Section 319
NONPOINT SOURCE PROGRAM SUCCESS STURY
Cleanup of Abandoned Copper Mine Restores the Ompompanoosuc River
and Lords Brook
A/ K r\' I r\ Acid mine drainage from the Elizabeth Mine had degraded
VaterDOaieS improved biological communities in the West Branch of the
Ompompanoosuc River (WBOR) and a small tributary stream, Lords Brook, for decades. As a result,
Vermont placed the waterbodies on its Clean Water Act (CWA) section 303(d) list for aquatic life use
impairments due to metals and acidity in 1998 and 2002, respectively. Elizabeth Mine was placed on
the U.S. Environmental Protection Agency's (EPAs) National Priorities List (also known as the Superfund
List) on June 14, 2001. Cleanup activities, which included diverting groundwater and surface water,
consolidating and capping waste rock and tailings, and treatment of the leachate have brought the
waterbodies into compliance with Vermont's water quality standards. As a result, the state of Vermont
delisted the Ompompanoosuc River and Lords Brook from the CWA section 303(d) list in 2014.
Problem
The Elizabeth Mine site is an abandoned cop-
per mine in the towns of Stratford and Thetford,
Vermont. The mine operated from the early 1800s
until its closure in 1958. Numerous studies, including
biological surveys performed in 1986, and again in
1998, by the Vermont Department of Environmental
Conservation (VTDEC) reported biological impacts
(i.e., very low numbers and species of macroinverte-
brates and fish) in waterbodies downstream of the
mined area, including an approximately four-mile
reach on the WBOR (Figure 1) and a small tributary
stream known as Lords Brook.
Project Highlights
EPA began response actions at the Elizabeth Mine
site in 2003 to stabilize a tailings dam to prevent a
catastrophic failure. EPA then focused on the waste
rock and tailings that were the major source of
copper, iron and acidity to the WBOR. EPA installed
6,300 linear feet of surface water diversion chan-
nels and a 1,150-linear foot shallow groundwater
diversion trench to divert water around an area
containing tailings and waste rock. EPA excavated
400,000 cubic yards of waste rock that was the
major source of copper in the WBOR and placed
the material on the 45-acre tailings impoundment.
A cover system was then installed over the waste
rock and tailings. In 2008 EPA installed a temporary
water treatment system to treat iron-rich leachate
discharging from the tailings impoundment during
construction activities. EPA plans to operate this
system until the reduction in leachate flow allows
Legend
Sites
Older sites
2012 & Reference Sit
Impaired waters
Waterbody
- Stream
Figure 1. Monitoring locations and impaired sections on the West
Branch of the Ompompanoosuc River and Lords Brook.
a passive treatment wetland to be installed. The
surface water, groundwater, waste excavation and
cover system installation activities were completed
in 2013.
The source of the toxic metals in Lords Brook is
from the area of the mine known as the South Cut, a
waste rock pile (referred to as TP-4), and the South
Mine. TP-4 and much of the waste rock around the
South Mine and at the outlet of the South Open
Cut were removed as part of the consolidation of
waste rock under the tailing impoundment cover
system. EPA is planning additional cleanup actions
for the South Open Cut and the contaminated areas
remaining at the South Mine to address impair-
ments in two un-named tributaries to Lord Brook.
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Results
Partners and Funding
Figure 2. The WBOR before (top:
pre-2009) and after (bottom:
post-2012) implementation of
restoration efforts.
VTDEC's Monitoring,
Assessment and Planning
Program-Biomonitoring and
Aquatic Studies Section con-
ducted biological assessments
before and after restoration
efforts, which were compared
with the Class B water guide-
lines for aquatic life support.
Data show that both the WBOR
and Lords Brook now meet
applicable aquatic life use
support biocriteria guidelines
for Class B at all previously
impaired sites (Table 1). Based
on all these assessments, both
the WBOR and Lords Brook are
eligible for removal from the
state's 2014 impaired waters
list because they now support
their aquatic life designated
uses (Figure 2).
Fish data also reflected this improvement in water
quality as seen in the change in the Index of Biotic
Integrity in WBOR from poor in 1998 to good'm
2013, and the increase in brook trout density in Lords
Brook from one fish per 100 square meters (100 m2)
in 2000 to 38.8fish per 100 m2 in 2013. The immedi-
ate headwater streams from the Elizabeth Mine area
remain impaired, including Copperas Brook and two
un-named tributaries to Lord Brook.
The cleanup involved a diverse group of stakehold-
ers. The U.S. Fish and Wildlife Service, the National
Oceanic and Atmospheric Administration, U.S. Army
Corps of Engineers and U.S. Geological Survey
have all been significantly involved in the studies
and assessments. The local community has been
engaged in the investigation, cleanup and historic
assessments. The Elizabeth Mine Study Group
(EMSG), a local volunteer effort, performed an
assessment of the Elizabeth Mine and helped bring
EPA Superfund attention to the Elizabeth Mine.
EMSG received $6,000 in CWA section 319 fund-
ing through the town of Strafford in 2000. EPA and
VTANR worked with the community to form the
10-member Elizabeth Mine Community Advisory
Group (EMCAG), which contributed valuable local
feedback regarding the investigation and cleanup
activities. Efforts by EMSG provided either the seed
or much of impetus for creation of EMCAG. The
EMCAG was given independent technical support
through the Copperas Hill Coalition (which received a
$130,000 Superfund Technical Assistance Grant and
provided in-kind contributions of $16,250). In 2004
the towns of Strafford and Thetford commissioned
an EPA-funded reuse assessment, in part to help
inform EPA's cleanup decisions. The overall federal
expenditure at the Elizabeth Mine is approximately
$70 million dollars through 2013, including $8 mil-
lion received under the American Recovery and
Reinvestment Act. This funding was critical to the
initiation of the cleanup actions to control the release
of toxic metals from the waste piles and tailings in
the Copperas Brook watershed.
Table 1. West Branch Ompompanoosuc River (WBOR) RM 3.8 and Lords Brook RM 3.3 Macroinvertebrate
Biomonitoring Results 2 years pre- and 3 years post-attainment
Waterbody
WBOR
WBOR
WBOR
WBOR
WBOR
Sampling site (River Mile)
3.8
3.8
3.8
3.8
3.8
Date
9/2000
9/2009
9/2010
9/2012
9/2013
Assessment Rating
Poor
Fair
Good
Very Good
Excellent
WBOR Class B Guideline11
Lords Br.
Lords Br.
Lords Br.
Lords Br.
Lords Br.
3.3
3.3
3.3
3.3
3.3
9/2000
9/2008
9/2010
9/2012
9/2013
Fair
Fair
Very Good
V. Good/Good
Excellent
Lords Br. Class B Guideline11
EPT
9.3a
14.0
24.0
31.5
30.0
>18
11.3
15.5
22.0
25.5
25.5
>16
Density (individuals/m2)
117
188
459
2552
1708
>300
164
172
613
901
1136.1
>300
Richness
20.0
33.5
40.0
54.0
50.0
>30
22.3
33.0
38.5
39.5
46.0
>27
a Bolded items indicate nonattainment.
b River-specific guidelines from Biocriteria for Fish and Macroinvertebrate Assemblages in Vermont Wadeable Streams and Rivers (2004).
http://www.watershedmanagement.vt.gov/bass/htm/bs _ biomon.htm
UJ
O
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-15-001T
March 2015
For additional information contact:
Edward Hathaway, EPA Region 1
617-918-1372 • Hathaway.ed@epa.gov
Steve Fiske, Vermont Dept. of Environmental Conservation
802-490-6156 • Steve.fiske@state.vt.us
John Schmeltzer, Vermont Dept. of Environmental Conservation
802-249-5620 • John.schmeltzer@state.vt.us
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