Under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), an evaluation of response actions at hazardous-waste sites where contaminants are present above levels that allow for unlimited use/unrestricted exposure is required at least every five years following the start of the cleanup at the site.
Purpose of the Five-Year Review
The purpose of the FYR is to determine whether the cleanup response continues to be protective of human health and the environment. These reviews begin five years after the initiation of the first response and continue in five-year cycles in perpetuity or at least until the site is documented in an FYR to meet unlimited use/unrestricted exposure requirements (UUUE).
St. Louis FUSRAP Sites
The FYR assesses the cleanups underway at FUSRAP St. Louis sites (SLS). SLS consist of two locations designated as the St. Louis Downtown Site (SLDS) in northern St. Louis City and the North St. Louis County sites that contain radiological and chemical contamination resulting from the Manhattan Engineer District/Atomic Energy Commission (MED/AEC) operations. SLDS is comprised of the Mallinckrodt Inc. property and 38 surrounding vicinity properties (VPs). The North St. Louis County sites are located near the St. Louis Lambert International Airport, once known as Lambert-St. Louis International Airport, and include:
· the St. Louis Airport Site (SLAPS);
· Latty Avenue Properties, including the Hazelwood Interim Storage Site (HISS) and Futura Coatings (Futura), and six VPs; and
· the SLAPS VPs, which encompass numerous properties between SLAPS, HISS/Futura, Coldwater Creek and the properties along Coldwater Creek. Of the 148 SLAPS VPs (named and unnamed within the industrial boundaries of the North County Record of Decision), 106 industrial properties have been released to date. Of the 200 Coldwater Creek properties that FUSRAP has sampled so far, 33 CWC properties have been released.
The Selected Remedy
The Selected Remedy for accessible areas at SLDS is presented in the 1998 SLDS Record of Decision (ROD) and requires excavation and off-site disposal of radiological and chemical contamination in surface and subsurface accessible soil resulting from MED/AEC processing activities. The selected remedy also includes monitoring of the Mississippi Alluvial Aquifer.
The U.S. Army Corps of Engineers released the Remedial Investigation (RI) and Baseline Risk Assessment (BRA) Report for the Inaccessible Soil Operable Unit at SLDS in 2012. Inaccessible soils are located under buildings, permanent structures, railroads, soils on buildings and permanent structures, sewers and soils adjacent to sewers. The RI/BRA identified and characterized properties/areas at SLDS that contained inaccessible soils.
The results from the RI/BRA revealed that 17 properties/areas out of 23 at SLDS with inaccessible soils met the EPA risk-and-dose criteria for release with no institutional controls.
USACE is currently preparing two RODs to address the inaccessible soils at SLDS. USACE will soon release a No-Action ROD that will release 17 properties/areas at SLDS that met EPA risk-and-dose criteria for release under UUUE. USACE will then prepare a ROD that addresses six properties/areas at SLDS that require institutional controls.
A separate remedy for the North County sites is presented in the 2005 ROD for North St. Louis County. The selected remedy consists of excavation and off-site disposal of radiological and chemical contamination in accessible soil resulting from MED/AEC processing activities. Other components of the North County ROD include:
· Using restrictions at areas under roads, active rail lines and other permanent structures where the residual condition isn't consistent with UUUE;
· Dredging contaminated sediments from Coldwater Creek to remediation goals that support UUUE;
· Monitoring groundwater long-term in selected areas where soils contaminated above remediation goals are left in place or where contaminated groundwater has the potential to degrade adjacent groundwater or surface-water systems.
How is a Five-Year Review conducted?
The FYR is conducted by a team led by the U.S. Army Corps of Engineers (USACE) with representatives from the U.S. Environmental Protection Agency (EPA) and the Missouri Department of Natural Resources (MDNR). The FYR consists of four components: document review, site inspection, site interviews and assessment of response-action protectiveness.
The “document review” is a review of the key documents identifying the approved response actions, how they are being carried out, legal requirements influencing the response actions, impacts of the response action on human health and the environment, and community concerns. These documents include the RODs, as-built drawings, site-monitoring information, the Federal Facilities Agreement (FFA) and the Community Involvement Plan (CIP).
The site-inspection process involves the team inspection of each site and identifies the condition of the site and surrounding area. The team verifies that key records (i.e. health and safety plans) are on site and available, verifies that access controls (i.e. fences) are in place and notes the general condition of site features (i.e. cover material).
The team also seeks community input regarding the implementation of the response actions through site interviews. Members of the community, site personnel, state/local authorities, community groups, property owners and neighboring residents/businesses are asked to identify any problems that need to be addressed at the sites and to identify concerns regarding the impacts of the cleanup as it progresses.
Assessing the protectiveness of the remedy
To assess the protectiveness of the remedy for SLDS and the North St. Louis County sites (using information gathered during the document review, site inspections and site interviews), three essential questions are asked:
1. Is the response action functioning as intended?
2. Are the exposure assumptions, toxicity data, cleanup levels and Remedial Action Objectives of the remedy valid?
3. Is any new information available that would call into question the protectiveness of the remedy?
At SLDS, the protectiveness of the remedy continues to be effective. Groundwater isn't currently used as a drinking-water source and existing access controls limit potential exposures to contaminated groundwater. USACE will conduct Phase 2 of the Groundwater Remedial Action Alternative Assessment (GRAAA) to evaluate the fate and transport of the site FUSRAP contaminants of concern (COCs) in the groundwater. In addition, USACE will continue monitoring the Mississippi Alluvial Aquifer (HU-B) to evaluate the effectiveness of the source-removal action.
At the North St. Louis County site, USACE will continue to monitor groundwater, surface water and sediment to ensure that the elevated total uranium (U) concentrations in shallow groundwater at the western edge of SLAPS doesn't impact Coldwater Creek. If the total U concentrations significantly increase and impacts to Coldwater Creek are anticipated, an evaluation of potential response actions will be conducted and an appropriate response will be implemented.
Protectiveness Statement for SLS:
As required by CERCLA, USACE and the EPA have completed the first, second and third FYRs for the St. Louis FUSRAP sites. (The third FYR was completed July 31, 2015.) The FYR is required because hazardous substances, pollutants or contaminants remain at SLS above levels that allow for UUUE. These reviews evaluated the protectiveness of the SLDS Operable Unit (OU) remedy and the North St. Louis County OU remedy.
Since the remedial actions of SLDS Operable Unit (OU) and the North St. Louis County OU are under construction and not completed, the remedies for SLS OUs are expected to be protective of human health and the environment upon completion. In the interim, exposure pathways that could result in unacceptable risks are being controlled.
The reviews indicate that, while conditions at SLS may be protective, conditions could be improved with relatively minor effort, consistent with the recommendations in the reviews, to ensure the safety and health of SLS workers and other potential exposure groups.
Next Five-Year Review
USACE plans to initiate activities for the next (fourth) FYR in 2018. USACE will be contacting businesses, property owners, representatives from government agencies, utility companies and private citizens to interview. USACE anticipates the completion of the fourth FYR in late 2019.
Finding the results of the Five-Year Review
The results of the FYRs are available to the public in the “Five-Year Review Report for the St. Louis FUSRAP Sites.” The final report documents the methods, findings and conclusions of the review. Any problems found and recommendations to address them are documented in the report.
Five-Year Review Report: Third Five-Year Review Report for Formerly Utilized Sites Remedial Action Program (FUSRAP) St. Louis Sites
Five-Year Review Report: Five-Year Review Report for Formerly Utilized Sites Remedial Action Program (FUSRAP) Iowa Army Ammunition Plant