United States Government Accountability Office

Washington, DC 20548 

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 

GAO-06-77R Columbia River Contamination from the Hanford site
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.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.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 

 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.

2 GAO-06-77R Columbia River Contamination from the Hanford Site
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 primarily3

 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). 

 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. 

3 GAO-06-77R Columbia River Contamination from the Hanford Site
• 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 

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.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. 

 4

Saltcake is a moist sand-like material such as sodium salts that have crystallized from the waste.

4 GAO-06-77R Columbia River Contamination from the Hanford Site
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.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 

 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. 

5 GAO-06-77R Columbia River Contamination from the Hanford Site
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.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. 

 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. 

6 GAO-06-77R Columbia River Contamination from the Hanford Site
• 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.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-andtreat 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 

 7

Chromium is toxic to fish and this portion of the Columbia River is a major salmon breeding area. 

7 GAO-06-77R Columbia River Contamination from the Hanford Site
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,8

 but no 

 8

Decommissioning of wells at Hanford requires removing or shredding the casing and sealing it with 

special materials. 

8 GAO-06-77R Columbia River Contamination from the Hanford Site
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.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 

 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). 

9 GAO-06-77R Columbia River Contamination from the Hanford Site
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. 

Gene Aloise 

Director, Natural Resources and 

 Environment 

Enclosure

10 GAO-06-77R Columbia River Contamination from the Hanford Site
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

11 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 2

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 TriParty Agreement), signed by DOE and its regulators, the U.S. 

Environmental Protection Agency, and the Washington State 

Department of Ecology.

12 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 3

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.

13 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 4

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.

14 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 5

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, technetium99, tritium, and uranium.

15 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 6

Objective 1: Sources of Contamination from the 

Hanford Site that Threaten the Columbia River

• 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:

Source: DOE

16 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 7

Objective 1: Sources of Contamination from the 

Hanford Site that Threaten the Columbia River

• 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.

17 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 8

Objective 1: Sources of Contamination from the 

Hanford Site that Threaten the Columbia River

• 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.

18 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 9

Objective 1: Sources of Contamination from the 

Hanford Site that Threaten the Columbia River

• 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.

19 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 10

Objective 1: Sources of Contamination from the 

Hanford Site that Threaten the Columbia River

• 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.

20 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 11

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.

21 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 12

Objective 2: DOE’s Planned Approach

• 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.

22 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 13

Objective 2: DOE’s Planned Approach

• 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. 

23 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 14

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.

24 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 15

Objective 2: DOE’s Planned Approach

• 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.

25 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 16

Objective 2: DOE’s Planned Approach

• 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.

26 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 17

Objective 2: DOE’s Planned Approach

• 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.

27 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 18

Objective 2: DOE’s Planned Approach

• 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. 

28 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 19

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-andtreat 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.

29 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 20

Objective 3: Preliminary Observations about 

DOE’s Efforts to Protect the River

• Observation 1: Performance of certain remedial actions

is generally not satisfactory.

• 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. 

30 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 21

Objective 3: Preliminary Observations about 

DOE’s Efforts to Protect the River

• Observation 1: Performance of certain remedial actions

is generally not satisfactory.

• 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.

31 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 22

Objective 3: Preliminary Observations about 

DOE’s Efforts to Protect the River

• 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.

32 GAO-06-77R Columbia River Contamination from the Hanford Site
Enclosure 

Preliminary Information 23

Objective 3: Preliminary Observations about 

DOE’s Efforts to Protect the River

• 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.

(360619) 

33 GAO-06-77R Columbia River Contamination from the Hanford Site
This is a work of the U.S. government and is not subject to copyright protection in the 

United States. It may be reproduced and distributed in its entirety without further 

permission from GAO. However, because this work may contain copyrighted images or 

other material, permission from the copyright holder may be necessary if you wish to 

reproduce this material separately. 
The Government Accountability Office, the audit, evaluation and 

investigative arm of Congress, exists to support Congress in meeting its 

constitutional responsibilities and to help improve the performance and 

accountability of the federal government for the American people. GAO 

examines the use of public funds; evaluates federal programs and policies; 

and provides analyses, recommendations, and other assistance to help 

Congress make informed oversight, policy, and funding decisions. GAO’s 

commitment to good government is reflected in its core values of 

accountability, integrity, and reliability. 

The fastest and easiest way to obtain copies of GAO documents at no cost 

is through GAO’s Web site (www.gao.gov). Each weekday, GAO posts 

newly released reports, testimony, and correspondence on its Web site. To 

have GAO e-mail you a list of newly posted products every afternoon, go 

to www.gao.gov and select “Subscribe to Updates.” 

The first copy of each printed report is free. Additional copies are $2 each. 

A check or money order should be made out to the Superintendent of 

Documents. GAO also accepts VISA and Mastercard. Orders for 100 or 

more copies mailed to a single address are discounted 25 percent. Orders 

should be sent to: 

U.S. Government Accountability Office 

441 G Street NW, Room LM 

Washington, D.C. 20548 

To order by Phone: Voice: (202) 512-6000 

TDD: (202) 512-2537 

Fax: (202) 512-6061 

Contact: 

Web site: www.gao.gov/fraudnet/fraudnet.htm 

E-mail: fraudnet@gao.gov

Automated answering system: (800) 424-5454 or (202) 512-7470 

Gloria Jarmon, Managing Director, JarmonG@gao.gov (202) 512-4400 

U.S. Government Accountability Office, 441 G Street NW, Room 7125 

Washington, D.C. 20548 

Paul Anderson, Managing Director, AndersonP1@gao.gov (202) 512-4800 

U.S. Government Accountability Office, 441 G Street NW, Room 7149 

Washington, D.C. 20548 

GAO’s Mission 

Obtaining Copies of 

GAO Reports and 

Testimony 

Order by Mail or Phone 

To Report Fraud, 

Waste, and Abuse in 

Federal Programs 

Congressional 

Relations 

Public Affairs 

PRINTED ON RECYCLED PAPER