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1 Bank of Stockton- Cutter Lumber Site Page 5 Groundwater Monitoring Well Construction ' Project No 102 2 April 24, 1998 ' 2 1.2 Soil Sample Collection Procedures ' Soil samples were collected for geological and analytical evaluation at five foot intervals using a 2 0 inch diameter (Y d ) California split spoon sampler with the sample contained in 2 by G inch stainless steel liners The sampler was driven ' up to 18 inches into the native soil using the 140 pound hammer mounted on the drill rig The blow count was recorded for each sample collected All soil samples were sealed with aluminum foil, capped, labeled and placed in a cooler ' at 4° Celsius for transport to the laboratory following Chain of Custody protocol Boring logs of soils encountered in each boring were kept by a registered ' geologist (Appendix B) Recorded in these logs were notes on sampling intervals, boring locations and sediments intersected by the boring Not all soil samples collected were submitted for laboratory analysis Accordingly, a field screening ' procedure was used to select those samples which were tested Special attention was paid to sediment type, color, grain size, sorting, odor and the readings above ' background on an organic vapor meter (OVM) The OVM is a field portable photo ionization detector that uses a 10 2 eV lamp to detect compounds with ionization potential below 10 2 eV (hydrocarbon range) In all borings except MW-8B, at least three soil samples were selected for laboratory analysis Soil samples from MW-8B were not submitted for laboratory analysis because equivalent samples from MW-8A, which lies just four feet away, were available for analysis ' 2.1.3 Monitoring Well Construction ' The monitoring wells were constructed as proposed with the exception of the depth and screened interval as described above The wells were cased with 2 0 ' inch diameter, schedule 40 PVC casing with flush threaded joints The screened interval consists of 0 020 inch perforated schedule 40 PVC pipe extending from total depth and upward a distance of 25 feet in all wells except the deep well, ' MW-8A In this well the screened interval extends 10 feet from total depth and the slot size is 0 010 inch A number three sand was used to form a filter pack about the perforations and extending two feet above the screened interval except ' the deep well where four feet of blank casing was covered An annular seal was constructed by installing sufficient bentonite to form a 2 foot thick seal A four- foot-thick seal was installed in the deep well The granular bentonite was ' hydrated with tap water and allowed to expand for a period of one hour In the remaining annulus, neat cement grout was installed using a slurry pump and tremae pipe The wells were secured with a water tight locking cap encased ' 2937 Veneman Ave ,#B240 Geo-Phase Environmental Inc Phone (209) 569-0293 Modesto, CA 95356 Fax (209) 569-0293