G.E. Penny
USDOE

J.E. Brower
BNL

One of the environmental restoration projects conducted at the Brookhaven National Laboratory (BNL) involves the removal of unknown radiological and chemical buried wastes at an area known as the Glass Holes and Chemical/Animal Pits. Implementation of this project began in the spring of 1997. This paper provides a site background, an overview of the characterization activities conducted; regulatory strategy; remediation alternatives evaluated; the basis for selecting the preferred alternative; a comparison of what was planned versus what was found during implementation.

The Chemical Holes Project consists of two distinct areas known as the Glass Holes area and the Animal/Chemical Pits (A/C Pits) area as shown in Figure No. 1. These areas are referred to collectively as the Chemical Holes and are located in a secluded, wooded zone in the south central portion of BNL that is part of Operable Unit I. This area has historically been used for waste disposal and also includes the Former and Interim Landfills and the Slit Trench which have been capped.

The A/C Pits are contained in an area of approximately three acres. Anecdotal evidence suggests approximately 33 pits were dug using a clamshell and crane during the 1960s for the disposal of chemical wastes and animal carcasses from Laboratory experiments. The maximum depths of waste debris in the pits was believed to be 15 feet. The bulk of the laboratory chemicals was believed to consist of acids and bases, although a variety of other chemicals may also have been disposed of in the pits. Animal carcasses from experiments performed at the Medical and Biology Departments may have included primates, rodents, cats, dogs, cows, etc. Both tritium, uranium isotopes and carbon-14 as well as several other very short-lived radionuclides were commonly used in animal experiments. Pit disposal practices reportedly consisted of pit excavation, and then alternating backfill with wastes and soil cover until the pit was nearly full. The pits were then capped with a soil cover, and another pit excavated.

The Glass Holes are situated in an area of approximately two acres just north of the A/C Pits. Previous reports prepared for this area identified 18 pits in the Glass Holes area. Previous reports also suggest that pits were excavated and used for waste disposal between 1966 and 1981, but aerial photographs indicate clearing activities as early as the late 1950s. The physical features of these pits and their use are assumed identical to those in the A/C Pits area. Additional isolated pits were discovered to the north of the Glass Holes area and are referred to as the Interim Landfill or "IL" pits. While only empty chemical containers and rinsed glassware were supposed to be disposed of the in the Glass Holes, the types of chemical wastes disposed of in the Glass Holes and IL pits were also assumed to be the same as those disposed of in the A/C Pits based on discussions with former employees.

The Brookhaven National Laboratory (BNL) environmental restoration program is conducted under an Interagency Agreement (IAG) among the U.S. Department of Energy (DOE), the U.S. Environmental Protection (EPA) and the New York State Department of Environmental Conservation (NYSDEC). The IAG integrates the requirements of the CERCLA, RCRA and State regulations. Based on historical records indicating that chemical wastes had been disposed of in the pits; it was determined that a removal action was needed. The major threat to public health or welfare and the environment identified from these sites consists of the migration of contaminants from deteriorating containers and potentially contaminated soils within the fill to groundwater if the source is not remediated. The Long Island aquifer system has been designated as a sole source and groundwater preservation has a high priority among Federal, State and local regulators.

Initial field investigations were designed and implemented between November 1993 and April 1994. Radiation, soil gas and electromagnetic surveys, test pitting and soil sampling were performed. The radiation survey several small areas of elevated radiation levels with the highest reading at 90 uR/hr. The soil gas survey conducted identified total and chlorinated organic compounds at the A/C Pits and Glass Holes. Methane was not detected in the soil gas samples though various chlorinated hydrocarbons were detected at several locations. Contamination was not found to be widespread. The electromagnetic survey conducted identified distinct changes in ground conductivity and isolated patterns of high and low conductance where landfilling activities had occurred. However, the exact locations of the pits were not able to be determined from the data.

One Glass Hole was partially characterized during the test pit program in April 1994. The top six feet was found to be composed of clean fill. Forty-two intact glass bottles were excavated ranging in size from 16 ounces to one gallon along with several empty and rusted drums were excavated from the pit at 6 to 10 feet deep. Test pitting was discontinued at 10 feet due to the amount of intact glassware containing liquid chemicals that was excavated. The remainder of the planned test pits were canceled due to the potential for causing contaminant migration due to breakage of containers and worker health and safety concerns about handling chemical unknowns.

Soil boring samples were also collected in April 1994 to identify contaminants that may have migrated into the soil south of the A/C Pits and Glass Holes. No compounds of significant concentrations were detected in the soil boring samples. However, the sample locations were not optimally placed since the exact locations of the Pits were unknown.

An Engineering Evaluation/Cost Analysis (EE/CA) was prepared to evaluate the potential removal action. No action, capping and excavation with off-site disposal alternatives were evaluated. The estimated cost of the excavation option was approximately $39.5 million. The main cost drivers involved the high costs of characterizing a large number of small containers and assumptions made on volumes and the costs for sending mixed waste soils to Hanford for interim storage. Because of the high costs of the proposed action and the uncertainties involved, no decision was made in the EE/CA and additional assessment activities were conducted in the summer of 1995 in coordination with the DOE's Office of Technology Development (EM-50) and the Landfills Stabilization Focus Group.

Additional investigations were planned and implemented during the summer of 1995. Ground penetrating radar and other geophysical surveys were performed to locate the pits and sub-surface sampling involving direct push technology (Geoprobe) was subsequently performed. Soil samples were collected adjacent to and beneath the pits (via angled drilling). Specific parameters that were investigated included pit diameter, depth to top and bottom of waste, the presence of metals, volatile/semi-volatile organic compounds and radionuclides. Estimates were made as to types and quantities of waste debris likely to be encountered in each pit based on the field studies. These estimates were the basis for the Evaluation of Alternatives Report (EAR) which evaluated Ground Freezing, Capping, Containment (Grouting) with Capping, In-Situ Vitrification, and several excavation alternatives (Bulk, Manual and Robotics). The EAR also developed soil cleanup levels which are described in Table I. Cleanup levels are based on an evaluation of post cleanup uses (recreational post cleanup and industrial in 50 years), practicality (published values for lead) and groundwater protection (VOCs, mercury, strontium-90).

Containment (Grouting) and In-Situ Vitrification appeared to be promising alternatives to excavation and Jet Grouting (EM-50 Demonstration) and In-Situ Vitrification pilot studies were conducted at BNL during the summer of 1996. In-Situ Vitrification was attractive because it eliminated the messy handling of buried chemical unknowns and was comparable in price ($10.8 million) to the excavation alternatives ($6.6 - 14.6 million). This technology was ultimately not selected because of uncertainties regarding the depths of contaminated soils and buried wastes; the ability of the system to capture and destroy migrating VOC gases and over uncertainties on to add fluxing agents to enhance the electrical conductivity of the native soils. Containment (using Jet Grouting) was rejected because of concerns over the compatibility of the buried wastes with the grout and higher costs at $23.3 million. Also, these two alternatives were not permanent solutions and left waste materials on-site.

Bulk excavation with a combination of off and on-site disposal at a cost of $6.6 million was selected and an Action Memorandum was issued in June 1997 documenting this decision. All hazardous wastes and soils above radiological cleanup levels would be disposed of off-site. Wastes and contaminated soils that were not hazardous were supposed to be disposed of on-site beneath the Interim Landfill Cap. This was subsequently reversed by NYSDEC which ultimately required that all soils above chemical cleanup levels be disposed of off-site since these materials were considered a solid waste. State regulations do not allow expansion of landfills on Long Island due to the sole source aquifer. Work and health and safety plans for the remediation and restoration of the A/C Pits and Glass Holes areas were prepared and compiled by BNL during the first part of 1997.

The objectives of the project are to remove the waste debris and associated contaminated materials from the pits; characterize, process, sort and dispose of the excavated materials; and restore the areas to original conditions. 51 known waste pits as well as four additional pits that were discovered were successfully excavated as of September 1997. Soils at the bottom of the pit were sampled and analyzed for compliance with the soil cleanup goals. Completion of the waste disposal phase is contingent upon the availability of acceptable treatment/disposal facilities to accommodate the waste materials as well as available funding. Final characterization and disposition of the excavated wastes is underway. Waste materials, including stockpiled soil, are currently stored on site in accordance with appropriate federal, state and local regulations. Site restoration activities will be completed following off site disposal of wastes.

A process flow diagram for the various waste excavation, sorting and analysis activities is shown in Figure 2.

The excavation process first involved removing topsoil and overburden materials from above the waste pits. These materials were stockpiled on site as potentially clean and sampled at a frequency of 1 per 500 cubic yards to determine if they were acceptable for use as backfill or required processing as potentially contaminated materials.

Once the overburden materials were removed, the waste pits were then excavated using a hydraulic excavator. Excavated waste materials were screened at the pits with field instruments for radioactivity (beta and gamma emissions), total volatile organic compounds (VOC) via Photo Ionization Detector and/or Flame Ionization Detector, and a mercury vapor analyzer. Shock sensitive materials, such as crystallized materials in containers, amber bottles with liquids and compressed gas cylinders detected at the pits were manually segregated by the Shock Sensitive Materials technician and transported to the on site bermed ("blast proof") area (see Figure 1) where the materials were temporarily stored until they were properly characterized for ultimate disposal. Visible containers with liquids and specific items yielding elevated field instrument responses encountered at the pits were also removed from the waste stream at the waste pits. Waste materials not separated at the waste pits were placed in roll off containers or dump trucks and transported to the on site screening and sorting area where they were staged prior to sorting.

Excavated waste materials were processed at the sorting area. From the waste pits, waste material was transported to the sorting area and dumped into a process feed stockpile. Larger objects such as miscellaneous metals were removed from the feed stockpile and placed directly into waste debris roll offs. Remaining stockpiled waste materials were then mechanically sorted into 2" diameter or smaller material and greater than 2" diameter material using a mechanical shaker and screen. Materials were taken from the feed stockpile and placed into a hopper from which they were conveyed via belt to a mechanical shaker and screen. The waste material was additionally monitored (for radioactivity, total VOCs and mercury vapor) and hand sorted (for potentially shock sensitive materials, containers with liquids, etc.) on the conveyor belt prior to reaching the mechanical shaker and screen. Once the materials reached the mechanical shaker and screen, the 2" diameter or smaller materials passed through the screen and into 20 cubic yard roll off containers or dump trucks. Materials greater than 2" in diameter passed over the screen and into a separate 20 cubic yard roll off container.

The 2" diameter or smaller materials consisted primarily of soil, small stones, broken glass and other various sharps including syringes, blood vials and hypodermic plungers. Samples of soil from the waste pits were collected from the conveyor belt at a frequency of 1 per 25 cubic yards and analyzed in an on site laboratory. This data, coupled with instrument readings collected at the pit and on the conveyor belt was used to direct the processed soil to a specific stockpile with similar characteristics (i.e. potentially hazardous, potentially non-hazardous, potentially radioactive and potentially mixed). The processed soil stockpiles were located in the laydown areas set up across the site. These soils would be further sampled for characterization utilizing off site laboratories to determine appropriate disposal options.

Materials greater than 2" diameter or waste debris materials, consisting mostly of large, empty glass bottles, jars, drums, plastic containers and bags, bones and miscellaneous plastics, metals and glass were fed directly to roll off containers. Once full, the roll off containers containing waste debris materials were removed from the sorting area and stored in roll off containers in the waste debris staging area northwest of the sorting operation (see Figure 1) or in debris stockpiles.

Once the excavation and preliminary screening and sorting was complete, secondary sorting, bulking and packaging of the waste materials was/will be performed to further reduce and consolidate wastes for final disposal.

With waste materials visually removed from the pits and no indications of contamination present (i.e. visibly stained soil, total VOC and mercury vapor headspace readings or rad responses), endpoint or confirmatory soil samples were collected from the bottom of the pit. After review of the results of the endpoint sample analyses, the individual pits were either considered remediated and backfilled with suitable stockpiled overburden materials or additional excavation of contaminated soil was performed and sampling process repeated. This process continued until the endpoint sampling results were within the soil clean up goals established for the project.

Prior to excavation activities, there was believed to be a total of 18 pits in this area. One additional pit (IL Pit A) did not contain waste material and is suspected to be the result of a survey error. IL Pit B nearby contained wastes bringing the total number of waste pits to 21. The other two additional pits (IL Pits C and D) were encountered during the construction of the Interim Landfill Capping project.

In general, the waste materials removed from the pits in the Glass Holes area were characterized by glass and plastic containers, jars, compressed gas cylinders, miscellaneous metal and debris. The 18 pits that were located using geophysical techniques in earlier studies were found to be accurately identified with respect to location of pit centers, however the average depth of the pits was approximately 18 feet as opposed to 13 feet. Pit diameters on average were found to be approximately 20 feet as opposed to an average anticipated diameter of 14 feet.

Excavation activities in the Glass Holes area began June 9, 1997 and continued through July 18, 1997. Additional Glass Holes area excavations were conducted in 1997 during the construction of the Interim Landfill cap as IL Pits C and D were discovered. Further exploratory trenching was done in the area of IL Pits C and D and the Interim Landfill to ensure that no additional pits existed. The Glass Holes area pits were generally found to be 5 feet deeper and 6 feet wider than originally anticipated. Waste debris and associated potentially contaminated soils were excavated from the Glass Holes area pits, processed, sorted stockpiled and characterized for disposal.

The primary types of waste debris excavated from the Glass Holes area pits included but were not limited to the following; glass bottles of various sizes, shapes, colors and conditions (i.e. full of liquid, partially full empty, intact, broken, etc.), plastic containers, syringes, needles, jars, blood vials, compressed gas cylinders, metallic drums, cans and miscellaneous glass, metals and plastics. Notable excavated items included a partially full cylinder containing a green colored, radioactive liquid identified as uranium-235 from pit G9A, an activated steel block from pit G4, large quantities of sharps such as syringes and needles from IL Pit B and the bentonite grout encapsulated waste monolith of pit G11.

A total of 34 pits were remediated in the A/C Pits area. One additional pit (pit C2A) was encountered near the western end of the A/C Pits area. This pit was originally reported as an anomaly but was found to contain waste materials consistent with the other A/C Pits.

Waste materials in the A/C Pits consisted of glass and plastic containers, jars, drums, metal debris, animal bones, compressed gas cylinders and plastic bags containing animal remains. Mercury was consistently found in intact bottles as well as in the soils in the A/C Pits and routinely required additional soil excavation from the pits to reach clean endpoint samples. Previous investigations accurately located pit centers, however, pit depths were found to average over 21 feet with a few pits reaching 30 plus feet as opposed to an anticipated average depth of 14 feet. An average diameter of over 14 feet was observed as opposed to the anticipated average diameter of 12 to 13 feet. The larger pit sizes resulted in the generation of more waste than anticipated.

Excavation activities in the A/C Pits began June 9, 1997 and continued through August 19, 1997. The A/C Pits were generally found to be 7 feet deeper and 1 to 2 feet wider than originally anticipated. Waste debris and associated potentially contaminated soils were excavated from the A/C Pits, processed, sorted stockpiled and characterized for disposal.

The principal types of waste debris recovered from the A/C Pits included but were not limited to the following; animal bones, animal carcasses, animal remains (i.e. flesh, fur, feces, blood, etc.), plastic bags, glass bottles, plastic containers, compressed gas cylinders, metallic drums, blood vials, jars, free elemental mercury and miscellaneous glass, plastics and metals. Notable wastes encountered in the A/C Pits included liquid bromine in intact bottles in several pits, the large size and extent of waste in two pits and incinerator ash found in one pit.

Upon completion of the preliminary processing and sorting, additional characterization and secondary sorting, bulking and packaging activities were conducted in order to prepare materials for final off site disposal. The following is a description of the activities conducted on the various waste streams and the problems encountered during processing and characterization of the wastes.

During the preliminary processing operation, a large number of plastic bags containing animal carcasses contaminated with radionuclides were separated from the debris waste stream. In order to avoid unnecessary storage of exhumed animal carcasses, this waste stream was the first to be prepared for off-site disposal. In addition to the carcasses, the plastic bags were also observed to contain laboratory instrumentation (tubing, scissors, test tubes, etc.). These materials required segregation from the carcasses in order to properly characterize the waste stream. Segregation of these materials was performed by opening and sorting through each individual plastic bag. The animal carcasses were then packaged into 13 fiber drums. An estimated 2,600 pounds of animal carcasses were generated. These wastes are planned to be shipped to SEG for incineration however SEG's disposal site for the ash is not a CERCLA approved landfill. BNL is currently reviewing their waste inventories to determine if they have enough materials for a dedicated burn with subsequent retrieval of the ash.

Processed soils were directed to a specific soil stockpile based upon field screening performed at the pit during excavation and at the sorting area during processing, and on site laboratory analyses. On site laboratory analytical results were used to characterize soils for stockpiling and were collected at a frequency of 1 per 25 cubic yards during the sorting operation. These activities resulted in 17 separate stockpiles totaling 11,590 cubic yards. The soils are classified as DOE rad-added, non-radioactive, mixed, hazardous and non-hazardous. The final waste classification is being made based on the results of a sampling plan implemented in the fall of 1997. Off-site disposal of 5,360 cubic yards of the non-radioactive and non-hazardous soils are underway at a CERCLA approved Subtitle D facility in Pennsylvania.

Anything that did not pass through the 2 inch screen when sorted was classified as debris. No hazardous debris is expected however there appears to be approximately 1,080 cubic yards of DOE rad-added debris. There is a potentially mixed waste debris pile of 300 cubic yards that contains mercury. Characterization of the debris piles are ongoing.

An estimated of total of 3,286 containers with visible liquids were removed from the waste stream during the preliminary processing and sorting phase of the project. These containers were transported to and temporarily stored in a separate liquid bulking area until the preliminary processing and sorting was complete. The liquids were then bulked together based upon chemical characteristics determined through the use of field test kits. The total volume of the bulked liquids is approximately 148 gallons and is undergoing final laboratory analysis and waste classification. The final disposal options for the recovered liquids were not available as of this date.

Potentially shock sensitive materials were removed from the waste stream at the pit excavation as well as during the preliminary processing and sorting. These materials included compressed gas cylinders, bottles with visible crystals and brown/amber bottles. Once isolated, these materials were transported and temporarily stored at the on site the on site bermed ("blast proof") area until the preliminary processing and sorting was complete (see Figure 1).

Cylinders were further evaluated by the Shock Sensitive Materials technicians and sorted based upon positive pressurization. Of the estimated 300 compressed gas cylinders removed from the waste stream, 90 percent were determined to be decommissioned or inert based upon the presence of intentional punctures in the cylinder walls or holes resulting from degradation. Bids are being requested from three companies to open, characterize and dispose of the remaining 181 cylinders.

Brown/amber bottles and bottles with visible crystal formations were opened remotely by the Shock Sensitive Materials technicians. The procedure involved an electronic, remote controlled opening device capable of unscrewing bottle tops or drilling holes into potentially shock sensitive containers. The device is enclosed in protective shielding and is monitored remotely via video surveillance.

None of the containers segregated were found to be shock sensitive. Resulting liquids from these bottles were directed to the liquid bulking area. Four 20 gallon overpacks of excavated bottles containing solids are in storage and awaiting characterization for radionuclides

These stockpiles are currently being sampled and characterized for off site disposal. Completion of the waste disposal phase is contingent upon the availability of acceptable treatment/disposal facilities to accommodate the waste materials as well as available funding. Site restoration activities will be completed following off site disposal of wastes.

The remedial actions taken at the Chemical Holes satisfied the overall project objective of eliminating potential sources of contamination by excavating buried waste debris and associated contaminated soils from the 51 known as well as 4 newly discovered waste pits. The waste debris contained in the fifty five waste pits was completely removed. Additionally, confirmatory sampling data indicated that project clean up goals for soil were achieved which was further supported by results from split samples collected and analyzed by external agencies. Further, the procedures and protocols established for the safe excavation and handling of waste materials were also found to be effective as demonstrated by the safe and timely completion of the excavation and processing phases of the project.

In general, the locations of the waste pits were accurately identified by the previous studies, however the pits were found to be an average of 3.5 feet wider and 6.25 feet deeper than anticipated.

The remediation of the 55 waste pits generated more than 11,590 cubic yards of soil, nearly 500 cubic yards of debris, approximately 2,600 pounds of animal carcasses and more than 3,200 bottles containing liquids. Table No. II compares the waste volumes and types from the EE/CA, post characterization as documented in the EAR and the as generated.

While fewer bottles were found than planned (3,286 versus 68,000), the most significant impact on the project was an approximately 10,000 cubic yard increase in the volume of contaminated soil (11,700 cubic yards). The major factors that contributed to the additional soil were the discovery of four additional pits, the larger pit sizes, the additional contaminated soil that required removal in order to meet the project clean up objectives. Also, more soils will require off-site disposal because of NYSDEC's reversal of their earlier decision to allow on-site disposal of non-hazardous wastes.

Regarding costs, Table III contains a comparison of costs from the EE/CA and the EAR versus what was spent and the current cost estimates based on the January 1998 update of the project's Waste Management Plan. Excavation costs were higher than planned due to the larger volumes of waste and contaminated soils encountered. Waste disposal and handling costs are higher than estimated in 1996 (but less than 1995) due to the complexity of the waste streams discovered, the amount of unexpected mercury and the larger volumes of contaminated soils encountered and the a change in the NYSDEC position on on-site disposal. The 1995 cost estimate as so high due to DOE prescribed disposal rates of low level radioactive and mixed wastes at the DOE Hanford site. The 1996 estimate is based on disposal of mixed and low level radioactive wastes at Envirocare. Uncertainties in waste disposal will be a key factor in the final costs for this project.

BNL is currently in the process of final characterization and determining disposal sites for these waste streams. Efforts are complicated by the CERCLA off-site rule and the current injunction on new commercial disposal contracts for low level and mixed waste. DOE and BNL are currently evaluating the potential for releasing (under DOE Order 5400.5) some contaminated soils that contain low levels of radionuclides to non-DOE and non-NRC licensed facilities.

Table III: Comparison of Costs from Conceptual Design through Implementation for
Chemical Holes Project ($1,000)

1. Brookhaven National Laboratory Final Report, Engineering Evaluation/Cost Analysis for Landfill Closure Action, Operable Unit I, Volume 1- prepared by CDM Federal Programs Corporation, March 29, 1995
2. Brookhaven National Laboratory Draft Integrated Geophysical Report for Chemical/Animal and Glass Hole Area (AOC 2B and 2C) - prepared by Idaho National Engineering Laboratory - December 13, 1995
3. Ground Penetrating Radar Investigation at the Animal-Chemical Pit, Final Report - prepared by J. J. Daniels, August 15, 1996
4. Brookhaven National Laboratory Chemical/Animal/Glass Holes Evaluation of Alternatives - prepared by CDM Federal Programs Corporation, April 1997
5. Supplemental Characterization Report for the Animal/Chemical Pits and Glass Holes Areas at Brookhaven National Laboratory, Upton, New York, Final Report - prepared by Environmental Assessment Division, Argonne National Laboratory, April 1997
6. Final Action Memorandum Phase III - Landfill Closure Removal Action - prepared by BNL Office of Environmental Restoration, June 16, 1997
7. Waste Management Plan Update Chemical Holes Project - prepared by BNL Office of Environmental Restoration, January 6, 1998

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