Summary
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Summary |
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This Hanford Site environmental report is prepared annually to summarize environmental data and information, to describe environmental management performance, to demonstrate the status of compliance with environmental regulations, and to highlight major environmental programs and efforts.
The report is written to meet requirements and guidelines of the U.S. Department of Energy (DOE) and to meet the needs of the public. This summary has been written with a minimum of technical terminology.
Individual sections of the report are designed to
More detailed information can be found in the body of the report, the cited references, and the appendixes.
The Hanford Site in southcentral Washington State is approximately 1,450 km2 (560 mi2) of semiarid shrub and grasslands located just north of the confluence of the Snake and Yakima Rivers with the Columbia River. This land, with restricted public access, provides a buffer for the smaller areas historically used for the production of nuclear materials, waste storage, and waste disposal. Approximately 6% of the land area has been disturbed and is actively used. This 6% is divided into operational areas:
The 600 Area is the designation for land between the operational areas. Areas off the Hanford Site used for research and technology development and administrative functions can be found in Richland, Kennewick, and Pasco, the nearest cities.
The Hanford Site was acquired by the federal government in 1943 and, until 1989, was dedicated primarily to the production of plutonium for national defense and the management of the resulting wastes. With the shutdown of the production facilities in the 1970s and 1980s, missions were diversified to include research and development in the areas of energy, waste management, and environmental restoration.
The DOE has ended the production of nuclear materials at the Hanford Site for weapons. The current mission being implemented by the DOE Richland Operations Office is now:
Current waste management activities at the Hanford Site include primarily managing wastes with high and low levels of radioactivity (from the nuclear materials production activities) in the 200-East and 200-West Areas. Key waste management facilities include the underground waste storage tanks, Environmental Restoration Disposal Facility, Plutonium Finishing Plant, Central Waste Complex, Low-Level Burial Grounds, B Plant/Waste Encapsulation Facility, Effluent Treatment Facility, Waste Receiving and Processing Facility, Transuranic Storage and Assay Facility, and 242-A Evaporator. In addition, irradiated nuclear fuel is stored in the 100-K Area in fuel storage basins.
Environmental restoration includes activities to decontaminate and decommission facilities and to clean up or restore inactive waste sites. The Hanford surplus facilities program conducts surveillance and maintenance of such facilities; the cleanup and disposal of more than 100 facilities have begun.
Research and technology-development activities are intended to improve the techniques and reduce the costs of waste management, environmental protection, and site restoration.
Operations and activities on the site are managed by the DOE Richland Operations Office through four prime contractors and numerous subcontractors. Each contractor is responsible for the safe, environmentally sound maintenance and management of its facilities and operations, waste management, and monitoring of operations and effluents for environmental compliance.
The principal contractors include the following:
Non-DOE operations and activities include commercial power production by the Washington Public Power Supply System's WNP-2 Reactor (near the 400 Area) and commercial low-level radioactive waste burial at a site leased and licensed by Washington State and operated by US Ecology (near the 200 Areas). Siemens Power Corporation operates a commercial nuclear fuel fabrication facility, and Allied Technology Group Corporation operates a low-level radioactive waste decontamination, supercompaction, and packaging disposal facility near the southern boundary of the Hanford Site.
DOE Order 5400.1, "General Environmental Protection Program," describes the environmental standards and regulations applicable at DOE facilities. These environmental standards and regulations fall into three categories: 1) DOE directives; 2) federal legislation and executive orders; and 3) state and local statutes, regulations, and requirements. The following subsections summarize the status of Hanford's compliance with these applicable regulations and list environmental occurrences for 1996.
A key element in Hanford's compliance program is the Hanford Federal Facility Agreement and Consent Order (also known as the Tri-Party Agreement). The Tri-Party Agreement is an agreement among the U.S. Environmental Protection Agency (EPA), Washington State Department of Ecology, and DOE for achieving compliance with the remedial action provisions of the Comprehensive Environmental Response, Compensation, and Liability Act and with treatment, storage, and disposal unit regulation and corrective action provisions of the Resource Conservation and Recovery Act. From 1989 through 1996, a total of 512 enforceable Tri-Party Agreement milestones and 223 unenforceable target dates were completed on or ahead of schedule. Sixty-four milestones scheduled for 1996 were completed.
This Act established a program to ensure that sites contaminated by hazardous substances are cleaned up by responsible parties or the government. The Act primarily covers waste cleanup of inactive sites.
Preliminary assessments conducted for the Hanford Site revealed approximately 2,200 known individual waste sites where hazardous substances may have been disposed of in a manner that requires further evaluation to determine impact to the environment.
The DOE is actively pursuing the remedial investigation/feasibility study process at some operable units on the Hanford Site. The operable units currently being studied were selected as a result of Tri-Party Agreement negotiations.
In 1996, the Hanford Site was in compliance with requirements of the Comprehensive Environmental Response, Compensation, and Liability Act. Cleanup is under way at various sites in the 100, 200, and other areas. Full-scale remediation of waste sites began in the 100 Areas in 1996. The Environmental Restoration Disposal Facility opened in the 600 Area in 1996; a central disposal site for contaminated soil generated during cleanup.
This Act requires that the public be provided with information about hazardous chemicals in the community and establishes emergency planning and notification procedures to protect the public from a release. The Act calls for creation of state emergency response commissions to guide planning for chemical emergencies. State commissions have also created local emergency planning committees to ensure community participation and planning.
To provide the public with the basis for emergency planning, the Act contains requirements for periodic reporting on hazardous chemicals stored and/or used near the community. The 1996 Hanford Site's emergency and hazardous chemical inventory was issued to the State Emergency Response Commission, local county emergency management committees, and local fire departments in March 1997. The inventory report contained information on hazardous materials in storage across the site. A toxic chemical release inventory report was issued in August 1996, which provided details regarding releases, offsite transfers, and source reduction activities involving ethylene glycol, the sole toxic chemical used in excess of regulatory thresholds during 1995. No such reporting thresholds were exceeded in 1996. During 1996, the Hanford Site was in compliance with the reporting and notification requirements contained in this Act.
This Act establishes regulatory standards for the generation, transportation, storage, treatment, and disposal of hazardous wastes. The Washington State Department of Ecology has been authorized by the EPA to implement its dangerous waste program in lieu of the EPA for Washington State, except for some provisions of the hazardous and solid waste amendments of 1984. The Washington State Department of Ecology implements the state's regulations, which are often more stringent. The Act primarily covers ongoing waste management at active facilities.
At the Hanford Site, over 60 treatment, storage, and disposal units have been identified that must be permitted or closed in accordance with the Act and Washington State regulations. These units are required to operate under the Washington State Department of Ecology's interim-status compliance requirements. Approximately one-half of the units will be closed.
Subtitle I of the Resource Conservation and Recovery Act deals with regulation of underground storage tank systems. These regulations were added to the Act by the hazardous and solid waste amendments of 1984. The EPA has developed regulations implementing technical standards for tank performance and management, including standards governing the cleanup and closure of leaking tanks. These regulations do not apply to the single- and double-shell tanks, which are regulated as treatment, storage, and disposal facilities.
The purpose of this Act is to protect public health and welfare by safeguarding air quality, bringing polluted air into compliance, and protecting clean air from degradation. In Washington State, the provisions of the Act are implemented by EPA, Washington State Department of Ecology, Washington State Department of Health, and local air authorities.
Washington State regulations require applicable controls and annual reporting of all radioactive air emissions. The Hanford Site operates under a license for such emissions. The conditions specified in the license will be incorporated into the Hanford Site air operating permit, scheduled to be issued in 1997.
Revised Clean Air Act requirements for radioactive air emissions were issued in December 1989. Emissions from the Hanford Site are within the state and EPA offsite emissions standard of 10 mrem/yr. Nearly all Hanford Site sources currently meet the procedural requirements for flow measurement, emissions measurement, quality assurance, and sampling documentation.
The local air authority (the Benton County Clean Air Authority) regulations pertain to detrimental effects, fugitive dust, open burning, odor, opacity, and asbestos handling. The Authority has also been delegated responsibility to enforce the EPA asbestos regulations under the revised Clean Air Act. The site remains in compliance with the regulations.
This Act applies to point discharges to waters of the United States. At the Hanford Site, the regulations are applied through National Pollutant Discharge Elimination System permits that govern effluent discharges to the Columbia River. The permits specify discharge points (called outfalls), effluent limitations, and monitoring requirements. Several permit exceedences occurred at the 300 Area Treated Effluent Disposal Facility in 1996 despite the use of best available technology. Preparations for a modification to the facility's discharge permit are under way.
The National Primary Drinking Water Regulations of the Safe Drinking Water Act apply to the drinking water supplies at the Hanford Site. These regulations are enforced by the Washington State Department of Health. In 1996, all Hanford Site water systems were in compliance with requirements and agreements.
The application of Toxic Substances Control Act requirements to the Hanford Site essentially involves regulation of the chemicals called polychlorinated biphenyls. The site is currently in compliance with an agreement to store these wastes beyond the regulatory limit. All radioactive polychlorinated biphenyl wastes are being stored pending development of treatment and disposal technologies and capabilities.
The EPA is responsible for ensuring that a chemical, when used according to label instructions, will not present unreasonable risks to human health or the environment. This Act and specific chapters of the Revised Code of Washington apply to storage and use of pesticides. In 1996, the Hanford Site was in compliance with these requirements.
Many rare species of native plants and animals are known to occur on the Hanford Site. Two of these (bald eagle and peregrine falcon) are listed by the U.S. Fish and Wildlife Service as endangered or threatened. Others are listed by the Washington State Department of Fish and Wildlife as endangered, threatened, or sensitive species. Hanford Site activities complied with the Endangered Species Act in 1996.
Cultural resources on the Hanford Site are subject to the provisions of these Acts. In 1996, the Hanford Site was in compliance with these Acts.
This Act establishes environmental policy to prevent or eliminate damage to the environment and to enrich our understanding of ecological systems and natural resources. This Act requires that major federal projects with significant impacts be carefully reviewed and reported to the public in environmental impact statements. Other documents such as environmental assessments are also prepared in accordance with requirements of the Act.
Several environmental impact statements related to programs or activities on the Hanford Site are in process or in the planning stage.
Onsite and offsite environmental occurrences (spills, leaks, etc.) of radioactive and nonradioactive effluent materials during 1996 were reported to DOE and other federal and state agencies as required by law. All emergency, unusual, and off-normal occurrence reports, including event descriptions and corrective actions, are available for review in the DOE Hanford Reading Room located on the campus of Washington State University at Tri-Cities, Richland, Washington. There were no emergency occurrence or environmentally significant unusual occurrence reports filed in 1996. There were 15 off-normal environmental release-related occurrence reports filed during 1996.
Environmental monitoring of the Hanford Site consists of 1) effluent monitoring and 2) environmental surveillance, including groundwater monitoring. Effluent monitoring is performed as appropriate by the operators at the facility or at the point of release to the environment. Additional monitoring is conducted in the environment near facilities that discharge, or have discharged, effluents. Environmental surveillance consists of sampling and analyzing environmental media on and off the site to detect and quantify potential contaminants and to assess their environmental and human health significance.
The overall objectives of the monitoring and surveillance programs are to demonstrate compliance with applicable federal, state, and local regulations; confirm adherence to DOE environmental protection policies; and support environmental management decisions.
Effluent monitoring includes facility effluent monitoring (monitoring effluents at the point of release to the environment) and near-facility environmental monitoring (monitoring the environment near operating facilities).
Liquid and gaseous effluents that may contain radioactive and hazardous constituents are continually monitored at the Hanford Site. Facility operators monitor effluents mainly through analyzing samples collected near points of release into the environment. Effluent monitoring data are evaluated to determine their degree of compliance with applicable federal, state, and local regulations and permits.
Measuring devices are used to quantify most facility effluent flows, with a smaller number of flows calculated using process information. Liquid and gaseous effluents with a potential to contain radioactivity at prescribed threshold levels are monitored for total alpha and total beta activity and, as warranted, specific gamma-emitting radionuclides. Nonradioactive hazardous constituents are also monitored, as applicable.
Radioactive effluents from many onsite facilities are approaching levels practically indistinguishable from the naturally occurring radioactivity present everywhere. This decrease translates to a very small offsite radiation dose attributable to site activities. The new site mission of environmental restoration rather than nuclear materials production is largely responsible for this trend. Consistent with these conditions of diminishing releases, totals of radionuclides in effluents released at the site in 1996 are not significantly different from totals in 1995.
The near-facility environmental monitoring program is designed to protect the environment adjacent to facilities and ensure compliance with federal, state, and local regulations. Specifically, this program monitored new and existing sites, processes, and facilities for potential impacts and releases; fugitive emissions and diffuse sources from contaminated areas; and surplus facilities before decontamination or decommissioning. Air, surface water and springs, surface contamination, vadose zone monitoring, soil and vegetation, external radiation, and investigative sampling (which can include wildlife) were sampled. Some of the parameters typically monitored are pH, radionuclide concentrations, radiation exposure levels, and concentrations of selected hazardous chemicals. Samples are collected from known or expected effluent pathways. These pathways are generally downwind of potential or actual airborne releases and downgradient of liquid discharges.
Near-Facility Air Monitoring. Radioactivity in air was sampled by a network of continuously operating samplers at 58 locations near nuclear facilities: 4 located in the 100-N Area, 4 in the 100-K Area, 38 in the 200 Areas, 3 at the Environmental Restoration Disposal Facility, 4 at the 100-D,DR Area, 3 at the 100-B,C Area, 1 near the 300 Area Treated Effluent Disposal Facility, and 1 collocated with samplers operated by the Pacific Northwest National Laboratory and the Washington State Department of Health at the Wye Barricade. Air samplers were primarily located within approximately 500 m (1,500 ft) of sites and/or facilities having the potential for, or history of, environmental releases, with an emphasis on the prevailing downwind directions. Of the radionuclide analyses performed, strontium-90, cesium-137, plutonium-239,240, and uranium were consistently detectable in the 100-N and 200 Areas. Cobalt-60 was consistently detectable in the 100-N Area. Air concentrations for these radionuclides were elevated near facilities compared to the concentrations measured offsite by Pacific Northwest National Laboratory.
Surface-Water Disposal Units and 100-N Springs Monitoring. Samples collected from surface-water disposal units included water, sediment, and aquatic vegetation. Only water samples were taken at 100-N shoreline springs. Radiological analyses of water samples from surface-water disposal units included strontium-90, plutonium-238, plutonium-239,240, uranium, tritium, and gamma-emitting radionuclides. Radiological analyses of sediment and aquatic vegetation samples were performed for strontium-90, plutonium-239,240, uranium, and gamma-emitting radionuclides. Nonradiological analyses were performed for pH, temperature, and nitrates.
Radiological analytical results for liquid samples from surface-water disposal units (i.e., ponds and ditches) located in the 200 Areas were less than the DOE derived concentration guides and in most cases, were equal to or less than the analytical detection limits. Although some elevated levels were seen in both aquatic vegetation and sediment, in all cases, the radiological analytical results were much less than the standards used for radiological control. The results for pH were well within the 2.0 to 12.5 pH standard for liquid effluent discharges based on the discharge limits listed in the Resource Conservation and Recovery Act. The analytical results for nitrates were all less than the 45-mg/L EPA drinking water standard for public water supplies.
Groundwater springs along the 100-N Area shoreline are sampled annually to verify the reported radionuclide releases to the Columbia River from past N Reactor operations. By characterizing the radionuclide concentrations in the springs along the shoreline, the results can be compared to the concentrations measured at the facility effluent monitoring well. In 1996, the concentrations detected in shoreline springs samples were highest in springs nearest the effluent monitoring well.
Near-Facility Radiological Surveys. In 1996, there were approximately 4,016 ha (9,923 acres) of posted outdoor contamination areas and 1,025 ha (2,532 acres) of posted underground radioactive materials areas, not including active facilities, at the Hanford Site. These areas were typically associated with burial grounds, covered ditches, cribs, and tank farms. The posted contamination areas vary between years because of an ongoing effort to clean, stabilize, and remediate areas of known contamination. During this time, new areas of contamination were being identified. It was estimated that the external dose rate at 80% of the identified outdoor contamination areas was less than 1 mrem/h measured at 1 m (3.28 ft), though direct dose rate readings from isolated radioactive specks (a diameter less than 0.6 cm [0.25 in.]) could have been considerably higher. Contamination levels of this magnitude did not significantly add to dose rates for the public or Hanford Site workers in 1996.
Vadose Zone Monitoring. The inactive liquid effluent facilities vadose zone monitoring program tracks the movement of radioactive contaminants that were discharged to the soil. There are over 300 liquid waste disposal sites at Hanford that have received over 53 billion L (14 billion gal) of waste, excluding the 1,620 billion L (430 billion gal) that were discharged at the surface to ponds and ditches. During 1996, approximately 70 boreholes were logged around these facilities for radioactive plume identification and tracking. In addition, approximately 35 wells scheduled for decommissioning onsite were surveyed for gamma-ray radiation to ensure the wells were not contaminated and for moisture and geologic data to help determine moisture migration pathways. The environmental restoration program also was supported by the collection of approximately 40 borehole logs for delineating subsurface radioactive contamination.
Soil and Vegetation Sampling from Operational Areas. Soil and vegetation samples were collected on or adjacent to waste disposal units and from locations downwind and near or within the boundaries of the operating facilities. Samples were collected to detect potential migration and deposition of facility effluents. Special samples were also taken where physical or biological transport problems were identified. Migration can occur as the result of resuspension from radioactively contaminated surface areas, absorption of radionuclides by the roots of vegetation growing on or near underground and surface-water disposal units, or by waste site intrusion by animals. Soil and vegetation sample concentrations for some radionuclides were elevated near facilities when compared to concentrations measured offsite. The concentrations show a large degree of variance; in general, samples collected on or adjacent to waste disposal facilities had significantly higher concentrations than those collected farther away. The number of sampling locations at the 100-N Area were reduced by approximately 50% in 1996.
Near-Facility External Radiation. External radiation fields were measured near facilities and waste handling, storage, and disposal sites to measure, assess, and control the impacts of operations.
A hand-held micro-rem meter (to measure low-level radiation exposure) was used to survey points along the N Springs area. The radiation rates measured in the N Springs area continued to decline in 1996, reflecting discontinued discharges to the 1301-N Liquid Waste Disposal Facility and the continuing decay of its radionuclide inventory.
The 1996 thermoluminescent dosimeter results indicate that direct radiation levels are highest near facilities that had contained or received liquid effluent from N Reactor. These facilities primarily include the 1301-N and 1325-N Liquid Waste Disposal Facilities. Because the results for these two facilities were noticeably higher than those for other 100-N Area thermoluminescent dosimeter locations, they were approximately 9% lower than exposure levels measured at these locations in 1995.
This is the fourth year that thermoluminescent dosimeters have been placed in the 100-K Area, surrounding the 105-K East and 105-K West Fuel Storage Basins and adjacent reactor buildings. Three of the thermoluminescent dosimeters have consistently shown elevated readings as a result of their proximity to radioactive waste storage areas or stored radioactive rail equipment.
Five new thermoluminescent dosimeter locations were established in the 100-D,DR Area during the fourth quarter of 1996 to evaluate environmental restoration activities at the 116-D-7 and 116-DR-9 Liquid Waste Disposal Facilities. Although no comparative data are available because of the recent placement of these dosimeters, the fourth quarter analyses indicate readings comparable to offsite background levels.
The highest dose rates in the 200/600 Areas were measured near waste handling facilities such as tank farms. The highest dose rate was measured at the 241-A Tank Farm complex located in the 200-East Area. The average annual dose rate measured in 1996 by thermoluminescent dosimeters was 120 mrem/yr, which equaled the average dose rate measured in 1995.
Two new thermoluminescent dosimeter locations were established at the Environmental Restoration Disposal Facility during the fourth quarter of 1996 to evaluate the disposal activities currently in progress. Although no comparative data are available because of the recent placement of these dosimeters, the fourth quarter analyses indicate readings comparable to offsite background levels.
The highest dose rates in the 300 Area were measured near waste handling facilities such as the 340 Waste Handling Facility. The average annual dose rate measured in the 300 Area in 1996 was 120 mrem/yr. This represents a decrease of 14% compared to the average dose rate of 140 mrem/yr measured in 1995. The average annual dose rate at the 300 Area Treated Effluent Disposal Facility in 1996 was 85 mrem/yr, which represents an increase of 5% compared to the average dose rate of 81 mrem/yr measured in 1995.
The average annual dose rate measured in the 400 Area in 1996 was 83 mrem/yr, which represents an increase of 8% compared to the average dose rate of 77 mrem/yr measured in 1995.
Investigative Sampling. Investigative sampling was conducted in the operations areas to confirm the absence or presence of radioactive or hazardous contaminants. Investigative sampling took place near facilities such as storage and disposal sites for at least one of the following reasons:
The maximum concentrations of radioactive isotopes from samples collected during these investigations are included in this report.
Generally, the predominant radionuclides discovered during these efforts were activation products and strontium-90 in the 100 Areas, fission products in the 200 Areas, and uranium in the 300 Area. Hazardous chemicals generally have not been identified above background levels in preoperational environmental monitoring samples.
Investigative samples collected in 1996 included air, water, soil (including sediment and radioactive specks), paint chips, vegetation (e.g., mosses, lichens, tumbleweeds), and wildlife (e.g., deer mice, starlings, pocket gopher).
Investigative samples were collected where known or suspected radioactive contamination was present or to verify radiological conditions at project sites. In 1996, 53 such samples were analyzed for radionuclides, and 43 showed some level of contamination. In addition, 62 contamination incidents were reported and disposed of without isotopic analyses, though field instrument readings were recorded for most, during cleanup operations.
Environmental surveillance at the Hanford Site includes sampling environmental media on and off the site for potential chemical and radiological contaminants originating from site operations. The media sampled included air, surface water and sediment, drinking water, food and farm products, fish and wildlife, soil and vegetation, external radiation levels, and groundwater.
Radioactive materials in air were sampled continuously at 40 locations onsite, at the site perimeter, and in nearby and distant communities. Nine of these locations were community-operated environmental surveillance stations that were managed and operated by local school teachers. At all locations, particulates were filtered from the air and analyzed for radionuclides. Air was sampled and analyzed for selected gaseous radionuclides at key locations. Several radionuclides released at the site are also found worldwide from two other sources: naturally occurring radionuclides and radioactive fallout from historical nuclear activities not associated with Hanford. The potential influence of emissions from site activities on local radionuclide concentrations was evaluated by comparing differences between concentrations measured at distant locations within the region and concentrations measured at the site perimeter.
For 1996, no differences were observed between the annual average total beta air concentrations measured at the site perimeter and those measured at distant community locations. Air concentrations of total alpha were slightly elevated at the site perimeter compared to the distant stations; however, the concentrations were within the range of historical values. Numerous specific radionuclides in quarterly composite samples were analyzed using gamma scan analysis; however, no radionuclides of Hanford origin were detected consistently.
Tritium concentrations for 1996 were slightly elevated at the site perimeter compared to the distant station; however, the difference was not statistically significant.
Iodine-129 concentrations were statistically elevated at the site perimeter compared to the distant locations, indicating a measurable Hanford source; however, the average concentration at the site perimeter was only 0.000003% of the DOE derived concentration guide of 70 pCi/m3. The DOE derived concentration guide is the air concentration that would result in a radiation dose equal to the DOE public dose limit (100 mrem/yr).
Strontium-90 was detected in 8 of the 15 onsite air samples, with the maximum concentration at 0.002% of the DOE derived concentration guide of 9 pCi/m3. Strontium-90 was also detected at three of the seven perimeter locations and at two of the six distant locations. The maximum concentration at the perimeter location was less than 0.0004% of the DOE derived concentration guide and at the distant location less than 0.0002% of the DOE derived concentration guide.
Plutonium-239,240 concentrations were similar for air samples collected at the site perimeter and the distant locations. The maximum plutonium-239,240 air concentration was 0.06% of the DOE derived concentration guide of 0.02 pCi/m3.
Uranium isotopic concentrations (uranium-234, uranium-235, and uranium-238) were similar onsite, at the perimeter, and at the distant locations for 1996. The uranium concentrations were 0.03% of the 0.1-pCi/m3 DOE derived concentration guide.
No samples were collected in 1996 to test for nonradionuclides.
The Columbia River was one of the primary environmental exposure pathways to the public during 1996 as a result of past operations at the Hanford Site. Radiological and chemical contaminants entered the river along the Hanford Reach primarily through seepage of contaminated groundwater. Water samples were collected from the river at various locations throughout the year to determine compliance with applicable standards.
Although radionuclides associated with Hanford operations continued to be identified routinely in Columbia River water during the year, concentrations remained extremely low at all locations and were well below standards. The concentration of tritium was significantly higher (5% significance level) at the Richland Pumphouse (downstream from the site) than at Priest Rapids Dam (upstream from the site), indicating contribution along the Hanford Reach. Transect sampling in 1996 revealed elevated tritium concentrations along the Benton County shoreline near the 100-N Area, Old Hanford Townsite, 300 Area, and Richland Pumphouse. Total uranium concentrations were elevated along the shorelines of both Benton and Franklin Counties near the 300 Area and Richland Pumphouse. The highest total uranium concentration was measured near the Franklin County shoreline of the Richland Pumphouse transect and likely resulted from groundwater seepage and irrigation return canals on the east shore of the river.
Several metals and anions were detected both upstream and downstream of the Hanford Site. Nitrate concentrations were elevated along the Franklin County shoreline of the Old Hanford Townsite, 300 Area, and Richland Pumphouse transects and likely resulted from groundwater seepage associated with extensive irrigation north and east of the Columbia River. With the exception of aluminum, iron, and nitrate which had the higher average quarterly concentration at the Richland Pumphouse, no consistent differences were found between average quarterly contaminant concentrations in the Vernita Bridge and Richland Pumphouse transect samples. All metal and anion concentrations in Columbia River water collected in 1996 were less than Washington State ambient surface water quality criteria levels for acute toxicity, except for silver and cadmium that both exceeded the criteria for a few samples. The chronic toxicity levels for lead and selenium were occasionally exceeded in Columbia River transect samples. Volatile organic compounds (chloroform, toluene, and trichloroethylene) were occasionally detected in Columbia River water in 1996.
Samples of Columbia River surface sediments were collected in 1996 from permanently flooded monitoring sites above McNary Dam (downstream of the site), above Priest Rapids Dam (upstream of the site), and along the Hanford Reach. Strontium-90 was the only radionuclide to exhibit consistently higher median concentrations at McNary Dam compared to the other locations. The median concentration of cobalt-60 was highest in sediment collected along the Hanford Reach. Sediment samples were also collected from five periodically inundated riverbank springs in 1996. The concentrations of radionuclides in sediment collected from riverbank springs were similar at all locations and were comparable to sediment collected behind Priest Rapids Dam.
Detectable concentrations of most metals were found in all Columbia River sediment samples with the exception of silver, which was below the detection limit for all samples. Median concentrations of most metals were highest in McNary Dam sediments. The highest median concentration of chromium was found in riverbank spring sediment.
Water samples were collected from six Columbia River shoreline springs in 1996. All radiological contaminant concentrations measured in riverbank spring water in 1996 were less than the DOE derived concentration guides. However, tritium concentrations in the 100-B Area and Old Hanford Townsite riverbank springs exceeded the Washington State ambient surface water quality criteria levels. There are currently no ambient surface water quality criteria levels directly applicable to uranium. However, total uranium exceeded the site-specific proposed EPA drinking water standard in the 300 Area riverbank spring. All other radionuclides were below the Washington State ambient surface water quality criteria.
All nonradiological contaminants measured in riverbank springs located on the Hanford shoreline in 1996 were below the Washington State ambient surface water acute toxicity levels with the exception of cadmium in the 100-F Area spring; chromium(IV) in springs in the 100-B, 100-D, and 100-F Areas; and copper in the 100-F and 300 Areas springs. The Washington State ambient surface water chronic toxicity levels for cadmium, chromium, selenium, and zinc were exceeded at some locations. It should be noted that riverbank spring sampling protocols do not lend themselves to a direct comparison of most metal concentrations measured in riverbank springs to ambient surface water acute and chronic toxicity levels. The standards are used instead as a point of reference. Nitrate concentrations were the highest in the 100-D Area and the Old Hanford Townsite springs. Concentrations of volatile organic compounds were similar to previous years with most compounds below the detection limits. Chloroform (100-B and 100-D Areas), tetrahydrofuran (100-B Area), and trichloroethylene (100-B Area) were the only volatile organic compounds detected.
Water was collected from three onsite ponds located near operational areas in 1996. Although the ponds were not accessible to the public and did not constitute a direct offsite environmental impact during 1996, they were accessible to migratory waterfowl and other animals. As a result, a potential biological pathway existed for the removal and dispersal of onsite pond contaminants. With the exception of uranium-234 and uranium-238 in water samples from West Lake, radionuclide concentrations in the onsite pond water were below the DOE derived concentration guides. The average annual total beta concentration in West Lake exceeded the ambient surface water quality criteria level. Concentrations of most radionuclides in water collected from all three ponds during 1996 were similar to those observed during past years. However, the tritium concentrations in the 1996 samples from the Fast Flux Test Facility pond were lower than observed in 1995. The elevated concentrations in 1995 most likely resulted from the use of a backup water supply in the 400 Area during June and July of 1995. The primary source of water to the Fast Flux Test Facility pond is 400 Area sanitary water.
Irrigation water from the Riverview canal was sampled three times in 1996 to determine radionuclide concentrations. The radionuclide concentrations in offsite irrigation water were below the derived concentration guides and ambient surface water quality criteria levels.
Surveillance of Hanford Site drinking water was conducted to verify the quality of water supplied by site drinking water systems and to comply with regulatory requirements. Radiological monitoring was performed by the Pacific Northwest National Laboratory and DE&S Hanford, Inc.; nonradiological monitoring was conducted by DynCorp Tri-Cities Services, Inc. Radiological results are discussed in this report; nonradiological results are reported directly to the Washington State Department of Health.
During 1996, radionuclide concentrations in site drinking water were similar to those observed in recent years and were in compliance with Washington State Department of Health and EPA annual average drinking water standards.
The Hanford Site is situated in a large agricultural area that produces a wide variety of food products and alfalfa. Milk, vegetables, fruit, and wine were collected from areas around the site and were analyzed for cobalt-60, strontium-90, iodine-129, cesium-137, and tritium.
Most of the farm products sampled did not contain measurable concentrations of these radionuclides. Iodine-129 was found at slightly elevated levels in milk samples from downwind locations. The levels were low, they have been decreasing over the past 6 years, and they are now indistinguishable between upwind and downwind locations. Tritium concentrations in wine have been reported in the past at levels higher than could be confirmed at other analytical laboratories (split samples). Recently, it was discovered that these high concentrations were caused by alcohol in the initial sample distillate; the alcohol produced spuriously high results. The problem was eliminated by removing the alcohol from the sample before analysis.
Analyses of fish and wildlife samples for radionuclides in 1996 indicated that some species had accumulated radionuclides at concentrations greater than background levels. Strontium-90 was detected in the offal (i.e., carcass without most of the muscle and viscera) of Columbia River bass and carp at levels slightly exceeding those found in fish collected upstream of Hanford in the Priest Rapids Dam reservoir. There was no apparent difference between concentrations of strontium-90 in Hanford Reach carp and background carp collected in 1996. Cesium-137 was detected in one bass fillet sample; all other fish and wildlife muscle samples did not have measurable concentrations of cesium-137. Strontium-90 was detected in all deer bone samples analyzed in 1996. Concentrations were similar to levels observed in prior years and did not indicate exposure to elevated levels of strontium in the environment. The mean concentration of strontium-90 (0.07 ± 0.005 pCi/g, wet weight) in pheasant bone was similar to levels observed over the preceding 5 years and exceeded concentrations observed in background samples collected from 1991 through 1995 by a factor of two. Collectively, the levels of radionuclides measured in Hanford fish and wildlife indicated accumulations of small amounts of specific radionuclides that possibly originated either from historic fallout or Hanford Site activities.
Soil and vegetation samples were not collected in 1996. Sampling will be conducted periodically in the future consistent with ongoing site cleanup activities.
Radiological dose rates were measured at both onsite and offsite locations using thermoluminescent dosimeters. Radionuclides contributing to these measured doses were of natural and artificial origin. In 1996, terrestrial dose rates did not change significantly from those measured in 1995. The annual average background dose rate measured in distant communities was 71 ± 1 mrem/yr compared to the 1995 average measurement of 72 ± 8 mrem/yr. The 1996 annual average perimeter dose rate was 88 ± 10 mrem/yr; in 1995, the average measured was 86 ± 8 mrem/yr at the same locations. All onsite dosimeters averaged 86 ± 5 mrem/yr in 1996; in 1995, the onsite average was 86 ± 4 mrem/yr. Thermoluminescent dosimeters along the Columbia River shoreline had an annual average of 89 ± 7 mrem/yr in 1996; in 1995, the average was 103 ± 12 mrem/yr. On average, the dose rate along the 100-N Area shoreline (129 ± 30 mrem/yr) was approximately 50% higher than the typical shoreline dose rate (82 ± 3 mrem/yr).
Monitoring of radiological and chemical constituents in groundwater at the Hanford Site was performed to characterize physical and chemical trends in the flow system, establish groundwater quality baselines, assess groundwater remediation, and identify new or existing groundwater problems. Groundwater monitoring was also performed to verify compliance with applicable environmental laws and regulations and to fulfill commitments made in official DOE documents. Samples were collected from approximately 800 wells to determine the distributions of radiological and chemical constituents in Hanford Site groundwater. In addition, hydrogeologic characterization and modeling of the groundwater flow system were used to assess the monitoring network and to evaluate potential impacts of groundwater contamination.
During 1996, groundwater surveillance and monitoring activities were restructured into the Groundwater Monitoring Project. This project incorporates sitewide groundwater monitoring mandated by DOE Orders with near-field groundwater monitoring conducted to ensure that operations in and around specific waste disposal facilities comply with applicable regulations. Groundwater monitoring was required by the Resource Conservation and Recovery Act at 26 waste treatment, storage, and disposal units. Monitoring status and results for each of these units are summarized in this report.
To assess the quality of groundwater, concentrations measured in samples were compared with the EPA drinking water standards and the DOE derived concentration guides. Groundwater is used for drinking at three locations on the Hanford Site. In addition, water supply wells for the city of Richland are located near the southern boundary of the Hanford Site. Radiological constituents including cobalt-60, strontium-90, technetium-99, iodine-129, cesium-137, plutonium, tritium, uranium, total alpha, and total beta were detected at levels greater than the drinking water standard in one or more onsite wells. Concentrations of strontium-90, plutonium, tritium, and uranium were detected at levels greater than the derived concentration guides.
Extensive tritium plumes extend from the 200-East and 200-West Areas into the 600 Area. The plume from the 200-East Area extends east and southeast, discharging to the Columbia River. This plume has impacted tritium concentrations in the 300 Area at levels of more than one-half the EPA drinking water standard. The spread of this plume farther south than the 300 Area is restricted by the groundwater flow away from the Yakima River and the recharge ponds associated with the north Richland well field. Groundwater with tritium at levels above the drinking water standard also discharges to the Columbia River at the 100-N Area. A small but high concentration tritium plume near the 100-K East Reactor also may discharge to the river. Tritium at levels greater than the drinking water standard was also found in the 100-B, 100-D, and 100-F Areas.
The strontium-90 plume in the 100-N Area, which contains concentrations greater than the DOE derived concentration guide, discharges to the Columbia River. Localized areas in both the 100-K and 200-East Areas also contain strontium-90 at levels greater than the derived concentration guide. Strontium-90 is found at levels greater than the EPA drinking water standard in the 100-B, 100-D, 100-F, 100-H, 100-K, and 200-West Areas and the 600 Area in the former Gable Mountain Pond area.
Technetium-99 concentrations greater than the EPA drinking water standard were found in the northwestern part of the 200-East Area and adjacent 600 Area. Technetium-99 was also detected at levels greater than the drinking water standard in the 100-H and 200-West Areas and adjacent 600 Area. Groundwater in one well completed in the upper basalt-confined aquifer in the northern part of the 200-East Area had technetium-99 concentrations above the drinking water standard. Increases in technetium-99 concentrations at wells near the S-SX and T Tank Farms are being evaluated as possible indications of groundwater contamination from tank leaks.
Iodine-129 was detected at levels greater than the EPA drinking water standard in the 200-East Area and in an extensive part of the 600 Area to the east and southeast. The iodine-129 and tritium plumes share common sources. Iodine-129 at levels greater than the drinking water standard also extends into the 600 Area to the northwest of the 200-East Area. Iodine-129 was also found at concentrations above the drinking water standard in the southern part of the 200-West Area and extending into the 600 Area. There is a smaller iodine-129 plume in the northcentral part of the 200-West Area.
Cobalt-60 was detected above the EPA drinking water standard in the 600 Area north of the 200-East Area in one well completed in the unconfined aquifer and in one well completed in the confined aquifer.
Cesium-137 was detected in one well in the 200-East Area and one well in the 200-West Area. Concentrations at the 200-East Area well were greater than the EPA drinking water standard.
Uranium was detected at levels greater than the EPA drinking water standard in wells in the 100-F, 100-H, 200-East, 200-West, 300, and 600 Areas. Groundwater with uranium concentrations greater than the drinking water standard appears to be discharging to the Columbia River from the 300 Area. Wells near U Plant in the 200-West Area had concentrations greater than the DOE derived concentration guide.
Plutonium was detected in groundwater samples from two wells in the 200-East Area. The level in one of these wells exceeded the DOE derived concentration guide.
Certain nonradioactive chemicals regulated by the EPA and Washington State were also present in Hanford Site groundwater. These were carbon tetrachloride, chloroform, chromium, cyanide, fluoride, nitrate, tetrachloroethylene, and trichloroethylene.
An extensive plume of carbon tetrachloride at levels greater than the EPA drinking water standard was found in groundwater at the 200-West Area and extends into the 600 Area. A less-extensive plume of chloroform, which may be a degradation product of the carbon tetrachloride, is associated with the carbon tetrachloride plume. Maximum chloroform levels are also greater than the drinking water standard.
Chromium was found at levels greater than the EPA drinking water standard in the 100-B, 100-D, 100-F, 100-H, 100-K, 100-N, 200-East, 200-West, and 600 Areas.
Cyanide was detected above the EPA drinking water standard in one 600 Area well north of the 200-East Area.
Fluoride was measured at levels greater than the EPA primary drinking water standard in the 200-West Area.
Nitrate concentrations exceeded the EPA drinking water standard at locations in all 100 Areas, with the exception of the 100-B Area. Those plumes discharge to the Columbia River. Nitrate from the 200-East Area extends east and southeast in the same area as the tritium plume. Nitrate from sources in the northwestern part of the 200-East Area is present in the adjacent 600 Area at levels greater than the drinking water standard. Nitrate is also present at levels greater than the drinking water standard in the 200-West Area and adjoining 600 Area. Some of the nitrate in the 600, 1100, and north Richland areas is believed to result from offsite sources.
Tetrachloroethylene was detected at levels below the EPA drinking water standard.
Trichloroethylene was found at levels greater than the EPA drinking water standard in the 100-F Area and the nearby 600 Area. Trichloroethylene was also detected at levels greater than the drinking water standard in the 100-K, 200-West, and 300 Areas and near the Horn Rapids Landfill in the southern part of the Hanford site.
In 1996, potential doses to the public resulting from exposure to Hanford Site liquid and gaseous effluents were evaluated to determine compliance with pertinent regulations and limits. These doses were calculated from reported effluent releases and environmental surveillance data using Version 1.485 of the GENII computer code and Hanford-specific parameters. The potential dose to the maximally exposed individual in 1996 from site operations was 0.007 mrem (0.00007 mSv) compared to 0.02 mrem (0.0002 mSv) calculated for 1995. The radiological dose to the population within 80 km (50 mi) of the site, estimated to be 380,000 persons, from 1996 site operations was 0.2 person-rem (0.002 person-Sv), which is slightly less than the 1995 calculated population dose of 0.3 person-rem (0.003 person-Sv). The average per-capita dose from 1996 site operations was 0.0005 mrem (0.000005 mSv). The national average dose from background sources is 300 mrem/yr (3 mSv/yr), and the current DOE radiological dose limit for a member of the public is 100 mrem/yr (1 mSv/yr). Therefore, the average individual potentially received 0.0005% of the DOE standard and 0.0007% of the national average background. Special exposure scenarios not included in the dose estimates above include the ingestion of game animals residing on the site and exposure to radiation at a publicly accessible location with the maximum exposure rate. Doses from these scenarios would have also been small compared to the DOE dose limit. Radiological dose through the air pathway was 0.005% of the EPA limit of 10 mrem/yr.
Environmental programs were conducted to restore environmental quality, manage waste, develop appropriate technology for cleanup activities, and study the environment. These programs are discussed below.
Meteorological measurements are taken to support site emergency preparedness, site operations, and atmospheric dispersion calculations. Weather forecasting and maintenance and distribution of climatological data are provided.
The Hanford Meteorology Station is located on the 200 Areas plateau where the prevailing wind direction is from the northwest during all months. The secondary wind direction is from the southwest. The average wind speed for 1996 was 12.9 km/h (8.0 mi/h), which was 0.5 km/h (0.3 mi/h) above normal; the peak gust for the year was 39 km/h (55 mi/h).
Precipitation for 1996 totaled 31.0 cm (12.2 in.), 195% of normal, with 146.0 cm (57.5 in.) of snow recorded. 1996 was the snowiest year on record.
Temperatures for 1996 ranged from -27.8°C (-18°F) in January and February to 42.8°C (109°F) in August.
Wildlife inhabiting the site is monitored to determine the status and condition of the populations and to assess effects of site operations. Particular attention is paid to species that are rare, threatened, or endangered nationally or statewide and those species that are of commercial, recreational, or aesthetic importance statewide or locally. Fluctuations in wildlife and plant species on the Hanford Site appear to be a result of natural ecological factors and management of the Columbia River system.
Cultural resources on the Hanford Site are closely monitored, and projects are relocated to avoid sites in cases where there is a possibility of altering any properties that may be eligible for listing on the National Register of Historic Places. The management of archaeological, historical, and traditional cultural resources is provided in a manner consistent with federal laws.
The community-operated environmental surveillance program was initiated in 1990 to increase the public's involvement in and awareness of Hanford's surveillance program. Nine citizen-operated radiological surveillance stations were operating in 1996.
Comprehensive quality assurance programs, which include various quality control practices and methods to verify data, are maintained to ensure data quality. The quality assurance programs are implemented through quality assurance plans designed to meet requirements of the American National Standards Institute/American Society of Mechanical Engineers and DOE Orders. Quality assurance plans are maintained for all activities, and auditors verify conformance. Quality control methods include, but are not limited to, replicate sampling and analysis, analysis of field blanks and blind reference standards, participation in interlaboratory cross-check studies, and splitting samples with other laboratories. Sample collection and laboratory analyses are conducted using documented and approved procedures. When sample results are received, they are screened for anomalous values by comparing them to recent results and historical data. Analytical laboratory performance on the submitted double-blind samples, the EPA Laboratory Intercomparison Studies Program, and the national DOE Quality Assessment Program indicated that laboratory performance was adequate overall, was excellent in some areas, and needed improvement in others.
