NFBWA Reuse and Conservation Considerations


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Melinda Silva NFBWA

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NFBWA Reuse and Conservation Considerations

  1. 1. North Fort Bend Water AuthorityDirect Reuse and Conservation Considerations February 2011
  2. 2. 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.Brown & Gay Engineers, Inc. 2
  3. 3. Current conservation efforts: Classroom materials (TEXAS WATER; WATER IS LIFE) •Sponsor Water Wise program •New mobile teaching lab •Water bill inserts •NewslettersBrown & Gay Engineers, Inc.
  4. 4. 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 additional early conversion credits (about 730 days) • Equivalent to about 800 total days or little over 2 yearsBrown & Gay Engineers, Inc. 4
  5. 5. 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 meters and 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 cafeteriasBrown & Gay Engineers, Inc.
  6. 6. 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.Brown & Gay Engineers, Inc.
  7. 7. 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 identifiedBrown & Gay Engineers, Inc.
  8. 8. 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 AuthorityBrown & Gay Engineers, Inc.
  9. 9. 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 nowBrown & Gay Engineers, Inc.
  10. 10. 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 developmentBrown & Gay Engineers, Inc.
  11. 11. 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 pumpageBrown & Gay Engineers, Inc.
  12. 12. Irrigation of Public Green Space Increasing Impact for New Development 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 3. Irrigate w/GW 2 yrs (up to X amt per SF), then Surcharge for GW Use 2. Water-Efficient Irrigation Plan w/Reuse or Other 1. Today – “Anything Goes” Increasing RestrictionBrown & Gay Engineers, Inc.
  13. 13. Amenity Lakes for New Development Increasing Impact 4. No Amenity Lakes 3. Lakes Filled w/ Reuse Water Only 2. Lakes Filled w/GW 2 yrs, Reuse Water After 1. Lakes Filled w/GW & SW Runoff Increasing RestrictionBrown & Gay Engineers, Inc.
  14. 14. 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 reuse and groundwater)Brown & Gay Engineers, Inc.
  15. 15. Wastewater Reuse vs. Demand Projections Year Authority Available Irrigation Wastewater Demand 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 methodsBrown & Gay Engineers, Inc.
  16. 16. Wastewater Reuse vs. Demand ProjectionsBrown & Gay Engineers, Inc.
  17. 17. Wastewater Reuse vs. Demand Projections Year Authority Available Irrigation Wastewater Demand 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 practicesBrown & Gay Engineers, Inc.
  18. 18. Wastewater Reuse vs. Demand ProjectionsBrown & Gay Engineers, Inc.
  19. 19. 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 MUDsBrown & Gay Engineers, Inc.
  20. 20. 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 mgdBrown & Gay Engineers, Inc.
  21. 21. 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 Reuse Project - GW Pumpage Fees - Capital Costs - Permit Fees - WWTP & Pipe - Engineering - Other - Debt Service - O & M CostsBrown & Gay Engineers, Inc.
  22. 22. 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 $949,000Brown & Gay Engineers, Inc.
  23. 23. 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 (% constn) 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 $1.33Brown & Gay Engineers, Inc.
  24. 24. Cost Analysis O&M Costs Unit Cost Cost Other Costs On-going GW production gpd 0 GW well power cost Required Pump Head feet 400 Pump Efficiency % 75% 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 $0.94Brown & Gay Engineers, Inc.
  25. 25. 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 Required Pump Head feet 400 Pump Efficiency % 75% 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 $1.89Brown & Gay Engineers, Inc.
  26. 26. 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&MBrown & Gay Engineers, Inc.
  27. 27. 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 mgdBrown & Gay Engineers, Inc.
  28. 28. 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 COH treated surface water • If reuse project is less, including lost revenue, it should move forwardBrown & Gay Engineers, Inc.
  29. 29. Cost Implications of Reuse • Authority sees a loss in revenue (groundwater pumpage fees) • Authority pays reuse incentives (5 years)Brown & Gay Engineers, Inc.
  30. 30. 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 waterBrown & Gay Engineers, Inc.
  31. 31. 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 revenueBrown & Gay Engineers, Inc.
  32. 32. 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 waterBrown & Gay Engineers, Inc.
  33. 33. 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 systemBrown & Gay Engineers, Inc.
  34. 34. 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 reductionsBrown & Gay Engineers, Inc.
  35. 35. NFBWA Website address: Contact: Melinda Silva, PE Brown & Gay Engineers, Inc 281-558-8700Brown & Gay Engineers, Inc. 35