November 17, 2015 Charting the Future of Water Reuse for the City of Raleigh Sheryl D. Smith, P.E. – CDM Smith Eileen M. Navarrete, P.E., PMP – City of Raleigh 2015 Annual Conference Raleigh, NC

Presentation Overview  Water Resources Background and Reuse Master Plan Objectives  Existing Reuse Program  Options for Expanding Non-Potable Reuse Program  Consideration of Potable Reuse  Utility Perspectives and Next Steps 2

Water Resources in Raleigh  Regional Utility  190,000 metered customers  525,000 citizens  Average Rainfall: 46 inches  Drought of Record: 33 inches

50 Year Raleigh Service Area Future Water Demand Projections (MGD) Surface Water Supply 77.3 Service Area Demand Future Water Supply Need

Future Water Sources  Conservation  “Traditional” reclaimed water  Infrastructure rehabilitation/replacement  Reallocation of existing reservoir storage  New reservoir  Quarry storage  River intake

Regulatory Restrictions on Potable Reuse  Reclaimed Water as a Source Water  Unplanned indirect potable reuse occurs throughout the State and the U.S.  Draft Legislation – Written early 2013 with NCDENR  Neuse River Study to inform the underlying conditions and assumptions of the Bill.  Prohibition against potable reuse was removed by NC legislature in August 2014

Legislation Requirements  Reclaimed water treated to highest standard (Type 2)  Reclaimed water and source water are combined in an impoundment, sized for 5 days storage (20% reuse)  Conservation measures  Unbilled leakage is maintained below 15%  Reuse Master Plan  Public Participation

Informing NC Bill – Project Objectives  Baseline Neuse River water quality  What happens in the river?  Pixie Dust Syndrome

Master Plan Project Objectives  Determine role of reuse in meeting the City utility’s water resources needs  Define best reuse strategies to reduce demands on the potable water system  Define acceptable balance of reuse costs and revenue  Provide data to support proposed potable reuse legislation

Existing Reuse Program

Existing Reuse Distribution Systems 11 Southeast Raleigh Distribution System Zebulon Distribution System Bulk Distribution at Treatment Plants Smith Creek WWTP Neuse River RRF Little Creek WWTP

Southeast Raleigh Distribution System  Approx. 23 miles of pipe (6 to 24-inch)  0.75 MG elevated storage tank  June 2015 Demand = 900,000 gpd Uses  On-site treatment plant  WW pump stations  Parks & rec irrigation  Other municipal facility irrigation  Golf course irrigation  Industrial cooling tower 12

Zebulon Distribution System  Approx. 4 miles of 12-inch pipe  0.25 MG elevated storage tank  June 2015 Demand = 90,000 gpd Uses  WW pump stations  Athletic field irrigation  Municipal facility irrigation  Industrial cooling towers, toilet flushing, irrigation  Concrete production 13

Options for Expanding Non- Potable Reuse

 Expand water reuse distribution system from treatment plant(s)  Existing Southeast Raleigh system  New distribution system from Smith Creek WWTP  Decentralized reuse facilities  Wetlands/streamflow augmentation  Stormwater storage

Approach to Reuse Distribution System Expansion  Identify reuse demand “nodes”  High density of non-residential water demand  Anchored by large user  Help justify cost of pipeline construction  Ideally non-irrigation uses to shave peaks  Phone/in person interviews conducted to gauge interest  Potential future development corridors considered  Proximity to existing reuse distribution system

Reuse Node Identification 17

Reuse Node Identification 18 Reuse node Potential anchor customer

Raleigh Distribution System Expansion 19  20 miles of new pipe  Additional demand  ADD ~ 0.9 mgd  MDD ~ 2.3 mgd  ~30% irrigation  ~70% cooling, toilet, other New booster pump station

New Smith Creek Distribution System  Industrial & institutional users  New residential development  5 miles of new pipe  Additional demand  ADD ~ 0.3 mgd  MDD ~ 0.8 mgd

Decentralized Reuse Options  Satellite treatment facilities significantly more $$ than pipeline options  Irrigation supply capacity limited since irrigation peaks coincide with low WW flows

Consideration of Potable Reuse

Neuse River Study Conducted to Inform NC Legislation  Objectives  Baseline Neuse River water quality  What happens in the river?  Constituents  6 microorganisms  110 chemical constituents  Including conventional parameters, pharmaceuticals, hormones, and other trace chemical constituents  Bulk genotoxicity  Sampling  3 events during low streamflow conditions 23

Eight Sites

Summary – General findings  River had acceptable water quality; similar to historical quality  Anthropogenic influence seen at all sites  Neuse River RRF is not a significant source of microbial contamination

Summary – Chemicals  Methods capable of detection at low concentrations (1 ppt)  Site C – greatest # of detections of chemicals  Mean of the # of detections per event for site C were not statistically different than those for sites D, E, and F 72% of the chemicals tested were detected at site C WTP WWTP 2 WTPs

Neuse River Study Conclusions 1.The Neuse River has acceptable water quality for a drinking water supply source. 2.The river is not degrading or removing most of the detected microbial indicators or trace chemical constituents. 3.No technical difference exists between reclaimed water as a source water than Neuse River water downstream.

Utility Perspectives and Next Steps 28

Potable Reuse – Potential Option 29 Decommissioned EB Bain WTP Decommissioned Raw Water Main

Next Steps  Cost /Benefit analysis  Phasing  Include potable reuse in Reuse Master Plan update  Basic structure of a pilot program  Evaluate potable reuse as another alternative for a reuse project

Questions?