Brackish Resources Aquifer

Characterization System (BRACS)

UIC Conference

February 23, 2017

by

John Meyer, P.G.

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

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� Aquifer Storage & Recovery (ASR)� Desalination� Water Reuse� Rainwater Harvesting� Brackish Resources Aquifer

Characterization System (BRACS)

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

Groundwater Salinity Classification

Source: modified from Winslow and Kister, 1956

Drinking Water Limit

Seawater

Major/Minor Aquifer Mapped Limit

Saltier than fresh water, less salty than seawater

Brackish Groundwater

Timeline: Brackish Groundwater Studies

• Pre-2009: Several studies evaluated the potential of brackish groundwater

• 2009: Texas Legislature funded the BRACS program.

• 2010 – present: TWDB conducts internal BRACS studies

• 2015: House Bill 30 (84th 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, 2022

• 2016: TWDB contracted seven projects to begin HB 30 work

– Four completed August, 2016

– Three due August, 20175

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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

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)

Rustler Aquifer

TWDB staff evaluated:

contractor report and data

stakeholder comments

HB 30 exclusion criteria

Recommended to management:

brackish groundwaterproduction zones

groundwater volumes

groundwater monitoring

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.

BRACS Well ID 42889

At 160 ft = 15 ohm-meter

Source: Lower Rio Grande Valley BRACS Study

Log analysis to interpret Total Dissolved Solids

Rwa Minimum Method interpreted TDS = 2,500 mg/L

Water Well TDS concentration = 2,264 mg/L(well screen 170-349 ft)

Moderately

Saline

Slightly

Saline

Moderately

Saline

Very

Saline

Brine

BRACS Database used for log analysis calculations

BRACS Database will store all parameters and completed

calculations.

BRACS Database: Primary Tables

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• 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

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TWDB BRACS Database

http://www.twdb.texas.gov/innovativewater/bracs/database.asp

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TWDB BRACS Geophysical Well Logs

http://www.twdb.texas.gov/innovativewater/bracs/WellLogs.asp

https://www2.twdb.texas.gov/apps/waterdatainteractive/groundwaterdataviewer

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

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TWDB BRACS Studieshttp://www.twdb.texas.gov/innovativewater/bracs/studies.asp

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TWDB BRACS Contracted Projects

http://www.twdb.texas.gov/innovativewater/bracs/projects.asp

Current and Completed Projects

Questions ?

John Meyer

Geologist

Innovative Water Technologies

Texas Water Development Board

John.meyer@twdb.texas.gov

(512) 463-8010

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