Executive Summary
This remedial investigation report, which was prepared by IT Corporation for Brookhaven National Laboratory (BNL), characterizes the physical conditions, the nature and extent of contamination, and the potential risks to human health and the environment for Operable Unit II/VII. This report details the findings of IT Corporationís field investigation conducted from November 1995 through February 1996 and assesses those risks posed by exposure to contaminated soils. The remedial investigation consists of two primary phases: data collection and data evaluation. The data collection phase was completed during the field investigation. This investigation included completion of sampling and analysis of soil for the following four areas of concern (AOC):
The data evaluation phase includes an assessment of the distribution and levels of contamination, potential human health risks, ecological conditions, and conclusions and recommendations.
The primary objective of the characterization of contamination in these four AOCs is to identify areas that may pose an unacceptable risk to human health and the environment. The conclusions drawn from this investigation form the basis for evaluation and selection of remedial action alternatives as part of the Operable Unit I feasibility study.
ES.1.0 Summary of Site Description
BNL is located in Upton, Suffolk County, New York, near the geographic center of Long Island, approximately 60 miles east of New York City. Although the principal population centers are shoreline communities, there has been some residential development near BNL. The site was formerly occupied by the U.S. Army as Camp Upton during World Wars I and II. Between the wars, it was operated by the Civilian Conservation Corp. The site was transferred to the Atomic Energy Commission in 1947, to the Energy Research and Development Administration in 1975, and to the U.S. Department of Energy (DOE) in 1977.
The BNL property is roughly square in shape, with approximately 3 miles on each side, encompassing an area of 5,265 acres (approximately 8.21 square miles). The production region includes the principal BNL facilities, which are located near the center of the site on relatively high ground. These facilities comprise an area of approximately 900 acres, of which 500 acres were originally developed for Army use. Outlying facilities occupy approximately 550 acres and include an apartment area, biology field, former hazardous waste management facility, sewage treatment plant, and several closed landfill areas.
The areas of concern and Sub-AOCs evaluated in the Operable Unit II/VII RI include:
ES.1.1 AOC 10: Waste Concentration Facility
At the Waste Concentration Facility, Building 811, liquid radioactive waste was temporarily stored and eventually distilled to remove particulates, and suspended and dissolved solids. After distilling, most radionuclides were concentrated in the residue. However, tritium was distributed between the slurry and the residue. Beginning in 1985, the evaporator bottoms were transferred to the former Hazardous Waste Management Facility for temporary storage in a double-walled 5,000-gallon underground storage tank. This underground storage tank was removed in 1995. At the Former Hazardous Waste Management Facility, the material was solidified and shipped in concrete vaults or steel bins to an authorized off-site disposal facility (e.g., Hanford, Washington) for disposal.
Since 1987, in an effort to control tritium release to the Peconic River, the distillate was discharged into poly-lined hold-up ponds at the BNL Sewage Treatment Plant, where it evaporated and/or mixed with precipitation and diverted effluent. The water was ultimately discharged to the river under BNL administrative release criteria (i.e., one-half of the Federal Safe Drinking Water Act drinking water standard for tritium). As of 1995, Peconic River discharges were stopped and all distillates are currently treated in a new evaporator.
The Waste Concentration Facility consisted of three 100,000-gallon aboveground storage tanks (out of service since 1987, and removed as part of Removal Action I, September 1994); six 8,000-gallon underground storage tanks; two new 25,000-gallon aboveground storage tanks (added in 1987 to replace the three 100,000-gallon tanks); a 4,000-gallon aboveground receiving tank; two 5,000-gallon aboveground blending tanks (removed as part of Removal Action I, October 1994); the evaporator/concentration apparatus (no longer in service); underground pipelines for transferring A, B, and D waste; and a small building that houses the evaporator/concentration apparatus.
The six 8,000-gallon underground storage tanks were used to store radioactive wastewater. These 8,000-gallon tank/vaults are being removed. Sludges are to be removed in 1999 and removal of the tanks is planned for 2000. The two Sub-AOCs are as follows:
Aboveground holding tanks D-1, D-2, and D-3, each with a capacity of 100,000 gallons, were used to store the received radioactive sludge and wastewater waste at the Waste Concentration Facility from 1949 to 1987. The waste was received from the Brookhaven Graphite Research Reactor, Hot Laboratory Complex-Building 801, High Flux Beam Reactor and other BNL facilities via underground pipes. The wastes contained mixed fission products and transuranic radioisotopes, as well as lead and chromium.
The waste storage tanks D-1 and D-3 have had three documented incidents of leaks: one in the spring of 1982, a second in February 1985, and a third in January 1987. There are no documented incidences of leakage from tank D-2.
Currently, all three D-waste tanks have been dismantled and removed as a removal action under the DOE/U.S. Environmental Protection Agency (USEPA)/New York State (NYS) Department of Environmental Conservation Interagency Agreement. The contaminated concrete pads were given an additional temporary cover in 1998 to prevent the collection of rainwater that could become contaminated through leaching. As part of the D-Tanks project, an engineering evaluation/cost analysis report, extensive sampling, and analysis of surface and subsurface soils were conducted around and under the foundation pad of the tanks. These data show levels of the radionuclides cesium-137 and strontium-90 higher than screening levels identified in the remedial investigation.
Underground pipelines were installed and used from 1949 to 1985 for transferring A, B, and D radioactive liquid waste to the Waste Concentration Facility from the Brookhaven Graphite Research Reactor, the Hot Laboratory Building 801, and the High Flux Beam Reactor. Approximately 25,000 gallons per year of radioactive liquids were transferred through these pipelines. In 1995, more than 700 feet of one D-waste pipeline were removed and replaced. The removed D-waste pipe to the Waste Concentration Facility was highly contaminated with cobalt-60, fission products, and transuranics. Removal of the out-of-service A and B waste lines is planned for 1999 and 2000.
ES.1.2 AOC 16: Aerial Radioactive Monitoring System Results
Since 1958, the Aerial Measuring System of the DOE-Remote Sensing Laboratory has documented nationwide the baseline radiological conditions surrounding energy-related sites of interest. Following a DOE request, an aerial radioactive survey was performed over an approximately 8-square-mile area surrounding BNL in 1980 and over a 25-square-mile area in 1983.
The results of the 1980 aerial radiation survey of the BNL site indicated that, in addition to the known source of external radiation on site, there were several unanticipated locations where external exposure rates exceeded background levels. These areas were investigated and the sources were determined to be cesium-137-contaminated soil located adjacent to or near the following buildings: Medical (Building 490), Chemistry (Building 555), Physics (Building 510), Contracts and Procurement (Building 355), Linear Accelerator (Building 930), Brookhaven Center (Building 30), Applied Math (Building 515), and the Criticality Facility (Building 526). The Brookhaven Linear Isotope Production facility (Building 931B) was also reviewed based on a 1998 finding of tritium in groundwater downgradient from the facility.
A total of 23 areas of manmade radioactivity were identified during the 1983 aerial survey. The dominant isotopes found over these areas were cesium-137, sodium-22, manganese-54, and cobalt-60. Ten new areas were detected that were not seen in the 1980 survey. Three 1980 areas were not detected in 1983, having diminished in strength. Overall, the results of the two surveys compared well.
ES.1.3 AOC 17: Area Adjacent to Former Low-Mass Criticality Facility
Limited written records regarding operational history are available at BNL on this area of concern. The only written records available are in regard to the use of this area as a temporary drum storage site. Otherwise, current knowledge is solely based on various maps and photographs and various conversations with both current and retired BNL employees. An aerial photograph taken of the aluminum testing silo and associated structures in 1962 indicates the area of concernís usage by the Low-Mass Criticality Facility (Building 526). The date of construction was likely between 1955 and 1960. The silo was used to study chain reactions of various materials used in graphite reactors.
About 1967, the silo and the Low-Mass Criticality Facility (Building 526) were decontaminated and decommissioned. The silo was then utilized for the storage of drums of ethylene dibromide, various nonhazardous equipment, and tools from the Department of Applied Sciences, which took over Building 526.
In 1983, twenty 30-gallon steel drums of ethylene dibromide were removed from Building 701, where they posed a threat to the general public visiting the museum, and stored in the silo. This material was intended to be used in an experiment by the Chemistry Department; however, the experiment was canceled. The perimeter of the storage area in the silo was diked with "speed dry," an absorbent material to contain any possible spills.
The silo was disassembled in August 1994, leaving the concrete slab foundation.
No spills occurred, according to historical log books and interviews with BNL personnel. The most likely possible source of contamination would be from a chemical spill of ethylene dibromide, but no evidence exists at this time to suggest that this had occurred. Residual radiation from past "silo" experiments is very unlikely to exist. However, the area was identified during the ground-based radiological survey as a location having elevated concentrations of cesium-137 (1.7 picocuries per gram [pCi/g]) in the top 10 centimeters of surface soil.
ES.1.4 AOC 18: Alternating Gradient Synchrotron Storage Yards
The Alternating Gradient Synchrotron Department currently maintains three steel storage yards. Two yards are intended for the storage of activated steel (Storage Yards Ia and Ib) and the other yard is used to store nonactivated steel (Storage Yard II). During the 1988 DOE survey, it was noted that clean steel and radioactive steel were not separated, but stored in either yard. It was also noted that neither yard was fenced.
The Alternating Gradient Synchrotron steel yards are not "scrap yards." The steel is stored in these areas for future reuse in the Alternating Gradient Synchrotron experimental areas, usually as shielding. Some of the steel has been stored in the yards for more than 20 years and has rusted. The rust flakes have fallen to the ground and, as a result, radioactive particles of steel may have contaminated the soil. The activated steel yard is now surrounded by posted snow fence except at the entrances.
The steel stored in the contaminated yard has surface exposure levels ranging from 10 to 100 milliroentgen per hour (mR/hr). In addition to the steel and activated steel, asbestos has been stored in an area at the Alternating Gradient Synchrotron Storage Yards.
ES.2.0 Summary of Findings and Risk Assessment
This section will combine the findings from Chapter 4.0, Nature and Extent of Contamination, and the results from Chapter 6.0, Risk Assessment. The following is a brief discussion on the basis of the risk assessment.
The purpose of the initial assessment of risk at BNL Operable Unit II/VII is to focus the risk assessment process on the detected chemicals of potential concern that pose the greatest potential threat to human health. Techniques employed to identify the chemicals of potential concern at BNL Operable Unit II/VII included data evaluation, screening procedures that included identification of NYS Technical and Administrative Guidance Memorandum values, development of risk-based preliminary remediation goals for chemical and radiological contaminants of potential concern, and comparison of measured soil concentrations of chemicals of potential concern with preliminary remediation goals concentrations.
The data used in this risk assessment were collected during the Operable Unit II/VII sampling phase conducted from November 1995 through February 1996, the walkover radiological survey performed during December 1995, and data collected from the D-tank removal action (Dames & Moore, 1993).
The media samples were collected, analyzed, and validated. After completion of validation, the sample results from analysis of radioactive species were further subjected to a data usability examination. An explanation of this approach is given in Section 4.1.2 of this report.
NYS guidance concentrations and site-specific risk-based preliminary remediation goals were developed for comparison to measured soil concentrations of constituents at Operable Unit II/VII sites. The preliminary remediation goals were developed using USEPA's standard conservative default assumptions to provide a sufficient level of confidence in the determination of whether unacceptable health risks may be associated with these constituents. The comparison of the maximum chemical concentration with preliminary remediation goals was performed as a two-tier process. In the first step, the maximum concentration detected was compared with the Tier-1 preliminary remediation goal (NYS Technical and Administrative Guidance Memorandum), which is generally based on an acceptable risk of one in a million (1x10-6). Chemicals that failed the first step were compared to Tier-2 site-specific preliminary remediation goals based on one in ten thousand (1x10-4) acceptable risk.
Site-specific chemical preliminary remediation goals derived from USEPA methodology were based only on an assumed residential land-use scenario at Operable Unit II/VII areas. The target risk level used in the derivation of preliminary remediation goals for carcinogenic effects is one in ten thousand (1 x 10-4), the upper end of the target risk range that is generally considered to be acceptable, and the target hazard index used in the derivation of preliminary remediation goals for noncarcinogenic effects is 1.0.
Radiological preliminary remediation goals were developed using the RESRAD computer program. Preliminary radiological remediation goals were developed for both site-specific residential and industrial scenarios. The RESRAD program was also used for other BNL operable units. The environmental pathways used to develop radiological preliminary remediation goals for the other operable units were used to develop the radiological preliminary remediation goals for Operable Unit II/VII. The preliminary remediation goals for radionuclides, except radium-226, radium-228, thorium-230, and thorium-232, were calculated to meet the 15 millirem per year (mrem/yr) dose limit above background for all radionuclides as specified in the USEPA guidance Establishment of Cleanup Levels for CERCLA Sites with Radioactive Contamination (Office of Solid Waste and Emergency Response No. 9200.4-18).
Two constituents, cesium-137 and thorium-230, were identified as chemicals of potential concern for Operable Unit II/VII. Other radionuclides, volatile organic compounds, semivolatile organic compounds, metals, pesticides, polychlorinated byphenyls, and ethylene dibromide (AOC 17 only) were analyzed for, but were eliminated as chemicals of potential concern due to their low detected concentrations or because no detections were found.
Cesium-137 was identified in surface soil at AOC 10A, D-Waste Tank soils, and several sites in AOC 16 sites (Aerial Radiative Monitoring System Results). Thorium-230 was identified in surface soil at AOC 16E.1 (Field South of Building 490). Cesium-137 is the major radiological contaminants of concern that exceeds specified risk or radiation dose limits.
The findings and risk assessment results for each area of concern or sub-area are given in the following subsections. Table ES-1 summarizes chemicals of potential concern that were greater than the preliminary remediation goals.
An assessment of deer contamination was conducted. Low levels of cesium-137 have been found in deer tissue on site. Concentrations are estimated to be below a level that would be a human health concern, if eaten. Although contamination is present in surface soils that could offer a pathway for exposure to other terrestrial wildlife through dermal contact, incidental soil ingestion, and plant consumption, the frequency of exposure is considered to be low, being limited by the amount of available habitat.
ES.2.1 AOC 10: Waste Concentration Facility
ES.2.1.1 Sub-AOC 10A: D-Waste Tanks, Foundations, Soils, and Yard Area
The only radiological contaminant was cesium-137, which was found in one sample (43.3 pCi/g) greater than the residential preliminary remediation goal (23 pCi/g), but less than industrial preliminary remediation goal (70.2 pCi/g). This sample was in the top 2 feet of soil. However, when considering the data presented in the D-Tanks Removal Action I (Dames & Moore, 1993), the cesium-137 (1,486 pCi/g) and strontium-90 (454 pCi/g) concentrations around the D-Tanks sump are well above residential and industrial preliminary remediation goals. No chemicals were detected in exceedance of the preliminary remediation goals in either the surface or subsurface soil. However, antimony, thallium (surface soil), and nickel (subsurface soil) concentrations exceed the generic soil screening levels (USEPA, 1996) for impacts to groundwater. Although unlikely, these metals may potentially impact groundwater quality and will be further evaluated in Operable Unit III.
Cesium-137 was detected at concentrations greater than the residential but less than the industrial preliminary remediation goal. When considering the data from the D-Tanks soil, the concentration is not acceptable for residential or industrial scenarios at the D-Tanks sump.
For the subsurface soils, the total contribution from each radionuclide is acceptable for the residential scenario.
ES.2.1.2 Sub-AOC 10B: Underground Pipeline
No radionuclide or chemical contaminants were detected in the surface or subsurface soil samples greater than the preliminary remediation goals. The total contribution from each radionuclide is acceptable for both the residential and industrial scenarios.
ES.2.2 AOC 16: Aerial Radioactive Monitoring System Results
Several Sub-AOCs associated with accelerator operations were eliminated
from further evaluation in this remedial investigation report based additional
information on facility operations. Areas associated with operating accelerator
facilities will continue to be monitored and controlled by BNL and corrective
action taken as needed.
ES.2.2.1 Sub-AOC 16E.1: Field South of Building 490
Cesium-137 concentrations exceeded the residential (23 pCi/g) preliminary remediation goal in seven samples (with a range of 24.0 to 66.0 pCi/g) in this Sub-AOC. One cesium-137 sample (81.4 pCi/g) exceeded the industrial preliminary remediation goal (70 pCi/g). Thorium-230 also exceeded its industrial preliminary remediation goal (5 pCi/g) in one sample (29.2 pCi/g). When correlating the walkover survey with analyzed concentrations of cesium-137, a "hot spot" exceeding 128 pCi/g was located. No radiological contamination greater than preliminary remediation goals was found below 2 feet. No chemical contamination greater than preliminary remediation goals was found in either the surface or subsurface soil. However, the concentration of thallium exceeds USEPAís soil screening levels. Although unlikely, this metal may potentially impact groundwater quality and will be further evaluated in Operable Unit III.
The dose contribution from all radionuclides is not acceptable for the residential and industrial scenario for the surface soils. For the subsurface soils, the contribution from all radionuclides is acceptable.
ES.2.2.2 Sub-AOC 16E.2: Field South of Building 490 Near Building 494
Cesium-137 concentrations exceeded the residential (23 pCi/g) preliminary remediation goal in two samples (43.1 and 67.3 pCi/g) in this Sub-AOC. One cesium-137 sample (348 pCi/g) exceeded the industrial preliminary remediation goal (70 pCi/g). No radiological contamination greater than the preliminary remediation goal was found below 2 feet. No chemical contamination greater than preliminary remediation goals was found in either the surface or subsurface soil.
The dose contribution from all radionuclides is not acceptable for the residential and industrial scenarios for surface soils. For the subsurface soils, the dose contribution from all radionuclides is acceptable for both the residential and industrial scenarios.
ES.2.2.3 Sub-AOC 16E.3: Field South of Pavilion No. 4 at Building 490
The cesium-137 concentration exceeded the residential (23 pCi/g), but not the industrial (70 pCi/g), preliminary remediation goal in one sample (32.9 pCi/g) in this Sub-AOC. When correlating the walkover survey data with analyzed concentrations of cesium-137, a "hot spot" in the range of 51 to 90 pCi/g was located. No radiological contamination greater than preliminary remediation goals was found below 2 feet. No chemical contamination greater than preliminary remediation goals was found in either the surface or subsurface soil. However, the concentration of thallium exceeds USEPAís soil screening levels; although unlikely, this metal may potentially impact groundwater quality and will be further evaluated in Operable Unit III.
The dose contribution from all radionuclides is not acceptable for the
residential scenario for surface soil but is acceptable for the industrial
scenario. However, when using the ground radiological survey data that were
correlated with the cesium-137 data, the dose contribution from all radionuclides
is not acceptable for the industrial scenario. The dose from all radionuclides
is acceptable for the residential scenarios for the subsurface soil.
ES.2.2.4 Sub-AOC 16F: Field Northwest of Building 555
Cesium-137 concentrations exceeded the residential (23 pCi/g) preliminary remediation goal in one sample (59.6 pCi/g) in this Sub-AOC. Two cesium-137 concentrations (110 and 198 pCi/g) exceeded the industrial preliminary remediation goal (70 pCi/g). No radiological contamination greater than preliminary remediation goals was found below 2 feet. No chemical contamination greater than preliminary remediation goals was found in either the surface or subsurface soil.
The dose contribution from all radionuclides is not acceptable for either
the residential and industrial scenarios for surface soils. For the subsurface
soils, the dose from all radionuclides is acceptable for both the residential
and industrial scenarios.
ES.2.2.5 Sub-AOC 16G: Field East of Building 30
Cesium-137 concentrations exceeded the residential (23 pCi/g) preliminary
remediation goal in two samples (26.7 and 56.5 pCi/g) in this Sub-AOC. No
concentrations exceeded the industrial preliminary remediation goal. No
radiological contamination greater than preliminary remediation goals was
found below 2 feet. No chemical contamination greater than preliminary remediation
goals was found in either the surface or subsurface soil.
The dose contribution from all radionuclides is not acceptable for the residential scenario for surface soil, but is acceptable for the industrial scenario. For both the residential and industrial scenarios, the dose contribution from all radionuclides is acceptable for the subsurface soil.
ES.2.2.6 Sub-AOC 16K: Building 931B, Brookhaven Linear Isotope Production Facility
Tritium was found to exceed the drinking water standard in the groundwater immediately downgradient from the Brookhaven Linear Isotope Production Facility. Data currently available on soil concentrations of tritium and sodium-22 associated with soil activation from Brookhaven Linear Isotope Production operations indicate sodium-22 concentrations up to 42,600 pCi/g and tritium concentrations up to 4,020 pCi/g at 28 to 30 feet below surface and 78.5 feet from the targets. Further investigations will be provided in an engineering evaluation/cost analysis report.
ES.2.2.7 Sub-AOCs 16S.1, 16S.2, 16S.3, 16S.4, 16S.6b, 16S.6c, 16S.6e, and 16S.6f: Contaminated Landscaping Soils
No radionuclide or chemical contaminants were detected in the surface or subsurface soil samples exceeding the preliminary remediation goals in these Sub-AOCs. However, for Sub-AOCs 16S.1, 16S.2, 16S.3, 16S.4, and 16S.6e, the concentration of thallium exceeds USEPAís soil screening levels; although unlikely, this metal may potentially impact groundwater quality and will be further evaluated in Operable Unit III.
The dose contribution from all radionuclides is acceptable for all scenarios.
ES.2.2.8 Sub-AOC 16S.5: Contaminated Landscaping Soils East of Building 355
No radionuclide or chemical contaminants were detected in the surface or subsurface soil samples exceeding preliminary remediation goals in this Sub-AOC. However, correlation of the walkover radiation surveys with analyzed soil concentrations of cesium-137 indicated two small areas that may exceed residential screening levels. These areas, one showing concentrations of approximately 33 pCi/g and the other showing 53 pCi/g, are very small, approximately 0.3 by 2.6 meters and 1.2 by 1.6 meters. The estimated contamination is above the residential preliminary remediation goal (23 pCi/g), but below the industrial preliminary remediation goal (70 pCi/g). However, the concentration of thallium exceeds USEPAís soil screening levels; although unlikely, this metal may potentially impact groundwater quality and will be further evaluated in Operable Unit III.
The dose contribution from all radionuclides is not acceptable for the residential scenario, but is acceptable for the industrial scenario.
ES.2.2.9 Sub-AOC 16S.6a: Contaminated Landscaping Soils South of Building 930 (Linear Accelerator)
No radionuclide or chemical contaminants were detected in the surface or subsurface soil samples exceeding preliminary remediation goals in this Sub-AOC. However, correlation of the walkover radiation surveys with analyzed soil concentrations of cesium-137 indicated that one very small area (0.5 meters across) may contain surface soil in the 51 to 90 pCi/g range. These concentrations are greater than the residential preliminary remediation goal, as well as the industrial preliminary remediation goal (when using the upper limit of the range). However, the concentration of thallium exceeds USEPAís soil screening levels; although unlikely, this metal may potentially impact groundwater quality and will be further evaluated in Operable Unit III.
The dose contribution from all radionuclides is not acceptable for either the residential and industrial scenario for this small isolated "hot spot."
ES.2.2.10 Sub-AOC 16S.6d: Contaminated Landscaping Soils Adjacent to Building 930 (Linear Accelerator)
The cesium-137 concentration (31.3 pCi/g) exceeded the residential (23 pCi/g) preliminary remediation goal in one sample in this Sub-AOC. No samples exceeded the industrial preliminary remediation goal. When correlating the walkover radiation surveys with the analyzed soil concentrations of cesium-137, three "hot spots" were identified. The most easterly of these contained the highest single point, an estimated 73 pCi/g, and was estimated to be less than 0.1 meter in width and 1 meter long. The central "hot spot" was estimated at approximately 27 pCi/g, with an area approximately _ meter across. The most westerly spot had a maximum of 24 pCi/g in a line approximately 1 meter long.
All of these spots exceed residential preliminary remediation goals and the highest "hot spot" exceeds the industrial preliminary remediation goal. No radiological contamination exceeding preliminary remediation goals was found below 2 feet. No chemical contamination exceeding preliminary remediation goals was found in either the surface or subsurface soil. However, the concentration of thallium exceeds USEPAís soil screening levels; although unlikely, this metal may potentially impact groundwater quality and will be further evaluated in Operable Unit III.
However, the dose contribution from all radionuclides is not acceptable for the residential scenario. The dose contribution from all radionuclides is acceptable for the industrial scenario in the surface soil when considering only the analytical data. However, when looking at the correlated survey data from the walkover, the dose contribution from all radionuclides is not acceptable for either the residential and industrial scenario for the highest "hot spot," and is not acceptable for the residential scenario for the other two areas.
The dose from all radionuclides is acceptable for both the residential and industrial scenarios for the subsurface soil.
ES.2.3 AOC 17: Area Adjacent to Former Low-Mass Criticality Facility
No radionuclide or chemical contaminants were detected in the surface or subsurface soil samples greater than the preliminary remediation goals. However, the concentration of thallium exceeds USEPAís soil screening levels; although unlikely, this metal may potentially impact groundwater quality and will be further evaluated in Operable Unit III.
The dose contribution from all radionuclides is acceptable for all scenarios for this AOC.
ES.2.4 AOC 18: Alternating Gradient Synchrotron Storage Yards
ES.2.4.1 AOC 18Ia: Alternating Gradient Synchrotron Storage Yard Ia
(Also Called AOC 18A)
No radionuclide or chemical contaminants were detected in the surface or subsurface soil samples greater than the preliminary remediation goals. The dose contribution from all radionuclides is acceptable for all scenarios for this subarea of concern.
ES.2.4.2 AOC 18Ib: Alternating Gradient Synchrotron Storage Yard Ib (Also Called AOC 18B)
No radionuclide or chemical contaminants were detected in the surface or subsurface soil samples greater than the preliminary remediation goals. However, the concentration of thallium exceeds USEPAís soil screening levels; although unlikely, this metal may potentially impact groundwater quality and will be further evaluated in Operable Unit III.
ES.2.4.3 AOC 18II: Alternating Gradient Synchrotron Storage Yard II
No radionuclide or chemical contaminants were detected in the surface soil samples exceeding the preliminary remediation goals. The dose contribution from all radionuclides is acceptable for all scenarios for this subarea of concern.
ES.3.0 Summary of Fate and Transport
Surface soils from 0 to 2 feet below the ground surface contain the radionuclides with concentrations greater than the residential preliminary remediation goal. The radionuclides of concern were cesium-137 and, in one case, thorium-230. No chemicals were identified in exceedance of the Tier 2 screening level.
Cesium-137 is a gamma and beta emitter with a relatively long half-life of 30.2 years. Therefore, cesium-137 is expected to persist for some time. However, it is relatively immobile in the environment and is expected to sorb strongly to soils and sediment, especially those with high clay or organic content. Cesium-137 is present at very low concentrations in most United States surface soils and sediment from atmospheric release during nuclear weapon testing in Nevada in the 1950s and 1960s.
Thorium-230 is an alpha emitter and has a relatively low isotopic activity. However, it is extremely persistent, with a half-life of approximately 8,000 years, and is, therefore, of concern in the environment. Thorium-230 is also relatively immobile and is expected to be found within the original source soils and not migrate to subsurface soils, groundwater, or surface water. Thorium-230 is part of the uranium-238 decay chain and is a daughter product of uranium-234. It is common and exists naturally in soils throughout the United States.
Potential migration/exposure mechanisms for constituents in contaminated media at the Operable Unit II/VII site include surface water runoff of constituents entrained in storm water, surface water and sediment transport; leaching from soil to groundwater; groundwater transport; release of contaminated materials via wind-blown dust emissions; volatilization; air transport; and wet and dry deposition. Based on the chemical characteristics of the constituents detected at the Operable Unit II/VII site, volatilization is not considered a significant pathway for constituent migration. The high concentration of some constituents in surface soils could lead to migration via stormwater runoff and surface drainage.
Groundwater transport is a potential migration pathway that exists at Operable Unit II/VII. Contaminants at this site, however, are relatively insoluble so that groundwater transport should be insignificant. Groundwater transport through Operable Unit II/VII is to the south and southeast. Fate and transport of contaminants within the groundwater at BNL is explored in detail as part of Operable Unit III.
ES.4.0 Summary of Ecological Risk Assessment
The various areas of investigation with Operable Unit II/VII are contained within the developed areas of the BNL site. Because of this, no ecological risk assessment was intended for Operable Unit II/VII. All areas of concern within these operable units are within habitat described as disturbed/developed and are characterized by buildings and structures, paved areas and roads, lawns, and nonnative plantings. Although the BNL site itself provides a variety of habitat types and is occupied by an array of wildlife, Operable Unit II/VII is limited to those species tolerant of humans and offers little habitat for residence by terrestrial species. Although contamination is present in surface soils that could offer a pathway for exposure to terrestrial wildlife through dermal contact, incidental soil ingestion, and food consumption, the frequency of exposure is considered to be low, being limited by the relative habitat area. However, low levels of cesium-137 have been found in some samples of deer tissue on site.
ES.5.0 Conclusions
The chemicals identified in surface and subsurface soils in Operable Unit II/VII are expected to have no detrimental impact on groundwater quality nor to have an adverse effect on human health through direct exposure pathways, groundwater will be further evaluated in Operable Unit III. No sites are recommended for further action due to chemical contamination.
The requirements for active remediation and/or required controls and duration of institutional controls will be addressed under the Operable Unit I feasibility study, and are based on potential future uses.
A summary of those contaminants that were encountered above their screening levels is presented in Table ES-1. Descriptive locations, sample identifiers, analytical results, and Appendix B cross references are included in this table.
As shown on Table ES-2, 14 of the 23 sites have radionuclide occurrences
less than both residential and industrial standards when considering both
the analytical data and data derived from the walkover surveys. These sites
are:
Sub-AOC 10B Underground Pipeline
Sub-AOC 16K Brookhaven Linear Isotope Production Facility, Building 931B
Sub-AOC 16S.1 Contaminated Landscaping Soils at the Gas Main North of Building 510
Sub-AOC 16S.2 Contaminated Landscaping Soils South and Southwest of Building 515
Sub-AOC 16S.3 Contaminated Landscaping Soils South of Building 515
Sub-AOC 16S.4 Contaminated Landscaping Soils South of Building 515
Sub-AOC 16S.6b Contaminated Landscaping Soils Adjacent to Building 930 (Linear Accelerator)
Sub-AOC 16S.6c Contaminated Landscaping Soils Adjacent to Building 930 (Linear Accelerator)
Sub-AOC 16S.6e Contaminated Landscaping Soils Adjacent to Building 930 (Linear Accelerator)
Sub-AOC 16S.6f Contaminated Landscaping Soils Adjacent to Building 930 (Linear Accelerator)
AOC 17 Area Adjacent to Former Low-Mass Criticality Facility
AOC 18Ia Alternating Gradient Synchrotron Storage Yard Ia
AOC 18Ib Alternating Gradient Synchrotron Storage Yard Ib
AOC 18II Alternating Gradient Synchrotron Storage Yard II.
Those areas with radionuclide dose contributions greater than residential
goals but less than industrial goals, when considering the analytical data,
and data derived from the walkover surveys:
Sub-AOC 16G Field East of Building 30
Sub-AOC 16S.5 Contaminated Landscaping Soils East of Building 355.
These areas can be released with industrial controls. Current and future access control is in effect at the BNL site. This should be sufficient for these areas.
Seven areas have concentration of radioactivity greater than preliminary
remediation goals for both residential and industrial scenarios for the
surface soils to a depth of 2 feet. This considers the analytical data,
data derived from the walkover survey, and data from the D-tank removal
project. These areas may require further action and are as follows:
Sub-AOC 10A D-Waste Tanks, Foundations, and Tank Pad Sump and Yard Area
Sub-AOC 16E.1 Field South of Building 490
Sub-AOC 16E.2 Field South of Building 490 Near Building 494
Sub-AOC 16E.3 Field South of Pavilion No. 4 at Building 490
Sub-AOC 16F Field Northwest of Building 555
Sub-AOC 16S.6a Contaminated Landscaping Soils South of Building 930 (Linear Accelerator)
Sub-AOC 16S.6d Contaminated Landscaping Soils to the North Corner of Building 930 (Linear Accelerator).
In addition, Sub-AOC 16K, Brookhaven Linear Isotope Production Facility,
Building 931B may require further action to prevent tritium in activated
soil from leaching into the groundwater. This facility is being evaluated
as a separate removal action.
ES.6.0 Recommendations
Radiological soil samples collected adjacent to areas identified for remediation will aid in reducing the volume of soil requiring remediation and to verify "hot spots" identified by the correlation of the walkover survey data with the analytical soil concentration of cesium-137. No contamination requiring remediation was found below 2 feet; additional sampling should be relatively inexpensive when compared to the reduction in remediation costs that could be associated with a reduced volume of soil requiring remediation.
In addition, surface soil samples (0 to 6 inches) should be collected since only 0 to 1 foot samples were collected for the remedial investigation. These samples should be collected prior to the design of any soil removal and implementation of institutional controls or monitoring plans.
Remedial action levels must be negotiated prior to soil sampling so that only hot spots requiring remediation will be targeted for further delineation. In order to evaluate any needed remedial actions, an analysis of remedial alternatives for these areas of concern will be made as part of the Operable Unit I feasibility study.
The Brookhaven Linear Isotope Production Facility is recommended to be evaluated as a removal action with recommendations provided in a separate engineering evaluation/cost analysis.
The six underground storage tanks and associated underground pipelines in the Waste Concentration Facility are no longer in service and no future use is planned. Removal of the tanks and pipelines is planned. This will be in keeping with Best Management Practices.
| Location | Sample Date | Boring Designation & Sample ID | Depth (ft) | Northing | Easting | Concentration (pCi/g) | Page No. in Appendix B for Analytical Result | ||
| AOC 10A | Waste Concentration Facility | 1/22/96 | AOC10MN03 | B.1 | |||||
| 10MN03 SS02 | 2 | 79074.41 | 394720.7 | Cs-137 | 43.3 | Page 1 | |||
| AOC 16E.1 | Field South of Building 490 | AOC16E1GP05 - GP06 | B.1 | ||||||
| 12/18/95 | 16E1GP05 SS02 | 2 | 78164.34 | 394140.3 | Cs-137 | 38.4 | Page 22 | ||
| 12/18/95 | 16E1GP06 SS02 | 2 | 78142.30 | 394158.4 | Th-230 | 29.2 | Page 35 | ||
| AOC16E1MN01 - MN07 | |||||||||
| 12/13/95 | 16E1MN01 SS01 | 1 | 78174.05 | 394106.8 | Cs-137 | 24.0 | Page 23 | ||
| 12/13/95 | 16E1MN02 SS01 | 1 | 78169.42 | 394142.6 | Cs-137 | 34.6 | Page 23 | ||
| 12/13/95 | 16E1MN03 SS01 | 1 | 78168.65 | 394094.0 | Cs-137 | 51.8 | Page 23 | ||
| 12/14/95 | 16E1MN04 SS01 | 1 | 78164.58 | 394110.0 | Cs-137 | 41.0 | Page 23 | ||
| 12/14/95 | 16E1MN05 SS01 | 1 | 78160.93 | 394124.1 | Cs-137 | 81.4 | Page 24 | ||
| 12/14/95 | 16E1MN06 SS01 | 1 | 78153.89 | 394143.1 | Cs-137 | 66.0 | Page 24 | ||
| 12/13/95 | 16E1MN07 SS01 | 1 | 78147.76 | 394159.4 | Cs-137 | 61.4 | Page 24 | ||
| AOC 16E.2 | Field South of Building 490 near Building 494 | AOC16E2GP01 | B.1 | ||||||
| 12/18/95 | 16E2GP01 SS02 | 2 | 78097.96 | 394089.4 | Cs-137 | 43.1 | Page 46 | ||
| AOC16E2MN04 - MN05 | |||||||||
| 12/14/95 | 16E2MN04 SS01 | 1 | 78094.19 | 394091.1 | Cs-137 | 348 | Page 47 | ||
| 12/14/95 | 16E2MN05 SS01 | 1 | 78094.56 | 394097.9 | Cs-137 | 67.3 | Page 47 | ||
| AOC 16E.3 | Field South of Pavilion No.4 at Building 490 | AOC16E3MN04 | B.1 | ||||||
| 12/14/95 | 16E3MN04 SS01 | 1 | 78189.26 | 394010.7 | Cs-137 | 32.9 | Page 59 | ||
| AOC 16.F | Field Northwest of Building 455 | AOC16FGP02 | B.1 | ||||||
| 1/29/96 | 16FGP02 SS02 | 2 | 78778.80 | 394251.0 | Cs-137 | 59.6 | Page 70 | ||
| AOC16FMN07 - MN08 | |||||||||
| 12/18/95 | 16FMN07 SS01 | 1 | 78783.98 | 394247.2 | Cs-137 | 110 | Page 73 | ||
| 12/18/95 | 16FMN08 SS01 | 1 | 78781.24 | 394256.0 | Cs-137 | 198 | Page 73 | ||
| AOC 16.G | Field East of Building 30 | AOC16GMN37 - MN38 | B.1 | ||||||
| 12/20/95 | 16GMN37 SS01 | 1 | 78050.49 | 393735.0 | Cs-137 | 26.7 | Page 104 | ||
| 12/20/95 | 16GMN38 SS01 | 1 | 78054.80 | 393741.9 | Cs-137 | 56.5 | Page 104 | ||
| AOC 16S.6d | Contaminated Landscaping Soils Adjacent to Building 930 | AOC16S6DMN01 | B.1 | ||||||
| 1/3/96 | 16S6DMN01 SS01 | 1 | 79495.32 | 394113.5 | Cs-137 | 31.3 | Page 211 | ||
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| 10A D-Waste Tanks, Foundations, Soils, and Yard Area | Institutional controls a Further action | ||
| 10B Underground Pipeline | Institutional controls Further action | ||
| 16E.1 Field South of Building 490 | Further action | ||
| 16E.2 Field South of Building 490 Near Building 494 | Further action | ||
| 16E.3 Field South of Pavilion No. 4 at Building 490 | Institutional controls Further action | ||
| 16F Field Northwest of Building 555 | Further action | ||
| 16G Field East of Building 30 | Institutional controls | ||
| 16K BLIP Facility - Building 931B | Additional sampling and assessment Industrial controls Further action | ||
| 16S.1 Contaminated Landscaping Soils at the Gas Main North of Building 510 | Institutional controls | ||
| 16S.2 Contaminated Landscaping Soils South and Southwest of Building 515 | Institutional controls | ||
| 16S.3 Contaminated Landscaping Soils South of Building 515 | Institutional controls | ||
| 16S.4 Contaminated Landscaping Soils South of Building 515 | Institutional controls | ||
| 16S.5 Contaminated Landscaping Soils East of Building 355 | Institutional controls | ||
| 16S.6a Contaminated Landscaping Soils South of Building 930 (LINAC) | Institutional controls Further action | ||
| 16S.6b Contaminated Landscaping Soils Adjacent to Building 930 (LINAC) | Institutional controls | ||
| 16S.6c Contaminated Landscaping Soils Adjacent to Building 930 (LINAC) | Institutional controls | ||
| 16S.6d Contaminated Landscaping Soils Adjacent to the North Corner of Building 930 (LINAC) | Institutional controls Further action | ||
| 16S.6e Contaminated Landscaping Soils Adjacent to Building 930 (LINAC) | Institutional controls | ||
| 16S.6f Contaminated Landscaping Soils Adjacent to Building 930 (LINAC) | Institutional controls | ||
| 17 Area adjacent to Former Low-Mass Criticality Facility | Institutional controls | ||
| 18Ia AGS Storage Yard Ia | Institutional controls | ||
| 18Ib AGS Storage Yard Ib | Institutional controls | ||
| 18II AGS Storage Yard II | Institutional controls |
a This considers data from the engineering evaluation/cost analysis (EE/CA) for the D-tank removal action (Dames & Moore, 2093). Only the soils around the D-tank drainage sump require further action.
b This considers concentrations derived by correlating the walkover survey data with analyzed concentrations of cesium-137.
c Only very small areas of the Sub-AOC are affected.
BLIP - Brookhaven Linear Isotope Production.
LINAC - Linear Accelerator.
AGS - Alternating Gradient Synchrotron.
