ASTM D6724-04(2010)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6724 − 04(Reapproved 2010)
Standard Guide for
Installation of Direct Push Groundwater Monitoring Wells
This standard is issued under the fixed designation D6724; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope consult with manufacturers or producers prior to specifying
program requirements.
1.1 This guide describes various direct push groundwater
monitoring wells and provides guidance on their selection and 1.5 This guide offers an organized collection of information
installation for obtaining representative groundwater samples oraseriesofoptionsanddoesnotrecommendaspecificcourse
and monitoring water table elevations. Direct push wells are of action. This document cannot replace education or experi-
used extensively for monitoring groundwater quality in uncon- ence and should be used in conjunction with professional
solidated formations. This guide also includes discussion of judgement. Not all aspects of this guide may be applicable in
somegroundwatersamplingdeviceswhichcanbepermanently all circumstances. This ASTM standard is not intended to
emplaced as monitoring wells. representorreplacethestandardofcarebywhichtheadequacy
of a given professional service must be judged, nor should this
1.2 Thisguidedoesnotaddressthesingleeventsamplingof
document be applied without consideration of a project’s many
groundwater using direct push water samplers as presented in
unique aspects. The word “Standard” in the title of this
Guide D6001. The methods in this guide are often used with
document means only that the document has been approved
other tests such as direct push soil sampling (Guide D6282)
through the ASTM consensus process.
and the cone penetrometer test (Guide D6067). The present
1.6 This standard does not purport to address all of the
guide does not address the installation of monitoring wells by
safety concerns, if any, associated with its use. It is the
rotary drilling methods such as those presented in Practice
responsibility of the user of this standard to establish appro-
D5092. Techniques for obtaining groundwater samples from
priate safety and health practices and determine the applica-
monitoring wells are covered in Guide D4448.
bility of regulatory requirements prior to use.
1.3 The installation of direct push groundwater monitoring
wells is limited to unconsolidated soils and sediments includ-
2. Referenced Documents
ing clays, silts, sands, and some gravels and cobbles. Penetra-
2.1 ASTM Standards:
tion may be limited, or damage may occur to equipment, in
D653 Terminology Relating to Soil, Rock, and Contained
certain subsurface conditions; some of which are discussed in
Fluids
5.5. Information in this guide is limited to groundwater
D4448 Guide for Sampling Ground-Water Monitoring Wells
monitoring in the saturated zone.
D4750 Test Method for Determining Subsurface Liquid
1.4 This guide does not purport to comprehensively address
Levels in a Borehole or Monitoring Well (Observation
all of the methods and issues associated with monitoring well 3
Well) (Withdrawn 2010)
installation. Users should seek input from qualified profession-
D5088 Practice for Decontamination of Field Equipment
als for the selection of proper equipment and methods that
Used at Waste Sites
would be the most successful for their site conditions. Other
D5092 Practice for Design and Installation of Groundwater
methods may be available for monitoring well installation, and
Monitoring Wells
qualified professionals should have flexibility to exercise
D5254 Practice for Minimum Set of Data Elements to
judgement concerning alternatives not covered in this guide.
Identify a Ground-Water Site
The practice described in this guide is current at the time of
D5299 Guide for Decommissioning of Groundwater Wells,
issue; however, new, alternative, and innovative methods may
Vadose Zone Monitoring Devices, Boreholes, and Other
become available prior to revisions. Therefore, users should
Devices for Environmental Activities
1 2
This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rock For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and is the direct responsibility of Subcommittee D18.21 on Groundwater and contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Vadose Zone Investigations. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved July 1, 2010. Published September 2010. Originally the ASTM website.
approved in 2001. Last previous editon approved in 2004 as D6724–04. DOI: The last approved version of this historical standard is referenced on
10.1520/D6724-04R10. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6724 − 04 (2010)
D5434 Guide for Field Logging of Subsurface Explorations or placed inside of direct push rods. With some monitoring
of Soil and Rock well designs, it may be necessary to add sand pack and seals to
D5474 Guide for Selection of Data Elements for Groundwa- isolate the screened test zone as the rods are retracted. The top
ter Investigations of the installation is usually completed in a manner consistent
D5521 Guide for Development of Groundwater Monitoring with regulatory requirements. The well can be developed to
Wells in Granular Aquifers remove mobile sediments. Water levels can be measured, and
D5730 Guide for Site Characterization for Environmental water samples are taken as required in the sampling plan.
Purposes With Emphasis on Soil, Rock, the Vadose Zone
and Groundwater (Withdrawn 2013)
5. Significance and Use
D6001 Guide for Direct-Push Groundwater Sampling for
5.1 The direct push ground method is a rapid and economi-
Environmental Site Characterization
cal procedure for installing groundwater monitoring wells to
D6067 Practice for Using the Electronic Piezocone Pen-
obtain representative groundwater samples and location-
etrometer Tests for Environmental Site Characterization
specifichydrogeologicmeasurements.Directpushinstallations
D6282 Guide for Direct Push Soil Sampling for Environ-
may offer an advantage over conventional rotary drilled
mental Site Characterizations
monitoring wells (Practice D5092) for groundwater investiga-
D6286 Guide for Selection of Drilling Methods for Environ-
tions in unconsolidated formations because they reduce distur-
mental Site Characterization
bance to the formation, and eliminate or minimize drill
D6452 Guide for Purging Methods for Wells Used for
cuttings.At facilities where contaminated soils are present, this
Groundwater Quality Investigations
can reduce hazard exposure for operators, local personnel, and
D6564 Guide for Field Filtration of Groundwater Samples
the environment, and can reduce investigative derived wastes.
D6634 Guide for Selection of Purging and Sampling De-
Additionally, smaller equipment can be used for installation,
vices for Groundwater Monitoring Wells
providing better access to constricted locations.
D6771 Practice for Low-Flow Purging and Sampling for
5.2 Direct push monitoring wells generally do not extend to
Wells and Devices Used for Ground-Water Quality Inves-
depths attainable by drilling. They are also typically smaller in
tigations (Withdrawn 2011)
diameter than drilled wells, thereby reducing purge water
3. Terminology
volumes, sampling time, and investigative derived wastes.
Practice D5092 monitoring wells are used when larger diam-
3.1 Terminology used within this standard is in accordance
etersand/orsamplevolumesarerequired,oratdepthstowhich
with D653.
itisdifficulttoinstalldirectpushwells.Directpushmonitoring
4. Summary of Guide
wells should be viable for monitoring for many years.
4.1 This guide provides information to be used by experi-
5.3 Prior to construction and installation of a direct push
enced groundwater professionals for investigation of the sub-
well or any other type of groundwater well the reader should
surface and ambient groundwater conditions.
consult appropriate local and state agencies regarding regula-
4.2 This guide outlines a variety of field methods for tory requirements for well construction in the state. A regula-
tory variance may be required for installation of direct push
installing direct push groundwater monitoring wells. Installa-
tion methods include: (1) soil probing using combinations of monitoring wells in some states.
dynamic (percussion or vibratory) driving with, or without,
5.4 To date, published comparison studies between drilled
additions of static (constant) force; (2) static force from the
monitoring wells and direct push monitoring wells have shown
surface using hydraulic penetrometer or drilling equipment;
comparability (1, 2, 3, 4, 5). However, selection of direct push
and (3) incremental drilling combined with direct push meth-
monitoring wells over conventional rotary drilled wells should
ods. Methods for installation of annular seals and annular
be based on several criteria, such as site accessibility and
grouts are also discussed as well as abandonment grouting.
penetrability, stratigraphic structure, depth to groundwater, and
aquifer transmissivity.
4.3 This guide addresses considerations for selection and
use of direct push well systems and installation techniques that
5.5 Typical penetration depths for installation of groundwa-
may be classified into two main categories; exposed screen
ter monitoring wells with direct push equipment depend on
techniques and protected screen techniques. In exposed screen
many variables. Some of the variables are the size and type of
techniques, the screened casing may serve as the drive rod, or
the driving system, diameter of the drive rods and monitoring
may surround a drive rod that is removed following installa-
well, and the resistance of the earth materials being penetrated.
tion. In protected screen techniques, the well may be advanced
Some direct push systems are capable of installing groundwa-
along with a protective outer casing, or may be lowered into a
ter monitoring wells to depths in excess of 100 feet, and larger
driven casing that is subsequently removed. Alternatively, the
direct push equipment, such as the vibratory sonic type drill
screen, riser, and a retractable shield may be driven simulta-
(Guide D6286) are capable of reaching much greater depths,
neously and all remain in the ground.
sometimes in excess of 400 ft. However, installation depths of
4.4 The interval to be tested is determined in advance by 10 to 50 feet are most common. Direct push methods cannot be
prior investigation, or by soil or water sampling during direct used to install monitoring wells in consolidated bedrock (for
push driving.Ascreen section, either protected or unprotected, example, granite, limestone, gneiss), but are intended for
is connected to riser pipes and either driven on the outside of, installation in unconsolidated materials such as clays, silts,
D6724 − 04 (2010)
sands, and some gravels. Additionally, deposits containing 6.2 For the installation to be successful, it is imperative that
significant cobbles and boulders (for example, some glacial the target aquifer be located accurately. As with any well
deposits), or strongly cemented materials (for example, cali- installation, the geologic conditions must be understood and
che) are likely to hinder or prevent penetration to the desired the stratigraphy must be known. Although direct push wells
monitoring depth. can monitor thinner aquifers, with more precision, they may be
ineffective is incorrectly placed. In thicker aquifers, and when
5.6 For direct push methods to provide accurate groundwa-
seeking dense non-aqueous phase liquids, screens may need to
ter monitoring results, precautions must be taken to ensure that
be located in the bottom of the water-bearing stratum. Wells
cross-contamination by “smearing” or “drag-down” (that is,
placed without determination of nearby geologic conditions
drivingshallowcontaminationtodeeperlevels)doesnotoccur,
can be ineffective and possibly dangerous. Geologic investiga-
and that hydraulic connections between otherwise isolated
tions should look for perched aquifers and use installation
water bearing strata are not created. Similar precautions as
methods which will avoid any crosscontamination of the unit.
those applied during conventional rotary drilling operations
6.3 Environmental site characterization approaches are de-
(Guide D6286) should be followed.
scribed in Guide D5730. Proper site characterization for
5.7 There have been no conclusive comparisons of effec-
monitoring well placement is reviewed in Practice D5092 on
tiveness of sealing between drilled monitoring wells and direct
Monitoring Well Design.
push monitoring wells. As with drilled monitoring wells,
6.3.1 Characterization Tools—In geologic settings ame-
sealing methods must be carefully applied to be effective.
nable to the use of direct push groundwater monitoring wells,
5.8 Selection of direct push monitoring wells versus con-
other direct push methods and tools can likely also be used to
ventional rotary drilled monitoring wells should be based on
effectively characterize the site. For example, the Cone Pen-
many issues. The advantages and disadvantages of the many
etrometer Test (CPT) (Guide D6067) is an effective tool for
available types of driving equipment and well systems must be
mapping stratigraphy and locating target layers. Other sensors,
considered with regard to the specific site conditions. Specific
such as electrical conductivity and optical detectors have been
well systems and components, as well as direct push driving
placed on CPT and other direct push systems. Direct push soil
equipment, are described in Section 7.
sampling (Guide D6282) and water sampling (Guide D6001)
can be used in advance to locate strata of concern. Direct push
5.9 Advantages:
characterization experience at a site can guide the user in well
5.9.1 Minimallyintrusiveandlessdisturbanceofthenatural
design or device selection.
formation conditions than many conventional drilling tech-
6.3.2 Sampling During Installation—Many direct push sys-
niques.
tems can take soil or water samples as part of the well
5.9.2 Rapid and economical.
installation process. For example, two-tube systems described
5.9.3 Smaller equipment with easier access to many loca-
in direct push soil sampling Guide D6282 can be used to
tions.
collect soil samples while driving. When the target aq
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