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02/01100 TUE 10:01 FAX 916 364 1889 SECOR-SACRAMMO IM003 FIELD PROCEDURES Groundwater Monitoring Wel,Reinstallation The existing 4-inch diameter groundwater water monitoring well(BBD-1)will be over drilled using a 12-inch diameter hollow-stem auger drilling equipment to a depth of approximately 30 feet bgs. A groundwater monitoring well consisting of a flinch diameter,flush-threaded,Schedule 40 PVC casing with 0 020-inoh_faotory-slotted screen will be installed in the boring. Approximately 25 feet of screen will be placed in the bottom of the boring, A grade of sand appropriate to the screen size will be placed in the annular space across the entire screened interval, and will extend approximately 2 feet above the top of the screen for the well. A bentonite seal will extend three feet above the sand pack. The monitoring well will be completed with neat cement from the bentonite seal to ground surface_ The well casing will be topped with a locking cap. The well head will be contained in a watertight,traffic rated well box. The boring log will show well construction details. The well will be developed after completion. The development procedure for the well will consist of pumping or bailing water from the well until the water is visibly clear,the well goes dry, or until a maximum of ten casing volumes have been removed. The newly installed well will be surveyed by a California State Licensed Surveyor. The well casing will be surveyed to the nearest 0.01 feet in elevation to a known benchmark- Please enchmarkPlease note, no soil sampling or logging will be done during drilling. All down-hole drilling and sampling equipment will be steam-cleaned following the completion of the soil boring. Down-hale sampling equipment will be washed in a tri-sodium phosphate or alconox solution between samples. Sail Cuttings and Rinsate Water Soil cuttings generated during drilling operations will be temporarily stored onsite and covered with plastic sheeting pending characterization and disposal. Soil cuttings will be removed by ARCO's disposal contractor to an appropriate disposal facility. Water generated during steam cleaning will be temporarily stored in DOT-approved 55-gallon drums pending transport by ARCO's disposal contractor to an appropriate disposal or treatment facility. Soil cuttings and purge water drums will be temporarily stored onsite for approximately 4 to 8 weeks.