FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

A hollow-stem rotary auger drill rig, set up with an 8-inch auger, will be used to complete the well drilling. • The well borings will be drilled to the depth described in the project workplan. Soil samples will be collected by driving an 18-inch long split spoon sampler at intervals indicated in the project workplan. One 6-inch sample tube will be retained for field description of the lithology. Soil samples will be submitted for analysis as described in the project workplan. • For the laboratory analysis, soil samples will be collected with a split spoon sampler 16- lined with stainless steel sleeves. The full stainless steel sleeve containing the soil sample will be sealed with Teflon sheets and plastic end caps. Each sample sleeve will be labeled with the job number, the sample identification, date and time of collection, the sampler's name, and the analyses required. Each sample will be placed in a sealed plastic bag and then in an ice chest (chilled to 4°C) until delivered to a California-certified laboratory under chain-of-custody documentation. • Soil types will be classified and logged using the ASTM Visual Manual Procedure (D 2488-93) and Munsell Soil Color Charts. Using a PID Meter, the soil headspace will +— be field screened within a sealed sample bag. • The lithology, moisture, density, color, sample identification, PID measurements and well construction details will be recorded on the boring logs as appropriate. • The screened interval for shallow wells will be placed to allow for fluctuations in the water table. • To prevent bridging, a uniform filter pack of 2112 sand will be slowly installed from the bottom of each boring to a depth of I foot above the top of the well screen. • A clean, weighted tape measure will be used to ensure proper placement of the sand. • All wells will be constructed using PVC flush thread casing and sandpack. Construction details will be documented on the boring log. • A 1-foot thick seal of clay will be installed above the sandpack and tremie grouted ` with a cement/bentonite slurry not exceeding 5 percent bentonite to I foot below the ground surface. The top of the PVC casing will be approximately 2 inches below grade. Well heads will be protected by flush-to-grade traffic rated well boxes. A slip cap will be placed over the top of the casing during well completion to prevent debris from entering the well. 6W The wells will be protected by 8-inch flush-mounted traffic boxes set in concrete, with locking well caps. The tops of the traffic boxes will be set slightly above grade with a gently sloping concrete rim. The monitoring well identification number will be ;.. scribed into the concrete rim before it completely set. • Upon completion of the well installations, each well will be closed and secured by +— replacing the well cap, securing the lock and bolting down the lid of the flush- SOP MW Installation 2 January 2004 L.