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I �.e-� �jM;1.;�";`�``�''"% -•----r � ,�yc "'S��'"n �� F�-k:, �`" .+s: SFr �r'��s., ,o y�.�a ia' xYi',?''-.."„��' aC�'.�,�.'�. �S ,� I 4 SITE SAFETY PLAN The site safety plan has been prepared and will be on-site during all field activities. All persons on site will be signed in on the site safety forms and informed of the safety regulations on site. Underground Service Alert(USA)will be notified to identify underground utilities and other possible subsurfa.e obstacles. An underground fine locating survey will be perforated in the vicinity e;f the proposed well locations. SOIL BORINGS AfQ9 SAMPLING The borings will be lithologically logged by a geologist under the direct supervision of a California-registered geologist using the Unified Soil Classification System(USCS). During drillir.•�,discrete soil samples will be collected at approximately 5.0 foot depth intervals to the top of groundwater for lithologic and hydrogeologic description and possible chemical analysis. Soil samples for chemical analysis are collected in pre-cleaned,thin-walled brass tubes, 6-inches long and 2-inches in the outside diameter. Soil samplescollected for Chemical analysis incl.}ie- ;a sarri to Collected at the approximate depth of the base of the former ' de and s'2i1 �t Iles• [, to soil`sample wilibe aFtalyzed at the soil-groundwater interface.Other suil samples wiII be analyzed if visual.staining,PID readings or obvi.us odor are noted in the soil sample. Three of these sample tubes are set in a 2-inch inside diameter, 18-inch modified California split-barrel sampler. The split-batrei sampler is driven its entire length using a drop hammer,typically 140 pounds. The sampler is extracted from the borehole and the brass tubes,containing the soil samples are removed. Upon removal from the sampler, the selected brass tubes ane immediately capped on both open ends with Teflon tape, trimmed and capped with plastic caps. The caps are then hermetically sealed in zip-lock type plastic bags. The samples are then labeled and refrigerated for delivery,under chain-of-custody,to a state-certified hazardous materials testing laboratory. The above mentioned procedures minimize the potential for cross-contamination and volatilization of volatile organic compounds(VOC)prior to chemical analysis. The sampler is rinsed with Alconox detergent between samples and steam-cleaned with all the other drilling equipmer=i between borings to prevent,cross-contamination. Drill cuttings will be labeled and contained in 55 gallon drums pending receipt of laboratory"results on soil samples. Soil will be stor-A on-site pending analytical results.WELL INSTALLATION The boreholes for monitor wells are drilled using a truck-mounted hollow-stem, continuous flight auger drill rig. Prior to the commencement of drilling each hole,augers will be cleaned to avoid the introduction ofofforcross contamination. T11e diameter of the borehole is a minimum of four inches larger than the outside diameter of the casing when installing the well screen(DWR Publication 74-81). The hollow-stem auger provides;:animal interruption of drilling while pennittin"soil sampling at the desired intervals. r ..�. The Wells will be drilled to approximatco- 5 Greet beiowlgrouiid surface. Cure will be exercised not to drill through more thall four feet of consolidated clay acting as an aquitard. If that occurs,the borehole will be settled to the top of the aquitard using bentonite chips and the well base will be at the base of the aquifer. a