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APPENDIX B iPROTOCOLS FOR WELL DRILLING, COMPLETION, DEVELOPMENT, AND SAMPLING B.1 DRILLING Boreholes are drilled with a truck-mounted rotary drill, using hollow-stem continuous-flight augers The diameter of the augers is selected to provide an annular space between the boring wall and the well casing of no less than 2 inches The borehole is drilled 10 feet below the static water level but will not be allowed to penetrate a competent clay layer that might act as an effective aquitard drilling is terminated after two consecutive samples indicate comparable, apparently impermeable clays below static water All augers, sampling rods, samplers, and otherieces of downhole equipment P q pment are steam cleaned before drilling begins and before each new borehole is drilled All drill cuttings and fluids from the steam cleaning are contained on the site in sealed 55-gallon drums The drums are labeled with the borehole number, site description (including owner's name), depth interval of soil contents, date, and monitoring equipment readings The drill cuttings are disposed of at proper 1 facilities on the basis of soil sample analysis A log of drilling and the borehole are recorded by an EA geologist overseeing the drilling operations and well installation The boring logs, which are signed and dated by the geologist, contain detailed geological information, including descriptions of the soils classified according to ' the Unified Soil Classification System, blow counts, OVA readings, moisture content of the soils, and initial and static water levels B.2 SOIL SAMPLING Soil samples are collected at 5-foot intervals and at any substantial change of soil type, beginning at 5 feet below ground surface, with a 2-inch-diameter, 18-inch modified California split-spoon sampler containing three nch brass liners The sampler and Iiners are steam cleaned before use in each hole, they are I ubbed in deionized water and Alconox detergent and rinsed with ' deionized water after use each sampling interval Soil samples are collected to the total depth of the borehole unless hr ing sand is encountered Every attempt is made to collect a soil sample dust above or at r water table At each sample depth, the sampler is driven 18 inches ahead of the augers into undisturbed soil When the sampler is retrieved, either the lowermost or the middle sample liner is removed and the ends of the tube are covered with aluminum foil and sealed with plastic caps, which are secured to the liner with tape The soil-filled liner is labeled with the location, sample number, date, time, depth, sampler, and borehole number The samples are placed in zip-lock bags and stored in a cooler containing ice Soil is removed from the other two liners and examined The soil is scanned with a Foxboro Century 128 organic vapor analyzer with a flame ionization detector (FID), and the OVA WP61 73942 R01397 APB 1 B-1