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k KLEINFELDER A-5 VADOSE ZONE MONITORING Prior to conducting lysimeter sampling, the pressure-vacuum equipment is checked and cleaned. A Soil-Moisture hand pump with a pressure-vacuum gage is used to measure residual and implied pressure-vacuum. Nitrogen gas is used to purge the lysimeter system for sampling. An air pump is available as a back up. Approximately one week to one month prior to conducting the sampling, the residual pressures at the air-line of each lysimeter are measured ad the vacuums reset to manufactured recommended value (usually 50 centibars). The measurements and applied vacuums are noted on a sampling log form. Kleinfelder has found that resetting the lysimeters vacuums before the sampling yields good sample recovery. The residual pressures are measured just prior to collecting the sample. The water line is then opened and nitrogen gas applied to the air line until either fluid or air is discharged (for dry lysimeters). The sample is contained in a 1 liter unpreserved bottle and the volume recovered is estimated. The fluid is then poured into appropriate preserved or unpreserved bottles of the requested analysis. After the sample is collected, the lysimeter vacuum is reset to the manufacturer's recommended value. The lysimeter is also tested to evaluate potential leaks that may cause vacuum pressure loss. A-6 LEACHATE MONITORING The leachate riser or wells are first opened and allowed to equilibrate with the atmosphere. The leachate elevation is then measured from a set location using a conductivity-based water-level meter. The level is generally measured from a surveyed mark on the north rim of the casing. A leachate sample is then collected using a clean, disposable bailer. The sample is labeled and immediately stored in an iced cooler pending transport to the analytical laboratory. The sample is logged on a chain-of-custody. 24134.E01 / STO3R304 Page A-8 Copyright 2003, Kleinfelder, Inc. February 26, 2003