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3 of 3 Pages ErDt oQp 1 s • Uri l ling Monitoring Wells : All downhole equipment will be decontaminated using steam, to clean off all soil prior to use Wells will be drilled with a continuous flight hollow stem auger All wells will have a diameter at least 4 inches greater than the rasing diameter (OD) Core samples will be taken every 5 feet A core of the capillary fringe will be obtained The well will be logged geologically and the blow counts will be recorded Also the odor of each sample will be noted and the presence of any free hydrocarbon product Prior to removing any equipment from the hole the TD will be measured Once the casing is placed in the hole an accurate mea;»rement of the total amount of casing must be made The difference between the two figures will be explained by the well logger All drill cuttings will be placed in drums, sealed and the drilling intervals for the cuttings in each drum will be marked an the drum The drum;. will remain stored at the site until the contamIuation can be assessed through the laboratory sampling • Completion Slotted ca,inr (0 02 inch slots ) wi1i be rapped with a bottom plug The slots will extend 5 feet above the estimated water table indicated during drilling Clean 0 3 sand will be placed opposite the slotted casing and 1 feet above the last slot. At this time: the well will be surged for 5 minutes to attempt to eliminate any voids in the sand pack At the end of the surging the top of the sand will be measured and additional sand will be added if necessary Directly above the sand a 3 foot plug of hydrated bentonite chips wi11 be placed Above the plug a seal of cement grout will be placed to the surface The top of the casing wall be crapped and a traffic box and will be cemented in Place around and above the top of the casing. The cement cox bentcan.ite grout will will be placed in the annulus by the use of a trime pipe if the total annulus seal distance as over 30 feet { Bul 74--90 Cal Water Well Standards ) The well will be developed by bailing within a day of drilling to remove most, of the sediment within the casing and to remove bridging fines within the slots and sand pack This will be done by surging using the well water if possible, if not then only Potable water may be used A log of the amount of introduced water will be kept, and its use will be kept to a minimum. Bailing and surging will continue until the water does not contain any fine . silt and or clay The amount of water added to the well to develop it must be removed from the well during developement. All purged water will be stored in drums, the drums will be sealed and left on site until the condition of the water is assessed