nfbwa reuse and conservation considerations

North Fort Bend Water Authority

Direct Reuse and Conservation Considerations

February 2011

Direct Reuse and Conservation Considerations

February 2011

Brown & Gay Engineers, Inc.

Multi-Pronged Approach

• GRP is based on surface water conversion only

• Board is developing incentives and other programs to encourage� Water Conservation

Water Wise Program-NFBWA directly sponsors students annually and purchases from

their MUDS credits for their support of the program.

Early delivery of surface water -At Developer or MUD request, Authority pays 100% of engineering costs, Developer pays 50% of construction cost of his share of capacity in pipe. All easements required by Authority will be donated by Developer. Timing and location are key.

� Water Reuse for irrigation

NFBWA provides a $0.39 per 1000 gallon credit for metered reuse. The board is considering raising that credit to $0.75 per gallon.

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Classroom materials (TEXAS WATER; WATER IS LIFE)

•Sponsor Water Wise program•New mobile teaching lab•Water bill inserts•Newsletters

Current conservation efforts:


Credits toward Conversion

• To date the Authority has acquired 754,824,000 gals of credit (about 70 days)

• MUDs served for 2011 and 2010 will generate 7 billion additionalearly conversion credits (about 730 days)

• Equivalent to about 800 total days or little over 2 years

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Other Conservation Efforts

• Sponsoring Texas A&M Turf Irrigation Study to determine how much water is really needed to keep grass healthy

• Implementing a Comparative Study in a new residential development to measure the effects of separate irrigation metersand water efficient upgrades to irrigation systems

• Evaluating subsidizing residential irrigation evaluations to educate homeowners about water conservation while irrigating

• Purchasing low-flow spray nozzles for school cafeterias


FBSD Policy Proposal

• NFBWA Water Use Reduction Credit Policy Proposal– Earn credits for actual reduction in use on a per capita basis over the initial 30% conversion requirement

– Any credits earned by NFBWA would be used to incentivize MUDs to implement meaningful conservation

– Under consideration now, NFBWA is hopeful decision will be made soon

– Any incentive to conserve water diminishes with each bond sale that fixes long term debt service. During the life of the bonds, conservation will only increase the cost of water to current rate payers.


Wastewater Reuse

• The Authority encourages wastewater reuse and recognizes its potential benefits

• Wastewater reuse can be used instead of potable water to conserve valuable groundwater resources

• As a focal point of the efforts by the Authority to engage itself in wastewater reuse, several goals have been identified


Authority Goals for Wastewater Reuse

• Encourage Direct Reuse by GRP participants

– Encourage changes for future development

– Increase the use of incentives

• Determine feasibility of reuse projects

– Utilize a cost template to evaluate projects on a case by case basis

– Understand the long term implications for the Authority


Reuse Strategy (Policy)

• The Authority has the ability to create policy to increase WW reuse

• Acting now maximizes the potential to increase reuse in Authority

• Various stages of development within the Authority– Existing Development – Much of the northeastern part of the Authority (Cinco Ranch) has been almost fully developed. It will be more difficult to instill reuse efforts within these areas. (approximately 27%)

– New Development –Many of these developments are including reuse piping systems within the development. (approximately 23%)

– Future (Unplanned) – Rules and regulations that are put in place by the Authority will ensure that wastewater reuse will be part of the future developments. (approx. 50%)

– The Authority can impact 73% of development by acting now


Reuse for Existing vs. Future Development

• Reuse for Existing Development– Higher installation costs– Minimal access, lack of planned routes– Retrofitting existing WWTP facilities can be difficult

• Reuse for Future Development– Lower installation costs– Installation part of planned development– Plan WWTP facilities for future reuse

• Reuse policy should focus on future development


Water Reuse Opportunities

• Irrigation– Golf Course Irrigation – Currently, there are 4 golf courses within the Authority.

– Green Space Irrigation (Esplanades, Green Belts, and Parks)

– Irrigation of School District Facilities

• Amenity Lakes– Many developments have amenity lakes that are fed by separate wells

– Providing reuse water to these lakes will reduce/minimize GW pumpage


Irrigation of Public Green Spacefor New Development

1. Today – “Anything Goes”

Increasing Impact

Increasing Restriction

6. No Irrigated Public Green Space

5. Irrigate w/Reuse Only

4. Irrigate w/GW 2 yrs (up to X amt per SF), then w/Reuse

2.Water-Efficient Irrigation Planw/Reuse or Other

3. Irrigate w/GW 2 yrs (up to X amt per SF), then Surcharge for GW Use


Amenity Lakes for New Development

1. Lakes Filledw/GW & SW Runoff

Increasing Impact

Increasing Restriction

4. No Amenity Lakes

3. Lakes Filled w/ Reuse Water Only

2. Lakes Filled w/GW 2 yrs, Reuse Water After


Amenity Lakes in Future Development

• Install purple pipe from the WWTP to the lakes for future use

• Design amenity lakes to maximize collection of storm water

• Amenity lakes shall be recharged by reuse water at a future point in time

• Encourage irrigation out of amenity lakes (if recharged by reuseand groundwater)


Wastewater Reuse vs. DemandProjections

Year Authority

Irrigation

Demand

Available

Wastewater

Reuse Supply

2010 6.5 mgd 4.9 mgd

2015 8.6 mgd** 6.4 mgd

2020 10.3 mgd** 7.7 mgd

2025 12.0 mgd** 9.0 mgd

2030 13.4 mgd** 10.1 mgd

**Through continued use of existing irrigation methods



Year Authority

Irrigation

Demand

Available

Wastewater

Reuse Supply

2010 6.5 mgd 4.9 mgd

2015 6.0 mgd** 6.4 mgd

2020 7.2 mgd** 7.7 mgd

2025 8.4 mgd** 9.0 mgd

2030 9.4 mgd** 10.1 mgd

**Through more efficient irrigation practices


Current Reuse Efforts

• New developments installing purple pipe (color designated for water reuse) for irrigation purposes– Cinco Southwest (MUD 1 - 4)

– Cross Creek Ranch (MUD 169 - 173)

– Avalon (FBCMUD 34)

• Several projects identified and preliminary engineering studies and/or design has been performed– Meadowbrook Farms Golf Course with FBCMUD 34

– Grand Lakes MUDs


Current Reuse Efforts (cont.)

• FBCMUD 34– Reuse water for the Meadowbrook Farms Golf Course, potentially others

– Initial Reuse = 350,000 gpd (golf course), potential = 1 mgd

• Cinco MUD 1 Reuse District– Design will be completed mid-2011, construction to follow

– Potential Reuse = 1.64 mgd ( $8.6M)

• Grand Lakes MUD 4– For Grand Lakes Districts (MUD 1-4)

– Reuse water for the amenity lake system for replenishment and public area irrigation

– Potential Reuse = 0.6 mgd


Cost Analysis

• GOAL: User’s cost to implement reuse project less than or equal to “do-nothing” alternative (i.e. continue to pay GW pumpage fee)

• Costs

Do-Nothing

- GW Pumpage Fees

- Permit Fees

- Other

Reuse Project

- Capital Costs- WWTP & Pipe- Engineering- Debt Service

- O & M Costs


Cost Analysis(MUD, User, Authority Perspectives)

Capital Costs Quantity Unit Cost Cost

Interceptor Structure 350 $10,000

Pump Station 350 $125,000

Filters (if Type I effluent

required) 350 $237,500

Storage Tank N/A

Pump Station N/A

Force Main

4" 0 $0

6" 0 $0

8" 0 $198,000

10" 0 $0

12" 0 $0

Pond liner (if existing pond is unlined) 0.00 $0

Total Construction Cost $570,500

Soft Costs (survey, geotech,

engineering, etc.) $0

Contingencies (applied to Soft

Costs, also)

WWTP modifications, PS

construction $0

Pond and FM construction $0

Total Project Capital Cost $949,000


Cost Analysis

O&M Costs Quantity Unit Cost Cost

Debt Service $79,411.68

Cost of treated effluent

WWTP Power to produce

effluent $/1000 gpd/yr $27.49 $9,621.25

WWTP Chemicals to produce

effluent $/1000 gal. $0.50 $63,875.00

Other O&M costs

Pump Station power

Required Pump Head feet 150

Pump Efficiency % 75%

Pump Station power $9,621.25

Filter, Interceptor, PS, FM O&M

costs (% const'n)

Interceptor 1.0% $100.00

Pump Station 2.0% $2,500.00

Filter 1.5% $3,562.50

Force Main 0.5% $990.00

Estimated Annual O&M Cost for

Reuse Alone $169,681.69

Cost of Treated Effluent $/1000 gallons $1.33


Cost Analysis

O&M Costs Unit Cost Cost

Other Costs

On-going GW production gpd 0

GW well power cost



GW well power cost $0.00

GW well chemical cost $0.00

GW pumpage fees $0.00

Estimated Annual Cost for GW $0.00

Cost of GW $/1000 gallons $0.00

Required SW use gpd 0

Cost of SW $/1000 gallons $1.85 $0.00

Total Annual Cost for Reuse, GW, and SW (WITHOUT REUSE CREDIT)

$/year $169,681.69

$/1000 gallons $1.33

Credit for Reuse $/1000 gallons $0.39 $49,822.50

Total Annual Cost for Reuse, GW, and SW (WITH REUSE CREDIT)

$/year $119,859.19

$/1000 gallons $0.94


Cost Analysis

Costs if Reuse NOT

Implemented ('Do-Nothing') Cost

GW well O&M costs

On-going GW production gpd 350,000

GW well power cost



GW well power cost $25,656.67

GW well chemical cost

GW pumpage fees $191,625.00

Estimated Annual Cost for GW $217,281.67

Cost of GW $/1000 gallons $1.70

ANNUAL Costs to the

Authority to Implement

Reuse Unit Cost Cost

Credit for Reuse $/1000 gallons $0.39 $49,822.50

Lost GW Pumpage Fee

Revenue $/1000 gallons $1.50 $191,625.00

Lost SW Revenue $/1000 gallons $1.85 $0.00

Total $241,447.50

$/1000 gallons $1.89


How this might work….

• Authority funds reuse project

• Participants enter multi-party agreement– MUD or producer of effluent

– The Authority

– The User of Effluent

• MUD operates and maintains the plant

• User pays at rate to cover Debt and O&M


Traditional vs. Alternative Approach

• Traditional Approach– Purchase Surface Water from City of Houston– 7.5 mgd to be reserved in 2015

• Alternative Approach– Develop Reuse Sources– 1.5 gallon credit = 5.25 mgd


Where should the Authority spend its money?

• 7.5 MGD required to meet conversion requirements from 2020 through 2024– Luce Bayou Project @$0.75/gal

– NEWPP Expansion @$1.56/gal

– 2nd Source Line @ $3.08/gal

– Internal Lines @ $2.29/gal

• Authority will pay in capital costs $7.68/gal for 7.5 MGD of COHtreated surface water

• If reuse project is less, including lost revenue, it should moveforward


Cost Implications of Reuse

• Authority sees a loss in revenue (groundwater pumpage fees)

• Authority pays reuse incentives (5 years)


Cost Implications of Reuse (cont.)

• MUD charges less than GW Pumpage Fee for producing reuse water

• GW Pumpage Fee increases over time

• Therefore the reuse fee will likely increase over time (but is always less than GW pumpage fee)

• Reuse fee should cover debt service and O&M cost for producing reuse water


Cost Implications of Reuse (cont.)

• At future point, debt service is paid and MUD makes profit on providing reuse water

• Potentially the Authority should receive a portion of the profit made by the MUD, to offset lost revenue


Timing Considerations

• Capacity decisions will have to be made for the 2nd Source Line by 2012, shortly thereafter for the NEWPP expansion

• Debt will be issued and debt service payments will be determined

• Any capacity reduction after the debt is issued will increase the rate for those who continue to use water


Action Now affects…

• $200M Debt has been issued for 2013 system, another $50M coming

• Any conservation/reuse we implement today will at best affect the 2015 and 2020 reservations for the 2025 system


Risk Considerations

• Option 1-Assume no conservation/reuse and maintain estimated capacity needs– Most conservative & costly

– Most flexible for unknowns

• Option 2-Assume some level of conservation/reuse and reduce capacity– More risk with some cost savings

– Requires commitment to achieve reductions

Brown & Gay Engineers, Inc. 35

NFBWA

Website address: www.nfbwa.com

Contact:Melinda Silva, PE

Brown & Gay Engineers, Inc281-558-8700

nfbwa reuse and conservation considerations

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