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B:\WPLATEXT.DOC <br /> feet to 50 feet with blank SCH 40 F480 TriLock PVC casing from 50 <br /> • feet to the surface . The sand envelope will be #2/16 Lapis Lustre <br /> sand and will be positioned from the 45' depth to the 70 foot <br /> depth, with 0/30 Lapis Lustre sand from the 45' depth to the 431 <br /> depth to prevent cement invasion. Cement (with less than 5% <br /> bentonite ) will be used to seal the annular space from the 43 foot <br /> depth up to the the steel traffic box. The traffic box , fitted <br /> with a locking system and well ID tag, will be set in concrete, <br /> see Figure 4 . <br /> The selection of filter pack and slot size for ground water <br /> monitor well construction is in using the previously installed <br /> wells . The ground water clarity from these wells and the expected <br /> similarity of lithologies to be encountered at this site are used <br /> as the basis for construction material selections . <br /> WELL DEVELOPMENT <br /> The new monitoring well will be developed by manually surging the <br /> wells over the entire length of the below water slots , with a <br /> plunger . Ground water will then be pumped from the well until it <br /> flows clear . The waste water producted by this process will be <br /> placed in the 1000 gallon "ConVault" tank stripper for <br /> treatment. <br /> GROUND WATER SAMPLES <br /> I <br /> M After the new monitor wells are developed WEGE personnel will <br /> i collect ground water samples and have them analyzed at a state <br /> ' <br /> certified laboratory for Total Petroleum Fuel hydrocarbons as <br /> gasoline with BTEX Distinction, utilizing EPA Method 602 . <br /> A second ground water monitoring round will follow approximately <br /> one month from the initial sampling of the wells , during the <br /> scheduled September quarterly sampling for this site . The purged <br /> ground water produced from the sampling rounds will be placed in <br /> the 1000 gallon "ConVault" for aeration treatment. <br /> Methods and Procedures <br /> Prior to sampling each well , WEGE personnel obtains two measure- <br /> ments : the depth to ground water and the product thickness <br /> using a depth to water-product interface probe. If no product is <br /> present in a given well , a ground water sample is <br /> collected using a fresh bailer . <br /> Before collecting the ground water sample, WEGE personnel purge <br /> the well . This is accomplished by removing ground water from the <br /> well until the water quality parameters (temperature, pH, and <br /> conductivity ) stabilize . Water produced by the purging process , <br /> at least four well volumes , is collected in a 55 gallon drum prior <br /> to `ransferri.ng the water to the 1000 gallon "ConVault" . <br /> The well is allowed to recover after purging , and a ground water <br /> 6 <br />