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TASK 10 - ANALYZE THE GROUNDWATER SAMPLES <br /> The groundwater samples will be analyzed by a CAL-EPA certified <br /> analytical laboratory for TPH-G, BTEX, and the fuel oxygenates MTBE, TBA, <br /> TAME, 1a1PE and ETBE, by EPA Method 8260. <br /> TASK 11' - SURVEY THE TOP OF CASING ELEVATION OF EACH WELL <br /> The ground surface elevation of each boring and top of casing elevation of <br /> each well will be surveyed relative to mean sea level by a California <br /> licensed surveyor. <br /> TASK I2 — CONDUCT STEP DRA IVD O 11IN AND CONSTANT RATE PUMPING <br /> TESTS FOR THE SITE <br /> A step drawdown test will be conducted to estimate sustainable pumping <br /> rates for a constant rate pumping test. Pumping rates for this test will b e <br /> determined in the field but rates of 0.5, 1, and 2 gallons per minute are <br /> planned. Higher pumping rates will also be used if pumping at higher <br /> rates can be sustained. Data will be collected manually as well as with a <br /> �.. data logger and pressure transducer. Groundwater produced during this <br /> test will be stored on-site in sealed and labeled 55-gallon steel drums until <br /> off-site disposal can be arranged. <br /> Based on the results of the step drawdown test, a 1,000-minute constant <br /> rate pumping test will be designed to determine the hydraulic <br /> conductivity and transmissivity in the water-bearing zone and to calculate <br /> the capture zone radius. Water levels will be measured in all site <br /> monitoring wells prior to pumping. If possible, pressure transducers will <br /> be placed in all monitoring wells and water levels will be recorded with a <br /> data logger. Manual water level measurements will also be collected as a <br /> backup from these wells. Purged water from this test will be contained in <br /> an appropriately sized Baker Tank. <br /> Groundwater samples will be collected from the pumping well during this <br /> test at the following times: Immediately upon the start of pumping, after <br /> 240-minutes of pumping, after 600-minutes of pumping, and at the end of <br /> the test. These groundwater samples will be contained in 40-m1 glass VOA <br /> vials, pre-preserved with hydrochloric acid, and sealed - without <br /> headspace. The samples will be labeled with the site location, sample <br /> designation, date and time the samples were collected, and the initials of <br /> the person collecting the samples. The samples will be placed on ice for <br /> transport to the analytical laboratory under chain of custody. The <br /> 574 West Grand Line Road, Tracy, CA Workplan — April 2001 <br /> -11- <br />