South
River Mercury TMDL
Fish Advisory: South River
|
Problem
The South River and South Fork Shenandoah River are scenic recreational streams, but they are contaminated with mercury.
The mercury contamination stretches from Waynesboro for 125 miles downstream to Front Royal. A major source of the mercury
is known to be a former DuPont facility in Waynesboro that disposed mercury waste from 1929 to 1950.
Regulatory actions dealing with the streams have focused on the
health threat to people who eat mercury contaminated fish.
The VADEQ regularly samples fish to monitor concentrations of mercury in fish.
In 2002, smallmouth bass had mercury concentrations as high as 4 ppm and
average concentrations of 1.3 ppm. These
numbers are higher than the state mandated maximum allowable mercury
concentrations in fish of 0.5 ppm. Because
of this, the Virginia Department of Health has placed a fish consumption
advisory on the South River and South Fork Shenandoah River.
Ongoing Studies
The US Environmental Protection Agency (EPA) has
required Virginia
to develop plans for cleaning polluted streams (those on the 303d list) in
the state. This TMDL study will form the foundation used to develop a cleanup plan for the South River and
South Fork Shenandoah River.
The Virginia DEQ samples fish every year and is
scheduled to do a comprehensive sediment survey in 2007.
DuPont sponsors numerous studies of the mercury problem
through a group known as the South River Science Team (SRST). The South
River Science Team consists of scientists and representatives from
government agencies, universities, environmental non-profit groups and
Dupont. The group meets
regularly to share scientific findings and plan future studies.
Studies currently being performed by SRST members include
investigations of mercury occurrence in stream water, groundwater, surface
runoff, soil, plants, fish, algae, earthworms, and birds.
In July, 2005, Dupont
signed an agreement with the Natural Resources Defense Council and the
Virginia Chapter of the Sierra Club that requires Dupont to perform a large
six-year ecosystem study of the South River
watershed. Click here for a Description of the Study (pdf file, 113 Kb) or
the legal Consent Decree (pdf file,
1.1 Mb).
Objective
The objective of the South River Mercury TMDL study is to develop a better
understanding of methyl mercury cycling in the
South River
and calculate mercury loading reductions that would protect fish from high
mercury concentrations.
Approach
Data will be collected to calculate fluxes of mercury and methyl-mercury in
the watershed. Four monitoring stations, operated jointly by the VDEQ and the
USGS, continuously measure stream discharge and/or water quality in the South
River. These stations are at Waynesboro (01626000), South Dooms (01626850),
Dooms (01626920), and Harriston (01627500). Water samples are periodically
sampled to measure mercury and methyl-mercury concentrations along with a suite
of related water-quality parameters. The data collection will continue for 2
years.
|
|
|
|
Continuous WQ monitoring equipment on South River
bridge at Dooms, VA.
|
|
The data will then be used to calculate mercury fluxes and to build a
model of mercury cycling in the river. From this model, reductions in
mercury loading required to lower fish tissue mercury concentrations to safe
levels will be calculated.
|
|
|
|
|
Multi-parameter WQ sensor out of the water.
|
Relevance and Benefits
Work on this project will develop a foundation for the future remediation of
the South River and South Fork Shenandoah River. Basic science benefits will come
from a better understanding of methyl-mercury cycling in fresh water systems
that is developed by this project. A
better understanding of the regional aquatic ecosystem will also result from the
collection and analysis of water quality data during this project.
Presentations
Presentation to South River Science Team, June, 2005 PDF (.6 MB)
Streamflow Data
South River near Waynesboro
https://waterdata.usgs.gov/nwis/uv?site_no=01626000
South River near Dooms
https://waterdata.usgs.gov/nwis/uv?site_no=01626850
South River at Harriston
https://waterdata.usgs.gov/nwis/uv?site_no=01627500
Water Quality Data
South River near Waynesboro
https://waterdata.usgs.gov/nwis/uv?site_no=01626000
South River near Dooms
https://waterdata.usgs.gov/nwis/uv?site_no=01626920
South River at Harriston
https://waterdata.usgs.gov/nwis/uv?site_no=01627500
Links
US Geological Survey (USGS) –
USGS
National Mercury Research
Active
stream flow and water-quality data stations on the South River
USGS
Mercury General Information
Virginia Department of Environmental Quality (VDEQ) –
South
River / South Fork Shenandoah
Mercury Information
TMDLs for
Virginia Streams
Virginia Department of Health –
Fishing
Advisories - South and South Fork Shenandoah River
Environmental Protection Agency (EPA) –
Report
on cleanup of former Dupont facility in Waynesboro (pdf file, 17 Kb)
Mercury
Information Page
South River Science Team (SRST) -
Conference
abstract describing team
Settlement between DuPont and Natural Resources Defense Council (NRDC) –
Description of
the Study (pdf file, 113 Kb)
Consent Decree
(pdf file, 1.1 Mb)
Note: PDF Reader available at
get.adobe.com/reader/
Site Updates
This site will be updated as new information becomes available.
Suggestions and contributions welcome.
|