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OWASA – UNC Water Reuse OWASA – UNC Water Reuse System Project:System Project:
A Technical and FinancialA Technical and FinancialPartnership to Promote MorePartnership to Promote MoreSustainable Water ManagementSustainable Water Management
About OWASA…About OWASA…
Serve ~80,000 people, 20,000 accounts Serve ~80,000 people, 20,000 accounts ~ 9 mgd average-day demand~ 9 mgd average-day demand
(UNC ~ 2.4 mgd) (UNC ~ 2.4 mgd) 3.4 billion gallon reservoir system3.4 billion gallon reservoir system ~11.5 mgd safe yield~11.5 mgd safe yield 20 mgd WTP20 mgd WTP 14.5 mgd WWTP14.5 mgd WWTP
Mason Farm WWTP Mason Farm WWTP
Jones Ferry Road WTPJones Ferry Road WTP
OWASA was created in 1977OWASA was created in 1977
Water and sewer utilities were Water and sewer utilities were previously owned & operated by previously owned & operated by Carrboro, Chapel Hill and UNCCarrboro, Chapel Hill and UNC
Contractually obligatedContractually obligated to meet the to meet the water/sewer needs of the Towns and water/sewer needs of the Towns and University University as determinedas determined by the by the Towns and UniversityTowns and University
Raw Water Supply, Demand, and Potential Deficits
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4
6
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1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Mil
lio
n G
allo
ns
Per
Day
Existing System (with 2007 quarry pump improvements) Expanded Quarry
30-Yr Safe Yield
2001-02 Drought
Pre-CCR
2001-02 Drought
Without Reuse
With Reuse
2001 Master Plan "Expected Growth"
Lesser PC & Less Reuse
Greater PC & More Reuse
30-yr Safe Yield
2002 Drought Was Call 2002 Drought Was Call for Actionfor Action
Board-adopted goals for Board-adopted goals for sustain-sustain-ability, environmental responsibility, ability, environmental responsibility, and water conservation and reuseand water conservation and reuse
OWASA’s water conservation OWASA’s water conservation program is part of our long-term program is part of our long-term supply plan – supply plan – not simply short-term not simply short-term drought response managementdrought response management
Water reuse a very key strategyWater reuse a very key strategy
Demands Have Been Demands Have Been StableStable
7.918.378.458.559.179.459.008.058.468.588.54
Monthly Average Customer Demand, January 1996 - December 2007
5
6
7
8
9
10
11
12
13
14
15
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
Ac
tua
l F
inis
he
d W
ate
r D
em
an
d (
mg
d)
Average Day Demand for Year
Peak Day Demand for Year
Monthly Demand Ratios for University'sHeating and Cooling Facility Water Demands, 2000 and 2002
As Compared to OWASA's System-Wide Monthly Demand Ratios
0%
20%
40%
60%
80%
100%
120%
140%
160%
180%
200%
Janu
ary
Febr
uary
Mar
ch
Apr
il
May
June July
Aug
ust
Sep
tem
ber
Oct
ober
Nov
embe
r
Dec
embe
r
System-Wide Ratios
UNC Ratios
UNC’s Peak Demand Ratios are Higher Than Our System-
wide Peaking Ratios
Is Water Reuse Feasible?Is Water Reuse Feasible?
Initially Evaluated in 1995 – Not Initially Evaluated in 1995 – Not PursuedPursued
2002 Drought Led to Joint Re-2002 Drought Led to Joint Re-evaluationevaluation
2003-2005 Study2003-2005 Study Technical, economic, and environmental Technical, economic, and environmental
feasibility analysisfeasibility analysis Pilot-scale testingPilot-scale testing Microbiological studyMicrobiological study
Mason Farm WWTP upgrade underwayMason Farm WWTP upgrade underway UNC main campus expansion underwayUNC main campus expansion underway
OWASA-UNC Reuse ProjectOWASA-UNC Reuse Project
Feasible for use in cooling towersFeasible for use in cooling towers Feasible for irrigation use, toilet Feasible for irrigation use, toilet
flushingflushing Other uses may also be possibleOther uses may also be possible
South South Chiller Chiller Cooling Cooling TowerTower
Cogeneration Cogeneration Plant Cooling Plant Cooling
TowerTower
Potential Reuse Demands* vs. Potential Reuse Demands* vs. Projected Potable Water Projected Potable Water
DemandsDemands
** Demands shown are for cooling tower make-up water and Demands shown are for cooling tower make-up water and irrigation uses, only. Potential demands may be higher if irrigation uses, only. Potential demands may be higher if other uses are met through reuse.other uses are met through reuse.
Water reuse may also be a strategy for meeting Carolina Water reuse may also be a strategy for meeting Carolina North water needs, but that potential is not reflected in the North water needs, but that potential is not reflected in the above table.above table.
Reclaimed Potable Total ReclaimedWater 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%
General Layout of the Planned Water Reuse System
Peak Day Demands – No Peak Day Demands – No ReuseReuse
Peak Day Water Demand vs Treatment Plant Capacity
10
15
20
25
30
35
1995 2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Pea
k D
ay D
eman
d (
mg
d) Projected Demand
With No Reuse, PF = 1.65
WTP Capacity
Reuse Defers WTP Reuse Defers WTP ExpansionExpansion
Peak Day Water Demand vs Treatment Plant Capacity
10
15
20
25
30
35
1995 2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Pea
k D
ay D
eman
d (
mg
d) Projected Demand
With No Reuse, PF = 1.65
Projected DemandWith Reuse, PF = 1.45
WTP Capacity
Reduction in Water Reduction in Water RevenueRevenue
Year 1Year 1 660,000 gpd loss in potable sales660,000 gpd loss in potable sales > $1,000,000 revenue reduction in Year 1> $1,000,000 revenue reduction in Year 1 Direct costs only reduced by $380,000Direct costs only reduced by $380,000
(Less energy and chemicals for potable water)(Less energy and chemicals for potable water) ~ 3.6% increase in water rate needed to ~ 3.6% increase in water rate needed to
balance water revenuesbalance water revenues
Projected RCW rate of @ $2.40/1,000Projected RCW rate of @ $2.40/1,000 > $466,000 direct/indirect O&M costs> $466,000 direct/indirect O&M costs
Deferred Capital CostsDeferred Capital Costs
Could defer 5 capital projects for Could defer 5 capital projects for several years through several years through reuse/conservationreuse/conservation
Net Present Savings of project Net Present Savings of project deferrals deferrals > $3,000,000 in > $3,000,000 in next 9 yearsnext 9 years
Potential deferral/elimination of Potential deferral/elimination of > $40 million to go to Jordan > $40 million to go to Jordan Lake Lake
OWASA-UNC Reuse ProjectOWASA-UNC Reuse Project
Sustainable management strategySustainable management strategy Save drinking water for human useSave drinking water for human use Reduce community’s risk to droughtsReduce community’s risk to droughts Reuse supply less vulnerable to Reuse supply less vulnerable to
droughtdrought Locally controlled sourceLocally controlled source Reduce discharge of nutrientsReduce discharge of nutrients
Reuse is cost-effective, safe and Reuse is cost-effective, safe and reliable approach for meeting reliable approach for meeting
multiple objectivesmultiple objectives
UNC UNC
> $10,000,000 for Phase I> $10,000,000 for Phase I $1.866 million CWMTF grant$1.866 million CWMTF grant $0.625 million EPA grant$0.625 million EPA grant Payback < 10 yearsPayback < 10 years
UNC pays $5.85/1,000 gallons for all UNC pays $5.85/1,000 gallons for all potable water use during May-Sept. potable water use during May-Sept. and $3.08/1,000 gallons in all other and $3.08/1,000 gallons in all other monthsmonths
OWASA Positions…OWASA Positions…
Water customers cover revenue Water customers cover revenue lossloss
No subsidy of RCW capital or O&M No subsidy of RCW capital or O&M by customersby customers
No reimbursement to UNCNo reimbursement to UNC OWASA owns and operates systemOWASA owns and operates system If RCW is down, UNC to pay for If RCW is down, UNC to pay for
potable water at then-current water potable water at then-current water raterate
OWASA-UNC Reuse ProjectOWASA-UNC Reuse Project
OWASA-UNC reuse contract: OWASA-UNC reuse contract: April, 2006April, 2006
UNC to pay full cost (less grants)UNC to pay full cost (less grants) Construction now underwayConstruction now underway
Pump station/storage tank at WWTPPump station/storage tank at WWTP 8,000 ft. of 24-inch main to south campus8,000 ft. of 24-inch main to south campus Phase I: 7,000 ft. of pipe on main campusPhase I: 7,000 ft. of pipe on main campus
Projected Start-up: March 2009Projected Start-up: March 2009
Is Reuse in Your Future?Is Reuse in Your Future?
RatesRates Non-potable demands Non-potable demands
(current/future)(current/future) Proximity of demandsProximity of demands WWTP capabilityWWTP capability Supplemental fundingSupplemental funding Full cost recovery may not be Full cost recovery may not be
possiblepossible Incentives for reuse may be neededIncentives for reuse may be needed
Thank YouThank You
If you would like more information If you would like more information about the OWASA-UNC reuse project or about the OWASA-UNC reuse project or OWASA’s conservation efforts, please OWASA’s conservation efforts, please contact:contact:
Patrick (Pat) DavisPatrick (Pat) DavisUtility ManagerUtility ManagerOWASAOWASAP.O. Box 366P.O. Box 366Carrboro, NC 27510-0366Carrboro, NC 27510-0366
Telephone:Telephone: 919-537-4210 919-537-4210 (Direct)(Direct)
Email:Email: [email protected] Website:OWASA Website: www.owasa.org
Increasing Block Rates Increasing Block Rates for Residential for Residential
CustomersCustomers
Financial GoalsFinancial Goals
Full-Cost RecoveryFull-Cost Recovery National survey National survey (1)(1)
34% of systems have performed a cost 34% of systems have performed a cost of service analysisof service analysis
Only about 14% of reclaimed water Only about 14% of reclaimed water systems in US are fully recovering systems in US are fully recovering their RW system coststheir RW system costs
(1)(1) AWWA/WEF Water Reuse Rate SurveyAWWA/WEF Water Reuse Rate Survey presented by Ken presented by Ken Thompson at 2004 Water Sources Conference, January 2004Thompson at 2004 Water Sources Conference, January 2004
Monthly Water Use by Residential Monthly Water Use by Residential CustomersCustomers
0
500
1,000
1,500
2,000
2,500
3,000
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37
Billed Use (1,000s of Gallons)
# C
ust
om
ers
July 06
Jan 07