CERCLA Remedial Action Site Closure Guidance

Figure 7. Typical CERCLA Post-Completion Activities

V. Post-Completion Activities
Section V addresses those activities that occur once site completion has been achieved. Superfund post-completion encompasses a number of related activities including:

• Operation and maintenance of engineered containment remedies as
  well as groundwater and surface water restoration systems;
  
• Implementation and management of institutional controls;
  
• Five-year reviews;
  
• Optimization of remedies based on actual operating experience; and
  
• Deletion from the NPL.

These post-completion activities support four broad objectives: 1) maintain the integrity of Superfund response actions; 2) provide relevant information to stakeholders; 3) ensure the efficiency of post-construction operations; and 4) delete sites from the NPL. Figure 7 depicts the standard post-completion elements at the site level. To find out more about these requirements, simply click on the section of the process that is of interest to you.

V-A Operation and Maintenance (O&M)    [top]
O&M are the activities required to maintain the effectiveness and integrity of the remedy. In the case of waste-in-place remedies, O&M involves maintaining engineered containment structures; operating leachate and gas collection systems; monitoring to ensure that the remedy is performing as expected and the environment is protected; and maintaining and enforcing institutional controls and access restrictions.

The DOE may have to perform O&M indefinitely for remedies that contain wastes on-site, or include institutional controls. Prior to the termination of the O&M, EPA approval is required.

V-B Institutional Controls   [top]
Institutional controls (also called land use controls, and activity and use restrictions) are non-engineered, administrative or legal instruments that minimize the potential for exposure to contamination by limiting land or resource use. Institutional controls can play an important role in remedy selection, and generally are used in conjunction with, rather than in lieu of, engineering measures for treatment or containment. Generally, institutional controls selected as part of a remedy should be implemented along with other components of the remedy before Superfund sites can be deleted from the NPL. Once institutional controls are in place, site managers should evaluate the administrative and legal documentation, as well as the physical site evidence, to ensure that they are fully effective. This review should be an integral part of the technical assessment performed during operation and maintenance inspections, as well as during the five-year review process.

V-C Five-Year Review    [top]
Five-year reviews generally are required following implementation of remedial actions selected under Section 121 of CERCLA, when hazardous substances, pollutants, or contaminants remain on-site above levels that allow for unlimited use and unrestricted exposure (as is the case for waste-in-place remedies depicted in Figure 7). In addition, five-year reviews generally are appropriate for sites where completion of the remedial action ultimately will allow for unlimited use and unrestricted exposure, but the remedy will take longer than five years to reach cleanup levels.

The purpose of a five-year review is to evaluate the implementation and performance of a remedy in order to determine if the remedy is or will be protective of human health and the environment. Five-year reviews provide an opportunity to identify potential problems or issues with the remedial action, and adjust O&M where necessary.

V-D Optimization of Remediation Systems   [top]
Once remediation systems have been functioning for a period of time, opportunities may exist to optimize the operations of the system. The purpose of optimization is to identify potential changes that will improve the effectiveness of the system and/or reduce operating costs, without compromising the protectiveness of the remedy or other response objectives, through a comprehensive evaluation of system performance. Optimization recognizes that long-term remedial approaches should not remain static, that conditions change over time, and that better technologies, tools and strategies evolve which allow for continuous improvement of remedy performance.

Optimization can be applied to groundwater restoration systems, as well as other remediation technologies (e.g., soil vapor extraction) and approaches (e.g., long-term monitoring).

V-E Deletion from the NPL   [top]
The NPL deletion process begins at most sites once the site completion milestone has been achieved. Site deletion requirements ensure that 1) the documentation of activities and decision making at the site is complete; 2) the activities conducted and documented are verified; and 3) the public has an opportunity for notice and comment before a site is formally deleted from the NPL.

The National Oil and Hazardous Substances Pollution Contingency Plan (NCP) dictates the deletion process. Specifically, the procedures are contained in the NCP, Subpart E, Section 300.425. The EPA must consult with the State in making this determination.

The deletion process is divided into three steps: process initiation, publication of the Notice of Intent to Delete (NOID), and preparation of a responsiveness summary (and publication of Notice of Deletion – NOD). It has been separated from the five-year review program (56 FR 66601, December 24, 1991). This means that a site can be deleted from the NPL even when five-year reviews are required.

The EPA has also released guidance to streamline and accelerate the deletion process. The Direct Final Process for Deletions guidance is appropriate for sites where deletion from the NPL is not expected to be controversial, and the Agency does not expect adverse comments from the public. The direct final process has been used successfully at several sites, and the guidance includes approved templates to aid in developing the required notices.

V-F Partial Deletion   [top]
The NPL partial deletion process begins at most sites once a portion of the site has been cleaned up and site deletion criteria are met for that portion of the site. Requirements for the partial deletion area are the same as for the full deletion. Two differences are the mapping requirements for the partially deleted area and the documentation that supports the decision to partially delete.

Partial deletion requirements ensure that the:

• Documentation of activities and decision making at the portion of the site is complete;
  
• Activities conducted and documented are verified;
  
• Area of the site to be deleted is clearly and accurately defined/delineated; and
  
• Public has an opportunity for notice and comment before the portion is formally deleted from the NPL.

The partial deletion process is divided into three steps: process initiation, publication of the Notice of Intent to Partially Delete (NOIPD), and preparation of a responsiveness summary (and publication of Notice of Partial Deletion – NOPD).