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\,, *,Of PROTOCOLS FOR EXPLORATORY BOREHOLE DRILLING AND INJECTION POINT INSTALLATION SUBSURFACE CLEARANCE SURVEY PROCEDURES Prior to drilling, the proposed locations of borings will be marked with white paint. Underground Service Alen(USA)will be contacted prior to subsurface activities and a"ticket"will be issued for this investigation. USA members will mark underground utilities in the delineated areas using standard color code identifiers. Once USA has marked the site, all proposed borehole locations will be investigated by subsurface _ clearance surveys to identify possible buried hazards(pipelines,drums,tanks). Subsurface clearance surveys use several geophysical methods to locate shallow buried man-made objects. The geophysical methods include electromagnetic induction (EMI)profiling, ground penetrating radar (GPR),and/or magnetic surveying. The choice of methods depends on the target object and potential interference from surrounding features. DRILLING Prior to drilling, all boreholes will be cleared of underground utilities to a depth of at least 4 feet below ground surface (bgs) in "non-critical zones" and to 8 feet bgs in "critical zones". Critical zones are defined as locations that are within 10 feet of the furthest edge of any underground storage tank(UST),within 10 feet of the product dispenser islands,within 10 feet of underground utilities, and the entire area between the UST field and the product dispenser islands. If only borings are being installed, an 8- to 12-inch-diameter circle will be cut in the surface cover at each boring location. If wells are being installed,a 10-inch circle to a 24-inch circle or a 2-foot by 2-foot square will be cut in the surface cover at each well location. A hole,greater than the diameter of the drilling tool being used, will then be cleared at each boring location, using a hand auger or vacuum excavation system. The vacuum system consists of a water lance or air knife,used to disturb native soil by injecting water or air into the soil, and a vacuum, used to remove the soil. _ 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. All augers are pressure-washed or steam-cleaned before drilling begins and before each new borehole is drilled. All drill cuttings are either placed on and covered with plastic sheeting or contained in sealed 55-gallon drums. All fluids generated during cleaning of drilling equipment are contained in sealed 55-gallon drums. All waste generated during drilling activities is stored onsite until appropriate disposal is arranged. The drums are labeled with the site description (including owner's name)and date. The drill cuttings are disposed of at a proper facility based on results of soil sample analysis. During drilling, an ETIC geologist generates a soil boring log for each borehole. The boring logs contain detailed geological information,including descriptions of the soils classified according to the Unified Soil Classification System(USCS),blow counts for soil sampling intervals,organic vapor analyzer(OVA)readings, relative moisture content of the soils, and initial and static water levels. GISHARED�Geob�APmcedwes�Prot«ob-mimb�POi Well IWAM n.d� l