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'I <br /> the cost to the responsible party low . If clay beds are <br /> found, which might be aquicludes (barriers to vertical water <br /> migration and presumably hydrocarbons ) , then additional <br /> ' sampling might be warranted dust below the potential <br /> "capping" bed . <br /> ' The monitor wells are located in a manner that places two <br /> wells in a "down dip" water table location, at distances <br /> that will permit an accurate water table slope determin- <br /> ation Past sampling showed that contamination had reached <br /> ' at least -29 ' bgl , only 18 ' above the 1986 water table at <br /> the site location <br /> PROGRAM <br /> All equipment used must be brought to the site in a clean, <br /> steam cleaned condition Any equipment used more than once <br /> must be either steam cleaned or washed at the drill site in <br /> a TSP or similar solution and double rinsed before using a <br /> second time <br /> ' Bore and sample three monitor wells as noted above using a <br /> hollow auger rig and sample using a 2" X 18" or 24" split <br /> ' spoon sampler MW # 1 to be bored using a nominal 10" OD <br /> flight size , 6 1/4" ID to about 90 ' bgl , about 131 into the <br /> water table Wells 2 and 3 are to be bored using an B" OD, <br /> 4 1/2 ID to approximately the same depth <br /> Samples will be taken as noted above , using a California <br /> ' type , split spoon sampler with an 18" to 24'' long <br /> collection chamber, holding 2 ' X 3'' or 4" brass collection } <br /> tubes <br /> ' All samples will be collected and described by a registered <br /> geologist Sterile brass tubes and water sample bottles <br /> supplied by a certified California laboratory will be used <br /> ' The brass samples chosen by the collector will be capped <br /> with either foil or Teflon, capped with an end cover, sealed <br /> with duct tape, labeled and placed in an ice chest until <br /> ' taken to the laboratory Chain-of-Custody forms will be <br /> used The EHD will be informed prior to any field work being <br /> done . <br /> ' After the holes are bored, 4' OD , screw type , interior flush <br /> PVC pipe will be inserted into hole MW # 1 and 2 ' OD, screw <br /> type , interior flush PVC pipe inserted into MW # 2 and 3 <br /> ' (see Fig 10 ) The wells will then be gravel packed, <br /> cemented and completed as shown In general , at least 12 ' of <br /> perforated pipe will be used with about a 10 ' penetration <br /> into the water table The hole will be gravel packed with <br /> the perforated well casing and gravel extending 2 ' or so <br /> above the top of the water table The gravel will be capped <br />' with about 3 ' of bentonite clay and hydrated Concrete will <br /> 4 <br />