Laserfiche WebLink
CLEARWXTER <br /> G R O U 2, [ N C. <br /> All wells will be surveyed to the north side of the top of casing'-for elevations <br /> to the nearest ±0.01 foot. Elevations will be referenced either to mean sea <br /> I level or to a project datum. A project datum is typically chosen for its <br /> location such that it will remain unchanged in the event of site construction <br /> or other site disturbances. Where required, the wells will be surveyed by a <br /> Ilicensed land surveyor, relative to the nearest benchmark. <br /> IWell Development <br /> All. newly installed wells will be developed prior to sampling to remove fine <br />' grained sediments from the well and stabilize the filter pack and the disturbed <br /> aquifer materials. Well development will consist of surging with a surge <br /> block and removing water from the well with either a pump or bailer, until <br />' the well is free of sediment, or after 10 well casing volumes have been <br /> removed. Where appropriate, temperature, pH, specific conductance and <br /> turbidity will be monitored during well development. All development <br /> Iequipment will be cleaned prior to use and between wells with an Alconox <br /> solution, then rinsed in clean water. All data collected during development <br /> will be presented on the well development data sheet. <br />' Ground Water Sampling <br /> Prior to the start of work, a decontamination area will be established. This <br />' will be in a secured area and consist of an Alconox solution wash, a first rinse <br /> and a second rinse. Any down hole equipment will be decontaminated prior <br /> to use. <br />' Prior to purging and sampling any well, the static water level will be <br /> measured with an electronic water sounder or an oil/water interface probe to <br />' the nearest ±0.01 foot. if floating product is detected, interface probe results <br /> will be confirmed by lowering a clear disposable polyethylene bailer down the <br /> well and measuring the product thickness to the nearest ±0.01 foot, in the <br />' bailer. Any monitoring well containing detectable amounts of floating <br /> product will not be purged or sampled. Field observations such as well <br /> integrity as well as water level measurements and floating product <br />' thicknesses will be noted on the gauging data/purge calculations form. <br /> All monitoring wells to be sampled shall be purged using either a PVC bailer <br />' or a submersible pump. Physical parameters {pH, temperature and <br /> . conductivity} of the purge water will be monitored for stabilization during <br />' <br /> CLEARWATER GROUP,INC. 3 June 2,1995 <br />