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' ATTACHMENT A ' FIELD METHODOLOGY ' A.1 Permitting and Notification Prior to initiating any field activities, a well installation permit will be obtained from the appropriate San Joaquin County agency. Based on the final location of the proposed piezometer, additional permits may be needed prior to mobilization. The field geologist will maintain copy of all permits onsite during all work. Underground Service Alert (USA)will be contacted at least 48 hours prior to implementing the field program. USA notifies utilities and others who have underground lines in a specified work area. As an additional precaution, a hand auger pilot hole will be advanced to a minimum depth of 5 feet bgs. A.2 Decontamination of Equipment All drilling rigs and sampling tools will be decontaminated prior to arrival on site. Augers and sampling equipment will be steam cleaned prior to daily drilling activities All sampling equipment will be washed between sample intervals using the triple-rinse cleaning method, which consists of washing the equipment in potable water containing detergent [i.e. trisodium phosphate (TSP)], rinsing in potable water, then rinsing with distilled water. All well development equipment will be steam-cleaned prior to and following use All water produced during decontamination will be contained for proper disposal in clean, properly labeled Department of Transportation (DOT) approved 55- gallon drums. A-3 Soil Sampling In order to minimize the possibility of breaching a competent (greater than 3 feet thick) ' confining unit, soil samples will be collected for lithologic descriptions at 2-foot intervals beginning at 50 feet below ground surface (bgs) to total boring depth. The maximum investigated depth at this site is 50 feet bgs. All borings will be logged by a geologist ' working under the supervision of a California Registered Geologist. The boring log form will be used to document drilling activities and observations. The Unified Soil Classification System and ASTM methods for identification of soils in the field (ASTM ' D2488)will be used to describe soil type and engineering properties. A standard color chart will be used to describe each sample's color. The on-site geologist will prepare a detailed geologic log of the boring and conduct field analyses of soil samples ' Organic vapor levels(OVI:s)will be monitored in soil samples collected during drilling, using a photo ionization detector (PID) equipped with a 10.6 electron-volt (ev) photoianization lamp or a flame ionization detector (FED). The PID/FID will be ' calibrated prior to commencement of the field activities. To establish the OVI, soil from each sample interval will be placed into a sealed container with headspace to allow for volatilization. Prior to obtaining the measurement, the soil will be allowed to stand ourfer- ' WM-swT1_8ARRARAMATAWRO EOWNOCALIC VA EYlW S REVIPACINW2kDOC ARCADIS GERAGHTY&MILLER