1、Designation: D6724 04 (Reapproved 2010)Standard Guide forInstallation of Direct Push Ground Water Monitoring Wells1This standard is issued under the fixed designation D6724; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、of last revision. A number 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 describes various direct push ground watermonitoring wells and provides guidance on their selection andi
3、nstallation for obtaining representative ground water samplesand monitoring water table elevations. Direct push wells areused extensively for monitoring ground water quality inunconsolidated formations. This guide also includes discussionof some groundwater sampling devices which can be perma-nently
4、 emplaced as monitoring wells.1.2 This guide does not address the single event sampling ofground water using direct push water samplers as presented inGuide D6001. The methods in this guide are often used withother tests such as direct push soil sampling (Guide D6282)and the cone penetrometer test (
5、Guide D6067). The presentguide does not address the installation of monitoring wells byrotary drilling methods such as those presented in PracticeD5092. Techniques for obtaining ground water samples frommonitoring wells are covered in Guide D4448.1.3 The installation of direct push ground water moni
6、toringwells is limited to unconsolidated soils and sediments includ-ing clays, silts, sands, and some gravels and cobbles. Penetra-tion may be limited, or damage may occur to equipment, incertain subsurface conditions; some of which are discussed in5.5. Information in this guide is limited to ground
7、 watermonitoring in the saturated zone.1.4 This guide does not purport to comprehensively addressall of the methods and issues associated with monitoring wellinstallation. Users should seek input from qualified profession-als for the selection of proper equipment and methods thatwould be the most su
8、ccessful for their site conditions. Othermethods may be available for monitoring well installation, andqualified professionals should have flexibility to exercisejudgement concerning alternatives not covered in this guide.The practice described in this guide is current at the time ofissue; however,
9、new, alternative, and innovative methods maybecome available prior to revisions. Therefore, users shouldconsult with manufacturers or producers prior to specifyingprogram requirements.1.5 This guide offers an organized collection of informationor a series of options and does not recommend a specific
10、 courseof action. This document cannot replace education or experi-ence and should be used in conjunction with professionaljudgement. Not all aspects of this guide may be applicable inall circumstances. This ASTM standard is not intended torepresent or replace the standard of care by which the adequ
11、acyof a given professional service must be judged, nor should thisdocument be applied without consideration of a projects manyunique aspects. The word “Standard” in the title of thisdocument means only that the document has been approvedthrough the ASTM consensus process.1.6 This standard does not p
12、urport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:
13、2D653 Terminology Relating to Soil, Rock, and ContainedFluidsD4448 Guide for Sampling Ground-Water MonitoringWellsD4750 Test Method for Determining Subsurface LiquidLevels in a Borehole or Monitoring Well (ObservationWell)3D5088 Practice for Decontamination of Field EquipmentUsed at Waste SitesD5092
14、 Practice for Design and Installation of Ground WaterMonitoring WellsD5254 Practice for Minimum Set of Data Elements toIdentify a Ground-Water SiteD5299 Guide for Decommissioning of Ground Water Wells,Vadose Zone Monitoring Devices, Boreholes, and OtherDevices for Environmental ActivitiesD5434 Guide
15、 for Field Logging of Subsurface Explorationsof Soil and Rock1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.21 on Ground Water andVadose Zone Investigations.Current edition approved July 1, 2010. Published September 201
16、0. Originallyapproved in 2001. Last previous editon approved in 2004 as D672404. DOI:10.1520/D6724-04R10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standar
17、ds Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.D5474 Guide for Selection of Data Elements for
18、 Ground-Water InvestigationsD5521 Guide for Development of Ground-Water Monitor-ing Wells in Granular AquifersD5730 Guide for Site Characterization for EnvironmentalPurposes With Emphasis on Soil, Rock, the Vadose Zoneand Ground WaterD6001 Guide for Direct-Push Ground Water Sampling forEnvironmental
19、 Site CharacterizationD6067 Practice for Using the Electronic Piezocone Pen-etrometer Tests for Environmental Site CharacterizationD6282 Guide for Direct Push Soil Sampling for Environ-mental Site CharacterizationsD6286 Guide for Selection of Drilling Methods for Envi-ronmental Site Characterization
20、D6452 Guide for Purging Methods for Wells Used forGround-Water Quality InvestigationsD6564 Guide for Field Filtration of Ground-Water SamplesD6634 Guide for the Selection of Purging and SamplingDevices for Ground-Water Monitoring WellsD6771 Practice for Low-Flow Purging and Sampling forWells and Dev
21、ices Used for Ground-Water Quality Inves-tigations3. Terminology3.1 Terminology used within this standard is in accordancewith D653.4. Summary of Guide4.1 This guide provides information to be used by experi-enced ground water professionals for investigation of thesubsurface and ambient ground water
22、 conditions.4.2 This guide outlines a variety of field methods forinstalling direct push ground water monitoring wells. Installa-tion methods include: (1) soil probing using combinations ofdynamic (percussion or vibratory) driving with, or without,additions of static (constant) force; (2) static for
23、ce from thesurface using hydraulic penetrometer or drilling equipment;and (3) incremental drilling combined with direct push meth-ods. Methods for installation of annular seals and annulargrouts are also discussed as well as abandonment grouting.4.3 This guide addresses considerations for selection
24、anduse of direct push well systems and installation techniques thatmay be classified into two main categories; exposed screentechniques and protected screen techniques. In exposed screentechniques, the screened casing may serve as the drive rod, ormay surround a drive rod that is removed following i
25、nstalla-tion. In protected screen techniques, the well may be advancedalong with a protective outer casing, or may be lowered into adriven casing that is subsequently removed. Alternatively, thescreen, riser, and a retractable shield may be driven simulta-neously and all remain in the ground.4.4 The
26、 interval to be tested is determined in advance byprior investigation, or by soil or water sampling during directpush driving. A screen section, either protected or unprotected,is connected to riser pipes and either driven on the outside of,or placed inside of direct push rods. With some monitoringw
27、ell designs, it may be necessary to add sand pack and seals toisolate the screened test zone as the rods are retracted. The topof the installation is usually completed in a manner consistentwith regulatory requirements. The well can be developed toremove mobile sediments. Water levels can be measure
28、d, andwater samples are taken as required in the sampling plan.5. Significance and Use5.1 The direct push ground method is a rapid and economi-cal procedure for installing ground water monitoring wells toobtain representative ground water samples and location-specific hydrogeologic measurements. Dir
29、ect push installationsmay offer an advantage over conventional rotary drilledmonitoring wells (Practice D5092) for ground water investiga-tions in unconsolidated formations because they reduce distur-bance to the formation, and eliminate or minimize drillcuttings.At facilities where contaminated soi
30、ls are present, thiscan reduce hazard exposure for operators, local personnel, andthe environment, and can reduce investigative derived wastes.Additionally, smaller equipment can be used for installation,providing better access to constricted locations.5.2 Direct push monitoring wells generally do n
31、ot extend todepths attainable by drilling. They are also typically smaller indiameter than drilled wells, thereby reducing purge watervolumes, sampling time, and investigative derived wastes.Practice D5092 monitoring wells are used when larger diam-eters and/or sample volumes are required, or at dep
32、ths to whichit is difficult to install direct push wells. Direct push monitoringwells should be viable for monitoring for many years.5.3 Prior to construction and installation of a direct pushwell or any other type of ground water well the reader shouldconsult appropriate local and state agencies re
33、garding regula-tory requirements for well construction in the state. A regula-tory variance may be required for installation of direct pushmonitoring wells in some states.5.4 To date, published comparison studies between drilledmonitoring wells and direct push monitoring wells have showncomparabilit
34、y (1, 2, 3, 4, 5). However, selection of direct pushmonitoring wells over conventional rotary drilled wells shouldbe based on several criteria, such as site accessibility andpenetrability, stratigraphic structure, depth to groundwater, andaquifer transmissivity.5.5 Typical penetration depths for ins
35、tallation of groundwater monitoring wells with direct push equipment depend onmany variables. Some of the variables are the size and type ofthe driving system, diameter of the drive rods and monitoringwell, and the resistance of the earth materials being penetrated.Some direct push systems are capab
36、le of installing groundwater monitoring wells to depths in excess of 100 feet, andlarger direct push equipment, such as the vibratory sonic typedrill (Guide D6286) are capable of reaching much greaterdepths, sometimes in excess of 400 ft. However, installationdepths of 10 to 50 feet are most common.
37、 Direct push methodscannot be used to install monitoring wells in consolidatedbedrock (for example, granite, limestone, gneiss), but areintended for installation in unconsolidated materials such asclays, silts, sands, and some gravels. Additionally, depositscontaining significant cobbles and boulder
38、s (for example, someglacial deposits), or strongly cemented materials (for example,caliche) are likely to hinder or prevent penetration to thedesired monitoring depth.D6724 04 (2010)25.6 For direct push methods to provide accurate groundwater monitoring results, precautions must be taken to ensureth
39、at cross-contamination by “smearing” or “drag-down” (thatis, driving shallow contamination to deeper levels) does notoccur, and that hydraulic connections between otherwise iso-lated water bearing strata are not created. Similar precautionsas those applied during conventional rotary drilling operati
40、ons(Guide D6286) should be followed.5.7 There have been no conclusive comparisons of effec-tiveness of sealing between drilled monitoring wells and directpush monitoring wells. As with drilled monitoring wells,sealing methods must be carefully applied to be effective.5.8 Selection of direct push mon
41、itoring wells versus con-ventional rotary drilled monitoring wells should be based onmany issues. The advantages and disadvantages of the manyavailable types of driving equipment and well systems must beconsidered with regard to the specific site conditions. Specificwell systems and components, as w
42、ell as direct push drivingequipment, are described in Section 7.5.9 Advantages:5.9.1 Minimally intrusive and less disturbance of the naturalformation conditions than many conventional drilling tech-niques.5.9.2 Rapid and economical.5.9.3 Smaller equipment with easier access to many loca-tions.5.9.4
43、Use of shorter screens can eliminate connectionsbetween multiple aquifers providing better vertical definitionof water quality than long well screens.5.9.5 Generates little or potentially no contaminated drillcuttings.5.9.6 Less labor intensive than most conventional drillingtechniques.5.10 Disadvan
44、tages:5.10.1 Cannot be used to install monitoring devices inconsolidated bedrock and deposits containing significantcobbles and boulders.5.10.2 Small diameter risers and screens limit the selectionof useable down-hole equipment for purging and sampling.5.10.3 Difficulty installing sand pack in small
45、 annular spaceif gravity installation of sand pack is used.5.10.4 Difficulty installing grout in same annular spaceunless appropriately designed equipment is used.6. Pre-Installation Considerations6.1 Site CharacterizationSuccessful installation of directpush ground water monitoring wells must be pr
46、eceded byappropriate site characterization activities. These activitiesmay include reconnaissance, research, conceptual model de-velopment, exploratory field investigations, and confirmationand re-evaluation of any existing flow models.6.2 For the installation to be successful, it is imperative that
47、the target aquifer be located accurately. As with any wellinstallation, the geologic conditions must be understood andthe stratigraphy must be known. Although direct push wellscan monitor thinner aquifers, with more precision, they may beineffective is incorrectly placed. In thicker aquifers, and wh
48、enseeking dense non-aqueous phase liquids, screens may need tobe located in the bottom of the water-bearing stratum. Wellsplaced without determination of nearby geologic conditionscan be ineffective and possibly dangerous. Geologic investiga-tions should look for perched aquifers and use installatio
49、nmethods which will avoid any crosscontamination of the unit.6.3 Environmental site characterization approaches are de-scribed in Guide D5730. Proper site characterization formonitoring well placement is reviewed in Practice D5092 onMonitoring Well Design.6.3.1 Characterization ToolsIn geologic settings ame-nable to the use of direct push ground water monitoring wells,other direct push methods and tools can likely also be used toeffectively characterize the site. For example, the Cone Pen-etrometer Test (CPT) (Guide D6067) is an effective tool formapping stratigraphy and locating
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