# Presentation: 432227

**SESSION 18**
**RCRA CORRECTIVE ACTION:**
**INTERIM MEASURES / STABILIZATION / ADVANCED NOTICE OF PROPOSED RULEMAKING / TECHNICAL IMPRACTICABILITY **

## Session 18 Agenda:Interim Measures/Stabilization/Advanced Notice of Proposed Rulemaking/Technical Impracticability

- Interim Measures/Stabilization
- Advanced Notice of Proposed Rulemaking
- Technical Impracticability

## Interim Measures

- Definition
- Umbrella term for wide range of institutional and physical corrective action activities to achieve stabilization
- The goal of interim measures (IM) and stabilization is to control or abate imminent threats to human health and the environment from releases at RCRA facilities
- Interim measures can be implemented at any time during the corrective action process
- Intent of IM is to be implemented more quickly                             than traditional remedial measures

- Interim Measures/Stabilization

## Factors to consider when determining the need for interim measures/stabilization

- Facility rank based on the National Corrective Action Prioritization System (NCAPs)
- Location of contamination
- Isolated or can it be isolated?
- Significant exposure threats for human or ecological receptors
- Potential for situation to deteriorate (i.e., new release may occur due to storms, floods, and structural design failure)
- Time required to develop and implement final remedies under corrective action program
- Information regarding contaminant and site characteristics

- Interim Measures/Stabilization

## Factors to consider when determining the need for interim measures/stabilization (continued)

- Presence of high levels of hazardous constituents in soil at or near the surface, and potential for release
- Risk of fire, explosion, or other accident
- Types of contaminants and volumes of releases
- Technical complexity of remediation
- Technical practicability of implementing a stabilization measure.  Refer to _Guidance for Evaluating Technical Impracticability of Groundwater Restoration_ (September 1993)
- Appropriate technologies to deal with known contaminants
- Media-specific characteristics, such as site hydrogeology or prevailing wind direction

- Interim Measures/Stabilization

## Achieving Stabilization 

- Stabilization can be achieved through
- Source control
- Media cleanup
- Exposure control
- Examples of stabilization
- Providing bottled water
- Pump and treat system
- Capping soil
- Soil excavation

- Interim Measures/Stabilization

## Advanced Notice of Proposed Rulemaking

- Published Corrective Action Advance Notice of Proposed Rulemaking (ANPR) 5/1/96 (61 _FR_ 19432)
- Three primary purposes:
-  Strategy to improve corrective action program
-  Guidance for program implementation
-  Emphasize areas of available flexibility and innovative approaches

- ANPR

## ANPR Content

- Section I identifies regulatory basis
- Section II discusses major guidance and policy milestones since 1990 proposal
- Section III describes current expectations regarding program implementation
- Section IV outlines key goals and strategies
- Section V requests comment/data that will help identify improvements

- ANPR

## ANPR Program Philosophy

- Corrective action should be based on risk
- Results driven rather than process driven
- Interim actions and stabilization should be used to reduce risk and prevent exposure
- Activities should be phased to focus resources on areas or pathways of greatest concern

- ANPR

## Philosophy (continued)

- Should provide meaningful inclusion of all stakeholders
- Should be implemented using most appropriate authority, including state authorities and voluntary actions
- States will be the primary implementers

- ANPR

## Examples of Flexibility Highlighted in ANPR

- Investigation tools and approaches
- Conceptual site model
- Data quality objectives
- Innovative sampling and analytical techniques
- Action levels
- Industrial-based action levels may be appropriate in some settings, especially for interim actions

- ANPR

## Examples of Flexibility (continued)

- Delineation of contamination
- Not always needed to background concentrations
- Future land use should be considered
- Non-residential cleanups can be acceptable
- Formal evaluation of remedial alternatives not always needed
- Technical impracticability
- Natural attenuation
- Performance-based remedies

- ANPR

## Presumptive Remedies Defined

- Presumptive remedies
- Preferred technologies for common categories of sites
- Based on historical patterns of remedy selection
- Effective remedial technologies for specific contaminants
- EPA’s scientific and engineering evaluation of performance data on technology implementation
- Advantages
- Ensures remedy selection/implementation consistency
- Reduces cost and time required as remedial technology is already accepted
- Example
- Soil Vapor Extraction for soil contaminated with VOCs

- ANPR

## Technical Impracticability refers to:

- A determination that restoration of an environmental medium or waste may not be achievable due to remediation technology limitations related to
- Hydrogeologic factors
- Contaminant-related factors
- Waste-related factors
- Site-related factors
- Cost

- Technical Impracticability

## Technical Impracticability (continued)

- For portions of the site that can be restored, a technical impracticability (TI) determination would not apply
- TI determinations are not a scaling back of efforts to achieve media cleanup goals
- Require exposure control
- Require source control
- Require aqueous plume remediation

- Technical Impracticability

## TI determinations are made:

- Early in the remediation process when possible
- At the time of statement of basis
- The possibility that certain remedies are technically impracticable should be considered throughout the remedial process

- Technical Impracticability

## Technical Impracticability (continued)

- Major factors that inhibit groundwater restoration
- Hydrogeologic
- Complex sedimentary deposits
- Aquifers of low permeability
- Fractured bedrock
- Contaminant
- NAPLs (particularly DNAPLs)
- TI requires an evaluation
- Prepared by facility
- Adequate site characterization data
- Presence of a constraint (DNAPL, low permeability aquifer) is not adequate justification
- Based on site conceptual model and data collected during the RFI

- Technical Impracticability

## Technical Impracticability evaluation components include:

- Specific media protection standards to which TI applies
- Spatial area over which TI is to apply
- Site conceptual model
- An evaluation of the restoration potential of the site
- Demonstration that sources have been identified and will be removed or contained
- An analysis of any ongoing corrective measures
- Estimate of time frame to achieve the media                              protection standards using available technologies
- Demonstration that technologies could not attain                                  cleanup levels

- Technical Impracticability

## TI evaluation components (continued)

- Estimate of costs for existing and proposed technologies
- Other information
- groundwater flow modeling
- contaminant fate and transport models

- Technical Impracticability

## Technical Impracticability (continued)

- TI determinations always include selection of an alternative corrective measure that includes:
- Exposure control via institutional controls
- Restrictions on groundwater use
- Deed notifications
- Source control
- Remove or treat source to the extent feasible
- Isolate the source using a slurry wall or hydraulic containment system
- If a source cannot be contained, plume restoration may be technically impracticable. However, facility must implement:
- Hydraulic containment of leading edge of aqueous plume
- pump and treat
- Hydraulic containment of the source area to the extent possible

- Technical Impracticability

## The following guidance provides additional information:

- U.S. Environmental Protection Agency. 2001. _Handbook of Groundwater Protection and Cleanup Policies for RCRA Corrective Action_.  October 2001.  (EPA 530-F-01-021)
- _[www.epa.gov/compliance/resources/policies/cleanup/rcra/index.html](http://www.epa.gov/compliance/resources/policies/cleanup/rcra/index.html)_
- _www.epa.gov/correctiveaction_

- Guidance