Appendix A- Operable Unit I Proposed Plan

Appendix A

Table A-1
Description of Operable Units at BNL

Operable Unit Description

I
Operable Unit I is a relatively undeveloped 950-acre area in the southeastern part of the site. It includes historical waste handling areas such as the Former and Current Landfills (AOCs 2 and 3), and the Former Hazardous Waste Management Facility (AOC 1). It also includes the Ash Pit (AOC 2F) and two recharge basins (AOCs 24E and 24F).

Operable Unit I contains six areas covered by accelerated removal actions: the Current and Former Landfills, Chemical/Animal Pits and Glass Holes, the Interim Landfill, the Slit Trench and Groundwater.

II/VII Operable Unit II/VII consists of several AOCs located in the developed central portion of the site. It includes contaminated soils and out-of-service underground storage tanks and pipelines proposed for removal at the Waste Concentration Facility (AOC 10), along with various isolated areas of contaminated surface soils (AOC 16, 17, 18). It also includes the BLIP facility (AOC 16K).

III Operable Unit III contains the south central and developed portions of the site. This Operable Unit contains most of the site's contaminated groundwater.

IV Operable Unit IV is located on the east-central edge of the developed portion of the site. It includes the 1977 Oil/Solvent Spill as well as the Reclamation Facility Building 650 and Sump Outfall Area (AOC 6), where radiologically contaminated soils have been found.

V Operable Unit V is located in the northeast portion of the site and includes the Sewage Treatment Plant (AOC 4) and releases to the Peconic River.

VI Operable Unit VI is located on the southeastern edge of the site. It is a largely wooded area which contains various agricultural research fields and manmade experimental basins known as the Upland Recharge/Meadow Marsh Area (AOC 8). No contaminated soils of concern have been found in this Operable Unit, however, contaminated sediments in two of the manmade basins pose an ecological risk to the Tiger Salamander. Ethylene dibromide, a pesticide, has been found in groundwater south of BNL's southern boundary, and is addressed in a separate Record of Decision.

Table A-2
Description of Areas of Concern with Radiologically Contaminated Soils

Operable Unit I Areas of Concern

Former Hazardous Waste Management Facility (AOC 1)
This Facility was the central receiving, processing and storage facility for radioactive waste generated at BNL since 1947. Since 1979, it has also been the receiving area for hazardous waste. There have been numerous spills during the Facility's operation. An asphalt cap was placed over spills in the slurry fission product area to prevent the spread of contamination. The Facility was closed in 1997 and was replaced by a new NYSDEC-permitted facility located in the northeastern part of the central portion of the BNL site.

This Facility is a fenced area covering 12 acres with controlled access. Approximately one-quarter of the area is paved, with the remainder consisting of a field of grass and weeds. It contains various buildings and operational areas, as well as containment pits, concrete vaults and trenches which were used to store radioactive materials and radiation sources. (See Figures 1 & 6.) All remaining low level radioactive wastes will be removed and the buildings will be demolished and, if contaminated, disposed of off-site. One 5,000 and one 1,000 gallon Underground Storage Tanks (USTs) were also located at the facility and were removed in 1994. These were used to store liquid radioactive wastes and acid from a mercury still.

This area was evaluated in the Operable Unit I/VI Remedial Investigation/Risk Assessment Report and contains the most of the radiologically contaminated soil at BNL. The predominant radionuclide found is Cesium-137, which emits beta and gamma radiation, at concentrations up to 180,000 pCi/g. This radionuclide is the primary source of direct exposure risk. Strontium-90, which emits beta radiation, is also present at concentrations up to 1,300 pCi/g. This radionuclide is a concern because it migrates to groundwater. Both radionuclides are relatively short-lived, with half-lives of 30 and 28 years, respectively. Most of the soil contamination is at or near the surface, although contamination in some locations extends to 12 feet below the soil surface. Figure 6 illustrates the principal areas of surface contamination, and relative concentrations within the facility. There is no significant chemical contamination of soil within the Facility though there are several locations where low concentrations of mercury were detected in surface soils. The maximum concentration of mercury found was 184 mg/kg.

There is also a shallow, seasonally ponded wetland partially located within the Facility. The wetland is divided by a fence which borders the facility's northwest boundary. This wetland is a confirmed breeding area for the Tiger Salamander.

Operable Unit II/VII Areas of Concern

Waste Concentration Facility (AOC 10)
This is the main liquid radioactive waste storage and processing facility at BNL. Certain liquid wastes received at the facility between 1947 and 1987 were stored in three 100,000-gallon aboveground D Tanks (AOC 10A). Leakages involving two of the tanks occurred in 1982, 1985 and 1987. These tanks were dismantled in 1995, but concrete and asphalt pads remain. Soil is contaminated to a depth of 12 feet beneath the pad. The maximum concentrations found of cesium-137 and strontium-90 are 464 pCi/g and 454 pCi/g, respectively. The concrete/asphalt foundation and underlying contaminated soils were capped with a temporary soil and asphalt cover in 1998.

The facility also contains six out-of-service 8,000-gallon underground storage tanks (AOC 10C) enclosed in a concrete vault. The tanks were used to store class A and B radioactive wastes. Residual sludges remaining in the tanks are to be removed and the tanks excavated. In-service equipment includes two 25,000-gallon aboveground storage tanks and underground pipe lines.

The Underground Pipelines (AOC 10B) consists of four lines used to transport class A, B, and D liquid wastes from various buildings to the Waste Concentration Facility and associated storage tanks. In 1995, one D-line was removed and replaced with a new line. Soil sampling adjacent to this underground pipeline during a 1995 upgrade project did not show chemical or radionuclide contamination. The remaining three A, B, and D lines are out-of-service and scheduled to be removed.

Sitewide Soils (AOCs 16, 17 & 18)
Radiologically Contaminated Surface Soils have been found adjacent to or near the following buildings as shown in Figure 3:

Building 30 - Brookhaven Center (subAOC 16G)
Building 355 - Contracts/ Procurement (subAOC 16S)
Building 490 - Medical (subAOC 16E)
Building 510 - Physics (subAOC 16S)
Building 515 - Applied Math (subAOC 16S)
Building 555 - Chemistry (subAOC 16F)
Building 930 - Linear Accelerator (subAOC 16S)
Building 526 - Low Mass Criticality Facility (AOC 17)
AGS Storage Yards (AOC 18)

These areas were evaluated in the Operable Unit II/VII Remedial Investigation Report. The dominant radionuclide found in these locations is cesium-137 with concentrations up to 348 pCi/g. Most of the elevated radiation levels are related to use and handling of activated materials (AOCs 17 and 18) or use of slightly contaminated landscaping soils (AOC 16) . Soils contaminated with low levels of radionuclides from the Hazardous Waste Management Facility were used as landscaping material outside several buildings during their construction. The contamination is found in the upper two feet of the soils.

Tritium and sodium-22 have been found in soils at the Building 931B - Brookhaven Linac Isotope Producer (AOC 16K). These radionuclides are isolated in an area adjacent to the target area approximately 24 feet to 32 feet below land surface. Maximum detected concentrations of tritium and sodium-22 were 4,023 pCi/g and 42,550 pCi/g, respectively. An Engineering Evaluation/Cost Analysis report is currently being prepared and recommendations on a final remedial action decision will be made when the report is issued for public review and comment.

Operable Unit IV Areas of Concern

Reclamation Facility (Building 650) Sump and Outfall Area (AOC 6)
The Building 650 sump outfall area is contaminated with several radionuclides which includes: cesium-137 (2,800 pCi/g), strontium-90 (140 pCi/g), and plutonium-239/240 (170 pCi/g).

Radiologically contaminated clothing and heavy equipment were decontaminated at this facility. Wastewater from equipment decontamination, performed outside the building on a concrete pad, drained into two of four underground storage tanks or sumps. Wastewater from clothing decontamination inside the building drained into the sump's other two tanks. The contents of these tanks were regularly transferred by truck to BNL's Waste Concentration Facility. In the summer of 1994, the underground storage tanks were removed and it was determined that they had not leaked.

During its operation, it was believed that the equipment decontamination pad located at Building 650 drained into the underground tanks, then discharged into BNL's sanitary sewage system. In 1969, however, five curies of tritium were released from the Building 650 Sump outdoor decontamination waste pad into what was believed to be BNL's sanitary sewer system, but was not detected at the Sewage Treatment Plant. The subsequent investigation revealed that the drainage pipe from the Building 650 Sump discharged into a natural depression in a wooded area about 800 feet northeast of Building 650. The area is now known as the Building 650 Sump Outfall Area.

This area is fenced off to prevent unnecessary access and is monitored as an interim action pending the proposal of the final remedy in this document. This interim action was documented in the Operable Unit IV Record of Decision.

Table A-1	Description of Operable Units at BNL
Operable Unit	Description
I	Operable Unit I is a relatively undeveloped 950-acre area in the southeastern part of the site. It includes historical waste handling areas such as the Former and Current Landfills (AOCs 2 and 3), and the Former Hazardous Waste Management Facility (AOC 1). It also includes the Ash Pit (AOC 2F) and two recharge basins (AOCs 24E and 24F). Operable Unit I contains six areas covered by accelerated removal actions: the Current and Former Landfills, Chemical/Animal Pits and Glass Holes, the Interim Landfill, the Slit Trench and Groundwater.
II/VII	Operable Unit II/VII consists of several AOCs located in the developed central portion of the site. It includes contaminated soils and out-of-service underground storage tanks and pipelines proposed for removal at the Waste Concentration Facility (AOC 10), along with various isolated areas of contaminated surface soils (AOC 16, 17, 18). It also includes the BLIP facility (AOC 16K).
III	Operable Unit III contains the south central and developed portions of the site. This Operable Unit contains most of the site's contaminated groundwater.
IV	Operable Unit IV is located on the east-central edge of the developed portion of the site. It includes the 1977 Oil/Solvent Spill as well as the Reclamation Facility Building 650 and Sump Outfall Area (AOC 6), where radiologically contaminated soils have been found.
V	Operable Unit V is located in the northeast portion of the site and includes the Sewage Treatment Plant (AOC 4) and releases to the Peconic River.
VI	Operable Unit VI is located on the southeastern edge of the site. It is a largely wooded area which contains various agricultural research fields and manmade experimental basins known as the Upland Recharge/Meadow Marsh Area (AOC 8). No contaminated soils of concern have been found in this Operable Unit, however, contaminated sediments in two of the manmade basins pose an ecological risk to the Tiger Salamander. Ethylene dibromide, a pesticide, has been found in groundwater south of BNL's southern boundary, and is addressed in a separate Record of Decision.

Table A-2	Description of Areas of Concern with Radiologically Contaminated Soils
Operable Unit I Areas of Concern
Former Hazardous Waste Management Facility (AOC 1)	This Facility was the central receiving, processing and storage facility for radioactive waste generated at BNL since 1947. Since 1979, it has also been the receiving area for hazardous waste. There have been numerous spills during the Facility's operation. An asphalt cap was placed over spills in the slurry fission product area to prevent the spread of contamination. The Facility was closed in 1997 and was replaced by a new NYSDEC-permitted facility located in the northeastern part of the central portion of the BNL site. This Facility is a fenced area covering 12 acres with controlled access. Approximately one-quarter of the area is paved, with the remainder consisting of a field of grass and weeds. It contains various buildings and operational areas, as well as containment pits, concrete vaults and trenches which were used to store radioactive materials and radiation sources. (See Figures 1 & 6.) All remaining low level radioactive wastes will be removed and the buildings will be demolished and, if contaminated, disposed of off-site. One 5,000 and one 1,000 gallon Underground Storage Tanks (USTs) were also located at the facility and were removed in 1994. These were used to store liquid radioactive wastes and acid from a mercury still. This area was evaluated in the Operable Unit I/VI Remedial Investigation/Risk Assessment Report and contains the most of the radiologically contaminated soil at BNL. The predominant radionuclide found is Cesium-137, which emits beta and gamma radiation, at concentrations up to 180,000 pCi/g. This radionuclide is the primary source of direct exposure risk. Strontium-90, which emits beta radiation, is also present at concentrations up to 1,300 pCi/g. This radionuclide is a concern because it migrates to groundwater. Both radionuclides are relatively short-lived, with half-lives of 30 and 28 years, respectively. Most of the soil contamination is at or near the surface, although contamination in some locations extends to 12 feet below the soil surface. Figure 6 illustrates the principal areas of surface contamination, and relative concentrations within the facility. There is no significant chemical contamination of soil within the Facility though there are several locations where low concentrations of mercury were detected in surface soils. The maximum concentration of mercury found was 184 mg/kg. There is also a shallow, seasonally ponded wetland partially located within the Facility. The wetland is divided by a fence which borders the facility's northwest boundary. This wetland is a confirmed breeding area for the Tiger Salamander.
Operable Unit II/VII Areas of Concern
Waste Concentration Facility (AOC 10)	This is the main liquid radioactive waste storage and processing facility at BNL. Certain liquid wastes received at the facility between 1947 and 1987 were stored in three 100,000-gallon aboveground D Tanks (AOC 10A). Leakages involving two of the tanks occurred in 1982, 1985 and 1987. These tanks were dismantled in 1995, but concrete and asphalt pads remain. Soil is contaminated to a depth of 12 feet beneath the pad. The maximum concentrations found of cesium-137 and strontium-90 are 464 pCi/g and 454 pCi/g, respectively. The concrete/asphalt foundation and underlying contaminated soils were capped with a temporary soil and asphalt cover in 1998. The facility also contains six out-of-service 8,000-gallon underground storage tanks (AOC 10C) enclosed in a concrete vault. The tanks were used to store class A and B radioactive wastes. Residual sludges remaining in the tanks are to be removed and the tanks excavated. In-service equipment includes two 25,000-gallon aboveground storage tanks and underground pipe lines. The Underground Pipelines (AOC 10B) consists of four lines used to transport class A, B, and D liquid wastes from various buildings to the Waste Concentration Facility and associated storage tanks. In 1995, one D-line was removed and replaced with a new line. Soil sampling adjacent to this underground pipeline during a 1995 upgrade project did not show chemical or radionuclide contamination. The remaining three A, B, and D lines are out-of-service and scheduled to be removed.
Sitewide Soils (AOCs 16, 17 & 18)	Radiologically Contaminated Surface Soils have been found adjacent to or near the following buildings as shown in Figure 3: Building 30 - Brookhaven Center (subAOC 16G) Building 355 - Contracts/ Procurement (subAOC 16S) Building 490 - Medical (subAOC 16E) Building 510 - Physics (subAOC 16S) Building 515 - Applied Math (subAOC 16S) Building 555 - Chemistry (subAOC 16F) Building 930 - Linear Accelerator (subAOC 16S) Building 526 - Low Mass Criticality Facility (AOC 17) AGS Storage Yards (AOC 18) These areas were evaluated in the Operable Unit II/VII Remedial Investigation Report. The dominant radionuclide found in these locations is cesium-137 with concentrations up to 348 pCi/g. Most of the elevated radiation levels are related to use and handling of activated materials (AOCs 17 and 18) or use of slightly contaminated landscaping soils (AOC 16) . Soils contaminated with low levels of radionuclides from the Hazardous Waste Management Facility were used as landscaping material outside several buildings during their construction. The contamination is found in the upper two feet of the soils. Tritium and sodium-22 have been found in soils at the Building 931B - Brookhaven Linac Isotope Producer (AOC 16K). These radionuclides are isolated in an area adjacent to the target area approximately 24 feet to 32 feet below land surface. Maximum detected concentrations of tritium and sodium-22 were 4,023 pCi/g and 42,550 pCi/g, respectively. An Engineering Evaluation/Cost Analysis report is currently being prepared and recommendations on a final remedial action decision will be made when the report is issued for public review and comment.
Operable Unit IV Areas of Concern
Reclamation Facility (Building 650) Sump and Outfall Area (AOC 6)	The Building 650 sump outfall area is contaminated with several radionuclides which includes: cesium-137 (2,800 pCi/g), strontium-90 (140 pCi/g), and plutonium-239/240 (170 pCi/g). Radiologically contaminated clothing and heavy equipment were decontaminated at this facility. Wastewater from equipment decontamination, performed outside the building on a concrete pad, drained into two of four underground storage tanks or sumps. Wastewater from clothing decontamination inside the building drained into the sump's other two tanks. The contents of these tanks were regularly transferred by truck to BNL's Waste Concentration Facility. In the summer of 1994, the underground storage tanks were removed and it was determined that they had not leaked. During its operation, it was believed that the equipment decontamination pad located at Building 650 drained into the underground tanks, then discharged into BNL's sanitary sewage system. In 1969, however, five curies of tritium were released from the Building 650 Sump outdoor decontamination waste pad into what was believed to be BNL's sanitary sewer system, but was not detected at the Sewage Treatment Plant. The subsequent investigation revealed that the drainage pipe from the Building 650 Sump discharged into a natural depression in a wooded area about 800 feet northeast of Building 650. The area is now known as the Building 650 Sump Outfall Area. This area is fenced off to prevent unnecessary access and is monitored as an interim action pending the proposal of the final remedy in this document. This interim action was documented in the Operable Unit IV Record of Decision.