Laserfiche WebLink
• f <br /> MOUNTAIN HOUSE DETENTION BASIN WELL INSTALLATION Page 2 <br /> WKA No. 6504.05 <br /> August 26, 2005 <br /> • Collecting a groundwater sample from each well for analysis by a California-certified <br /> laboratory; <br /> • Surveying the well location and the top of the well casing to the nearest 10`h of a foot; <br /> • Preparing a Well Installation Report; and <br /> • Performing monthly monitoring of groundwater elevations. <br /> All work will be completed under the supervision of a California-registered Professional <br /> Geologist in accordance with the field procedures described in this Workplan. <br /> Well Construction and Sampling <br /> Groundwater monitoring wells will be completed with two-inch diameter, flush joint, Schedule 40 <br /> PVC casing with 10-foot long, 0.010-inch slotted casing for the screened interval. The filter pack <br /> will consist of#2/12 sand placed in the annular space from the bottom of the screened interval to <br /> approximately two feet above the top of the screen. The total depth of the well and the screen <br /> interval will be determined in the field based on groundwater elevation encountered in the boring. <br /> A two- to four-foot thick bentonite seal will subsequently be placed in the well annulus above the <br /> filter pack. A grout seal (consisting of Portland cement/bentonite slurry)will be placed from the <br /> top of the bentonite seal to the surface. The well will be completed with a locking well cap and a <br /> stove pipe protective casing set in concrete. Typical well construction details are provided on <br /> Figure 2. <br /> The wells will be developed using a vented surge block and submersible pump. Following <br /> development, a sample will be obtained with a bailer, decanted into appropriate containers, <br /> and transported under chain-of-custody to a California-certified laboratory for analysis. The <br /> samples will be analyzed for General Minerals that includes alkalinity, calcium, chloride, <br /> fluoride, hardness, potassium, magnesium, sodium, nitrate, specific conductance, sulfate, <br /> total dissolved solids, and pH. This will be conducted on a one-time sampling event. The <br /> wells are not expected to be included in a quarterly water quality monitoring program. <br /> Monthly groundwater elevation monitoring of each well may be conducted until construction <br /> of the detention basin begins to determine seasonal trends. <br /> INK <br /> WALLACE•KUNL <br /> &ASSOCIATES INC. <br />