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Attachment A Geosyntec Consultants Monitoring Well Installation and Development Procedures of the augers. Well casing will consist of 2-inch.diameter threaded joint Schedule 40 PVC pipe. Well screen will consist of 5 to 10 feet of the same PVC pipe with 0.01-inch slots. Actual length of the well screen will be selected in the field, based on the geologic materials encountered during drilling. The bottom caps on each well will be threaded. The tops of the well casings will be fitted with expandable-gasket lockable caps. After installing the casing and screen, an appropriate sand filter pack will be placed to about 2 feet above the top of the well screen. As the sand is added, the augers will be pulled up to allow the sand pack to fill the borehole annulus. A bentonite seal-consisting of a minimum of 2 feet of compressed bentonite pellets will be placed above the sand pack. The pellets will be allowed to hydrate before grouting. Cement and bentonite grout will be used to seal the borehole annulus from the top of the bentonite seal to the ground surface. The grout mix will consist of Type I/II Portland cement, bentonite powder, and potable water. The grout will be tremmied into place. The well will be,completed at the surface with flush mount well boxes or with an above ground locking well cover and guard posts. A locking well cap and lock will be installed on the well. Site personnel will be consulted about whether completions are preferred to be at-grade or above ground. Surveying The north side of the well box and PVC well casing will be surveyed for elevation and location by a licensed surveyor. The well will be surveyed to North American Datum (NAD) 83 and North American Vertical Datum (NAVD) 88, in accordance with the RWQCB GeoTracker database reporting requirements. Well Development DMW-513 will be developed at least 48 hours after installation. The purpose of well development is to stabilize the filter pack and remove fines from the filter pack and well screen. Development will be completed according to the following general.procedures: • All downhole equipment will be decontaminated by steam cleaning or washing in a solution of laboratory-grade detergent prior to;between, and after use; + The total depth of the well and the water level will be measured; • Approximately one casing volume of water will be removed from the well using a submersible pump or bailer; • The well will be surged for a period of 15 to 30 minutes; Page 2 of 4 January 2014