CERCLA Remedial Action Site Closure Guidance

Figure 4. Type B: Typical Long Term Cleanups for CERCLA Groundwater Operable Units

III-B. Type B: Long-Term Cleanup
Type B, ‘Long-Term Cleanups,’ usually addresses cleanups associated with ground water remediation of CERCLA operable units. The two types of groundwater treatment are in-situ and ex-situ. In-situ treatments allow groundwater to be treated without being brought to the surface, which can result in significant cost savings. In-situ treatment, however generally requires longer time periods and there is less certainty about the uniformity of treatment. The variability of aquifer characteristics and the difficulty of verifying the efficacy of the process are two drawbacks with in-situ treatment.

In-situ treatments typically involve either biological or physical/chemical technologies. Available in-situ physical/chemical treatment technologies include air sparging, bioslurping, directional wells, dual phase extraction, thermal treatment, hydrofracturing, in-well air stripping, and passive/reactive treatment walls. For example, available in-situ biological treatment technologies include enhanced biodegradation (nitrate and oxygen enhancement with either air sparging or hydrogen peroxide), monitored natural attenuation, and phytoremediation of organics. However, monitored natural attenuation is not a “technology” per se; rather it is an approach that relies on natural processes and monitoring. The expectation is that natural subsurface processes such as dilution, volatilization, biodegradation, adsorption, and chemical reactions with subsurface materials will reduce contaminant concentrations to acceptable levels.

By contrast, ex-situ treatments generally require shorter time periods, and there is more certainty about the uniformity of treatment because of the ability to monitor and continuously mix the groundwater. However, ex-situ treatments require pumping of groundwater, leading to potential increased costs and engineering for equipment, possible permitting, and material handling. Like in-situ treatment, ex-situ treatments typically involve either biological or physical/chemical technologies. For example, available ex-situ biological treatment technologies are bioreactors and constructed wetlands. Available ex-situ physical/chemical treatment technologies include adsorption/absorption, advanced oxidation processes, air stripping, granulated activated carbon/liquid phase carbon adsorption, ion exchange, precipitation/coagulation/flocculation, separation, and sprinkler irrigation.

Regardless of the type of groundwater treatment technology employed, the required activities for completing groundwater remedies are the same. Figure 4 depicts the standard remedial action completion elements for groundwater treatments. To find out more about these requirements, simply click on the section of the process that is of interest to you.

B.1 Remedial Action   [top]
The RA is the implementation of the remedy selected in the Record of Decision (ROD). The RA start date is defined as the date the contractor has mobilized and begun substantial and continuous physical on-site remedial action, as documented by a memo or letter to EPA.

B.2 Operating Properly and Successfully (OP&S)   [top]
OP&S activities are conducted after the physical construction of the treatment system is complete. The purpose of OP&S is primarily to test the treatment system. This ‘testing period’ could last up to one year. OP&S start and finish times should be documented with EPA and the State. No OP&S is necessary if no waste is left on-site (Clean Closure, Type-A). The phrase "operating properly and successfully" involves two separate concepts. A remedial action is operating "properly" if the treatment system is operating as designed. That same system is operating "successfully" if its operation will achieve the cleanup levels or performance goals (removal of contaminant) as described in the decision document. Additionally, in order to be successful, that remedy must be protective of human health and the environment. For instance, an ex-situ pump and treat system may be operating properly according to its design for pumping and extracting so many gallons of ground water per day, but not operating successfully because the amount of contaminant removed does not meet the requirements as described in the ROD.

B.3 Final Inspection   [top]
With any RA construction contract, normal construction industry practice is to conduct contract pre-final and final inspections prior to closing out the construction contract. These inspections are conducted to determine whether the treatment system has been completed in accordance with the contract design and specifications. The inspections are generally held between the contracting party (DOE) and the construction contractor, although others can be invited (e.g., EPA).

During the contract pre-final inspection, the contracting party’s project manager and the construction contractor inspect all elements of work to see if the work is complete and ready for acceptance under the terms of the contract. Some minor defects may come to light during the inspection. The construction manager develops a “punch list” of all items that need correction or completion before the work can be accepted. A pre-final inspection report is prepared, including the punch list, completion dates for outstanding items, and a date for a final inspection.

If punch list items are minor, the pre-final inspection may automatically serve as the final inspection. Otherwise, a final inspection is conducted later to determine that punch list items are corrected and all work has been completed in accordance with the contract plans and specifications. Federal Facility Agreements (FFAs) generally require a set of inspections to determine that all aspects of the remedy have been implemented in accordance with applicable enforcement documents and the ROD. Participants for the final inspection usually include: DOE, the State, EPA, and the DOE oversight contractor. For long-term cleanups, the treatment system(s) must meet the OP&S criteria.

B.4 Interim Remedial Action Report   [top]
The interim report for a given operable unit is used only for remedial actions that include ground or surface water restoration remedies, including monitored natural attenuation. Interim reports are used because of the long delay between construction of the treatment facility (or ROD signature for monitored natural attenuation) and attaining cleanup goals as specified in the ROD. This delay could last many years. The interim report is identical in content to the final RA report.

B.5 Preparing the Interim RA Report   [top]
DOE is the lead agency and as the lead agency DOE should prepare the Interim Report in consultation with EPA and the State.

The Interim RA Report, like the final RA Report, usually contains ten sections and these sections should be tailored to the site depending upon the type of remediation used. Also, the final contract inspection for the Interim RA Report must be completed before the report can be written and submitted to the appropriate EPA Regional official. The sections in the Interim Report are as follows:

I.		Introduction
II.		Operable Unit Background
III.		Construction Activities
IV.		Chronology of Events
V.		Performance Standards and Construction Quality Control
VI.		Final Inspection and Certifications
VII.		Operation and Maintenance
VIII.		Summary of Project Costs
IX.		Observations and Lessons Learned
X.		Operable Unit Contact Information
Appendix A.		Remedial Action Report
		Cost and Performance Summary

B.6 Submitting the Interim RA Report to EPA    [top]
Following completion of the final contract inspection, submit the Interim Report to the designated EPA Regional Official. The goal is for DOE to submit the report for approval within 90 days of the final inspection for OP&S.

When the report is received at the EPA Regional Office, EPA uses the following criteria to approve the Interim RA Report:

• The remedy includes ground water restoration with active treatment (ex-situ) or monitored natural attenuation to reduce contaminant concentrations to meet cleanup goals at some future date;
  
• For active treatment, all construction activities of the treatment system are completed and the system is operating as intended (OP&S);
  
• For monitored natural attenuation, any necessary remedial action, such as monitoring wells, has been constructed;
  
• A contract final inspection or equivalent has been conducted; and
  
• The Interim RA Report is consistent with the EPA guidance, Close Out Procedures for National Priorities List Sites.

B.7 Interim RA Report Approval   [top]
EPA will return the report with the signature (of the Branch Chief or above) on the cover sheet or by letter to DOE. At the operable unit level, EPA Headquarters does not have to review the report or concur with the EPA Region.

Once the designated Regional EPA Official approves in writing the Interim RA Report, this CERCLA milestone has been achieved. The Interim RA Report can simply be amended (updated) to create the Final RA Report. The Final RA Report would include any additional information on activities since the Interim RA Report was completed.

B.8 Operation and Maintenance (O&M)   [top]
O&M are the activities required to maintain the effectiveness and integrity of the remedy after OP&S. In the case of groundwater remedies, O&M involves operating and maintaining the groundwater containment and restoration 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.

O&M completion is accomplished when the cleanup goals as specified in the ROD are achieved for groundwater restoration.

B.9 Final Remedial Action Report   [top]
The Final RA report documents the cleanup activities that took place at the operable unit under remedial authority. In the case of long-term cleanups, an Interim RA Report has already been prepared; therefore, the Interim RA Report can simply be amended to create the Final RA Report. The amendment would add information on activities that occurred after the Interim RA Report was completed.

B.10 Submitting the Final RA Report to EPA   [top]
Following completion of the O&M period, DOE submits the Final RA Report to the designated EPA Regional Official. When the report is received at the EPA Regional Office, EPA uses the following criteria to approve the Report:

• All construction activities are complete, including site restoration;
  
• All cleanup goals as specified in the ROD have been achieved;
  
• A contract final inspection or equivalent has been conducted; and
  
• The RA Report is consistent with the EPA guidance, Close Out Procedures for National Priorities List Sites.

B.11 Final RA Report Approval   [top]
EPA will return the report with the signature (of the Branch Chief or above) on the cover sheet or by letter to DOE. At the operable unit level, EPA Headquarters does not have to review the report or concur with the EPA region.

Once the designated Regional EPA Official approves in writing the RA Report, this CERCLA milestone has been accomplished.

B.12 Cleanup Goals Achieved   [top]
Cleanup Goals Achieved is a milestone used for groundwater restoration, including monitored natural attenuation remedies. These long-term cleanup remedies have not yet achieved cleanup goals when the Interim RA Report is signed and the remedy transitions from the remedial action phase into O&M. The cleanup goals achieved milestone signals the completion of the remedial action and is accomplished on the date the designated Regional EPA Official approves in writing the Final RA Report. This report should update information previously provided in the Interim RA Report.

B.13 Checklist For Type B – Long Term Cleanups   [top]

1. Remedial Action
   
2. Operating Properly and Successfully
3. Pre-Final Inspection
4. Interim RA Report
5. Preparing the Interim RA Report
6. Submitting the Interim RA Report to EPA
7. Interim RA Report Approval
8. Operation and Maintenance
9. The Final RA Report
10. Submitting the Final RA Report
11. Approval of the Final RA Report
12. Cleanup Goals Achieved