1 / 26

Benefits and Challenges of Developing Brackish Groundwater Supplies

WATER Supply. Benefits and Challenges of Developing Brackish Groundwater Supplies. Presented by: Kevin J. Spencer, P.G. R.W. Harden and Associates, Inc. Objectives. The Need to Develop Brackish Groundwater Supplies Potential Advantages Practical Considerations.

leo-sloan
Download Presentation

Benefits and Challenges of Developing Brackish Groundwater Supplies

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. WATER Supply Benefits and Challenges of Developing Brackish Groundwater Supplies Presented by: Kevin J. Spencer, P.G. R.W. Harden and Associates, Inc.

  2. Objectives • The Need to Develop Brackish Groundwater Supplies • Potential Advantages • Practical Considerations

  3. Rio Grande Regional Water Planning Group Southmost Regional Water Authority Valley MUD #2 • City of Los Fresnos • Indian Lake • Port of Brownsville

  4. Water Levels Amistad and Falcon Reservoirs (U.S.Ownership) Acre Feet in Millions Reservoir Capacity 4.0 3.5 Water Level at 100% Capacity 3.3 3.0 2.5 2.0 Water Level at 50% Capacity 1.5 1.0 Summer 2002 – 25% Capacity 0.5 Source: TNRCC Watermaster Surface Reservoir Conditions

  5. What Can We Expect? • Increased demand/less water • Implementation of drought management strategies • Irrigation shortages • “Piggy Back” by municipalities • Hydrilla/ Hyacinth blockage

  6. Alternative Sources • Conservation • Reuse • Desalination • Sea Water • Brackish Groundwater

  7. Brackish Groundwater Desalination • Significant brackish groundwater reserves in Gulf Coast aquifers • Independent of river flows • Not subject to water rights purchases* • Cost of treatment comparable to surface water • Improved water quality

  8. Cost Trends Cost per 1000 gallon including debt service and operations Source: NRS Consulting Engineers

  9. Cost Factors • Degree of total dissolved solids • Power costs • Economies of scale • Location • Concentrate disposal

  10. Brackish Groundwater • Advantages over sea water • Significant reduction in plant capital and O&M • Reduced environmental impact • Advantages over surface water • Drought tolerant • Improved water quality • Water rights savings

  11. Brackish Groundwater • Advantages over fresh groundwater • New Supply Resource • Less Competition • Less Regulation • Positive Public Perception

  12. Regional Water Supply • Establish economies of scale • Favorable to funding agencies • Texas Water Development Board policy statement • Infrastructure financing

  13. Southmost Regional Water Authority Allocation of Water 7.5 MGD Phase I

  14. Southmost Regional Water Authority Capacity Provided

  15. Planned Brackish GW Projects • North Alamo WSC (5-10 MGD) • City of Edinburg (5 MGD) • City of Raymondville (~2 MGD) • City of Combs (~0.5 MGD) • Laguna Madre WD (2-3 MGD)

  16. Implementation Challenges • Proving up the supply • Concentrate Disposal • Well Design Considerations

  17. Proving Up the Supply • Initial Modeling • Test Drilling • Development of Geologic Framework • Long-Term Aquifer Testing • Refinement of the Model • Locating Suitable Well Sites

  18. Concentrate Disposal • Discharge to brackish surface water • Discharge to ocean • Injection • Waste water systems • Evaporative

  19. Well Design Considerations • Corrosion Protection • Casing Design • Stainless Steel • PVC • Carbon Steel • Fiberglass • Coatings • Pump Column Design • Stainless Steel • PVC • Fiberglass • Pump Construction Materials • Bowls and Motors - Stainless Steel • Impellers - Brass/Stainless Steel/Ceramic

  20. Summary and Conclusions • Brackish groundwater is the least cost alternative for each entity • Regional Advantages • Economy of Scale • Personnel cost savings • Common well field • Potential for additional partners • Favorable grant potential

  21. Summary and Conclusions • Cost Factors • Improvement in Membrane Technology • Operation of RO at peak capacity • Increasing expense of surface water treatment and water rights • Water Quality Improvement • Decreased Competition

  22. Questions?

More Related