LOOW & NFSS Frequently Asked Questions (FAQs)
Click on a question below to be taken to the answer.
A. General questions about the process
- How does the Corps implement the Formerly Utilized Sites Remedial Action Program (FUSRAP) and the Defense Environmental Restoration Program for Formerly Used Defense Sites (DERP-FUDS)?
- What are the steps in the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA)?
- What is a remedial investigation?
- What is a baseline risk assessment?
- What is a screening level ecological risk assessment?
- Why do we need a groundwater model and how does a groundwater model work?
- Can a health study be conducted?
- How can I get more information about the Niagara Falls Storage Site (NFSS) and the Lake Ontario Ordnance Works (LOOW) Site?
- How do I provide input on Corps reports?
B. General questions about the LOOW Site and the NFSS
- Where are the LOOW Site and the NFSS located and who owns them?
- How big are the sites?
- What are the LOOW Site and NFSS histories?
- How and why is the Corps investigating the NFSS property?
- How and why is the Corps investigating the LOOW Site?
- What is the scope of the Corps projects at the NFSS?
- When will the Corps investigate the Vicinity Properties?
C. Niagara Falls Storage Site - Site Information
- Tell me more about the Interim Waste Containment Structure (IWCS) at the NFSS?
- Is there a build-up of radon gas within the IWCS at NFSS?
D. Niagara Falls Storage Site - Remedial Investigation
- What are the findings of the NFSS remedial investigation?
- What investigations were performed on the IWCS as part of the NFSS remedial investigation?
- What does the Remedial Investigation Report say about the safe life expectancy of the IWCS?
- Did the remedial investigation identify any off-site contamination in the area surrounding NFSS?
- I've heard there is "radioactive slag" in roads and parking lots around Niagara County. Is this from the NFSS?
- What is the Corps going to do about the contamination found off site?
- What does the NFSS groundwater model show?
E. Niagara Falls Storage Site - Human Health Risk Assessment
- How was the baseline risk assessment (BRA) performed for the NFSS?
- What are the findings of the NFSS BRA under current exposure scenarios?
- What are the findings of the NFSS BRA under future exposure scenarios?
- Are there any findings that require immediate attention?
F. Niagara Falls Storage Site - Ecological Risk Assessment
- Are there any threatened or endangered species at the NFSS or any sensitive habitats which warrant special protection?
- What are the findings of the NFSS screening level ecological risk assessment?
- What is the outcome of the NFSS screening level ecological risk assessment?
G. Niagara Falls Storage Site - Background Locations
- What is a background location and what are the background locations for the NFSS?
- Are the Lewiston-Porter schools contaminated?
- Have elevated levels of radon been discovered in the northeast corner of the Lewiston-Porter schools?
- How were sites chosen to represent background for radiation in soils?
- If the Corps is not authorized to answer questions about health risks, then why did the Corps present results of the gamma walkover at the Lewiston-Porter school and say that no hazard to the public was found?
A. General questions about the process
1. How does the Corps implement the Formerly Utilized Sites Remedial Action Program (FUSRAP) and the Defense Environmental Restoration Program for Formerly Used Defense Sites (DERP-FUDS)?
When implementing both FUSRAP and DERP FUDS, the Corps follows the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), which was enacted by Congress on December 11, 1980. This law:
- Established prohibitions and requirements concerning closed and abandoned hazardous waste sites
- Provided for liability of persons responsible for releases of hazardous waste at these sites
- Authorizes response actions for both short-term removals and long-term remedial response actions to permanently and significantly reduce the dangers associated with releases of hazardous substances.
2. What are the steps in the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) process?
Preliminary Assessment/Site Investigation
- To determine whether environmental contamination from past Federal activities on a site poses little or no threat to human health and the environment or if it does pose a threat, whether the threat requires further investigation.
- To determine the nature and extent of contamination resulting from past federal activity
- To evaluate impacts, fate and transport of contaminants through groundwater
- To assess human health and/or ecological risks resulting from contaminants in the environment
- To identify and evaluate potential remedial response alternatives and cleanup technologies
- To screen alternatives based on effectiveness, implementability and cost
- To perform a detailed analysis and evaluation of each screened alternative
Record of Decision
- To document the lead agency's preferred response alternative
- To seek and consider comments from the Federal and State agencies
- To seek and consider comments from the public through a mandatory 30-day public review period
- To document the lead agency's selection of the response alternative based upon the remedial investigation, the feasibility study, and comments received from Federal and State regulatory agencies and the public on the proposed plan.
- Detailed designs, plans, specifications, and bid documents for conducting the remedial action are developed during this phase.
- Upon approval of the remedial design, remedial action, the actual construction and implementation of the selected clean up alternative, is initiated. The remedial action is implemented until cleanup objectives are achieved.
Long Term Management
- Documents and demonstrates agreement from both the executing agency and regulatory agencies that the response action was completed in accordance with Record of Decision criteria and in compliance with CERCLA (1980), as amended, and the National Contingency Plan.
- After remedial action activities have been completed, the site is monitored to ensure the effectiveness of the response. Typically, FUSRAP CERCLA sites undergo reviews every five years after implementation of the remedy to evaluate the continued protectiveness of the remedy.
3. What is a remedial investigation?
A remedial investigation is a step in the Comprehensive Environmental, Response, Compensation and Liability Act (CERCLA). The investigation is performed to:
- Determine the nature and extent of contamination resulting from past federal activity;
- Evaluate impacts, fate and transport of contaminants through groundwater; and
- Assess human health and/or ecological risks resulting from contaminants in the environment.
4. What is a baseline risk assessment?
The NFSS baseline risk assessment evaluates current and potential future risks to human health and the environment from site contamination to provide a decision-making tool for use in determining the need for further investigation or site cleanup based upon present site conditions.
The assessment attempted to model the potential risks to the only current site occupant, i.e., the site maintenance workers. In addition, risks to other hypothetical receptors who may come onto the site now or in the future were also modeled. The modeled exposures for these receptors are based on EPA-approved models and parameters such that a reasonable estimate of the risk to these receptors can be calculated. The mathematical models were based on guidance documents prepared by the regulatory agencies. These models are recommended as a reasonable means to provide a conservative estimate of the effect of chemicals radionuclides of potential concern on human receptors.
5. What is a screening level ecological risk assessment?
A screening level ecological risk assessment is a prelude to a baseline ecological risk assessment. The baseline ecological risk assessment may only be conducted if warranted based on results of the simpler, screening level ecological risk assessment. The screening level ecological risk assessment includes a multi-step screen that identified areas on site where contaminant concentrations are above values deemed safe for one or more receptors (such as mice, deer, birds, etc.). Back
6. Why do we need a groundwater model and how does a groundwater model work?
A groundwater model is constructed using the large amount of physical data collected during the RI; the physical data may include soil permeability and engineering properties, geologic layers, water-level information, and observed groundwater-contamination plumes or such items of interest. The model is an assembly (or storehouse) of these site information that a computer then can mathematically reproduce using verified, yet innovative, technologies (or software). The groundwater model simulates the movement of natural groundwater and the transport of contamination within the groundwater in its current state and in future years. The future predictions show whether contaminants migrate (or flow) in groundwater or are attenuated (or slowed) by soil properties. As it pertains to the Niagara Falls Storage Site, the animations available on the CD in the groundwater modeling report also indicate both where and when off-site migration may occur if the site was allowed to persist in its present state (and several modified states) for a thousand years. Back
7. Can a health study be conducted?
The Corps does not perform health studies. We have no health personnel (e.g., medical researchers, epidemiologists, nurses, etc.) because we are not authorized by Congress to do health work. People with health concerns should contact the New York State Health Department at (518) 402-7550 or the Niagara County Health Department at (716) 439-7595. Additionally, you may call the U.S. Department of Labor's Energy Employees Occupational Illness Compensation Program at 1-866-888-3322 if you previously worked on the site. These contacts can provide information on the health studies that have been performed. Back
8. How can I get more information about the NFSS and LOOW Site?
The U.S. Army Corps of Engineers welcomes inquiries about the NFSS. Call us toll-free at 1-800- 833-6390 with your questions or to be included on the site's mailing list to receive information about site activities, release of documents for public review and comment, and/or upcoming public meetings. By mail, contact us at: U.S. Army Corps of Engineers, 1776 Niagara St., Buffalo, NY 14207-3199. Also, reports and documents in the Administrative Record File may be viewed at the Lewiston Public Library, 305 South Eighth Street, Lewiston, NY; Youngstown Free Library, 240 Lockport St., Youngstown, NY; and by appointment at the Buffalo District office of the U.S. Army Corps of Engineers at 1776 Niagara Street in Buffalo, NY. Back
9. How do I provide input on Corps reports?
Questions or comments may be e-mailed to email@example.com. Comments may be mailed to:
U.S. Army Corps of Engineers
1776 Niagara Street
Buffalo, NY 14207
B. General questions about the LOOW Site and the NFSS
1. Where are the LOOW Site and the NFSS located and who owns them?
The former LOOW (7,500 acres), developed for producing explosives during World War II, is located in the Towns of Lewiston and Porter (Niagara County) in northwestern New York, about 19 miles northwest of Buffalo and 10 miles north of the City of Niagara Falls. The NFSS is a 191-acre portion of the former LOOW, located off Pletcher Road in the Town of Lewiston. The site is currently United States Government property. The Corps serves as the site caretaker and performs site operations, maintenance, and environmental surveillance activities. The United States Department of Energy (DOE) is the long-term steward of the site.
The NFSS is bounded on the northeast, east, and south by two privately-owned landfills, on the west by a power line right of way, and on the northwest by the former LOOW wastewater treatment plant, which is owned by the Town of Lewiston. The local school district (elementary through high school) campus is less than one mile from the NFSS. There is a wide variety of land use around the site including residential, commercial, industrial, agricultural, and educational.
Approximately 5,000 acres of the LOOW site was declared excess and sold by the United States Government during the late 1940s. Current landowners include Lewiston-Porter Schools, local and federal governments, residents, and private corporations.
2. How big are the sites?
The Niagara Falls Storage Site consists of 191 acres and is located within the original 7,500-acre Lake Ontario Ordnance Works boundary. The 10-acre interim waste containment structure (IWCS) that contains radioactive residues is located within the NFSS.
The LOOW site has two primary components other than the NFSS - the 2,500-acre developed area on the east side of the former LOOW, which was used in the early 1940s for manufacturing of trinitrotoluene (TNT) during World War II; and approximately 5,000 acres that were historically left undeveloped, called the buffer zone.
(Click here for a site map)
3. What are the LOOW Site and NFSS histories?
The NFSS is a small parcel (191 acres) of a much larger defense site - the former Lake Ontario Ordnance Works (LOOW). The original LOOW site was constructed in 1942 and encompassed approximately 7,500 acres. During World War II, the U.S. Army built and operated a trinitrotoluene (TNT) plant on approximately 2,500 acres of the site known as the "developed zone". The remaining 5,000 acres were used as a "buffer zone" around the TNT plant. The plant manufactured bulk TNT for approximately nine months and was decommissioned in 1943.
In 1944 the Manhattan Engineer District (MED) started storing radioactive wastes on approximately 1,650 acres of the former "developed zone" of the LOOW. In 1947 the Atomic Energy Commission (AEC) took over from the MED and continued to import, store and dispose of radioactive wastes from other sites on the NFSS through 1952. The AEC gradually consolidated the storage of these radioactive wastes and reduced the footprint of its operation. Excess property was subdivided and sold to the public or transferred to defense ownership. Defense activities included a U.S. Army NIKE missile site, U.S. Navy and U.S. Air Force rocket fuel production, and U.S. Air Force electronic research.
Of the original AEC acreage, only the 191-acre NFSS remains under federal ownership. The NFSS was entered into the Formerly Utilized Sites Remedial Action Program (FUSRAP) by the U.S. Department of Energy (DOE). In the 1980s the DOE consolidated the wastes into an Interim Waste Containment Structure (IWCS) of approximately ten acres. This structure resembles a small landfill and contains approximately 2,000 curies of radioactive wastes including thorium and radium (which generates radioactive radon gas). The Corps serves as the site caretaker and performs site operations, maintenance, and environmental surveillance activities. The Corps has been conducting the remedial investigation of the site as part of the overall project objective to determine the nature (or type) and extent of contamination on the NFSS property under FUSRAP. In addition to the IWCS there are other areas of contamination to be addressed on the NFSS including contaminated soils, buildings, and underground infrastructure.
The Corps is also authorized under FUSRAP to investigate and respond to MED/AEC contamination at three open vicinity properties, designated as Vicinity Property (VP)-E, E-Prime, and G, on an adjacent private parcel owned by CWM Chemical Services LLC. These open vicinity properties were impacted by MED/AEC, however not all portions of the properties were accessible for investigation by the DOE.
4. How and why is the Corps investigating the NFSS property?
NFSS is being addressed by the Corps under the Formerly Utilized Sites Remedial Action Program (FUSRAP). This program was initiated in 1974 to identify, investigate, and clean up or control sites throughout the United States that were part of the nation's early atomic weapons and energy programs during the 1940s, 1950s, and 1960s. Activities at the sites were performed by the Manhattan Engineer District (MED) or under the Atomic Energy Commission (AEC). Both MED and AEC were predecessors of the Department of Energy (DOE). In October 1997, Congress transferred the management of FUSRAP to the Corps.
The waste at FUSRAP sites consists mainly of low levels of uranium, thorium and radium, along with some mixed radiological and chemical wastes. Upon completion of remedial activities, these sites are transferred to DOE for long-term stewardship activities.
5. How and why is the Corps investigating the LOOW Site?
The former LOOW site is being addressed under the Defense Environmental Restoration Program for Formerly Used Defense Sites (DERP-FUDS), which addresses environmental hazards caused by Department of Defense (DoD) activities. The program is used to clean up DOD-related chemical contamination on property that was once owned or used by DoD, but is no longer owned by the DoD.
6. What is the scope of the Corps projects at the NFSS?
Under FUSRAP the Corps investigation of the NFSS and the open vicinity properties is broken down into individual components. Each component will be investigated in accordance with the CERCLA process and ultimately result in a decision from the Corps on the appropriate actions to make each component safe for future use. Once the decision process is complete, remedial action would begin where required.
7. When will the Corps investigate the Vicinity Properties?
The Corps' focus is on the IWCS and the balance of site soils and groundwater at the NFSS, however, investigations of these vicinity properties will begin once all areas are accessible for investigation and sufficient funding is available to not hinder the current progress on the NFSS property.
C. Niagara Falls Storage Site - Site Information
1. Tell me more about the Interim Waste Containment Structure (IWCS) at the NFSS?
The 10-acre interim waste containment structure (IWCS) on the NFSS property contains more than 250,000 cubic yards of radioactive residues, wastes, and contaminated soil and debris from the previous waste consolidation effort of the U.S. Department of Energy (DOE). Of greatest concern are the 4,000 cubic yards of high activity K-65 residues which contain an average of 520,000 pCi/g of radium-226 that are contained in the IWCS. Radium-226 has a long half-life of 1,600 years and decays by emitting an alpha particle to radon-222, a gaseous radionuclide. The K-65 residues were placed in the foundation of a former freshwater treatment building and are covered by over 129,000 cubic yards of low-level contaminated soils and an interim cap. The interim cap consists of three feet of compacted clay, topped by one foot of fill and six inches of topsoil. The IWCS was designed and constructed to safely contain the radioactive materials for a period of 25 to 50 years.
The IWCS cap was installed in a manner to minimize water infiltration into the contained residues and wastes, and also to minimize radon gas emissions to the atmosphere. The clay liner in the IWCS cap greatly retards the movement of radon gas, allowing it to decay to solid radionuclides prior to the gas being released to the atmosphere. These decay products are charged particulates (ions) which have short half-lives and quickly attach to the surfaces of nearby solid particles. Radon gas generated in the residues and wastes in the IWCS does not present a significant risk to the general public under current conditions given the design features of the IWCS cover.
In 1991 the DOE cut into the cover on a section of the IWCS, placed additional contaminated material into the cell, and then place compacted clay on top of the contained waste. The cap was repaired following this action. Maintenance of the IWCS cover is routinely performed to ensure no cracking of the clay cap occurs. Environmental surveillance has been conducted at the site since 1981 to monitor radon gas emissions, external gamma radiation, and radiological constituents in sediment, surface water, and groundwater. Radon flux measurements on the surface of the IWCS cap have been comparable to those at nearby background locations, indicating that there are no measurable releases of radon from the contained residues and wastes.
2. Is there a build-up of radon gas within the IWCS at NFSS?
Yes, there was a buildup of radon gas in the IWCS shortly after the residues were sealed in this cell. Radon-222 ingrowth occurs at a rate proportional to its half-life of 3.82 days, and equilibrium conditions are quickly established between radon-222 and its short-lived decay products. These decay products are solid particulates which quickly attach to the surfaces of nearby solid particles. This natural decay process of a gas to solid charged particulates greatly limits the amount of gas buildup in the IWCS, and equilibrium conditions were established long ago.
D. Niagara Falls Storage Site - Remedial Investigation
1. What are the findings of the NFSS remedial investigation?
The NFSS Remedial Investigation Report documents the Corps' conclusions on the nature and extent of contaminants, and risks from environmental contamination resulting from MED and AEC activities. On site these include:
- Soils (Radiological Contamination): Radionuclides significantly exceeded background for both surface and subsurface site soils in both the surface and the subsurface. For surface soils, radium-226, thorium 230, uranium-238 and cesium-137 were radionuclides with the greatest frequency of exceeding background concentrations in both surface and subsurface soils. The most widespread contaminant is radium-226.
- Soils (Chemical Contamination): Chemical contamination was also found in both surface and subsurface soils, although at exceedances with smaller orders of magnitude than those found for the radionuclides. Volatile organic compounds (VOCs) in soil included chlorinated solvents, benzene, toluene, methylene chloride, carbon disulfide and 2-butanone, which were found commonly in areas associated with historic activities near LOOW buildings. Pesticides, polychlorinated biphenyls (PCBs), poly cyclic aromatic hydrocarbons (PAHs) and metals were also found in localized areas of the site.
- Groundwater (Radiological and Chemical Contamination): Groundwater plumes, or areas of contaminated groundwater, were found in the uppermost water bearing zone; these plumes consist of total uranium, thorium-230, manganese, boron, tetrachloroethene (PCE), trichloroethene (TCE), cis-1,2-DCE, trans-1,2-dichloroethene, vinyl chloride, and bis (2-ethylhexyl) phthalate. While some contamination (primarily metals) was found in the lower water bearing zone, the contaminants were isolated in extent and did not warrant identification of a plume.
- Sediment and Surface Water (Radiological Contamination): Sediment and surface water are present at some limited areas on site, and in most cases surface water is only present for a limited portion of the year. Radionuclides and metals were found to exceed background, primarily in ditches.
- Pipelines, Floor Drains and Subsurface Utilities (Radiological and Chemical Contamination): Subsurface pipelines and underground utilities are present on most of the NFSS property, which were originally constructed in the 1940's by the U.S. War Department for the TNT manufacturing plant. Contaminants are localized and are a function of previous operations but generally include: radionuclides, metals (lead, boron, cadmium and mercury), PAHs, VOCs, pesticides and PCBs.
2. What investigations were performed on the IWCS as part of the NFSS remedial investigation?
No direct sampling through the protective clay cap or side clay cut-off walls of the IWCS was performed to ensure that the integrity of this protective layer was not breached. The IWCS cap was designed and is maintained to ensure that it properly retards radon emissions and inhibits infiltration of water (in the form of precipitation) that would enhance leaching of contaminants into groundwater.
However, two types of evaluations (in addition to a thorough document review of historic waste inventories and past waste management practices) were performed to assess the continued protectiveness of the cap.
- A multi-technology geophysical walk over, which used non-intrusive techniques to infer the condition of the subsurface below the cap.
- A site-specific groundwater model was created to evaluate the potential for the radioactivity in the residues to leach to onsite groundwater and then also evaluate whether or not any radioactivity would ever migrate off-site in the groundwater.
In addition, annual environmental surveillance was continued to evaluate any radon emissions from the IWCS cap. The Environmental Surveillance Technical Memorandums are published yearly, explaining this monitoring. More information about the environmental surveillance program may be found on the NFSS Public Website.
3. What does the Remedial Investigation Report say about the safe life expectancy of the IWCS?
A 2001 geophysical survey of the Interim Waste Containment Structure (IWCS) confirmed that there are not any voids or areas of increased water saturation, within the IWCS, which indicates no significant deterioration of the structure. Additionally, the geophysical survey did not identify any significant fractures, faults, or seismic pressure points near the structure that would make the IWCS susceptible to earthquakes.
- The Corps conducted more in-depth assessments regarding the potential for radionuclides to leach to the upper and lower groundwater-bearing zones through a site-specific, numerical groundwater flow and contaminant transport model. This model was developed to simulate transport over a 10,000- year timeframe.
- Corps' transport simulations indicate that the IWCS will adequately mitigate off-site contaminant migration for 200 years (until 2186), provided it is maintained to prevent erosion of the clay cap.
- A study by the National Academy of Sciences commissioned by the DOE in 1995 determined the IWCS has a baseline safe life expectancy of 25-50 years (2011 - 2036) with continued site maintenance.
- In addition to the baseline life expectancy, several simulations were conducted by USACE to model worst case scenarios of IWCS failure such as inadvertent penetration of the IWCS cap, a breach of the IWCS, and an earthquake where no emergency repairs to the IWCS cap were made after the event. It was assumed in the modeling that the damaged IWCS cap would be exposed to the elements allowing greater rainwater infiltration and leaching of contaminants. Based upon these worst case conditions, USACE transport simulations indicate that if any of the worst-case events were to occur in present day, the long-term effectiveness of the IWCS is predicted to be reduced to 50 years or less (until 2057).
4. Did the remedial investigation identify any off-site contamination in the area surrounding NFSS?
Three areas of off-site contamination were identified and evaluated during the remedial investigation of the NFSS. What the investigation found and the risks associated with what was found are listed below:
- National Grid Property (electrical transmission power-line right of way): This property, located to the west of the NFSS, is prone to trespassers, hunters, all-terrain vehicle riders, and others. During the 2001 site-wide gamma walkover survey of the NFSS property, gamma radiation in surface soil above background was detected on the western border of the NFSS property adjacent to the National Grid property. The Corps continued the gamma walkover survey from the NFSS fenceline westerly into the west ditch on National Grid property. A strip of ground, including the ditch, approximately 60 feet x 820 feet was surveyed. Several isolated spots in this area displayed elevated radioactivity two to three times the natural background level of approximately 9,000 to 13,000 counts per minute.
The West Drainage Ditch was previously remediated by the U.S. DOE. The Corps performed a gamma walkover survey and took soil samples in this portion of the National Grid property immediately adjacent to the NFSS property and just east of the West Drainage Ditch.
The results indicate there is no imminent threat to human health in these small isolated areas. The baseline human health risk assessment concluded that concentrations of radionuclides, primarily Ra-226 and Th-230 in the surface soil in some areas of the site could pose an unacceptable radiological dose (defined by Nuclear Regulatory Commission as 25 mrem/year) only to the future, hypothetical, and most-conservative receptors evaluated, e.g., the subsistence farmer or resident. No other receptors evaluated (workers or trespassers) would receive any unacceptable radiological doses in this area of the site.
Limited chemical data collected for waste disposal purposes from the property were also evaluated. The results of the chemical BRA indicate that no chemicals found on the National Grid property would pose an unacceptable risk.
- Modern Disposal Property (Municipal Landfill): This property is located to the east and south of the NFSS. During background sampling activities, uranium above background levels was detected in groundwater near railroad tracks used by the Former LOOW and MED/AEC operations. While elevated, the levels of radioactivity were low and did not exceed USEPA Maximum Contaminant Levels for total uranium in drinking water or DOE criteria.
- CWM Chemical Services, LLC Property (Hazardous Waste Treatment, Storage and Disposal Facility): This property is located to the north of the NFSS. Chemical contamination in the upper groundwater water-bearing zone is present on both sides of the boundary of the Waste Management property and the NFSS. Analysis of potential source and localized direction of flow was inconclusive.
The Waste Management property has been used for a variety of chemical waste storage, treatment, and disposal operations by both federal (defense) and private owners and operators. The USACE will need to evaluate this situation and make a decision on the appropriate agency response with regard to potentially responsible party liability.
5. I've heard there is "radioactive slag" in roads and parking lots around Niagara County. Is this from the NFSS?
No. The slag material found is not related to the NFSS or the materials brought to the NFSS by the federal government.
Slag has been used as a cheap and plentiful bedding material under paved road surfaces. Slag is a rocky-gravelly byproduct from commercial processing of metal ores. The processing of ores can concentrate naturally occurring radioactive elements found in the earth. This results in the slag having elevated radioactivity.
The U.S. Department of Energy investigated areas of elevated radioactivity in Niagara County. They found slag with elevated radioactivity present at 62 locations in Niagara County. This was determined to be a phosphate slag material previously identified as cyclowollastonite. This slag material is attributed to the electrochemical production of elemental phosphorus using uranium-bearing raw materials which reportedly originated from the former Oldbury Furnace in Niagara Falls (see the U.S. Department of Energy "Results of Radiological Measurements Taken in the Niagara Falls, New York, Area (NF002), November 1986")
6. What is the Corps going to do about the contamination found off site?
All of the property owners have been made aware of our findings.
- National Grid Property (electrical transmission power-line right of way): The material located on the National Grid Property is MED/AEC material and will be addressed in the feasibility study. It should be noted that the National Grid Property was never designated by the U.S. DOE as a NFSS Vicinity property.
- CWM Chemical Services, LLC Property (Hazardous Waste Treatment, Storage and Disposal Facility): The material that is on CWM property straddles the CWM/NFSS property line. Chemical contamination on the NFSS property will be addressed under FUSRAP because NFSS is a federally owned property. The material that is off site, because it is chemical, will be addressed under the DERP-FUDS if it is determined that the government is liable for the contamination. It should be noted however, that CWM has implemented corrective measures (i.e., groundwater extraction wells) to address this contaminant from documented past poor management practices from previous private owners.
- Modern Disposal Property (Municipal Landfill): In regard to the Modern Disposal Property, since the levels of uranium detected in groundwater near the railroad tracks did not exceed USEPA maximum contaminant levels for total uranium in drinking water, no further action is required.
7. What does the NFSS groundwater model show?
The model predicts that uranium isotopes (U-234, U-235, and U-238), cis-1,2-dichloroethene, and vinyl chloride will exceed screening levels in the lower water bearing zone on the NFSS property after 1,000 years. Additionally, U-238 and U-235 are predicted to exceed background levels at the property boundary after 1,000 years.
To make the model more conservative, the contaminant-transport components of the overall modeling effort were designed to ensure that site constituents were mobile and provided indications of off-site exposure areas.
E. Niagara Falls Storage Site - Human Health Risk Assessment
1. How was the baseline risk assessment (BRA) performed for the NFSS?
- The NFSS baseline human health risk assessment was conducted consistent with CERCLA, USACE Guidance (EM 200-1-4), EPA guidance (Risk Assessment Guidance for Superfund), and used industry-accepted computer modeling software (RESRAD). All environmental media (surficial and deeper soils down to ten feet, surface water and sediment, groundwater) as well as pipeline and underground utility contents were evaluated. The evaluation included all chemical and radionuclides detected on site (and on the adjacent National Grid power right-of-way) above background concentrations.
- A broad range of receptors were evaluated to encompass every possible current and future exposure and land-use scenario:
- Current: Maintenance workers, trespassers (adult and adolescent),
- Future: Trespassers (adult and adolescent), maintenance worker, construction worker, industrial worker, residential (adult and child) and subsistence farming (adult and child)
- Exposure pathways evaluated included dermal absorption (chemicals only), external gamma (radionuclides only), inhalation (of volatiles and particulates), and ingestion (contaminated soils for all receptors, and contaminated surface water/sediment, groundwater, and food such as homegrown produce and game meat for some receptors).
- The evaluation period included the present time and extended 1,000 years into the future, to consider transport, decay and ingrowth of radionuclides.
- The IWCS was evaluated in its present state only ("baseline" state of continued maintenance), with the assumption that any significant breach of the cap would lead to an unacceptable risk, requiring evaluation in the feasibility study.
2. What are the findings of the NFSS BRA under current exposure scenarios?
Current receptors evaluated included the on-site maintenance worker and trespasser.
- On-site Maintenance Worker (Radiological Exposure): The Corps evaluated the current risks to an on-site maintenance worker. The model indicated that with unrestricted access to all areas of the site a maintenance worker could receive an unacceptable radiological dose (defined by the Nuclear Regulatory Commission as 25 mrem/year) due to concentrations of Ra-226 in the surface soil in some areas of the site. The comparison to the NRC's acceptable dose limit to the public is made for information only; the site does not hold an NRC license and so would not be subject to NRC's regulations.
This finding is based upon an assumption that the on-site maintenance worker has unrestricted access to the entire site and is spending every day exposed to only the most elevated radiological soil contamination present at specific locations on the site. When the risk model was run based upon the maintenance worker being exposed to average radioactivity concentrations throughout the site (more reflective of the actual conditions), the dose was below the NRC's dose limit for exposure to the public.
- On-Site Maintenance Worker (Chemical Exposure): There are localized areas of PAHs and PCBs in surface soils that the model indicates could pose an unacceptable risk (as defined by EPA) to on-site maintenance workers.
- Trespasser (Radiological Exposure): Human health risk modeling indicates that trespassers would not receive an unacceptable radiological dose.
- Trespasser (Chemical Exposure): The modeling indicates there are areas of PCBs in surface soils and sediment that could pose an unacceptable risk (as defined by EPA) to trespassers. Some of these surface soil areas are the same areas described in the maintenance worker scenario.
3. What are the findings of the NFSS BRA under future exposure scenarios?
The future exposure scenarios evaluated risks to a wide variety of future human receptors including trespassers/recreational users, maintenance workers, construction workers, industrial workers, residents, and subsistence farmers. The baseline human health risk assessment concluded that the following list of chemicals and radionuclides posed an unacceptable risk under at least one of the exposure scenarios. These are defined as chemicals or radionuclides of concern, and so will be carried forward to the feasibility study for development of remedial action objectives.
Chemicals of Concern
Radionuclides of Concern
Poly cyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), metals (including arsenic, boron, and lead), and pesticides in several localized areas on site.
Isotopes (and some decay products) of radium, thorium, uranium, as well as cesium. Radium-226 is a risk driver throughout the site.
Chlorinated solvents (including tetrachloroethene (PCE)/trichloroethene (TCE) and their degradation products), metals (including arsenic, boron, and lead), one semi-volatile organic compound (SVOC), bis (2-ethylhexyl) phthalate in localized areas of the site.
Isotopes of radium, thorium, uranium, as well as cesium. Uranium is the most wide spread contaminant in groundwater across the site.
PCBs and lead are COCs.
No ROCs (although radium, thorium, uranium, cesium, and strontium exist above background in the pipelines)
4. Are there any findings that require immediate attention?
Areas of physical hazards and radiological hazards within the NFSS are marked and controlled appropriately in accordance with Corps Engineering Memorandum 385-1-1.
There are currently no imminent hazards to safety or health from radiological or chemical exposure within the NFSS or to a member of the public outside the site.
F. Niagara Falls Storage Site - Ecological Risk Assessment
1. Are there any threatened or endangered species at the NFSS or any sensitive habitats which warrant special protection?
No threatened and endangered species exist on the site. Wetlands are present, but they are of low function/value because they have been disturbed and are of low quality for habitat purposes.
2. What are the findings of the NFSS screening level ecological risk assessment?
For radionuclides, the Department of Energy's Guide to Biota Dose Assessment indicated that there are not any concentrations of radionuclides on NFSS that would result in an unacceptable radiological dose (as defined by the International Atomic Energy Commission) to any ecological receptors.
For chemicals, several chemicals failed the very conservative screening steps (i.e., metals in surface water).
3. What is the outcome of the NFSS screening level ecological risk assessment?
The outcome of the NFSS screening level assessment is a recommendation of no further action for the relatively productive habitats, vegetation and wildlife at NFSS.
G. Niagara Falls Storage Site - Background Locations
1. What is a background location and what are the background locations for the NFSS?
An adjacent unimpacted area where data is collected to determine what the naturally occurring levels of compounds are for that area. This data is then used to compare with site data to determine what compounds are above background. The background locations used for the NFSS Remedial Investigation are found in Figure 3-14 of the Remedial Investigation Report. Section 4.4.1 of the Remedial Investigation Report discusses how background was determined. Specifically, background samples for the NFSS were collected along the inside perimeter of the boundary of the former Lake Ontario Ordnance Works Defense Environmental Restoration Program for Formerly Used Defense Sites Site. Because the potential for impact to these sample locations could not be absolutely eliminated, an outlier test was used in conjunction with a review of the historical use of these properties. Any sample that contained elevated levels of constituents of potential concern was not used in establishing background levels for the project.
2. Are the Lewiston-Porter schools contaminated?
The Corps has no evidence of radioactive contamination from MED/AEC activities at the school. The recent background radiation study (History Search Report, prepared for the U.S. Army Corps of Engineers, Baltimore District by EA Engineering, Science and Technology, August 1998, available in the Administrative Record File) supports this conclusion. The Corps also took some background soil samples on the school property, and analyzed them for metals and organic compounds. This study was completed to support the Niagara Falls Storage Site (NFSS) work, conducted under the Formerly Utilized Sites Remedial Action Plan (FUSRAP). USACE presented the results of this background soil sampling at the June 2001 LOOW Restoration Advisory Board (RAB) meeting (for further information, please see fact sheet, "Investigation of Lewiston-Porter School Property," dated June 2001). The only significant findings of these background samples were that lead and arsenic are above the NY State background concentration for residential soils. The concentrations of lead, while slightly elevated above background, are below the level that the USEPA has found to be acceptable for a child's play area (as per TOSC regulation, 40 CFR Part 745: Lead; Identification of Dangerous Levels of Lead; Final Rule). According to information provided by the NYDOH, the levels of arsenic are comparable to levels of arsenic found in old fruit orchards in this part of New York State.
In December 2001, USACE conducted a site-wide gamma walkover survey of the Lewiston-Porter School campus to compare with other background data. Representative background gamma radiation levels were measured for the purpose of comparing gamma walkover results on the NFSS property. Gamma-activity measured on the Lewiston-Porter School property was comparable to background levels and can be used for comparative purposes to the NFSS gamma activity data.
3. Have elevated levels of radon been discovered in the northeast corner of the Lewiston-Porter schools?
As part of the NFSS Environmental Surveillance Program, the Corps maintains a background radon monitoring location near the center of the Lewiston-Porter school property. The radon results have all been normal (i.e. typical of natural background) at the school monitoring location.
4. How were sites chosen to represent background for radiation in soils?
There are two sites chosen for this purpose - the National Guard Training Site and the Lew-Port School property. They were chosen because records indicate that no radiological activities have taken place in the survey areas. According to Corps health physicists, radiation levels observed were typical for regional geology and for types of surfaces surveyed (soil, concrete, and gravel). During the Remedial Investigation, the Corps took many background samples on and around the LOOW and NFSS properties.
5. If the Corps is not authorized to answer questions about health risks, then why did the Corps present results of the gamma walkover at the Lewiston-Porter school and say that no hazard to the public was found?
A risk assessment is a little different than a public health assessment (study). The risk assessments that the Corps conducts at DERP-FUDS and FUSRAP sites, such as LOOW and NFSS, follow the USEPA's Risk Assessment Guidance for Superfund sites. The Corps is responsible for determining the nature and extent of contamination to determine if and how people may ever be exposed to the contamination at the site, under both current and future conditions. From these present and projected future exposure assessments, the Corps evaluates the potential for harmful health effects to occur. The primary purpose of a risk assessment is to determine whether or not an area of contamination poses an unacceptable risk to the public. If the risk of potential human health effects is unacceptable, then this risk assessment information is used to devise a solution that will reduce this risk. This can be done by (1) treating or removing the contamination, or by (2) ensuring that no one becomes exposed. A public health assessment can only be conducted by an agency with a mandate to do so, such as the NYDOH, or the federal Agency for Toxic Substances and Disease Registry (ATSDR), which is part of the U.S. Department of Health and Human Services. The U.S. Army Corps of Engineers does not have a Congressional mandate to do a public health assessment, only to do risk assessments that support remedial action decisions at the hazardous waste sites that it is responsible for managing. A public health assessment (as conducted by ATSDR) begins with an exposure assessment, in order to determine whether or not people are actually being exposed to contamination from a hazardous waste site. If there is no route of exposure from the waste site, then the public health assessment does not progress any further. The public health assessment is more focused on actual, rather than potential health effects, to the existing community. A full public health assessment may include the results of medical, toxicological, and epidemiological studies and the data collected in disease registries.