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<br /> Artesian Environmental Consultants, Inc.
<br /> Standard Operating Procedures
<br /> GROUNDWATER MONITOR / I:\TRACT1ON WELL INS-TALLATION
<br /> AND DEVELOPMENT
<br /> WELL INSTALLA-110N
<br /> i he boreholes for monitor/cxuaction wells are drilled using a uuck-mounted hollo%�-stere
<br /> auger drill ti”- file diameter of tttc borehole is a rrtinirnum of four inches largcr than [lie
<br /> outside diameter of the casing when installing rite well screen(1)1VR f ublication 7-1-81).
<br /> -fhe hollow-stem auger provides minimal intcruption of drilhn, wltife permitting soil
<br /> sampling at the desired intervals- All wells are installed by ware-li^ensed drillers.
<br />�. The monitor I extraction wells are cased with threaded,factory-sfor d.blank schedule 40
<br /> polyvinyl chhloride (PVC). The perforated int4rval consists of slotted casing,generally
<br /> 0.020-inch wide by 1.5-inch long slot size, with 42 slots per foot. I% threaded PVC cap is
<br /> fastened to the bottom of die casing. Ce,tterior-'devices tray be fastened to the casin« (o
<br /> assure even distribution of filter material and grout within the b--eholc annulus. The v ell
<br /> casing,is thoroughly washed and steam-cleaned prior to installation
<br /> After setting the casing inside the hollow stem,sand or gravel filter material is poured into
<br /> the annular space to till from the bo.�-)m of the boring to I foot above the slowed interval. A
<br /> 1 to 2 foot thick bentonite ping is placed above the filter material to prevent the grout from
<br /> infiltrating down into the filter material. New cement,containing about 59r bentonite, is then
<br /> trernied into die annular space from the top of[he bentonite plug to rhe surface. A IockabIc
<br /> PVC cap is placed on each wellhead- Traffic-rared flush-mounted steel covers a-re installed
<br /> around wellheads for wells in parking lots and driveways,while steel stove pipes are usually
<br /> set over~,wellheads in landscaped areas.
<br /> VVV:LL Dl=VELOP,MENl'
<br /> After instaliation,the wells are thoroughly developed to remove residua(drilling' materials
<br /> From the wellbore,and to improve well peifonn;uice by rentovirr�z any fine n-,-aerial in the
<br /> Filter pact;that can pass from the formation into the well well develoI menl is performed in
<br /> accoldarice with California Rcgiona} Water-Quality Control Board(P%VQCB3 procedures
<br /> described in the Leaking Underground Fuel Tank(LUPI)Field;Wanda!, tilt Tri-Regional
<br /> Board Staff fi ecuninte nzdatioits for Prelhninuiy Evaluation and Investigarion of Under g;round
<br /> f Tank Sires,and local regulatory euidelines. Well dcvelopnicm technigzres irrc-ltldc pumping,
<br /> bailing,surging, swabbing,jetting, flushing, and airlifting. During well development from
<br /> duce to ten well volumes arc evacuated from the wet:,afiowin�, pf1, specific conductivity.
<br /> ternperiMire and sediment content of the water tc stabilize. All de'vc1opmem water:md
<br /> rinseate i'- ;ollcctcd for temporary storage in labeled 55—allon c!1nt;1iners or profxr story e
<br /> tanks, ai,c, is then disftc5rti R.. properly dcpcndin'!on anal}tical r-suhs 'l-o a,,;ure that
<br /> Cr055-c011tartunaucua does not occur bctwem '.yells durinf> drillr is' lilt] dcvelopngcrtt. ,ill
<br /> development ecltnpntent is either steam cleaned or cleaned osmg,Aik•onox and rinsed t%%icc
<br /> Mill dionizcd tivarcr.
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