&EPA
www.epa.gov/research
science in ACTION
INNOVATIVE RESEARCH FOR A SUSTAINABLE FUTURE
Developing Rapid and Cost-Effective Tools for Assessing Groundwater
Impacts on Contaminated Sediments
Research Value
How contaminants interact with
sediments and aquatic organisms
is often complex. In cases where
groundwater discharges into
surface waters such as lakes, the
picture can get even more
complicated, as groundwater
input may influence the
concentrations and availability of
contaminants in sediments.
The flux of sediment
contaminants, which are
influenced by groundwater
discharge, may vary in space and
time. The variability in
contaminant discharge presents a
challenge for restoration efforts,
since assessing the magnitude of
its contribution to sediment
impairment can be a time and
cost-intensive effort. Natural
resource managers need cost-
effective tools to rapidly assess
the impact of groundwater
discharge on surface water
bodies at varying scales.
EPA is developing approaches to
combine routine physical
measurements of the impacted
surface water body, as a function
of space and time, with aquatic
chemical measurements to
support design of restoration
activities.
Research Details
EPA land risk management
researchers conduct field and lab
research to:
1) Develop methods to best
characterize hydrologic and
chemical processes at the
groundwater / surface water
(GW/SW) interface.
2) Understand the role of
groundwater flow on sediment
processes that govern levels and
types of sediment contaminants.
This research aims to
characterize the interaction of
water and solids within the
GW/SW transition zone to
explain processes that occur
during physical contact between
groundwater and sediments. The
first step in characterizing the
influence of groundwater
discharge on sediment
contamination is identification of
the locations of discharge and the
variability in magnitude over
space and time. Measurement of
water parameters such as
temperature and conductivity
provides an inexpensive
approach to efficiently define the
need for more detailed data
acquisition. These measurements
are conducted to capture the
spatial and temporal variability
that is commonly encountered in
these natural systems.
EPA is developing methods that
make use of self-contained, off-
the-shelf devices to efficiently
assess the spatial and seasonal
variability in groundwater
discharge. As an example,
changes in water temperature
data with depth and time within a
surface water body can be
measured using small
temperature buttons and
evaluated to quickly assess the
distribution and magnitude of
groundwater discharge.
Use of self-contained, off-the-shelf
devices (temperature buttons) to
continuously monitor water
temperature as a way to detect
the presence and estimate the
magnitude of GW discharge.
U.S. Environmental Protection Agency
Office of Research and Development (ORD), National Risk Management Research Laboratory (NRMRL)
Land Remediation and Pollution Control Division (LRPCD)
-------
A plunger used to place
temperature buttons at different
depths in sediment.
Outcomes and Impacts
Groundwater discharge may
serve as a long-term source of
contaminants to sediments within
a watershed and/or may affect
processes controlling the
properties of existing
contaminants.
This research provides EPA with
practical knowledge to guide site
characterization and remediation,
at sites where groundwater
influences sediment
contamination.
Field and laboratory studies have
enabled the EPA to better predict
the fate of contaminants in
sediments, including their
mobility, their ease of uptake by
plants and animals
(bioavailability), and to develop
remediation strategies that
effectively manage risks to
human and ecosystem health.
Research impacts include
Identification of links between
groundwater discharge and
sediment contaminants,
especially arsenic, lead and zinc.
Development of new approaches
to identify spatial variability of
groundwater discharge into
surface-water ecosystems using
direct measurements and cost-
effective surrogate measures.
EPA Region 1 office and ORD
field researchers coordinate to
design restoration approaches.
They also collaborate on
monitoring strategies to evaluate
success of sediment remediation
efforts at sites impacted by
contaminated groundwater
discharge.
CONTACTS
Technical Inquiries.
Robert Ford, 513-569-7501, EPA/
ORD/NRMRL/ LRPCD/SSMB
ford. robert(@,epa. gov
Bob Lien, 513-569-7443, EPA/
ORD/NRMRL/LRPCD/SSMB
lien.bob(@,epa.gov
Steven Acree, 580-436-8609, EPA/
ORD/NRMRL
acree.steven(@,epa.gov
Communications: Roger Yeardley,
513-569-7548. EPA/ ORD/NRMRL/
LRPCD veardlev.rogertgiepa.gov
more Risk Management Land Research:
www.epa.gov/nrmrl/lrpcd/
l/Jj/JJMHIIIi
MM -f
Examples of type of buttons used
to log temperatures. Foreground:
intact button, showing size.
Background: opened to show the
computer chips enclosed in
durable weather resistant
stainless steel.
REFERENCES
Ford, R.G., Acres, S., Lien, B., Scheckel,
K.G., Luxton, T., Ross, R., Williams, A. G.,
and Clark, P. 2011. Delineating landfill
leachate discharge to an arsenic contaminated
waterway. Chemosphere, 85(9):1525-1537.
Ford, R.G., Acree, S., Lien, B., Scheckel,
K.G., Ross, R., Luxton, T., and Clark, P.
2009. Devens 2008 Monitoring update, U.S.
Environmental Protection Agency, Cincinnati,
OH. EPA/600/R-09/064.
Ford, R.G., Acree, S., Lien, B., Scheckel,
K.G., Ross, R., Luxton, T., and Clark, P.
2008. Final Report: Arsenic Fate, Transport
and Stability Study - Groundwater, Surface
Water, Soil and Sediment Investigation, Fort
Devens Superfiind Site, Devens,
Massachusetts. U.S. Environmental
Protection Agency, Cincinnati, OH,
EPA/600/R-09/063.
Ford, R. G., Wilkin, R. T., Hernandez, G.
2006. Arsenic cycling within the water
column of a small lake receiving
contaminated ground-water discharge.
Chemical Geology, 228(1-3): 137-155.
Ford, R. G. 2005. The Impact of Ground
Water-Surface Water Interactions on
Contaminant Transport with Application to an
Arsenic Contaminated Site, EPA
Environmental Research Brief, U.S.
Environmental Protection Agency, Cincinnati,
OH, EPA/600/S-05/002.
National Risk Management Research Laboratory
Land Remediation and Pollution Control Division
EPA/600/F-12/533
May 2012
www.epa.gov/nrmrl/
------- |