Department of Energy
Preliminary Information on the Potential for Columbia River Contamination from the Hanford Site Gao ID: GAO-06-77R November 4, 2005The Department of Energy's (DOE) Hanford site in southeastern Washington state was established in 1943 to produce nuclear materials, especially plutonium, for the nation's defense. The site occupies 586 square miles northwest of the cities of Richland, Pasco, and Kennewick, with a combined regional population of over 200,000. The Columbia River, the nation's second largest river and a source of hydropower production and drinking water for downstream communities, as well as a major route for salmon migration, flows through the site for almost 50 miles. DOE built nine nuclear reactors to produce plutonium and other materials near the river shore to take advantage of river water for reactor cooling. Several miles away from the river, DOE built other facilities used in making nuclear materials. During operations from 1943 to 1989, activity at these reactors and other facilities generated large volumes of hazardous and radioactive waste. Some of this waste was deposited directly into the ground in trenches, injection wells, or other facilities designed to allow the waste to disperse into the soil. Some of the most hazardous and radioactive material was stored in large underground tanks. Over time, concern has developed about the impact of Hanford's waste moving through the ground and toward the Columbia River. Besides the waste discharged directly into the ground, DOE has assumed, based on tank monitoring data and other techniques to detect contamination in the soil, that 67 of the 177 underground storage tanks have also leaked contaminants into the soil. Many types of hazardous and radioactive waste produced at Hanford can be borne by water through the ground. While Hanford is a near-desert location with limited rainfall and thick layers of soil and rock beneath its surface, water from precipitation and other sources moves through these layers, and the groundwater moves in the general direction of the river. In the center of the site, the groundwater is more than 200 feet below the surface, but at the river, the groundwater is at or near river level. Over time, the movement of these contaminants through the "vadose zone"--the span of soil and rock between the surface and the groundwater beneath--has resulted in a number of contaminant "plumes." These plumes are volumes of contamination extending downward and outward from their sources. When these plumes reach the level of the groundwater, the contamination they contain enters the groundwater. In some cases, contamination from these plumes has already reached the river. Since the early 1990s, DOE has shifted its efforts at the Hanford site from production of nuclear materials to cleaning up the contamination and other materials left over from the production era. Milestones and requirements for this cleanup are specified in an agreement between DOE and its regulators--the U.S. Environmental Protection Agency and the Washington State Department of Ecology. DOE spends about $2 billion per year on the cleanup of the Hanford site and estimates that the cost of Hanford's cleanup effort will eventually total about $45 billion and will be completed around 2035. The cleanup effort includes exhuming and treating buried waste, cleaning up facilities, and other necessary steps, including protecting the Columbia River by keeping contamination from migrating through the groundwater to the river. This report responds to a Congressional request for preliminary information about DOE's efforts to address river contamination. It addresses (1) the past, current, and future sources of contaminants to the Columbia River and the status of the contaminant plumes that threaten the river; and (2) DOE's planned approach to prevent contamination from reaching the Columbia River and DOE's efforts to implement its plan.
Contamination from the Hanford site that may threaten the Columbia River includes (1) contamination that resulted from disposal activities during the era in which DOE produced nuclear material; (2) contamination that could occur during cleanup activities, such as from an accidental spill; and (3) possible future migration of contamination from waste that will be permanently disposed of on the Hanford site in accordance with the cleanup actions DOE and the regulators plan to use. Based on groundwater sampling results, DOE reports that plumes of contamination continue to move through the vadose zone and the groundwater and are leaching into the river. DOE estimates that about 80 square miles of groundwater under the site contain contaminants at or above federal drinking water standards. Because the groundwater and the river are at the same relative elevation, these plumes are leaching directly into about 10 of the nearly 50 miles of river shore on the site. DOE's approach to addressing contaminants in the vadose zone and groundwater that threaten the river is to first address threats from contamination at sites located near the river or requiring immediate action and then to address contamination threats that are farther away from the river's edge. In conjunction with these efforts, DOE has a groundwater monitoring program to better understand the threats. These efforts are carried out by several DOE and contractor organizations. Both the National Academy of Sciences and the DOE Inspector General have issued reports noting concerns about DOE's management of the program.
GAO-06-77R, Department of Energy: Preliminary Information on the Potential for Columbia River Contamination from the Hanford Site
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Washington, DC 20548:
United States Government Accountability Office:
November 4, 2005:
The Honorable David L. Hobson:
Chairman:
The Honorable Peter J. Visclosky:
Ranking Minority Member:
Subcommittee on Energy and Water Development:
Committee on Appropriations:
House of Representatives:
Subject: Department of Energy: Preliminary Information on the Potential
for Columbia River Contamination from the Hanford Site:
The Department of Energy's (DOE) Hanford site in southeastern
Washington state was established in 1943 to produce nuclear materials,
especially plutonium, for the nation's defense. The site occupies 586
square miles northwest of the cities of Richland, Pasco, and Kennewick,
with a combined regional population of over 200,000. The Columbia
River, the nation's second largest river and a source of hydropower
production and drinking water for downstream communities, as well as a
major route for salmon migration, flows through the site for almost 50
miles. DOE built nine nuclear reactors to produce plutonium and other
materials near the river shore to take advantage of river water for
reactor cooling. Several miles away from the river, DOE built other
facilities used in making nuclear materials. During operations from
1943 to 1989, activity at these reactors and other facilities generated
large volumes of hazardous and radioactive waste. Some of this waste
was deposited directly into the ground in trenches, injection wells, or
other facilities designed to allow the waste to disperse into the soil.
Some of the most hazardous and radioactive material was stored in large
underground tanks.
Over time, concern has developed about the impact of Hanford's waste
moving through the ground and toward the Columbia River. Besides the
waste discharged directly into the ground, DOE has assumed, based on
tank monitoring data and other techniques to detect contamination in
the soil, that 67 of the 177 underground storage tanks have also leaked
contaminants into the soil. Many types of hazardous and radioactive
waste produced at Hanford can be borne by water through the ground.
While Hanford is a near-desert location with limited rainfall and thick
layers of soil and rock beneath its surface, water from precipitation
and other sources moves through these layers, and the groundwater moves
in the general direction of the river. In the center of the site, the
groundwater is more than 200 feet below the surface, but at the river,
the groundwater is at or near river level. Over time, the movement of
these contaminants through the "vadose zone"--the span of soil and rock
between the surface and the groundwater beneath--has resulted in a
number of contaminant "plumes." These plumes are volumes of
contamination extending downward and outward from their sources. When
these plumes reach the level of the groundwater, the contamination they
contain enters the groundwater. In some cases, contamination from these
plumes has already reached the river.
Since the early 1990s, DOE has shifted its efforts at the Hanford site
from production of nuclear materials to cleaning up the contamination
and other materials left over from the production era. DOE carries out
these activities primarily under the requirements of two environmental
laws: (1) the Comprehensive Environmental Response, Compensation, and
Liability Act of 1980, as amended (CERCLA), and (2) the Resource
Conservation and Recovery Act of 1976, as amended (RCRA). Milestones
and requirements for this cleanup are specified in an agreement between
DOE and its regulators--the U.S. Environmental Protection Agency and
the Washington State Department of Ecology.[Footnote 1] DOE spends
about $2 billion per year on the cleanup of the Hanford site and
estimates that the cost of Hanford's cleanup effort will eventually
total about $45 billion and will be completed around 2035. The cleanup
effort includes exhuming and treating buried waste, cleaning up
facilities, and other necessary steps, including protecting the
Columbia River by keeping contamination from migrating through the
groundwater to the river. To this end, DOE established a groundwater
management program at Hanford in 1997. Overall efforts to address
groundwater and related activities, such as eliminating contaminated
soil and monitoring river water and sediments, received about $100
million in fiscal year 2005.
This report responds to your request for preliminary information about
DOE's efforts to address river contamination. It addresses (1) the
past, current, and future sources of contaminants to the Columbia River
and the status of the contaminant plumes that threaten the river; and
(2) DOE's planned approach to prevent contamination from reaching the
Columbia River and DOE's efforts to implement its plan.
To address these objectives, we reviewed key documents, including
Hanford's 2003 Groundwater Management Plan, the 2004 Hanford Site
Groundwater Strategy, and various other DOE technical, budget, and cost
related reports. We also reviewed a 2001 National Academy of Sciences
study and two recent DOE Inspector General reports on Hanford's
groundwater protection program.[Footnote 2] We visited various
groundwater protection projects at the Hanford site and discussed river
contamination issues with DOE and contractor officials at Hanford and
with state and federal regulators. In reviewing the data related to the
groundwater and river programs, we determined that it was sufficiently
reliable for the purposes of our report. We conducted our work from
August through October 2005 in accordance with generally accepted
government auditing standards.
On September 21, 2005, we briefed your staff on our results to date.
This report summarizes that briefing, and includes the briefing slides
we presented. Our work on these objectives is continuing. We plan to
complete our work and issue a final report in the spring of 2006.
Sources and Extent of Contamination from the Hanford Site that May
Threaten the Columbia River:
Sources of contaminants to the groundwater--and possibly the Columbia
River--are numerous and stem both from past production activities,
current and future cleanup efforts, and the permanent storage of waste
on the Hanford site. While some contamination has already reached the
river, DOE has found that it is barely detectable in the water because
of the high volume of water in the river, which dilutes the
contamination. DOE routinely monitors the river's water quality, which
meets federal drinking water standards.
Sources of Contamination:
Contamination from the Hanford site that may threaten the Columbia
River includes (1) contamination that resulted from disposal activities
during the era in which DOE produced nuclear material; (2)
contamination that could occur during cleanup activities, such as from
an accidental spill; and (3) possible future migration of contamination
from waste that will be permanently disposed of on the Hanford site in
accordance with the cleanup actions DOE and the regulators plan to use.
Contamination from production era. Contamination at Hanford resulting
from plutonium production (which occurred from 1943 to 1989) that is
currently migrating to the river is primarily[Footnote 3] from:
* Intentional disposal of liquid waste and contaminated water to the
ground (about 450 billion gallons). DOE and its contractors disposed of
this waste in various facilities including trenches, ponds, wells into
which waste was pumped, and underground structures known as cribs that
allow the waste to percolate to the soil.
* Leaks into the soil from waste tanks and the pipelines that connect
them (between 500,000 to 1 million gallons containing about 1,000,000
curies of radioactivity).
* Contamination that has begun to migrate from solid waste (more than
710,000 cubic meters) disposed of on site in burial grounds, pits, and
other facilities. The extent of contaminants coming from this waste is
unknown but DOE believes it is not a major contributor to the
contamination found in the vadose zone.
These past practices, illustrated in figure 1, resulted in chemical and
radioactive contamination currently affecting more than 180 of the 586
square miles of the site's groundwater and large areas of the vadose
zone. As the figure shows, much of the Hanford site sits above the
elevation of the Columbia River, with the groundwater beneath the site
at roughly the elevation of the river itself. Contaminants entering the
groundwater thus have opportunity to enter the river. While there are
numerous contaminants now in the vadose zone and the groundwater below,
DOE has reported that the key contaminants in the groundwater include
hazardous chemicals (such as carbon tetrachloride, chromium, nitrate,
and trichloroethane) and radioactive materials (such as iodine-129,
strontium-90, technetium-99, tritium, and uranium). These contaminants
are of concern because of the extent of the contamination, its mobility
in the groundwater, and the potential health risk. The health risk
occurs because at sufficient levels, some of the contaminants are toxic
to humans or fish while others are potential carcinogens.
Figure 1: Contamination of the Columbia River:
[See PDF for image]
[End of figure]
Potential contamination from current activities. Current cleanup
efforts at the Hanford site could contribute some additional
contamination to the vadose zone and groundwater that eventually
reaches the river. For example, some of the waste put into underground
storage tanks as liquid has since turned into sludge or
saltcake.[Footnote 4] To dissolve it, more water will have to be
introduced into the tanks--including tanks known to have leaked. This
process may cause additional discharges into the soil. To minimize this
risk, DOE is attempting to develop technologies that will reduce the
amount of liquid needed. Another source of potential contamination from
current activities is DOE's discharge of treated waste water into the
river and soil as permitted by Washington state. This treated waste may
still contain small amounts of contaminants, including tritium.
Possible future contamination. Under DOE's cleanup plans and with
regulator approval, a large amount of contaminants will remain on site
even after the cleanup is completed. This contamination may be in
buildings, in mostly empty underground tanks, in covered burial grounds
and waste disposal areas, and in approved disposal facilities.
Contaminants may leach out of these facilities in the future and join
existing contamination in the vadose zone and migrate to the
groundwater, where they could migrate to the river. DOE is currently
using computer modeling to develop an overall analysis to estimate the
effects of potential contaminant migration.
Extent of Contamination:
Based on groundwater sampling results, DOE reports that plumes of
contamination continue to move through the vadose zone and the
groundwater and are leaching into the river. DOE estimates that about
80 square miles of groundwater under the site contain contaminants at
or above federal drinking water standards.[Footnote 5] Because the
groundwater and the river are at the same relative elevation, these
plumes are leaching directly into about 10 of the nearly 50 miles of
river shore on the site. Specific examples of this include:
* Groundwater in one such plume leaching into the river contains
uranium at up to three times the federal drinking water standard. This
groundwater enters the river about four miles above the drinking water
intake for the city of Richland, which has about 43,000 residents.
* Strontium-90 is found in the groundwater at up to 900 times drinking
water standards near the river and key nesting areas for salmon, which
migrate to the Pacific Ocean and return to lay their eggs.
* Chromium is entering the river at more than twice drinking water
standards.
* Strontium-90, chromium, and technetium-99 have been detected in river
shellfish located near the point that groundwater containing these
contaminants enters the river.
According to environmental monitoring studies performed by Pacific
Northwest National Laboratory (under contract to DOE), because of the
large volume of water in the river, the contamination seeping into the
river from the groundwater is generally barely detectable after
entering the river and the river water meets all federal drinking water
standards. As required by various environmental regulations, DOE
performs routine monitoring of water quality and aquatic life, and its
conclusions are based on samples taken both above and below the Hanford
site. For example, DOE's annual environmental reports state that no
uranium above background levels is detectable at the Richland drinking
water intake.
DOE's Approach to Addressing Columbia River Contamination from the
Hanford Site:
DOE's approach to addressing contaminants in the vadose zone and
groundwater that threaten the river is to first address threats from
contamination at sites located near the river or requiring immediate
action and then to address contamination threats that are farther away
from the river's edge. In conjunction with these efforts, DOE has a
groundwater monitoring program to better understand the threats. These
efforts are carried out by several DOE and contractor organizations.
Both the National Academy of Sciences and the DOE Inspector General
have issued reports noting concerns about DOE's management of the
program.
Addressing Threats from Contamination Near the River:
DOE's efforts to address contamination near the river take two main
forms. The first is actively removing waste and contaminated soil as a
way of reducing contaminants that could begin migrating. DOE has
removed 6 million tons of soil and debris from waste disposal areas,
burial grounds, and buildings since 1996. As of August 2005, it had
done so at 354 locations on the Hanford site. DOE has been disposing of
this material in a lined trench in the site's central area located
about 5 miles from the river.[Footnote 6] DOE plans to complete cleanup
of the river shoreline and areas near the river by 2015.
DOE's second main effort to address contamination near the river is to
treat the groundwater to prevent contaminants from further migrating.
DOE has three main approaches to treating the groundwater:
* Pump-and-treat. With this approach, DOE uses wells to extract
contaminated groundwater, treats the groundwater in above-ground
facilities, and reinjects the treated water back into the ground. Since
1995, DOE has operated five pump-and-treat systems to remove strontium-
90, chromium, carbon tetrachloride, or uranium from the groundwater.
Four of the five groundwater pump-and-treat systems that DOE is
currently operating are intended to address near-river contamination of
chromium and strontium-90. DOE spent about $8 million in 2004 to
operate and maintain these 5 systems.
* Chemical treatment. This approach has been used in one instance: DOE
relies on a chemical barrier near the Columbia River to block chromium
from entering the river near major fish breeding areas.[Footnote 7] The
barrier consists of a 750-yard series of wells through which DOE
injected a chemical into the groundwater that reacts with the chromium
to change it to a less hazardous and less mobile form.
* Natural attenuation. This approach relies on subsurface processes
such as dilution, adsorption, and chemical reactions with subsurface
materials to reduce contaminant concentrations to acceptable levels. A
large uranium plume in the groundwater from past fuel fabrication
activities is entering the river about 4 miles above city drinking
water intakes. In 1996 DOE and its regulators agreed to allow the plume
to dissipate through natural attenuation of the contamination.
DOE is experiencing problems with all three of these approaches,
leading both DOE and its regulators to determine that, in several
instances, the results are unsatisfactory. More specifically:
In a 2004 report, the DOE Inspector General concluded that the pump-
and-treat system to remove strontium-90 was ineffective and that the
other systems have shown mixed results. A DOE Hanford project manager
told us that while the four other pump-and-treat systems are meeting
remedial objectives agreed to with Hanford's regulators, the system to
remove strontium-90 is largely ineffective. DOE and the regulators have
agreed to continue to operate the strontium-90 pump-and-treat system so
that some treatment is in place until a more effective remedy is found.
DOE has begun field testing of a chemical barrier to prevent the
strontium-90 from entering the river.
In 2004, DOE reported that, based on groundwater samples, the chemical
barrier for dealing with chromium was not fully effective, and that the
hazardous form of chromium was detected beyond the barrier and close to
the river. DOE is currently evaluating alternative approaches to
contain the chromium or improve the barrier.
DOE's approach for addressing a uranium plume near the city of Richland
by relying on natural attenuation is failing to control the migration
of uranium to the river. According to monitoring well data, the plume
has not dissipated over the 10-year period since the natural
attenuation strategy was adopted. DOE is currently investigating the
plume and ways to mitigate the problem but no treatment decision is
expected before 2006.
To improve its groundwater treatment and monitoring programs, DOE funds
research and technology efforts totaling about $4 million a year. A
2001 study by the National Academy of Sciences criticized DOE's
technology development effort and identified several improvements
needed, such as the need to develop new methods to understand the
nature and extent of contamination in the vadose zone. In addition,
site regulators have expressed concerns about the lack of technologies
available to address contamination issues. While DOE is investing in
some limited technology testing and development to support groundwater
remediation, the DOE groundwater project manager at Hanford said that
other program activities generally have a higher priority under current
funding levels.
Addressing Contamination Threats that Are Farther from the River:
For those production activities that took place several miles away from
the river, DOE's efforts have involved four main types of actions:
Characterization of the vadose zone and groundwater to help understand
the risks. DOE is investigating numerous sites where liquid wastes were
discharged into the ground and numerous areas where spills occurred to
determine the extent and nature of contamination and how contaminants
move through the vadose zone. The investigations involve activities
such as reviewing operating records, sampling the soil, and analyzing
results in the laboratory. DOE relies primarily on data from monitoring
wells to identify the migration of contaminants and the condition of
the groundwater. Once the investigation is complete at each group of
sites, DOE will prepare a report proposing appropriate remedies. This
report is due to regulators by December 2008. Upon regulatory approval,
DOE plans to implement the remedies.
Remediation of contaminated sites. DOE is studying potential problems
from certain production era disposal areas in Hanford's central plateau
which it believes may present a high-risk of waste migration. These
disposal areas, which mainly received waste from facilities involved in
extracting and purifying plutonium, are located about 8 miles from the
Columbia River and between 200 and 300 feet above groundwater. At some
sites, DOE is considering installing surface barriers to prevent water
from infiltrating the soil and driving existing contamination farther
toward the groundwater. For most of these sites, however, DOE is still
studying the nature and extent of the contamination and its migration.
Under its agreement with regulators, proposed remediation plans for
these sites are not due until December 2008.
Decommissioning unneeded monitoring wells. The Hanford site has over
7,000 wells for monitoring groundwater, the vadose zone and other
purposes. Monitoring wells are important, but they can also contribute
to pollution by serving as conduits for rain, snow melt, or other
liquids to flush contaminants into the vadose zone and groundwater.
About half of these monitoring wells are no longer used because of
shifts in groundwater flow, lower groundwater levels, or problems with
individual wells. The Washington State Department of Ecology, one of
DOE's regulators, requires well owners, in this case DOE, to
decommission unused wells,[Footnote 8] but no schedule is prescribed.
From fiscal years 2003 to 2005, DOE decommissioned 257 wells.
Reducing water intrusion. Water leaking from pipelines and from surface
drainage is a source that can drive contamination from the vadose zone
to the groundwater. DOE is modifying surface drainage and repairing
leaking water and pipelines to reduce the discharge of water to the
ground above contaminated areas. From 2001 through 2002, DOE took steps
to eliminate water intrusion above some of the underground waste
storage tanks by modifying surface water drainage and eliminating six
leaking water lines. Also, from 2003 through 2005, DOE refurbished
about 26,000 linear feet of water line to reduce the risk of leaks. DOE
officials said that they are repairing Hanford's aging infrastructure
of water pipes but much more needs to be done. They said problems will
be addressed as funding becomes available.
Groundwater Monitoring Program:
Monitoring groundwater and its effect on the river to detect and assess
threats involves three interrelated efforts. First, DOE monitors
groundwater contamination levels to detect new or increasing levels of
contamination. These monitoring efforts have detected emerging plumes
containing high levels of technetium-99 and/or tritium in the
groundwater from certain waste sites. Second, DOE conducts studies to
detect radionuclide and chemical contamination in river life and river
sediments that could impact human health and the environment. DOE has
detected such contamination but the effects of the contamination are
not fully understood. Third, DOE uses the results of these monitoring
efforts to identify, propose, and evaluate remedial actions and
treatment strategies. These efforts are ongoing.
Program Management:
While DOE has had a groundwater monitoring and management effort for
years, some studies have raised concerns about DOE's management of the
program. DOE first took steps to establish a comprehensive and
integrated groundwater and vadose zone program in response to a 1998
GAO report.[Footnote 9] In a 2001 review of DOE's groundwater science
and technology efforts, the National Academy of Sciences expressed
concern about management of DOE's integrated program. The Academy
reported that responsibility for the groundwater program was
distributed among two DOE offices and eight site projects. It reported
that DOE had superimposed its integration program over a collection of
preexisting, highly complex projects, which left unclear who had
authority for making final cleanup decisions. The Academy also reported
that it was unclear which project had responsibility for achieving
results from technology development efforts. Although DOE had
reorganized the program by 2002, various program elements continue to
be fragmented among two DOE site operations offices (the Richland
Operations Office and the Office of River Protection) and four site
contractors. The DOE Inspector General also raised concern about
management of the groundwater effort at Hanford. He noted in a 2004
review of the groundwater program that actions DOE planned to take,
such as installing surface barriers on the ground to prevent water
infiltration, may be premature. Since a final end state for the
groundwater has not been agreed to between DOE and the regulators,
these expensive barriers may be inconsistent with final remedies.
However, DOE officials said that the proposed surface barriers are
needed to protect the groundwater from further degradation and the
barriers will be installed in consultation with site regulators.
Because of these issues, the potential for inefficiencies still exists
in DOE's efforts to protect the Columbia River.
We provided a draft of this report to DOE's Office of Environmental
Management, the Richland Operations Office, and the Office of River
Protection. We obtained views on the report's contents from the Deputy
Manager of the Richland Operations Office and other officials from each
of these offices who were knowledgeable about DOE's efforts to protect
the Columbia River. DOE generally agreed with our report's findings.
However, DOE did not fully agree with the information we cited from the
Inspector General's 2004 report that installing surface barriers to
prevent water infiltration may be premature since final cleanup
standards have not been established. We modified our report to more
fully explain DOE's strategy for using surface barriers. DOE also
offered technical comments on the draft report, which we incorporated
as appropriate.
As agreed with your offices, we will make copies of this report
available to others upon request. This report will also be available at
no charge on GAO's Web site at http://www.gao.gov.
If you or your staff has any questions about this report, please
contact me at (202) 512-3841 or aloisee@gao.gov. Contact points for our
Offices of Congressional Relations and Public Affairs may be found on
the last page of this report. Major contributors to this report include
Chris Abraham, Nancy Kintner-Meyer, Jeff Larson, Tom Perry, Stan
Stenersen, and Bill Swick.
Signed by:
Gene Aloise:
Director, Natural Resources and Environment:
Enclosure: Briefing Slides:
Department of Energy: Potential for Columbia River Contamination from
the Hanford Site:
GAO Preliminary Information:
Briefing for Subcommittee on Energy and Water Development, House
Committee on Appropriations:
September 21, 2005:
Introduction:
Beginning in the 1990s, DOE has been working to clean up the Hanford
site including addressing impacts to the Columbia River. DOE plans to
complete the cleanup by about 2035.
To address migration of contaminants, DOE established a groundwater
management program at Hanford in 1997. DOE's fiscal year 2005 budget
for groundwater remediation and protection is about $100 million.
Hanford cleanup is governed primarily by two environmental laws: (1)
the Comprehensive Environmental Response, Compensation, and Liability
Act of 1980, as amended (CERCLA), and (2) the Resource Conservation and
Recovery Act of 1976, as amended (RCRA).
Cleanup milestones and requirements are laid out in the Hanford Federal
Facility Agreement and Consent Order (known as the Tri-Party
Agreement), signed by DOE and its regulators, the U.S. Environmental
Protection Agency, and the Washington State Department of Ecology.
Objectives:
We:
1. Examined the past, current and future sources of contaminants to the
Columbia River, and the status of the contaminant plumes that threaten
the river.
2. Determined what DOE's planned approach is to prevent contamination
from reaching the Columbia River and whether DOE is adhering to its
plan.
3. Provided preliminary observations about DOE's efforts to prevent
contamination of the Columbia River.
Scope and Methodology:
To address these objectives we:
Reviewed key documents, including Hanford's Groundwater Management Plan
(2003) and Hanford Site Groundwater Strategy (2004); and various
technical, budget, and cost related reports.
Toured groundwater protection projects at the Hanford site.
Discussed river contamination issues with key DOE and contractor
officials at Hanford, and with state and federal regulators.
Reviewed DOE Inspector General reports (2004 and 2005) and a National
Academy of Sciences study (2001) on Hanford groundwater protection. We
did not assess the scientific content of these reports.
Based on our general knowledge and discussions with DOE and regulators,
we determined the data were of sufficient reliability for this
briefing.
We performed our work in accordance with generally accepted government
auditing standards.
GAO Objective 1: Sources of Contamination from the Hanford Site that
Threaten the Columbia River:
Past Sources--Contamination from past Hanford practices that has
reached or is currently migrating to the river is primarily from:
* Direct discharges to the river from reactor operations (about 110
million curies of mostly short-lived radionuclides);
* Air emissions drifting into the river (about 20 million curies from
1944 to 1972; the portion that went to the river is unknown);
* Intentional liquid disposal to the ground (about 450 billion
gallons);
* Waste tank and pipeline leaks into the soil (between 500,000 to 1
million gallons containing about 1,000,000 curies);
* Limited contamination from solid waste disposed on site (more than
710,000 cubic meters);
Key contaminants now in the groundwater from past operations include:
* Chemical contaminants: carbon tetrachloride, chromium, nitrate, and
trichloroethene.
* Radionuclide contaminants: iodine-129, strontium-90, technetium-99,
tritium, and uranium.
These past activities resulted in extensive chemical and radioactive
contamination of the site's groundwater and the soil above the
groundwater, known as the vadose zone.
Mobility of these and other contaminants in Hanford soils varies. For
example, nitrate, tritium, and technetium-99 are highly mobile while
uranium and strontium-90 are less mobile. Others, such as cesium and
plutonium, are generally not mobile.
Past sources of contamination:
[See PDF for image]
Source: DOE:
[End of figure]
Current Sources--Current cleanup efforts at Hanford could contribute to
some additional contamination eventually reaching the river:
* Waste retrieval from old single-shell tanks may cause unplanned
releases or leaks into the soil (DOE has developed technologies for use
in these tanks to reduce the amount of liquid used for retrieval); and:
* While disposal of untreated liquid waste to the soil is no longer
occurring at Hanford, some operating treatment facilities have permits
to discharge waste water which contains some contaminants including
tritium.
Any large water deposit to the ground, such as from a broken water
line, can drive the existing contaminants in the soil toward the
groundwater.
Potential Future Sources--Once site cleanup is complete, DOE plans to
leave radioactive and hazardous waste permanently on the site in
disposal facilities. Some contaminants may eventually leach out of the
facilities and begin migrating to the groundwater.
Other potential sources of future contamination include all other
locations where waste or contamination remains on the site, including
buildings, closed tanks, and contamination already in the vadose zone
and groundwater.
DOE is currently developing an overall analysis using computer modeling
to estimate the effects of contaminant migration in future years.
Status of plumes--Hanford site contaminant plumes from past practices
are still substantial with:
* Contamination in 80 square miles of groundwater at or above federal
drinking water standards;
* 10 of the 49 miles of river shore on the site leaching contaminants
into the river from plumes that are above federal drinking water
standards; and:
* A uranium plume with readings as high as three times federal drinking
water standards is leaching into the river within about four miles of
the City of Richland water intake. Because of the high river volume and
low leach rates, no uranium above background levels is detectable at
the water intake.
Plumes vary in size and location.
The impacts of contamination on the river ecosystem are not yet fully
understood. Routine monitoring of water quality and aquatic life is
performed. Findings from 2003 include:
* Strontium-90, chromium and technetium-99 have been detected in river
shellfish near the point that the contamination enters the river.
* Strontium-90 is found in the groundwater near the river and key
salmon nesting areas at up to 900 times drinking water standards.
* Chromium is entering the river at more than 2 times drinking water
standards.
* According to DOE's river monitoring studies, because of the volume of
water in the river, the contamination seeping into the river from the
groundwater is generally barely detectable after entering the river and
the water meets federal drinking water standards near Richland.
Objective 2: DOE's Planned Approach:
DOE's cleanup agreement with regulators outlines many activities to
address contamination moving towards or reaching the Columbia River.
* For surface contamination, DOE has projects underway, such as
stabilizing waste, cleaning up facilities, and exhuming and treating
buried waste. These are funded separately.
* Regarding below-surface contamination in the site's vadose zone and
groundwater, DOE has interim actions underway, but, in many cases,
final remediation actions needed to comply with RCRA and CERCLA are
still being determined. DOE must provide its remediation plan to
regulators by 2008.
According to DOE's Groundwater Project Manager, to address contaminants
in the vadose zone and groundwater that threaten the river, DOE's
current priorities are:
* first, address threats near the river;
* then minimize contamination threats that are farther from the river;
and
* monitor levels of contamination in the groundwater and river
throughout the cleanup effort.
Addressing threats near the river involves two main efforts:
* Soil and waste removal:
- Removal of waste and contaminated soil from past operations near the
river, including contaminated trenches, pits, ponds and spill areas
near old reactors and other facilities.
- Since 1996, DOE has removed 6 million tons of soil and debris from
waste sites, burial grounds, and buildings and disposed of the material
in a lined trench in the site's central area.
- DOE recently signed a new contract to complete cleanup of the river
shoreline and near river areas by 2015.
- Status: As of August 2005, DOE had remediated 354 sites.
Addressing threats near the river:
* Groundwater treatment and barriers:
- Four out of 5 groundwater pump and treat systems that DOE is
operating are intended to address near-river threats of chromium and
strontium-90.
- DOE also installed a below-surface chemical barrier to convert
chromium to a less harmful and less mobile form.
- Status: These efforts have shown mixed results:
-- The chromium pump-and-treat systems have removed more than 1,000
pounds since 1996 while the strontium pump-and-treat system has not
been effective, removing less than 2 curies of strontium-90.
-- The chemical barrier has not been fully effective in keeping
chromium from the river.
Objective 2: DOE's Planned Approach:
Minimizing contamination threats that are farther from the river
involves four main efforts:
* Characterization of the vadose zone and groundwater to help
understand the risks:
- DOE is investigating numerous old liquid waste sites and the tank
farms to determine the extent and nature of contamination and how
contaminants of concern are moving through the vadose zone.
- DOE is drilling wells and sampling others to investigate quality of
groundwater and migration of contaminants.
- Once characterization is complete, DOE will prepare a report
proposing appropriate remedies, due to the regulators by December 2008.
Upon regulatory approval, DOE plans to implement the remedies.
- Status: DOE has a number of characterization efforts underway;
however it is too early to tell if this effort is on track to allow DOE
to meet its December 2008 report deadline.
Minimizing contamination threats that are farther from the river:
* Remediation of contaminated sites located farther from the river:
- DOE is working with regulators to take actions, such as installing
surface barriers to prevent water from infiltrating the soil, to
address certain high risk sites in Hanford's central area.
- For most waste sites farther from the river, DOE is currently
studying the nature and extent of contaminant migration by monitoring,
such as through groundwater wells.
- DOE's proposed remediation plan for these sites is not due to
regulators until December 2008.
- DOE has undertaken some efforts to address contamination in some
waste sites in the central area, for example actions to contain a
uranium and technetium plume have been successful in meeting remedial
action objectives.
- Status: Although DOE has a number of studies underway to monitor
these sites, it is too early to tell whether the department will meet
its December 2008 milestone to propose remedies.
Minimizing contamination threats that are farther from the river:
* Decommissioning unneeded wells:
- Old, unused wells located in or near waste sites can allow rain and
snow melt or other liquid to flush contaminants down into the vadose
zone and groundwater.
- Hanford site currently contains over 7,000 wells but less than half
are in use. Some of the unused wells are in areas of high
contamination, such as tank farms or cribs.
- State regulations require unused wells to be decommissioned, but no
schedule is prescribed.
- Status: From fiscal years 2003 to 2005, DOE decommissioned 257 wells.
Minimizing contamination threats that are farther from the river:
* Reduce water intrusion:
- The main goal is to repair leaking water and pipe lines and surface
drainage in order to reduce discharge of water to the ground above
contaminated areas.
- The Tri-Party Agreement has no requirement that DOE must perform
these maintenance and repairs.
- In 2001-02, DOE modified drainage controls, such as installing soil
and rock berms, to reduce surface water drainage in single-shell tank
farms and eliminated 6 leaking water lines.
- Status: From 2003 to 2005, DOE refurbished about 26,000 linear feet
of water line.
Monitoring groundwater and the river to detect and assess threats
involves three efforts:
* Monitoring groundwater contamination levels to detect new or
increasing contamination.
- Monitoring efforts have detected emerging plumes containing high
levels of technetium-99 and/or tritium in the groundwater from certain
waste sites.
* Conducting studies to detect radionuclide and chemical contamination
in river life and river sediments that could impact human health and
the environment.
* Using results of monitoring studies to determine appropriate remedial
actions and treatment strategies.
* Status: These efforts are ongoing activities. DOE produces various
reports as required.
Objective 3: Preliminary Observations about DOE's Efforts to Protect
the River:
Observation 1: Performance of certain remedial actions is generally not
satisfactory.
* Groundwater pump-and-treat systems:
- Since 1995, DOE has operated 5 pump-and-treat systems to remove
strontium-90, chromium, carbon tetrachloride, or uranium from the
groundwater at a cost of about $8 million in 2004.
- In its 2004 report, the DOE Inspector General concluded that the
system to remove strontium-90 was ineffective and that the other
systems have shown mixed results.
- A DOE Hanford project manager told us the pump-and-treat system to
remove strontium-90 is largely ineffective but the remaining systems
are meeting remedial objectives.
- DOE and the regulators have agreed to continue to operate the
strontium-90 pump-and-treat system so some treatment is in place.
* Chromium barrier near the Columbia River:
- The barrier consists of an approximately 750-yard series of wells
where DOE injected a chemical into the groundwater that reacts with the
chromium to change it to a less hazardous and less mobile form.
- However, in 2004, based on groundwater readings, DOE reported that
the barrier was not fully effective, and that the hazardous form of
chromium was detected beyond the barrier.
- DOE is currently evaluating alternative approaches to contain the
chromium or fix the barrier.
* Treatment of uranium plume near the city of Richland:
- A large groundwater plume from past fuel fabrication activities is
entering the river about 4 miles above city drinking water intakes.
- The original treatment plan was to allow "natural attenuation" of the
contamination.
- However, the plume has not dissipated over the 10-year period.
- DOE is investigating the plume and ways to mitigate the problem but
no treatment decision is expected before 2006.
* Observation 2: Different technologies may be needed to address
remediation challenges.
- Technology used in several of DOE's current remedies is not
performing satisfactorily.
- A 2001 study by the National Academy of Sciences criticized DOE's
technology development effort and identified several improvements
needed in DOE's research effort.
- Site regulators have raised a concern about the lack of new
technologies to solve contamination issues.
- DOE is doing some limited technology testing and development but the
DOE groundwater project manager said that under the current funding
constraints, other program activities are higher priority.
Observation 3: Changing organizational structure and management of
groundwater and vadose zone cleanup program raises concerns.
* In response to a 1998 GAO report, DOE established a comprehensive
integrated groundwater and vadose zone program.
* In a 2001 report, the National Academy of Sciences expressed concern
that DOE's integrated program was not satisfactory, and that the
groundwater program was operating in an unstable organizational
environment, with responsibility for program activities distributed
among 2 DOE offices and 8 site projects.
* Although DOE reorganized the program by 2002, various program
elements continue to be fragmented among two DOE site operations
offices (Richland Operations Office and the Office of River Protection)
and four site contractors. Because funding and various activities are
scattered among several projects, the potential still exists for
duplication, gaps, and inefficiencies.
[End of slide presentation]
[End of section]
(360619):
FOOTNOTES
[1] Formally titled the Hanford Federal Facility Agreement and Consent
Order, it is better known as the Tri-Party Agreement. The Agreement was
signed in May 1989.
[2] National Research Council, Science and Technology for Environmental
Cleanup at Hanford (Washington, DC: 2001); Office of Inspector General,
Groundwater Remediation Activities at Hanford, DOE/IG-0655,
(Washington, DC: July 22, 2004); and Office of Inspector General, Well
Decommissioning Activities at the Hanford Site, DOE/IG-0670,
(Washington, DC: Jan. 3, 2005). We did not assess the scientific
content of these reports.
[3] In addition, during Hanford's past operations, DOE directly
discharged to the river contaminated cooling water from the reactors
containing about 110 million curies of mostly short-lived
radionuclides. (Radioactivity is measured in curies. One curie equals
37 billion atomic disintegrations per second.) Operations also resulted
in air emissions of about 20 million curies from 1944 to 1972. The
portion that went to the river is unknown. These discharges are no
longer occurring.
[4] Saltcake is a moist sand-like material such as sodium salts that
have crystallized from the waste.
[5] While the groundwater at Hanford is generally not used as a source
for drinking water, drinking water standards are still a common measure
of the extent of contamination. The EPA sets the maximum contaminant
level which is the maximum amount of a contaminant allowed in water
delivered to a user of any public water system. This is the federal
standard for the contaminant.
[6] Because the waste will be permanently on the site, it is possible
that it will eventually leach out of the lined trench. DOE is currently
analyzing the potential long-term impacts of this and other waste that
will remain on the site.
[7] Chromium is toxic to fish and this portion of the Columbia River is
a major salmon breeding area.
[8] Decommissioning of wells at Hanford requires removing or shredding
the casing and sealing it with special materials.
[9] U.S. General Accounting Office, Nuclear Waste: Understanding of
Waste Migration at Hanford is Inadequate for Key Decisions GAO/RCED-98-
80 (Washington, DC: March 13, 1998).
