEnvironmental, Inc. r <br /> ;q <br />