Brackish Resources Aquifer Characterization System (BRACS)

Transcription

1 Brackish Resources Aquifer Characterization System (BRACS) by John Meyer, P.G. UIC Conference February 23, 2017

2 The following presentation is based upon professional research and analysis within the scope of the Texas Water Development Board s statutory responsibilities and priorities but, unless specifically noted, does not necessarily reflect official Board positions or decisions. Source: TWDB General Counsel

3 Innovative Water Technologies Our mission is to educate the water community on the use of nontraditional water supplies. Aquifer Storage & Recovery (ASR) Desalination Water Reuse Rainwater Harvesting Brackish Resources Aquifer Characterization System (BRACS) 3

4 Brackish Groundwater Saltier than fresh water, less salty than seawater Groundwater Salinity Classification Salinity Zone Code Total Dissolved Solids Concentration (units: milligrams per liter) Fresh FR 0 to 1,000 Slightly Saline SS 1,000 to 3,000 Moderately Saline MS 3,000 to 10,000 Very Saline VS 10,000 to 35,000 Brine BR Greater than 35,000 Drinking Water Limit Major/Minor Aquifer Mapped Limit Seawater Groundwater Salinity Classification Source: modified from Winslow and Kister, 1956

5 Timeline: Brackish Groundwater Studies Pre-2009: Several studies evaluated the potential of brackish groundwater 2009: Texas Legislature funded the BRACS program present: TWDB conducts internal BRACS studies 2015: House Bill 30 (84 th Leg.) directed TWDB to: define brackish groundwater production zones estimate productivity over a 30 and 50 year period recommend groundwater monitoring four aquifers due December, 2016 all aquifer studies due December, : TWDB contracted seven projects to begin HB 30 work Four completed August, 2016 Three due August,

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7 Example House Bill 30 Project: Rustler Aquifer, West Texas Contractor defined: hydrogeology and salinity zones potential production areas (PPA) exclusion zones Stakeholder meeting held in Fort Stockton

8 Rustler Aquifer Contractor modeled a number of hypothetical well field locations and pumping scenarios. Contractor estimated 30- and 50- year aquifer productivity based on scenarios. Draft report/data sent to TWDB (posted for stakeholder input) Final report/data sent to TWDB (posted for stakeholder input) Stakeholder meeting (September, 2016, for all studies)

9 Rustler Aquifer TWDB staff evaluated: contractor report and data stakeholder comments HB 30 exclusion criteria Recommended to management: brackish groundwater production zones groundwater volumes groundwater monitoring

10 TWDB Board approved brackish groundwater production zones in October, 2016 and provided 2016 Biennial Report on Seawater and Brackish Groundwater Desalination to Texas Legislature in December, 2016.

11 Log analysis to interpret Total Dissolved Solids Moderately Saline Slightly Saline At 160 ft = 15 ohm-meter Rwa Minimum Method interpreted TDS = 2,500 mg/l Moderately Saline Water Well TDS concentration = 2,264 mg/l (well screen ft) Very Saline Brine BRACS Well ID Source: Lower Rio Grande Valley BRACS Study

12 BRACS Database used for log analysis calculations

13 BRACS Database will store all parameters and completed calculations.

14 BRACS Database: Primary Tables Microsoft Access Database Available on the TWDB web site (with data dictionary) Relational table design All wells are assigned a unique well id, linking records together 14

15 TWDB BRACS Database 15

16 TWDB BRACS Geophysical Well Logs 1. Download logs on a per well basis using Water Data Interactive website 2. Instructions for requesting a large volume of logs on a county basis 16

17 TWDB BRACS Studies 17

18 TWDB BRACS Contracted Projects Current and Completed Projects 18

19 Questions? John Meyer Geologist Innovative Water Technologies Texas Water Development Board (512)