190 likes | 363 Views
Feasibility Study for a Desalination Plant Using Brackish Edwards Aquifer Water. Robert Larsen, Ph.D. Kirk Holland, P.G. Brian Smith, Ph.D., P.G. Barton Springs Edwards Aquifer Conservation District. Today’s Topics. The Need for Additional Water in Region Desalination Overview
E N D
Feasibility Study for a Desalination Plant Using Brackish Edwards Aquifer Water Robert Larsen, Ph.D. Kirk Holland, P.G. Brian Smith, Ph.D., P.G. Barton Springs Edwards Aquifer Conservation District
Today’s Topics • The Need for Additional Water in Region • Desalination Overview • Feasibility Study for Desalination Project in the Saline Edwards • A Uniquely Advantageous Situation • Current Project Status • Why PCCD Should Participate
Projected Population Growth in Central Texas Item 1: CAMPO projections estimate traffic volumes to double and on some roads triple in areas south of Austin. Item 2: Central Texas will add over a million people in the next 20 to 30 years – Envision Central Texas
Water Sources vs. Demand Current supplies/storage are diminishing and won’t be able to serve even existing demand in long term Current sources can’t serve projected growth in demand Freshwater Edwards is over-subscribed Need to investigate alternative supplies including brackish groundwater.
Groundwater Management Zones - Why Needed? Current rules focused on Freshwater Edwards aquifer Alternative supplies needed Obstacle to alternative GW supplies New interest in the Trinity and Saline Edwards aquifers One size does not fit all
Surface Management Zones • Western Edwards • Eastern Edwards • Saline Edwards • Trinity Outcrop TDS
Desalination of Brackish Groundwater: A “Future Water Source” Whose Time Has Come
What is Desalination? • Any of several processes that remove excess salt and minerals from water • New, more efficient technologies emerging:
Desalination Feasibility Drivers • Availability and cost of electrical power • Supply of brackish/saline water in adequate amounts • Unmet demand for water as a sustainable market • Access to treated water storage and distribution system • Means to dispose (or utilize) concentrate that is a residual of treatment process • Environmental suitability and public acceptance
Demonstration Plant Objectives • Provide 1 to 10 MGD in additional potable water supplies • Be commercially self-sustaining: acceptable costs and risks • Serve a high-growth area with new water • Develop data and basis for other sites
Feasibility Study for Saline Edwards A Nexus of Site Advantages • TDS facility has a 50+ year supply of renewable waste material that has high energy value. • A large reservoir of brackish groundwater underlying the TDS site, and extending hundreds of miles to N and S. • Nearby physical and institutional infrastructure and a growing population. • Deep geologic strata out of the biotic zone that may serve as a feasible disposal site for saline wastewater.
Feasibility Study for Saline Edwards Project Team Members • Texas Disposal Systems • BSEACD • Texas State University, Government Partnership Program • Terrabon Inc. • University of Texas, Center for Sustainable Development • Carbon Shrinks, LLC • Undesignated Engineer-Constructor (Contractor) • Potential Members: • Plum Creek CD • EAA • Travis County • TWDB • Lower Colorado River Authority • Guadalupe-Blanco River Authority • City of Austin • Several WSCs
Feasibility Study for Saline Edwards Ongoing/Near-term Research Topics • What volumes and rates of brackish groundwater are available on a sustainable basis? • What markets exist for potable water produced through desalination process? • What are the economically and environmentally feasible options for dealing with project residuals? • What community concerns need to be considered? • What regulatory requirements apply to the project?
Feasibility Study for Saline Edwards Specific Tasks for Subsurface Characterization(Critical Path) First year:1. Install multiport monitor well (($150,000)2. Install test well ($140,000)3. Conduct pump/aquifer tests ($10,000) Additional tasks in 2nd year:1. Injection test well for concentrate disposal ($250,000)2. Surface geophysics survey to investigate salinity distribution and faults ($50,000)
Benefits to PCCD for Participating in Prospective Feasibility Study • Assisting in enabling a pioneering, relatively minimal-risk project to go forward in logical, step-wise fashion • Creating a potential additional firm-yield water supply available to PCCD from this project • Generating specific data relevant to development and regulation of additional brackish Edwards water in PCCD jurisdiction of Hays County • Providing a demonstrable return on tax monies to citizens in Hays County
Dr. Bob Larsen, Board President: rlarsen@bseacd.orgKirk Holland, P.G. General Manager: kholland@bseacd.orgDistrict Office: (512) 282-84411124 Regal Row, Austin, TX 78748Website: www.bseacd.org Contact Info