The document addresses the important aspects of closing ash ponds, emphasizing regulatory requirements, strategic considerations, and environmental liabilities. It outlines the factors influencing the closure timeline and methods, including potential future land use and the pros and cons of in-place versus removal strategies. Additionally, it highlights the need for planning and assessing risks associated with groundwater and environmental impacts.

1. Are You Prepared to Close Your Ash Ponds?
R. Kent Nilsson, P.E.
Senior Consulting Engineer
TRC Environmental Corporation

2. Drawbacks of Learning by Trial and Error…

3. Drivers for Pond Closure
Regulatory requirements
Plant retirements
Changes to facility operations
Environmental liability management
Political/social pressures

4. Regulatory Requirements
EPA has agreed to take final action on Coal Combustion Residuals (CCR) by December 19, 2014
Revised RCRA Subtitle “D” standards are the most likely outcome
Likely to be implemented at state level
Closure also affected by Effluent Limitation Guidelines (ELGs)
Recent developments may influence outcome
Final rule likely to be litigated

5. Regulatory Requirements – Ash Ponds
Anticipated RCRA Subtitle “D” requirements:
Rule effective 6 months after promulgation
Ponds not meeting liner requirements must stop accepting waste within 5 years of finalization of rules
Groundwater monitoring required within 1 year after effective date
Ponds must be closed within 2 years of last receiving waste

6. Strategy
Mapping out a strategic plan must consider the questions:
Close now or later?
Future end use of property?
Close in-place or remove the residuals?
What are the costs?

7. Strategy
A Generic Decision Matrix

8. Strategy – Close Now or Later?
Dictated by:
Regulatory framework and its timing
Short and long-term risk profile
Retiring plant or continuing to operate
Changes to facility operating requirements (e.g. wet ash v. dry ash handling)
Costs and funding

9. Strategy – Close Now or Later?
Closure schedule affected by:
Regulatory requirements/deadlines
Future site use
Pond size
Ash pond assessment and preparation of design and bid package
Regulatory approvals

10. Strategy – Future End Use of Property?
Retiring plants need to clearly define
Prime redevelopment locations may require stricter clean-up
Site specific conditions (e.g., wetlands)
Ash geotechnical properties

11. Strategy – Close In-place or Remove the Residuals?
Viable market for pond material?
Long-term obligations?
Long-term environmental liabilities?
Future land use?
Sufficient on-site borrow material?
Construct on-site landfill?
Staffing demands/outside resources?
Political/social pressures?
Cost?

12. Need a Plan and Schedule

13. Risk Considerations
Planning for potential risks and liabilities:
Geotechnical evaluation
Environmental assessment (including risk assessment)
Social/political analysis
Landfill/pond closure design
Permitting
Construction engineering

14. Groundwater Investigation/Remedial Options
Groundwater Investigation
–Likely required to ascertain environmental impact of existing unlined ponds
–Investigation plan should take into account
Point of compliance
Constituents of concern
Well placement
Well construction
Sampling protocol
Quality assurance/quality control
Background conditions
Remedial Options
–Evaluate as warranted
–Incorporate into closure plan

15. Closure Considerations
Pond size
Dewatering requirements/methods
Final use considerations
Remediation integration
Constructability concerns
Health and safety
Site configuration constraints
Long-term maintenance

16. Pond Closure – Health and Safety
Dust control and monitoring

17. In-place Closure
Pros:
Generally less expensive than relocation to a lined landfill
Approach keeps haul vehicles off of public roads and highways
Proximate to existing facilities
If space-constrained, can be used as landfill base

18. In-place Closure
Cons:
Perceived “unknowns” in the final storage conditions
Increased social/political opposition to in-place closure, especially in environmentally sensitive areas

19. In-place Closure
May not be feasible in an environmentally sensitive or recreational area

20. In-place Closure Solutions

21. In-place Closure Solutions

22. In-place Closure Solutions

23. Pond Closure – Final Use Considerations
Solar farm

24. Closure by Removal Considerations
Beneficial reuse
Disposal in off-site Subtitle “D” landfill
Disposal in on-site Subtitle “D” landfill
Consolidation with ash in existing lined pond

25. Closure by Removal
Beneficial reuse opportunities:
Engineered fill*
Stabilized road base
Concrete admixture
Other
* Pending EPA ruling

26. Removal of Residuals
Beneficial reuse as a road construction material

27. Closure by Removal

28. Closure by Removal

29. Closure by Removal

30. Closure by Removal– Final Use Considerations

31. Closure by Removal
Ash dewatering using geotubes

32. Pond Closure - Constructability
Slope stability

33. Pond Closure - Constructability
Ash liquefaction

34. Construction costs
Ash volumes–actual conditions v. designed
Moisture content – don’t pay to haul water
Haul distances – keep them short
Double handling of material
Synthetic construction materials
Long-term monitoring
On-site landfill v. off-site commercial landfill
Leachate management

35. Questions/Comments?