Quarry conversion: CRITICAL planning & design elements

1. Quarry conversion: CRITICAL planning & design elements DRAFT Water resources Practice leader BLACK & VEATCH Water Pamela p. kenel

2. AGENDA Benefits of Quarry to Reservoir Conversion Feasibility Evaluations • Volume of Storage • Limiting Geotechnical Conditions • Groundwater Interaction Program Schedule / Implementation

3. Benefits of quarry reservoirs Re-use of retired rock quarries for beneficial use Limited environmental impacts Location in developed and urbanizing areas Storage provides climate resilience Storage of water for range of purposes • Water supply operational or emergency storage • Wet weather storage

4. Piedmont plateau region New Jersey Pennsylvania Delaware Maryland Virginia North Carolina South Carolina Georgia Alabama "Piedmontmap". Licensed under Creative Commons Attribution-Share Alike 2.5 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Piedmontmap.png#mediaviewer/File:Piedmontmap.png

5. Quarry reservoir examples Thornton Quarry Reservoir 7.9 BG Elmhurst Quarry Reservoir 4 BG Travilah Quarry Reservoir 17 BG McCook Quarry Reservoir 10 BG

6. Feasibility evaluations To Answer the Key Questions: What volume of storage will quarry provide? Are there existing geological or geotechnical conditions that may prevent use or limit usefulness? Potential for negative groundwater interactions? Potential water quality issues affecting long-term use? How to integrate reservoir asset in to the existing system?

7. What volume of storage will the quarry provide?

8. What Volume of Storage will quarry provide? Mining plan and future volume • Can mining plan be altered to optimize capacity? • Consider range of scenarios To what level can quarry be filled and drawn down? • Ground improvement needs • Groundwater influence • Low level limitations (water quality, physical pumping limitations)

9. Mining plan and schedule Consider range of scenarios in multi-year increments Can mining be concurrent with reservoir operation? Can mining plan be altered to optimize capacity? Can mining plan accommodate timing needs?

10. Travilah quarry 1964 Environmental review

11. Travilah quarry 1981 Environmental review

12. Travilah quarry 2000 Environmental review

13. existing geological features or geotechnical conditions that limit quarry's use as a reservoir?

14. Will the quarry hold water? Geotechnical Impacts • Permeability of rock (floor and walls) Geologic and Hydrogeological Assessment: • Geologic mapping • Confirm and identify other major geologic features • Identify quarry seeps and estimated flows • Determine if deleterious rock is present • Confirm quarry sump discharge • Obtain regional groundwater data • Evaluate wall stability and permeability

15. Ground improvement required

16. Is there potential for harmful local groundwater interaction?

17. Operating quarry is a sink

18. Environmental Database search for past contamination Environmental review

19. Groundwater Protection System

20. Can the mining plan be coordinated to facilitate conversion to use as a reservoir?

21. Mining plan optimization Improve pipeline / tunnel connection constructability Maximize capacity Improve quarry highwall stability Improve long-term reservoir access Reduce contaminants from quarry operations

22. Quarry pumping station options • Submerged Intake • Inclined Cans • Vertical Cans Pump Station Design More economical / potential maintenance issues/ easy to maintain

23. program schedule Steps: • Planning, Feasibility Studies (2-10 years) • Agency Review and Permitting (6mths – 2yrs) • Design (~2 yrs) • Construction (2 -10 yrs) Potential Approaches: • Construction Packaging & Phasing • Early Partial Utilization of Quarry Dependent on Owner and Operator Coordination

24. Multiple quarries provide flexibility -to mining operation and future owner

25. Continued evaluation of opportunities Investigation of hydropower potential