Section 319
NONPOINT SOURCE PROG
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Cleaning Up Contaminated Sites Improves Water Quality
M SOCCE
Waterbody Improved
Seeps from contaminated soil and contaminated groundwater
contributed petroleum hydrocarbons and other pollutants to
Alaska's Chena River. As a result, the Alaska Department of Environmental Conservation
(ADEC) added a 15-mile-long segment of Chena River to Alaska's 1994 Clean Water Act
(CWA) section 303(d) list of impaired waters for petroleum hydrocarbons/oil and grease.
Beginning in the mid-1990s, the U.S. Army cleaned up several contaminated areas. River
monitoring data collected between 2005 and 2009 show that petroleum hydrocarbon levels
now meet water quality standards, prompting ADEC to remove the Chena River from Alaska's
2010 CWA section 303(d) list of impaired waters for petroleum hydrocarbons/oil and grease.
Problem
e \
The Chena River originates about 90 miles east of
the city of Fairbanks in Interior Alaska and flows into
the Tanana River about three miles southwest of the
city (Figure 1). The Chena Riverflows through Fort
Wainwright, a U.S. Army base that is on the National
Priorities List as a site with known releases or threat-
ened releases of hazardous substances, pollutants
or contaminants. Areas of contaminated soil and
groundwater were indentified around landfills, areas
used for drum storage or disposal, and areas around
pipelines and fuel-loading facilities. Several contami-
nated areas were directly next to the Chena River.
In 1992 and 1994 ADEC conducted statewide water
quality assessments that indicated a suspected
petroleum hydrocarbon problem on the Chena
River. Documents on file indicated a visible sheen
on the river, as well as reports of petroleum spills
in the vicinity of the river. Reports also identified
problems with elevated sediment levels in the river.
Based on best professional judgment, ADEC added
a 15-mile-long segment of the Chena River (Alaska
ID Number 40506-007) to the 1994 CWA section
303(d) list as impaired by petroleum hydrocarbons/
oil and grease and sediment. The impaired segment
extends from the mouth of the Chena River upriver
to Fort Wainwright.
Subsequent investigations indicated that con-
taminated sites on the Fort Wainwright military
base were contributing most of the petroleum
products to the Chena River. While conduct-
ing a Comprehensive Environmental Response,

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Chena River
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Wainwright
Tanana River
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Fairbanks
International
Airport
Figure 1. The Chena River is in eastern Alaska's
Tanana River watershed.
Compensation and Liability Act program investiga-
tion of the Chena River on Fort Wainwright, the
U.S. Army found a number of samples that showed
levels of petroleum-related compounds exceeding
surface water and sediment criteria considered
protective of aquatic life.
Project Highlights
The contaminated sites at Fort Wainwright con-
tributed petroleum products and other chemicals
to the Chena River through surface runoff and
groundwater flow. The U.S. Army completed physi-
cal cleanup activities at numerous contaminated
Fort Wainwright sites between the late 1980s

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Figure 2. The Army cleaned up
and shading) next to the Chena
and 2001 (Figure 2).
For example, in 1985
the Army discovered
a 45-acre area of
contaminated soil
and groundwater
on an oxbow of the
southern bank of the
Chena River. The Army
removed the contami-
nated soil between
1993 and 1996. Shortly
thereafter, the Army
Installed a vapor
extraction/air sparging
treatment system to
address groundwater
contamination. A
similar system was
installed at a railcar
off-loading facility
site on the south bank
of the Chena River. This area had been the site
of numerous petroleum leaks and spills in the
mid-1900s.
Another area directly next to the Chena River
had been used for drum storage from 1954 until
1974. The drums were reported to have contained
diesel fuel, gasoline, jet fuel, solvents, asphalt,
pesticides and lubricants. Between 1995 and
1997, the Army removed 226 drums and 850 cubic
yards of contaminated soil. The Chena River also
flows near an unlined landfill (installed in the early
1950s). Monitoring data from 1993 showed that the
groundwater below the landfill was contaminated
by numerous pollutants, including hydrocarbons
that might be seeping into the Chena River. In 1997
the U.S. Army capped the inactive portion of the
landfill to prevent rainwater from seeping through
In addition to cleanup projects that occurred near
the Chena River, the Army completed numerous
other remediation projects throughout the Fort
Wainwright property.
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several contaminated areas (noted by cross-hatches
River on Fort Wainwright.
Results
periods included low- and high-water events. ADEC
water quality standards require that petroleum
hydrocarbons not cause a film, sheen or discol-
oration on the surface or floor of the waterbody
or adjoining shorelines, and that total aromatic
hydrocarbons (TAH) not exceed 10 micrograms per
liter. During visual assessments of the Chena River,
ADEC found no sheens with odors or other charac-
teristics typical of hydrocarbon sheens. Additionally,
ail samples met the TAH water quality standard; in
fact, TAH results have been non-detect since 2005.
Because the Chena River has met water quality stan-
dards for multiple years, ADEC removed it from the
CWA section 303(d) list of impaired waters in 2010
for petroleum hydrocarbons/oil and grease. The river
remains on the impaired waters list for sediment.
Partners and Funding
ADEC collected water samples and visually
assessed the Chena River downstream of Fort
Wainwright in 2005, 2007 and 2009. The sampling
The U.S. Army coordinated with ADEC and the
U.S. Environmental Protection Agency to investigate
and remediate all known sources of environmental
contamination on Fort Wainwright. The Army funded
physical cleanup activities throughout the military
base, including activities at numerous sites that were
thought to be contributing petroleum hydrocarbons
and other pollutants directly to the Chena River.
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U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA EPA 841-F-11-001C
February 2011
For additional information contact:
Cindy J. Gilder
Alaska Department of Conservation
907-269-3066
cindy.gilder@alaska.gov

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