Managing RiskFeedback

What is Long-Term Stewardship?

Long Term Stewardship (LTS) applies to sites where risk-based cleanups make long-term management of land, surface water, or groundwater necessary to prevent exposure to contamination left in place at a site. Long-term stewardship generally includes the following factors:

Who is Responsible for LTS?

Risk-based cleanup and reuse of properties requires coordination of LTS activities among many government agencies and stakeholders. Risk-based cleanups involve long term operation and maintenance, monitoring, evaluation, periodic repairs, and sometimes replacement of remedy components. Each stakeholder plays a particular role and has certain responsibilities for carrying out one or more of the LTS activities listed above. These stakeholders may include the following:

What are engineering controls?

Physical, or “engineered”, controls are the engineered physical barriers or structures designed to monitor and prevent or limit exposure to the contamination. These processes and technologies typically include containment or treatment technologies designed to remedy contamination and reduce or eliminate the threat while allowing the revitalization and future use of the property to progress. Certain engineered cleanups will involve ongoing operation and maintenance (O&M) monitoring, evaluation, periodic repair, and sometimes replacement of remedy components.

Containment technologies are designed to isolate the contaminants of concern to prevent exposure by potential receptors and to prevent further migration of the contaminants. Containment technologies include such technologies as cutoff walls, grout curtains, capping or encapsulation technologies, and solidification/stabilization technologies. With the increased use of innovative technologies prompted by the revitalization movement, there are a number of promising new technologies that may prove useful in applications at revitalization sites. Examples include technologies designed to operate effectively while being incorporated into the architectural elements of the development property. See notes from the field entitled Clever Capping for examples of encapsulation that is incorporated into the architecture of a redevelopment. Such encapsulation may include groundwater and vapor control technologies that are incorporated into building plans to allow remediation activities to continue, largely un-noticed, following redevelopment. The advantages of incorporating such technologies include limiting the impact to the project schedule and an indefinite duration to the time required for clean up.

In situ (or on-site) treatment technologies can also be used to clean up contamination in one area while permitting the revitalization and future use to continue in another area. Increasingly, innovative technologies and approaches to implementing treatment technologies are being incorporated into revitalization design.

What are Institutional Controls?

Two primary purposes of institutional controls are to protect the integrity of engineering controls and to minimize the potential for exposure to residual contamination. Institutional controls (IC) or legal controls, are non-engineered instruments, such as administrative and/or legal orders or permits intended to minimize the potential for humans to use the redeveloped land in a way that is incompatible with the remedy. Institutional controls work by limiting resource use or by providing information that helps modify or guide human behavior to recognize that residual contamination remains on the site. Institutional controls may be used to supplement engineering controls and also must be operated, monitored, and evaluated for effectiveness for as long as the risks at a site are present. Institutional controls may include cap inspection and maintenance; proper management of any soil excavated as part of site maintenance or capital improvement projects; and notification to workers who may penetrate the surface cap and contact contaminated soil or groundwater.

Additional information related to Institutional Controls can be found on EPA’s Office of Brownfields Cleanup and Redevelopment, Tools and Technical Information, Land Use and Institutional Controls web site.

Estimating the Cost of Institutional Controls, establishes a framework of IC activities and the timeframes for these actions that regulators and land owners can consider in estimating costs. The guide divides the IC process into various steps, including: planning, record-keeping, monitoring, inspection and enforcement. The steps are also categorized by how frequently they must occur, whether annually or periodically, or only as an initial measure.

A Land Use Control Implementation Plan (LUCIP) can be used by federal, state, and local governments to map out a strategy for engineering and institutional control implementation, monitoring and enforcement. LUCIPs should be tailored to fit the specific types of sites, the relevant regulatory frameworks, and the stakeholders involved in LUCs. The model provided by the hyperlink is designed as a menu from which local governments and other stakeholders can pick and choose elements appropriate to their particular LUC circumstances. Stakeholders using this model should liberally tailor it to fit their own particular needs.

In 2003, the Uniform Environmental Covenants Act (UECA) was promulgated by the Uniform Law Commissioners to overcome the inadequate common law rules. The statutory legal mechanism it creates is called an “environmental covenant.” Covenants are generally recognized in the common law as a means of conveying restrictions on use of land. The environmental covenant relies on the common law base, but re-creates it for the specific purpose of controlling the use of contaminated real estate, perpetually if necessary, while allowing that real estate to be conveyed from one person to another subject to those controls. Section 12 of UECA contains language creating an optional Environmental Covenants Registry, which maps out a strategy for tracking and enforcement of institutional controls. This model language would be only effective in states that adopt UECA and elect to use optional Section 12.

Land-Use Controls (LUCs) The International City/County Management Association (ICMA) has created a Web site to help local governments and communities learn more about how LUCs can be used to promote revitalization at potentially contaminated, military and federal facilities, and Superfund sites. The Web site includes documents and information collected from federal, state, and local governments, non-governmental organizations, municipal authorities, restoration advisory boards, and local revitalization authorities. The documents are maintained in a searchable electronic library (e-Library).

Click on the LUC WebRing to explore the virtual community around the issue of risk-based cleanups and the land use controls that make such cleanups possible. The LUC WebRing links governmental online institutional control tracking systems, academic land use control research, commercial land use control services, nongovernmental organization land use control information, and environmentally-impaired real estate and lending services. The LUC WebRing is managed by the International City/Council Management Association (ICMA) and supported by U.S. EPA.

The ITRC Brownfields Team has developed a Vapor Intrusion Issues at Brownfield Sites document that provides an overview of vapor intrusion, contaminant types with vapor intrusion potential, brownfield sites' potential to have indoor air exposure from vapor intrusion, and steps that can be taken to limit exposures.

Challenge: Investigations at this 1950's landfill identified surface and subsurface soil contamination, causing the site to be placed under Superfund.

Solution: Constructed a stable, flood-resistant river bank/dike. Incorporated a combined soil/asphalt cap into the closure plan, meeting the requirements of the regulators and the needs of the community.

Location: McArthur Drive Landfill, St. Joseph, Missouri

Project Description: This municipal and industrial landfill is listed as a Superfund site as a result of its past use as a wash down area for City vehicles using fumigants for mosquito control. Investigations conducted by the U.S. Environmental Protection Agency (EPA) identified pesticides, volatile organics, and heavy metal contaminants on the site.

Working with the EPA on behalf of the City, SCS Engineers, an environmental contractor, assisted in the clean up of this site, proceeding under a streamlined approach outlined in the Presumptive Remedy for CERCLA Municipal Landfill Sites. SCS’ work began with an investigation of alternative caps, followed by development of design and construction documents for the bank stabilization project, an Engineering Evaluation/Cost Analysis (EECA), and a groundwater monitoring system evaluation work plan.

Construction of the bank stabilization, a time-critical element identified in the EPA’s first Administrative Order on Consent (AOC), was completed in the spring of 1997. The non-critical closure of the site has also been completed, including capping one-half of the 14-acre site with a designed and certified, asphaltic concrete cap. The remainder of the site is capped with soil

The closed facility includes a hike/bike trail running along the Missouri River, a public parking area, (used by the adjacent Missouri Department of Conservation boat launch), and a green area. The facility will eventually be incorporated into a future community park system, which is being developed by the City along the Missouri River.

Source: SCS Engineers

McArthur Drive Landfill Before

McArthur Drive Landfill After

The following before and after photos are examples of various implemented engineering controls.