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The OWASA-UNC Water Reuse System Project aims to promote sustainable water management by utilizing reclaimed water for non-potable uses, such as cooling towers and irrigation. Created in 1977, OWASA serves approximately 80,000 people and has developed a water conservation program as part of its long-term supply plan. The project, influenced by the 2002 drought, evaluates the technical, economic, and environmental feasibility of water reuse to reduce community drought risk and conserve drinking water for essential human needs.
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OWASA – UNC Water Reuse System Project: A Technical and Financial Partnership to Promote More Sustainable Water Management
About OWASA… • Serve ~80,000 people, 20,000 accounts • ~ 9 mgd average-day demand (UNC ~ 2.4 mgd) • 3.4 billion gallon reservoir system • ~11.5 mgd safe yield • 20 mgd WTP • 14.5 mgd WWTP
Jones Ferry Road WTP Mason Farm WWTP
OWASA was created in 1977 • Water and sewer utilities were previously owned & operated by Carrboro, Chapel Hill and UNC • Contractually obligatedto meet the water/sewer needs of the Towns and University as determined by the Towns and University
2002 Drought Was Call for Action Board-adopted goals for sustain-ability, environmental responsibility, and water conservation and reuse OWASA’s water conservation program is part of our long-term supply plan – not simply short-term drought response management Water reuse a very key strategy
UNC’s Peak Demand Ratios are Higher Than Our System-wide Peaking Ratios
Is Water Reuse Feasible? • Initially Evaluated in 1995 – Not Pursued • 2002 Drought Led to Joint Re-evaluation • 2003-2005 Study • Technical, economic, and environmental feasibility analysis • Pilot-scale testing • Microbiological study • Mason Farm WWTP upgrade underway • UNC main campus expansion underway
Cogeneration Plant Cooling Tower South Chiller Cooling Tower OWASA-UNC Reuse Project • Feasible for use in cooling towers • Feasible for irrigation use, toilet flushing • Other uses may also be possible
Reclaimed Potable Total Reclaimed Water Water Demand as % of (mgd) (mgd) (mgd) Total 2009 0.66 8.21 8.87 7.4% 2028 1.94 10.96 12.90 15% Potential Reuse Demands* vs. Projected Potable Water Demands * Demands shown are for cooling tower make-up water and irrigation uses, only. Potential demands may be higher if other uses are met through reuse. Water reuse may also be a strategy for meeting Carolina North water needs, but that potential is not reflected in the above table.
Reduction in Water Revenue • Year 1 • 660,000 gpd loss in potable sales • > $1,000,000 revenue reduction in Year 1 • Direct costs only reduced by $380,000 (Less energy and chemicals for potable water) • ~ 3.6% increase in water rate needed to balance water revenues • Projected RCW rate of @ $2.40/1,000 • > $466,000 direct/indirect O&M costs
Deferred Capital Costs • Could defer 5 capital projects for several years through reuse/conservation • Net Present Savings of project deferrals > $3,000,000 in next 9 years • Potential deferral/elimination of > $40 million to go to Jordan Lake
OWASA-UNC Reuse Project • Sustainable management strategy • Save drinking water for human use • Reduce community’s risk to droughts • Reuse supply less vulnerable to drought • Locally controlled source • Reduce discharge of nutrients Reuse is cost-effective, safe and reliable approach for meeting multiple objectives
UNC • > $10,000,000 for Phase I • $1.866 million CWMTF grant • $0.625 million EPA grant • Payback < 10 years • UNC pays $5.85/1,000 gallons for all potable water use during May-Sept. and $3.08/1,000 gallons in all other months
OWASA Positions… • Water customers cover revenue loss • No subsidy of RCW capital or O&M by customers • No reimbursement to UNC • OWASA owns and operates system • If RCW is down, UNC to pay for potable water at then-current water rate
OWASA-UNC Reuse Project • OWASA-UNC reuse contract: April, 2006 • UNC to pay full cost (less grants) • Construction now underway • Pump station/storage tank at WWTP • 8,000 ft. of 24-inch main to south campus • Phase I: 7,000 ft. of pipe on main campus • Projected Start-up: March 2009
Is Reuse in Your Future? • Rates • Non-potable demands (current/future) • Proximity of demands • WWTP capability • Supplemental funding • Full cost recovery may not be possible • Incentives for reuse may be needed
Thank You If you would like more information about the OWASA-UNC reuse project or OWASA’s conservation efforts, please contact: Patrick (Pat) Davis Utility Manager OWASA P.O. Box 366 Carrboro, NC 27510-0366 Telephone: 919-537-4210 (Direct) Email: pdavis@owasa.org OWASA Website: www.owasa.org
Full-Cost Recovery National survey (1) 34% of systems have performed a cost of service analysis Only about 14% of reclaimed water systems in US are fully recovering their RW system costs (1)AWWA/WEF Water Reuse Rate Survey presented by Ken Thompson at 2004 Water Sources Conference, January 2004 Financial Goals