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SC&D Boyett Petroleum 419 South Main Street October 27, 1999 Manteca, California Page: 3 contamination was noted. All water-bearing zones and the depths at which they were encountered are noted on these logs. The cuttings from the drilling operation were containerized in 55 gallon drums, pending the results of laboratory data. 3.2 Well Construction All materials used in well construction were thoroughly cleaned prior to introduction into the boring. A Bentonite or cement and Bentonite grout was placed at the bottom of the boring as necessary. A two inch diameter well casing (stainless steel or PVC) with end cap and factory perforations for placement in the saturated zone (taking into account seasonal variation) was placed in the boring after the seat had been allowed to set long enough to support the weight of the casing. The screen and filter pack sizes are noted in the well construction drawing. The casing and end caps were threaded; no PVC cement was used. The filter pack extends one to three feet above the perforated zone. A Bentonite seal 3-feet thick was placed in the annular space above the filter pack followed by a cement grout to the surface (Appendix A). 3.3 Well Development and Sampling The wells were developed until the well water appeared clear of sediment, or until an appropriate number of well volumes (based upon the judgment of the responsible professional) had been evacuated. The water produced during well development was containerized and left on-site in 55-gallon drums for disposal as hazardous waste if deemed necessary upon receipt of laboratory results. The wells were allowed to stabilize for twenty-four (24) hours prior to sampling. All groundwater samples were properly labeled with date collected, project number, sample coordinator, and sample identification. Field records document the above information and other significant data, such as names of on-site personnel, sampling methods, date and time of sampling, the number of well volumes removed before sampling, preservatives added (if any), and any filtration performed on samples. The samples were refrigerated immediately for delivery to the laboratory and were under no circumstances opened by anyone other than laboratory personnel. Chain of Custody records were maintained at all times (Appendix Q.