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sail sampling at desired intervals- Sail samples are calleded analysis(VOA)Mals,with'TeRen'septa,are used as sample-
<br /> by either hammering(vrtth a 1<0-pound drop hammer)or containers.
<br /> hydraulically pushing a conventional split-barrel sampler
<br /> containing pre-cleaned 2-inch-diameter brass tubes. A The groundvrater sample is decanted into each VOA Hal in
<br /> geologist or engineer(ram Apex Envirotech,Inc.,continuously such a manner that there is no meniscus at the tap of the via(.
<br /> logs each borehole during drilling and constantly checks drill A maned and is kentt tare ed tto the
<br /> Copt air bubbles eat the vial. tre previal
<br /> is then
<br /> cuttings toe indications of both the first recognizable g y pp
<br /> occurrence al groundwater and umlaute hydrocarbons using none are present,the vial is labeled and refrigerated for
<br /> either a portable ph dwatera not detector,name ionization delivery,under strict chain-al-custody,to the analytical
<br /> detector.r ar,or an exptosimniz The sampler is rinsed hetvrten laboratory. Label information should include a unique sample
<br /> samples and either steam cleared or washed vrth all other identiRcatkan number,jab then mple number,date,time,type
<br /> drilling equipment bet men harings to minimize the potential for of analysis requested,and the samplels name.
<br /> cross•contamination. For quality control purposes,a duprcate water sample is
<br /> Ntanharing wells are cased with threaded,factory-perforated collected from each well. This sample may also be analyzed or
<br /> and blank Schedule SC PVC. The perforated interval consists put an hold at the laboratory. Vlhen required,a trip blank,
<br /> at slotted casing,generally with 0.020-inch wide by 1.E_knch prepared at the laboratory,is placed in the transport caeler- it
<br /> long slats,with 42 slats per fact. A PVC cap may be secured islabeled
<br /> itransilac Ort.and to a well
<br /> sa dpie the gains in t e cooler
<br /> to the bottom of the casing with stainless steel screws;no durinthe roundwater samples. In add,
<br /> a field blank may be
<br /> :solvents or cements are used. Centering devices may re ared in the field when sampling equipment is not
<br /> fastened to the casing to ensure even distribution of filter dedicated. The Meld blank is prepared alter a pump or baler
<br /> material and grant within the bcrehata annulus. The well
<br /> rice to
<br /> se
<br /> d,or may 6e has
<br /> ext well. am cleaned cc properly wa
<br /> casing is thoroughly washed aninns ot analyzed along with the othersamples.d/or steam cleanems.
<br /> purchased as pre-cleaned,prior to installation. The field blank analysis demonstrates the effectiveness of the
<br /> crass-contamination.
<br /> Atter setting the casing inside the hallow-stem auger,sand or in-detd cleaning procedures to preverd
<br /> gravel Miter material is poured into the annular space to All from To minimize the potential lar ucsstantamination between
<br /> boring bottom to generally 1 lace above the perforated inmate- P
<br /> A 1-to 2-fact thick bentonite plug is set above this Atter material dedicated ted tela weft is either steam cleaned pment and watir lot properrlywash d
<br /> to prevent grout tram inARrating the Alter pack. Either neat
<br /> cement,containing about 5 percent bentonite,ar sand-cement between use. As a secondary precautionary measure,wells
<br /> Scout is then tremmied into the annular space from the top of are sampled in order at establ hed by ave lablelpra previous ane tical data.st to highest atians as
<br /> the bentaniite plug to near surface. A tratRc-rated veno is
<br /> installed around.each wellhead far wells located in parking tats In the event the Prater samples cannot be submitted to the
<br /> ac driveways,while steel-stow_pipes'are usually set over analytical laboratory on the same day they are collected(e.g.,
<br /> wellheads In landscaped areas. due to weekends ac holidays),the samples are temporarily
<br /> stared until the first opportunity far submittal either on water ice
<br /> After installation,the wells are thoroughly developed to remove
<br /> residual dolling materials from the wellbore,and to improve well in a cooter•such as when in the Meld,or in refrigerator at
<br /> performance by removing fine material from the.Alter pack that Apmes afMee.
<br /> may pass into the well. Well dev.eIepment techniques used SOP - 2 Z
<br /> may include pumping,surging,bailing.s:robbing,Jetting, M gr p%S U R I N G LIQUID LEVELS USING
<br /> flushing,and aic-lining. Ali development water is collected WATER LEVEL METER OR INTERFACE t
<br /> either in drums or tanks far temporary storage,and properly
<br /> disposed at depending an laboratoryanal•7ticat results. To PROBE °
<br /> minimize the potential lac cross-contamination between wells, sed q gauging `call includes
<br /> alt development equipment is either steam cleaned or property the mField easuring nnt stcumentr(water stet meter otrnterface probe)
<br /> washed prior to use. FaUnvanq development,the well is 9 also
<br /> allowed to stand undisturbed tar a minimum of 24 hours before and
<br /> ppliies(bCuckets(solution spras). The field ycbcttles.cand detanized water)
<br /> its Rest sampling. to be used in cleaning the equipment tidween wells-
<br /> 7 Prior to measurement,the instrument Up is lowered into the welt
<br /> GROUNDWATER PURGING AND until it touches bottom. Using the previously established top-af-
<br /> SAM P LING casing cc top-0f-box(i-e.,wellhead vault)point.the probe cord
<br /> Prior to water sampling,each well is purged by evacuating a foe hdc. undrhalyaredths
<br /> is marked and a measuring tape(graduated In
<br /> minimum att three
<br /> wade well-casings continueuntil s at the discharge hub ndRteedUi a probe end not to mariang on theo determine the dcard distance
<br /> When req purgingwill mesuremerk
<br /> water temperature,candudivtty,or pH stabilize,a me.dmum of thaaMeasuradlTotal t7than epth'of the wellliquid.
<br /> level data sheet as
<br /> ten wetted-casing volumes of groundwater have been
<br /> recavered,or the well is baited dry. When pcadlcal,the
<br /> groundwater sample should be collected when the water level When necessary in using the Interface probe to measure liquid
<br /> In the well recovers to at least So percent of its static level- levels•the prole Is first electrically grounded to either the metal
<br /> stove pipe or another metal object nearby. When no ground is
<br /> The sem lin equipment consists of either a"Teflon'bailer, available,reproducible measurements can be obtained by
<br /> P g eq P a-Tanori clipping the ground lead to the handle at the irtertace probe
<br /> PVC baiter,or stainless steel bladder pump With
<br /> bladder. it the sampling system is dedicated to the well•then ca se
<br /> the bailer Is usually'Teflon."but the bladder pump Is PVC Wtth
<br /> a polypropylene bladder. In general and depending on the
<br /> intended laboratory analysis,40-rnlllder glass,valatila organic
<br />
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