1. CCR Rule: Consultant’s Perspective 2015 Air & Waste Management Association Meeting Callaway Gardens, GA Presented by: Randy Sullivan, Principal & Senior Practice Leader Golder Associates Inc.

2. Outline Varied Client Responses State Rules Technologies & Tools Well established Emerging 2

3. The Path to CCR Compliance- Varied Client Responses 3 New and Existing Surface Impoundments and Lateral Expansions New and Existing CCR Landfills and Lateral Expansions Inactive Surface Impoundments State requirements may be more stringent. !

4. State Rules North Carolina 2014 law Mandated ash removal at High & Intermediate risk sites Decision by Commission based on data supplied by utility in 2015 Legality of Commission challenged Ruled unconstitutional by lower court Appeal to NC Supreme Court pending Commission currently inactive DNER preparing for plan reviews Others: funding & staffing limited so impoundments rules uncertain 4

5. Active CCR Surface Impoundment Schedule Considerations Failure to meet structural integrity requirements Failure to meet location restrictions Groundwater contamination Triggers to SI Closure **Closure timeframes vary: < 40 acres – up to 7 years > 40 acres – up to 15 years Once triggered  SIs must cease receiving CCR and initiate closure (file permit application) within 6 months 5

6. SI Closures Schedule Considerations Design/Permit/Build New Lined SI  Typical schedule, 2 ½ to 3+ years Wet to Dry Conversion  Requires regulated dry disposal  Typical schedule, 2 ½ to 3+ years Closure  Cap in place, excavate and landfill on/off-site, beneficial re-use  Typical schedule, 2+ years Water Balance Impacts  Combined impacts of ELG Rule  Treatment and reuse  Treatment and discharge  Zero liquid discharge 6 Example Closure Planning Schedule

7. Client Responses Key drivers Generation plans CCR portfolios State Rules or expectations for them Risk management Public perceptions Current focuses Groundwater monitoring Structural assessments Closures: alternatives analysis, cost estimating, implementation 7

8. Well-Established Technologies & Tools Technologies Dams & impoundments Landfills Groundwater monitoring 8

9. Well-Established Technologies & Tools Tools: Feasibility studies Work Breakdown Structures(WBS) for cost estimating Scheduling Qualitative risk ratings March 25, 20159

10. Emerging Technologies & Tools Technologies: Ash excavation & dewatering Rim ditches & sumps, stockpiling Well points & deep wells 10

11. Emerging Technologies & Tools Technologies: Seepage water/leachate handling Onsite treatment: plant/wetlands Storage, hauling & offsite treatment March 25, 201511

12. Emerging Technologies & Tools Technologies: Remediation Cutoff walls Permeable reactive barrier (PRB) walls Recovery wells and trenches Risk assessment & monitored natural attenuation 12

13. Emerging Technologies & Tools Technologies: Beneficial re-use Concrete Structural fills Mine reclamation exclusion Thermal beneficiation March 25, 201513

14. Emerging Technologies & Tools Technologies: Ash conveyance 14

15. Emerging Technologies & Tools Emerging Tools: GoldSET – tool for multi-criteria analysis 15 Project Description DescriptionProject Evaluation of Options Interpretation & Decision Making Option Development Indicator Selection A 5-Step Evaluation Process Results

16. Emerging Technologies & Tools Emerging Tools: Probabilistic cost & schedule risk analysis 16

17. Questions and Answers March 25, 201517