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t [^ soil sampling at desired intervals. Soil samples are collected analysis(VOA)Mals,YAh'Te,1an-septa,are used as sample.
<br /> by either hammering(YAh a 140-pound drop hammer)or containers.
<br /> hydraulically pushing a conventional split-barrel sampler
<br /> containing pre-c[eaned 2-inch-diameter brass tubes. A The ground,,vater sample is decanted into eac-h VOA vial in
<br /> geologic~or engineer from Apex Envirotech,Inc..continuously such a manner that there is no meniscus at the top of the tial.
<br /> logs each borehole during drilling and constantly checks drill A cap is quickly secured to the tap of the vial. The tial is then
<br /> # cuttings for indications of beth the first recognizable og inverted and gently tapped to spa if air bubbles are present. It
<br /> occurrence of groundwater and wlatile hydrocarbons using none are present,the vial is labeled and refrigerated for
<br /> either a portable phctaianization detector,flame ionization delivery,under strict chain-of-custody,to the analytical
<br /> detector,at an explosimeter. The sampler is rinsed between laboratory. babel information should include a unique sample
<br /> samples and either steam cleaned or washed IeAh aA other identification number.,job identification number,date,time,type
<br /> drilling equipment bet.veen barings to minimize the potential for of analysis requested,and the sariplees name.
<br /> cross{cntaminaticn.
<br /> For quality control purposes,a dupacace water sample is
<br /> t Mankaring wells are cased vrtth threaded,factory-perforated collected from each well. This sample may also be analyzed or
<br /> and blank Schedule 40 PVC. The perforated interval consists put on hold at the laboratory. When required, a trip blank,
<br /> of slatted casing,generally with 0,020-inch wide by 1.5-tnch prepared at the laboratory,is placed in the transport cooler, it
<br /> i long slots,with 42 slats per fact. A PVC cap may be secured is labeled similar to the Yell samples,remains in the cooler
<br />} to the bottom of the casing vrth stainless steel screws;no during transport.and is analyzed by the laboratory along with
<br /> solvents or cements are used. Centeringdevices may be
<br /> Y the groundwater samples. In addition,a field blank maybe
<br /> fastened to the casing to ensure even distribution of filer prepared in the field when sampling equipment is not
<br /> material and grout whin the hceehole annulus. The well dedicated. The field blank is prepared alter a pump or bailer
<br /> casing is thoroughly vmshed and/or steam cleaned,or may be has been either steam cleaned or property washed,prior to use
<br /> purchased as pre-cleaned.prior to installation. in the next well,and is analyzed along wr h the other samples,
<br /> The field blank analysis demons rates the effectiveness of the
<br /> After setting the casing inside the hallow-stem auger,sand ar in-field cleaning procedures to prevent crass-contamination.
<br /> gravel filter material is poured into the annular space to 611 from
<br /> baring bottom to generally 1 fact above the perforated interval. To minimize the potential for cross-contamination between
<br /> A 1-to 2-foot thick bentonite plug is set above this fitter material veils,all well development and water sampling equipment not
<br /> to prevent grout from'tnfilrating the filter pacts Either neat dedicated to a well is either steam cleaned or properly washed
<br /> cement,containing about 5 percent bentonite,or sand-cement between use. As a secondary precautionary measure,%ells
<br /> grout is then tremmied into the annular space from the top of are sampled in ceder of least to highest concentrations as
<br /> the bentonite plug to near surface. A traffic-rated vault is established by available previous analytical data.
<br /> installed around each wellhead far wells located in parking lots
<br /> or driveways,while steel"stovepipes'are usually set over In the event the Yeater samples cannot be submitted o
<br /> A t the
<br /> wellheads In landscaped areas, analytical laboratory an the same daythey are collected(e.g.,
<br /> due to weekends or holidays),the samples are temporarily
<br /> After installation,the wells are thoroughly developed to remove stared until the first oppertuni yfor submittal either an water ice
<br /> residual drilling materials tram the wellbore,and to improve well. in a cooler,such as v,hen in tha'Feld,or in refrigerator at
<br /> performance by removing fine material from the filter pack that Ape)es office.
<br /> may pass into the welt. Well development techniques used
<br /> may include pumping,surging,bailing,swabbing,jetting, SO P
<br /> flushing,and air-lifting. All development water is collected MEn_ .SURING LIQUID LEVELS USING
<br /> either in drums or tanks far temporary storage,and properly WATER LEVEL METER OR INTERFACE i
<br /> disposed of depending an laboratory analytical results. To PRC)BF—
<br /> minimize the potential for cross-contamination between wells,
<br />+ all development equipment is either steam cleaned or property Field equipment used for liquid4evel gauging typically includes
<br /> Yrashed prior to use. Fol[eY,ing development,the well is the measuring instrument-(water-level meter ar interface probe)
<br /> allowed to stand undisturbed for a minimum at 24 hours before and product bailer(s). The field ict also includes cleaning
<br /> its first sampling, supplies(buckets,solution,spray bcdles,and deionized Prater)
<br /> to be used in cleaning the equipment between wells.
<br /> i SOh - 7
<br /> GROUNDWATER PURC;ING AND Prior to measurement,the instrument tip is lowered into the well
<br /> SAMPLING until it touches bottom. Using the previously established top-of-
<br /> casing ar tap-01-box(i.e..Yeellhead vault)paint,the probe card
<br /> i Prior to Prater sampling, each Y,--Il is purged by evacuating a (or halyard)is marked and a measuring tape(graduated In
<br /> minimum of three wetted well-casing w1umes of groundwater, hundredths of a foot)is used to determine the distance
<br /> When required,purging will continue until either the discharge between the preba end and the marking an the card.This
<br /> water temperature,conductivity,or pH stabilize,a ma.)dmum of measurement is then recorded on the liquid-lave)data sheet as
<br /> ten wetted-casing'wlumes of groundYrater haw been the'Measured Tctal Depth'at the well - -
<br /> recavered,or the wall is bailed dry. When pracdcal,the
<br /> I groundwater sample should to collected when the water level When necessary in using the Irrterace probe to measure liquid
<br /> In the well recovers to at least a0 percant of its static lave]. levels,the probe is first electrically grounded to either the metal
<br /> stove pipe ar another metal object nearby. When no ground Is
<br /> The sampling equipment consists of either a'Taftan'bailer, available,reproducible measurements can be obtained by
<br /> PVC bailer,or stainless steel bladder pump vdth a'Teflon' clipping the ground lead to the handle of the interface probe
<br /> bladder. If the sampling system is dedicated to the%roll,then case,
<br /> tho bailor is usually"Teriars,'but the bladder pump is PVC with
<br /> a polypropylene bladder. In general and depending on the
<br /> intended laboratory analysis,43-milliliter glass,volatile organic
<br /> i
<br /> i SOP- Monitoring Wells
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