17 November 2015 WATER RESOURCES PRACTICE LEADER BLACK & VEATCH WATER PAMELA P. KENEL QUARRY CONVERSION: CRITICAL PLANNING & DESIGN ELEMENTS DRAFT

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

1.Re-use of retired rock quarries for beneficial use 2.Limited environmental impacts 3.Location in developed and urbanizing areas 4.Storage provides climate resilience 5.Storage of water for range of purposes Water supply operational or emergency storage Wet weather storage BENEFITS OF QUARRY RESERVOIRS 3

"Piedmontmap". Licensed under Creative Commons Attribution-Share Alike 2.5 via Wikimedia Commons - New Jersey Pennsylvania Delaware Maryland Virginia North Carolina South Carolina Georgia Alabama PIEDMONT PLATEAU REGION 4

QUARRY RESERVOIR EXAMPLES 5 Thornton Quarry Reservoir 7.9 BG Elmhurst Quarry Reservoir 4 BG Travilah Quarry Reservoir 17 BG McCook Quarry Reservoir 10 BG

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? FEASIBILITY EVALUATIONS 6

WHAT VOLUME OF STORAGE WILL THE QUARRY PROVIDE? 7

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) WHAT VOLUME OF STORAGE WILL QUARRY PROVIDE? 8

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? MINING PLAN AND SCHEDULE 9

ENVIRONMENTAL REVIEW TRAVILAH QUARRY

ENVIRONMENTAL REVIEW TRAVILAH QUARRY

ENVIRONMENTAL REVIEW TRAVILAH QUARRY

EXISTING GEOLOGICAL FEATURES OR GEOTECHNICAL CONDITIONS THAT LIMIT QUARRY'S USE AS A RESERVOIR? 13

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 WILL THE QUARRY HOLD WATER? 14

GROUND IMPROVEMENT REQUIRED 15

IS THERE POTENTIAL FOR HARMFUL LOCAL GROUNDWATER INTERACTION? 16

OPERATING QUARRY IS A SINK 17

ENVIRONMENTAL REVIEW ENVIRONMENTAL DATABASE SEARCH FOR PAST CONTAMINATION 18

GROUNDWATER PROTECTION SYSTEM

CAN THE MINING PLAN BE COORDINATED TO FACILITATE CONVERSION TO USE AS A RESERVOIR? 20

Improve pipeline / tunnel connection constructability Maximize capacity Improve quarry highwall stability Improve long-term reservoir access Reduce contaminants from quarry operations MINING PLAN OPTIMIZATION 21

PUMP STATION DESIGN Submerged Intake Inclined CansVertical Cans QUARRY PUMPING STATION OPTIONS 22 More economical / potential maintenance issues/ easy to maintain

Dependent on Owner and Operator Coordination 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 PROGRAM SCHEDULE 23

MULTIPLE QUARRIES PROVIDE FLEXIBILITY - TO MINING OPERATION AND FUTURE OWNER 24

Investigation of hydropower potential CONTINUED EVALUATION OF OPPORTUNITIES 25