United States
Environmental Protection
Agency
Solid Waste and
Emergency Response
(OS-110W)
EPA/542/N-93/008
September 1993
SEPA Ground Water Currents
Developments in innovative ground water treatment
ResonantSonicSMDrill Increases
Speed and Depth at Hanford
By Gregory W. McLellan, Westinghouse Hanford Company
Westinghouse Hanford Com-
pany (WHC) has demonstrat-
ed a ResonantSonic drilling
method for the Department of
Energy (DOE) at the Hanford,
Washington site. This service
mark technology, developed by
Water Development Corpora-
tion, can drill two to three
times faster than traditional
drilling methods-30 to
40 feet (ft.) a day (up to one
foot per second in some forma-
tions). Additionally, the Reso-
nantSonic drill achieves
greater penetration depths—
230 ft. at Hanford and over
500 ft. when tested at Sandia
by Pacific Northwest Laborato-
ries (PNL). The technology,
applicable for both ground wa-
ter and soil, renders continuous
clean core samples because the
ResonantSonic drill rod is
hollow, which allows for sam-
ple tubes to be inserted into
the middle of the rod to ex-
tract samples. Less soil needs
to be drummed because no air,
water, mud or other circulation
medium is needed for penetra-
tion. Contamination is main-
tained at the wellbore; and,
the waste stream of drill cut-
tings is greatly minimized. The
technology can drill at any
angle, from vertical to hori-
zontal. It is safe in highly
hazardous conditions and
has been shown to be cost
effective.
At Hanford, the Resonant-
c • SM ,
Some system was used to
drill and complete eight
ground water monitoring
wells, one carbon tetrachlo-
ride monitoring/extraction
well and two vadose charac-
terization boreholes. Here's
how the system works.
A technologically ad-
vanced hydraulically acti-
vated drill head transmits
pressure waves through a
steel drill pipe to create a
cutting action at the bit face
in order to take a continuous
core. A standing wave condi-
tion of vibration is created
when the steel drill pipe
achieves a resonant status;
and, massive amounts of pow-
er efficiently flow through
the pipe to effectuate pene-
tration of any type formation.
Excess cuttings are displaced
into the borehole wall during
drilling as the drill pipe ex-
pands and contracts in width,
thus reducing any dampening
of the vibrations caused by
formation swelling. As the
hole is advanced, additional
sections of the drill pipe are
added. The soil enters the
drill string through an open-
face (core-type) drill bit and is
contained in an inner core
tube that rests on the inside
shoulder of the bit. When the
core barrel is filled with soil,
as signaled by a position indi-
cator, it is removed via a wire-
line retrieval system. As a
result, a continuous core of
the formation is obtained.
After the well is drilled to to-
tal depth, a permanent casing
for the ground water monitor-
ing well is lowered inside the
drill pipe and is seated on the
bottom of the well. As the
drill is removed, an annular
seal is placed between the per-
manent casing and the forma-
tion to prevent downward
migration of contaminants
along the annulus of the well.
At Hanford, data on the
ResonantSonic system was
compared to data from a
cable-tool system of wells in
close proximity to the sonic
wells with similar geologic
conditions and well purpose.
The average drill rate for the
11 wells drilled with the Reso-
nantSonic drill was 23.0 ft.
per eight-hour work day; the
(See Sonic Drill, page 3)
This Month in Currents
This month's Currents features news
from the Department of Energy.
Sonic Drill
Ground Water Issues
Natural Bioremediation
Recycled/RecyclableV
Printed with Soy/Canola ink on paper that contains at least 50% recycled fiber
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ISSUES
Ground Water Issues of Interest
l~rom time to time, the Super-
fund Technology Support
Center for Ground Water at
EPA's Robert S. Kerr Environ-
mental Research Laboratory
publishes "Ground Water Is-
sue" which addresses issues
and information needs for
those in the held of ground
water monitoring and remedi-
ation. Four such information
issues are summarized below.
Behavior of Metals in Soils
One of the major issues of
concern in ground water re-
mediation at Superfund sites is
the mobility of metals in the
soil environment. Joan E.
McLean of the Utah Water
Research Laboratory at Utah
State University and Bert E.
Bledsoe of RSKERL discuss
the metals most commonly
found at Superfund sites in
terms of the processes affect-
ing their behavior in soils as
well as laboratory methods
available to evaluate this be-
havior. The retention capacity
of soil is discussed in terms of
the movement of metals be-
tween the other environmen-
tal media, including ground
water, surface water or the at-
mosphere. Long-term changes
in soil environmental condi-
tions, due to the effects of
remediation systems or to
natural weathering processes,
are also discussed with respect
to the enhanced mobility of
metals in soils.
The metals selected for dis-
cussion are: lead (Pb), chromi-
um (Cr), arsenic (As),
cadmium (Cd), nickel (Ni),
zinc (Zn), copper (Cu), mer-
cury (Hg), silver (Ag) and
selenium (Se). The paper ad-
dresses: fate of metals in the
soil environment [soil solution
chemistry, solid phase forma-
tion, surface reactions, anions
in the soil environment, soil
properties affecting adsorp-
tion, factors affecting adsorp-
tion and precipitation
reactions (competing cations,
complex formation, pH, oxi-
dation-reduction, co-waste)];
behavior of the specific met-
als; computer models; analysis
of soil samples (total concen-
tration, sequential extractions,
and Toxicity Characterization
Leaching Procedure); and
evaluating the behavior of
metals in soils (sorption, des-
orption, and kinetics).
A copy of "Ground Water
Issue: Behavior of Metals in
Soils" can be ordered from
EPA's Center for Environ-
mental Research Information
(CERI) at 513-569-7562.
When ordering, please refer to
the Document Number: EPA/
540/S-92/018.
Fundamentals of Ground
Water Modeling
Ground water flow and
contaminant transport model-
ing has been used at many
hazardous waste sites with
varying degrees of success.
Models may be used through-
out all phases of the site in-
vestigation and remediation
processes. The ability to reli-
ably predict the rate and di-
rection of ground water flow
and contaminant transport is
critical in planning and im-
plementing ground water re-
mediations.
The issue paper presents an
overview of the essential com-
ponents of ground water flow
and contaminant transport
modeling in saturated porous
media. While fractured rocks
and fractured porous rocks
may behave like porous media
with respect to many flow and
contaminant transport phe-
nomena, they require a sepa-
rate discussion and are not
included in this paper. Simi-
larly, the special features of
flow and contaminant trans-
port in the unsaturated zone
are also not included. This pa-
per was prepared for an audi-
ence with some technical
background and a basic work-
ing knowledge of ground wa-
ter flow and contaminant
transport processes. A suggest-
ed format for ground water
modeling reports and a select-
ed bibliography are included
as appendices A and B,
respectively.
The paper, "Ground Water
Issue: Fundamentals of
Ground-Water Modeling,"
was prepared by Jacob Bear of
Technion-Israel Institute of
Technology, Milovan S.
Beljin of the University of
Cincinnati and Randall R.
Ross of RSKERL. A copy can
be ordered from EPA's Center
for Environmental Research
Information (CERI) at 513-
569-7562. When ordering,
please refer to the Document
Number: EPA/540/S-92/005.
Suggested Operating
Procedures for Aquifer
Pumping Tests
One very important aspect
of ground water remediation is
the capability to determine
accurate estimates of aquifer
hydraulic characteristics. Paul
S. Osborne of EPA's Region 8,
provides an overview of all
the elements of an aquifer
test. The goal of the docu-
ment is to provide the reader
with a complete picture of all
the elements of aquifer
(pumping) test design and
performance and an under-
standing of how those ele-
ments can affect the quality of
the final data. It is intended as
a primer, describing the pro-
cess for the design and perfor-
mance of an "aquifer test"
(how to obtain reliable data
from a pumping test) to ob-
tain accurate estimates of
aquifer parameters. The audi-
ence includes professionals in-
volved in characterizing sites
which require corrective
(See Ground Water, page 4)
Ground Water Currents
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RESEARCH RESULTS
Natural Bioremediation of TCE
By Don Kampbell, Robert S. Kerr Environmental Research Laboratory
The EPA's Robert S. Kerr
Environmental Research Lab-
oratory (RSKERL) has dem-
onstrated through laboratory
studies that in situ bioremedia-
tion can be an effective way
to cleanse fuel and solvent
contaminated subsurfaces.
Although the time period for
remediation will take longer
than active intervention
methods, natural, intrinsic
bioremediation can be effec-
tive, provided that sufficient
indigenous acclimated micro-
organisms are present.
RSKERL discovered that
intrinsic bioremediation was
occurring in a ground water
plume on the east side of Lake
Michigan near St. Joseph,
Michigan. The plume con-
taining trichloroethene (TCE)
was originally characterized to
be used as a benchmark to de-
velop methodology for in situ
treatment by methanotrophic
bacteria. However, when the
water quality data showed that
natural anaerobic degradation
of TCE was taking place,
RSKERL conducted a series of
site characterization studies to
develop data on natural biode-
gration.
Intrinsic bioremediation of
TCE was supported by the
presence of transformation
products (breakdown products
of TCE) and further supported
by the utilization of oxidation
stimulators. For example, oxy-
gen is first consumed in the
TCE natural degradation pro-
cesses; then, the oxidation
stimulators of nitrate and sul-
fate take over the degradation
process.
The geological formation at
the spill site consisted of a
fine sand unconfined aquifer
with a thickness of 15 to
30 feet, with the water table
at about 40 feet. The suspect-
ed point of the surface spill is
less than one mile from the
lake shore with ground water
flow toward the lake. Variable
depth ground water samples
were collected where high
contaminant concentrations
were present. Zones in which
TCE transformations to break-
down products were occurring
were identified. Generally,
the upper depth of the ground
water had reduced concentra-
tions of TCE which was
caused by dilution with perco-
lating rain and/or microbial
metabolism processes. Most
importantly for determining
natural biodegration was the
presence of relatively high
concentrations of the break-
down products of dichlo-
roethene, vinyl chloride,
ethene and methane. Addi-
tionally, the plume was not
only devoid of dissolved oxy-
gen, but there were also re-
duced concentrations of
nitrate and sulfate. When
compared to adjacent control
well water with 4.7 milli-
grams per liter (mg/1)
dissolved oxygen, a plume
sample had 1,000 times more
methane, 100 times less ni-
trate, ten times less sulfate, six
times more bacteria cells and
three times more total organic
carbon. Additionally, neither
chlorinated hydrocarbons nor
ethene were detected in the
control well. Concentrations
of TCE as high as 60 mg/1 did
not seem to have an adverse
influence on degradation pro-
cesses, since high methane
Sonic Drill (from page 1)
average drill rate for the
10 cable-tool-drilled wells
was 12.6 ft. per work day.
Cost analyses show that Reso-
nantSonic drilled wells are
less expensive than traditional
methods.
The ResonantSonic sys-
tem has been used at other
sites, including various De-
partment of Defense facilities.
and vinyl chloride were di-
rectly related to TCE.
RSKERL plans to conduct
similar studies at other spill
sites contaminated with fuel
and chlorinated solvents.
They will conduct field moni-
toring for extended durations
to establish the rate and ex-
tent of intrinsic bioremedia-
tion in restoring contaminated
aquifers. Further details of the
field site studies can be ob-
tained from Don Kampbell,
RSKERL, at 405-436-8564.
An initial report will be avail-
able by mid-1994.
Additionally, the system is be-
ing refined through a DOE
Cooperative Research and De-
velopment Agreement with
WHC, PNL and WDC.
For more information, call
Greg McLellan of WHC at
509-376-2260 or Dave Bian-
cosino of DOE at 301-903-
7961. A report can be ordered
from Greg McLellan.
Ground Water Currents
-------
Ground Water (from page 2)
action as well as sites which
are proposed for ground water
development, agricultural de-
velopment, industrial devel-
opment or disposal activities.
A copy of "Ground Water
Issue: Suggested Operating
Procedures for Aquifer Pump-
ing Tests" can be ordered from
EPA's Center for Environ-
mental Research Information
(CERT) at 513-569-7562.
When ordering, please refer to
the Document Number: EPA/
540/S-93/503.
Evaluation of Soil Venting
Application
Another major issue of con-
cern to those involved in
ground water remediation is
the transport and fate of con-
taminants in soil and ground
water as related to subsurface
remediation. Dominic C.
DiGiulio of RSKERL presents
information that can assist in
evaluating the feasibility of
using venting. Methods to op-
timize venting application are
also discussed. Information
covered in DiGiulio's paper is
highlighted below.
The ability of soil venting
to inexpensively remove large
amounts of volatile organic
compounds (VOCs) from con-
taminated soils is well estab-
lished. However, the time
required using venting to re-
mediate soils to low contami-
nant levels often required by
state and federal regulators
has not been adequately in-
vestigated. Most field studies
verify the ability of a venting
system to circulate air in the
subsurface and remove, at
least initially, a large mass of
VOCs. They do not generally
provide insight into mass
transport limitations which
eventually limit performance,
nor do field studies generally
evaluate methods such as en-
hanced bio degradation which
may optimize overall contami-
nant removal. The paper
addresses: determining con-
taminant volatility; evaluating
air flow; evaluating mass
transfer limitations and reme-
diation time; enhanced aero-
bic biodegradation; location
and number of vapor extrac-
tion wells; screen interval of
extraction wells; and place-
ment of observation wells.
A copy of "Ground Water
Issue: Evaluation of Soil Vent-
ing Application" can be or-
dered from EPA's Center for
Environmental Research In-
formation (CERI) at 513-
569-7562. When ordering,
please refer to the Document
Number: EPA/540/S-92/004.
To order additional copies of Ground Water Currents, or to be included on the permanent mailing list, send a fax request to the National
Center for Environmental Publications and Information (NCEPI) at 513-891-6685, or send a mail request to NCEPI, 11029 Kenwood Road,
Building 5. Cincinnati, OH 45242. Please refer to the document number on the cover of the issue if available.
Ground Water Currents welcomes readers' comments and contributions. Address correspondence to:
Managing Editor, Ground Water Currents (OS-110W), U.S. Environmental Protection Agency,
401 M Street S.W., Washington, DC 20460.
United States
Environmental Protection Agency
National Center for Environmental
Publications and Information
Cincinnati, OH 45242
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