1、Designation: D8006 16Standard Guide forSampling and Analysis of Residential and CommercialWater Supply Wells in Areas of Exploration and Production(E the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb
2、er in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide presents a methodology for obtaining repre-sentative groundwater samples from domestic or commercialwater wells that are in prox
3、imity to oil and gas exploration andproduction (E these tankscontain a rubber bladder filled with air that is used inassociation with a pressure switch to regulate the pressure ofthe water in the tank.3.2.7 water softener, nwater treatment system that substi-tutes sodium ions for ions that cause wat
4、er to be “hard,” inmost cases, calcium and magnesium ions and having a cationresin in the sodium form that removes cations such as calciumand magnesium from water and releases another ion such assodium.3.2.7.1 DiscussionWater softeners are also used to re-move iron, manganese, some radiological mate
5、rials, nitrate,arsenic, chromium, selenium, and sulfate.4. Significance and Use4.1 A supply well provides groundwater for household,domestic, commercial, agricultural, or industrial uses.4.2 Using a standardized protocol based on an existingindustry standard or approved regulatory methods and proce-
6、dures to collect water samples from a supply well is essentialto obtain representative water quality data. These data can becritical to efforts to protect water uses, and human health, andidentify changes when they occur. Use of this guide will helpthe project team to design and execute an effective
7、 watersupply sampling program.4.3 It is important to understand the objectives of thesampling program before designing it. Water supplies may besampled for various reasons including any or all of thefollowing:(1) baseline sampling before an operation of concern,(2) periodic sampling during such an o
8、peration,(3) investigative responses to perceived changes in waterquality, or(4) ongoing monitoring related to known or potentialgroundwater constituents of concern in the area.Sampling programs should be based on these objectives andbe developed in coordination with the prospective laborato-ry(ies)
9、 to ensure its procedures, capabilities, and limitationsmeet the needs of the program, protect human health and fulfillregulatory requirements.5. Well Purging and Sampling Requirements5.1 Sampling Equipment:5.1.1 Gas or multiple meters to provide, at a minimum,information on lower explosive limits f
10、or combustible gasesand oxygen levels to be used for atmospheric screening;5.1.2 Sample containers, made of compatible materials,preservatives appropriate for the sampling to be performed,labels, and chain-of-custody forms (COCs).5.1.3 Field notebook, preferably with waterproof, numberedpages or ele
11、ctronic equivalent such as a tablet.5.1.4 Schedule and contact information for the properties(locations) to be sampled and contact information for labora-tory and carrier/shipping company (if used).5.1.5 Area maps, including GPS coordinates of well(s).5.1.6 Large cooler and bagged ice for storing al
12、l samplesand a mini cooler that can be brought inside the home/buildingto put samples directly on ice after collection and gallon andquart size zip-lock bags in which to put sample containers, ice,and COC, and trash bags for site-derived waste.5.1.7 Intrinsically safe flashlight or headlamp (sample
13、portsare commonly located in low light areas).5.1.8 Pan or other secondary containment system to catchany water that may have dripped during sampling. Make surecleanup is performed after sampling is complete.5.1.9 Safety equipment including: gloves (work and latex ornitrile), safety glasses, shoes w
14、ith slip resistant soles, cleanrags or towels, pails and buckets, basic tool kit, first aid kit, andfire extinguisher.5.1.10 Specific health and safety plan.5.1.11 Watch or wristwatch with second hand, or a digitaltimer, and graduated container to calculate flow rate andvolume.5.1.12 Supplies need t
15、o include apparatus used to measurefield parameters such as pH, turbidity, specific conductance,and dissolved oxygen.5.1.13 Digital Camera.5.2 Field Visit and Sample CollectionAfter arrangementswith the property owner or responsible party have been made,the following steps should be taken:D8006 1635
16、.2.1 Confirm location and note time of arrival, weatherconditions, including barometric pressure, and all onsite per-sonnel.5.2.2 Provide the property owner/occupant an explanationof the work to be undertaken, how long it is expected to take,and what the owner/occupant can expect. Provide identifica
17、tion(for example, personal identification badge (with photograph)and a card or letter that can be provided to the propertyowner/occupant with the appropriate contact information).5.2.3 Document information from property owner includingcomments on water quality and water usage the day of thesampling.
18、5.2.4 Record the well permit number if one has been issued(check with local authorities), and refer to D5980 for furtherinformation on pulling monitoring well permits that show thedepth of the well and the location of the screened interval.5.2.5 Sketch the area including the location of the supplywe
19、ll(s) and photo-document with a digital camera, and sketchlocation in logbook. Be aware that a property may have morethan one supply well or other water sources. It is important tounderstand and document the uses of these supply sources (forexample, drinking and agricultural) and understand and docu
20、-ment if they are connected to the system being sampled (intoone pressure tank or separate pressure tanks); this will allowthe sampling team to choose the correct sample location(s) andthe source of the sample.5.2.6 As appropriate, photograph features on the property(buildings, septic systems, wells
21、, surface water, chemicalstorage areas, fuel tanks, vehicle and equipment storage/parking areas, visual surface staining, signs of stressedvegetation, and cracks in foundation) and the water deliverysystem (pressure tank, water treatment equipment, wellheadand pump, sampling port, and floor drain if
22、 present). Allphotographs should have a date/time stamp and be annotated towhere the photograph was taken.5.2.7 Locate the water shutoff valve. It is critical this step isundertaken before starting any purging or sampling to reduceany potential damage if a leak or break does occur.5.3 Determining Sa
23、mple LocationsSamples should be col-lected as close to the water well as possible; however, theactual water supply well should only be accessed by a licensedplumber or similarly qualified individual as contaminants canbe introduced if this work is undertaken by untrained person-nel. The sampling tea
24、m should not remove well caps, plugs, orports from water supply wells, unless permissible by applicablestatue or regulations.5.3.1 The sampling team should review the water systemconfiguration to determine the closest water tap to the watersource; this is commonly, but not always, a drain port on th
25、efront near the base of the bladder/pressure tank. Care should betaken to ensure the valve is operational. Do not force valvesopen. Treatment systems and exact sample locations should bedocumented. Samples should be collected before the waterreaches any treatment systems. Collecting treated water sh
26、ouldbe avoided since it will not be representative of actual inflowconditions. Usually, water treatment systems are designed toallow temporary bypass flow without alteration to the systemitself. If the sample is collected after treatment, it should benoted in the field notebook.5.3.2 Water lines sho
27、uld be traced to determine exactly whatis being sampled (for example, water from pressure tank, watertreated through a treatment system). The sampling team shouldnot alter the piping or water delivery system in any way,including turning treatment systems off or removing tubing orboth; however, if th
28、e sampling team needs to take a samplethrough existing tubing, this should be noted.5.4 Purging and Sampling of Supply WellsStagnant, non-representative water should be purged from the water supplysystem before samples are collected to ensure that the sampleis representative of actual well condition
29、s. The convention ofpurging monitoring wells of three well volumes before sam-pling is not necessarily applicable to nor practical for supplywells. Supply wells may contain hundreds of gallons of water,the purging of which would be time-consuming, potentiallydetrimental to the well pump, may result
30、in short-term deple-tion of the property owners water supply, could overfill septicsystems if discharged to a sink, and increase electric utility costto the property owner. Additionally, while monitoring wellstend to remain stagnant for long durations, supply wells arecommonly pumped more frequently
31、. Thus, it is important topurge the plumbing system but not necessarily the supply well.An unused or infrequently used supply well may require agreater purge volume. The water supply system should bepurged until two times the holding tank volume is removed orfield parameter measurements stabilize. T
32、his ensures water iscoming from the well and not just residual water in theplumbing system.5.4.1 Holding tank volumes are commonly listed on the sideof the pressure tank, or can be determined based on thedimensions of the tank or both. A good rule of thumb is tolisten for the bladder/pressure tank s
33、witch to click, whichindicates that the bladder/pressure tank is filling with waterfrom the well.5.4.2 Field parameters, including temperature, pH, specificconductance, dissolved oxygen, color/appearance, and flowrate should be recorded at established sample time intervals(every 3 to 5 min) during p
34、urging with instruments calibratedin accordance with manufacturer specifications. This is mostaccurately and efficiently accomplished with flow-through cellsequipped with probes for temperature, pH, and specific con-ductance. When the field parameters vary less than 610%inreplicate measurements for
35、dissolved oxygen and specificconductance, 60.2 pH units, and 610 NTUs for turbidity, thewell is adequately stabilized. Purging may be terminated 30minutes following removal of two holding tank volumesshould parameter stabilization not be achieved. In this case atleast one casing volume should be rem
36、oved. This sample maynot reflect groundwater conditions, because it may consist onlyof water from the well casing, which has been in the wellcasing for an unknown period of time. Barometric pressure andfield temperature should also be recorded.5.4.3 The sampling team should establish whether the wel
37、lhas deliverability problems and if a drawdown would beobjectionable to the well user. In such a case, it may beacceptable to obtain a sample before purging, prior to removalD8006 164of two holding tank volumes, or prior to parameter stabilizationand note the exceptionable circumstances.5.4.4 In the
38、 event a treatment system must be bypassed, thesampling team should also take into account the presence ofunwanted residual treated water that will be present in the linethat is to be purged. The treatment system shall be returned toits original working status immediately after the sample iscollecte
39、d. Treatment systems designed for bacteriological de-contamination (such as UV lights or chlorinators) should not beswitched off or bypassed.5.4.5 Typically, purging occurs at a sink connected to thewater delivery system and water runs down the drain; however,the property owner/occupant should be co
40、nsulted about this incase they would like this water collected for another use. Flowrate shall be estimated and recorded during purging.5.4.6 Once purging is complete, the flow rate should bereduced to a steady, non-turbulent stream before collecting thesamples (if possible) to minimize suspended so
41、lids and thepotential for loss of dissolved gas or other volatile constituents,if present.5.4.7 The sample should be collected directly from thewater delivery system as close to the well as possible intolaboratory supplied sample containers; intermediate collectioncontainers should not be used. Ther
42、e may be times whensamples will need to be collected from taps located in otherareas. Taps in residential homes are often equipped withscreens that may aerate samples before collection. In thosesampling scenarios, and where feasible, screens should beremoved before sampling. If samples cannot be col
43、lectedwithout removing screens, it should be documented in the fieldsampling logbook and included in the notes for the analyticallaboratory. The sampling team should include samplinglocation, collection date and time, and method and purgedetails (for example, field parameters) in the field notebook.
44、Sampling methodology should be documented in such detailthat a third party could duplicate it in the future. Preservativesand mitigation of interferences may be necessary depending onthe laboratory analysis to be performed.5.4.8 The sampling team should also record a physicaldescription of the water
45、 including color, odor, and sediment.Note that samples that require analysis for dissolvedconstituents, or that are excessively turbid, may need to be fieldfiltered to obtain representative analytical results for dissolvedconstituents. Resulting solids should be retained for separateanalyses. If ana
46、lysis for total and dissolved constituents isdesired, a filtered sample for dissolved analysis and a separateunfiltered sample for total analysis may be needed fordigestion, prior to analysis.5.4.9 Following sampling, the sampling team must ensurethe sample point is completely closed and not leaking
47、 and thearea is clean. If the leak cannot be stopped, the sampling teammust notify the owner or the property who should call aplumber to fix the leak at the expense of the responsible party.The sampling team must document the time of completion andinform the owner/occupant of task completion. It is
48、recom-mended that the sampling team complete a pre- and post-sampling checklist to document the condition for the waterdelivery system before and after sampling.6. Sampling Team Qualifications6.1 It is strongly recommended that the sampling be per-formed by a third-party sampling company or agency i
49、ndepen-dent of the firm requesting the services. The sampling teamshould consist of experienced individuals who have receivedtraining in the areas shown below and work under thedirection/supervision of an appropriately credentialed profes-sional (for example, registered or licensed professional) or anindependent laboratory approved in the jurisdiction where thewater supply well is located. In addition, a qualified samplingteam shall have the following knowledge and experience:6.1.1 Collection, interference mitigation, preservation,storage, and handling procedures of representative
