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CLEARWAOTER <br /> G R O U P, I N C <br /> 1 <br /> • Total petroleum hydrocarbons as gasoline (TPHg, California LUFT Manual) <br /> • Total petroleum hydrocarbons as diesel fuel (TPHd, modified EPA Method 8015) <br /> • Benzene, toluene, ethylbenzene, and xylenes (BTEX, California LUFT Manual) <br />' Methyl-tert-butyl ether (MTBE, California LUFT Manual) <br /> The laboratory reporting limits fo or alyses were <br /> • TPHg 0 2 parts per million (ppm) (1) <br /> • TPHd 5 0 ppm (D <br /> • Benzene, toluene, and ethylbenzene 0 001 ppm ob 5 <br /> • Xylenes 0 002 ppm <br /> • MTBE 0 005 ppm <br /> 2.2 Monitoring Well Installation <br /> Each boringwas converted into a monitoring well constructed of 4-inch diameter <br /> g <br /> schedule 40 PVC flushed-threaded casing and screen Twenty feet of slotted well <br /> screen (0 020-inch slot width) extends from the bottom of each well at 68 feet bgs to <br /> 48 feet bgs A filter pack of Monterey #3 sand was placed in the annular space <br /> against the screen from the bottom of each well to approximately three feet above <br /> iwell screen (68 feet bgs to approximately 45 feet bgs) A bentonite seal approximately <br /> three feet thick was placed above the filter pack by hydrating bentonite pellets The <br /> remaining annular space was sealed with grout (Portland cement) by gravity <br />' emplacement through the augers The wells are protected at the surface by locking <br /> expansion plugs and flush mounted traffic-rated well boxes Well construction <br /> details are included in Appendix B <br /> 2.3 Monitoring Well Development, Sampling, and Surveying <br />' The monitoring wells were developed by alternate surging and bailing on July 14, <br /> 1995. At least ten well casing volumes of water were removed from each well <br /> During well purging the water temperature, conductivity, and pH were monitored <br /> to confirm that no grout had breached the bentonite seal All groundwater <br /> parameter measurements were within normal ranges. <br /> On Ju1x27, 1995, depth to water was measured from the top of the well casing using <br /> an electric water sounder At least three well volumes of wafter were then removed <br /> C-115 PRE AR 10/95 October 1 <br />' 3 1, 1995 <br />