Frequently Asked Questions
Also see Desalination FAQs
BRACS
- What is BRACS?
- What is brackish groundwater?
- How much brackish groundwater is present in Texas?
- What does a BRACS project consist of?
- How do I obtain BRACS project reports and data?
- How do I obtain digital geophysical well logs?
- How do you select which areas of Texas to study?
- What projects have you completed, and which projects are in progress?
- How can I get a copy of the BRACS Database?
- Have there been other brackish groundwater studies in Texas?
- How do I get a copy of the BRACS contract reports and deliverables?
- Where is the brackish groundwater in Texas?
- How deep is the brackish groundwater?
- How does water become brackish?
BGPZ
- What is the salinity range of groundwater in a designated BGPZ?
- Can BGPZs be designated in very saline groundwater (10,000 to 35,000 mg/L TDS)?
- Can I develop a brackish groundwater source outside of a BGPZ?
- Is a BGPZ’s production volume separate from the MAG volume?
- What is House Bill 722?
- Does House Bill 722 expedite the permitting of brackish wells inside of a BGPZ?
- What are the benefits of having a designated BGPZ in my groundwater conservation district (GCD)?
- Does the permitting process for brackish groundwater apply to a GCD without a BGPZ?
- Can a BGPZ be amended?
- Would a brackish groundwater permit application for a location outside of a BGPZ that is currently being amended be placed on hold while the BGPZ is amended?
- What kinds of projects are eligible for a permit from a groundwater conservation district in a BGPZ?
- If a BGPZ is designated in an area without a GCD, would a GCD need to be created as a result?
- Are BGPZs limited to zones hydrologically isolated from other zones of the associated aquifer?
- Will production from BGPZs impact other zones of the associated aquifer?
- Will production from BGPZs result in increased salinity to any zone of aquifer?
- Will production from BGPZs contribute to subsidence?
Other FAQs
Answers to Frequently Asked Questions
What is BRACS?
TWDB's Brackish Resources Aquifer Characterization System (BRACS) program maps and characterizes the brackish aquifers of Texas in greater detail than previous studies. The study deliverables include a report with companion geographic information system data files. Data is also entered into the BRACS Database.
What is brackish groundwater?
Brackish groundwater contains dissolved minerals in the range of 1,000 to 9,999 milligrams per liter (mg/L). Water is classified as fresh (0–999 mg/L), slightly saline (1,000–2,999 mg/L), moderately saline (3,000–9,999), and saline (greater than 10,000 mg/L). For comparison, seawater contains approximately 35,000 mg/L of total dissolved solids.
How much brackish groundwater is present in Texas?
Texas has an abundance of brackish groundwater, estimated at more than 3.2 billion acre-feet based on the cumulative storage volume of in-place brackish groundwater for completed BRACS studies. This estimate does not address recoverability and is an estimate of brackish groundwater volume within the aquifer formation(s). This in-place brackish groundwater storage volume will increase over time as the studies are completed.
What does a BRACS project consist of?
A typical study involves evaluating existing well records, geophysical well logs, and geologic reports associated with the aquifer(s) of interest. Geologic structure and net sand (where applicable) is evaluated and updated with additional subsurface well data. The aquifer formations are then mapped individually with estimated salinity from water well records and calculated salinity from geophysical well logs. This information is then used to prepare estimated volumes of brackish groundwater. All well data used for a study are entered into the BRACS Database. The project is summarized and mapped in a TWDB numbered report.
How do I obtain BRACS project reports and data?
Each of the BRACS studies/projects consists of a report, digital geographic information system (GIS) files, database tables, and digital geophysical well logs. The project reports and GIS files are available on individual study webpages that are linked from TWDB's BRACS Studies webpage.
How do I obtain digital geophysical well logs?
You can download a copy of the database (see instructions below) or view the Water Data Interactive (WDI) map-based approach (select the Brackish Groundwater Database application) to determine available well control. The majority of the logs are in a TIFF file format and are filed in a state and county folder system. Generally, to save handling time, we provide the entire county folder of logs unless an individual requests a few specific logs. Learn more about requesting well logs at the BRACS Geophysical Well Logs webpage.
How do you select which areas of Texas to study?
Selection of past project areas were based on recommended desalination projects listed in the state water plan. Current projects are based on Water Code Section 16.060 requirements.
What projects have you completed, and which projects are in progress?
To learn more about completed, current, and future studies visit the TWDB's BRACS Studies webpage for summary maps and links to completed studies.
How can I get a copy of the BRACS Database?
The BRACS Database in Microsoft® Access® for Microsoft 365 format is available in a compressed file format for download from the TWDB Website. A companion report titled Brackish Resources Aquifer Characterization System Database Data Dictionary describes the database design and the primary tables including field names, types, lookup table references, and field contents. Each of the five primary project related tables are also described.
Have there been other brackish groundwater studies in Texas?
completed in 1972 as TWDB Report 157 is available in an eight-volume compendium on the TWDB Website. Another report, U.S. Geological Survey Water Supply Paper 1365, completed in 1965 by A.G. Winslow and L.R. Kister is available in PDF format on the U.S. Geological Survey Website. Many of the hydrogeology reports completed by the state and the U.S. Geological Survey discuss brackish portions of the major and minor aquifers in the lower salinity ranges (for example, 1,000 to 3,000 milligrams per liter of total dissolved solids). These reports, often completed by county, groups of counties, or aquifer wide, are available on the TWDB's Publications webpage.
How do I get a copy of the BRACS contract reports and deliverables?
All of the BRACS study reports with related geographic information system files and the BRACS contract reports and deliverables are available on TWDB's BRACS Studies webpage.
Where is the brackish groundwater in Texas?
We have prepared several one-page maps showing the distribution of fresh and brackish water wells in Texas. These maps are available on TWDB's BRACS Maps webpage. Additionally, there are other brackish groundwater resources in geologic formations that are not designated as a major or minor aquifer. The lateral extent and potential volume of this resource are unknown.
How deep is the brackish groundwater?
It varies, from a few feet to thousands of feet deep. The depth depends on the aquifer and the geographic area of the state in which the aquifer is located. For lower salinity ranges (for example, 1,000 to 3,000 mg/L of total dissolved solids) of brackish groundwater, the TWDB's Groundwater Database can be used to provide an estimate. This database is available for download in Microsoft® Access® format. Alternatively, well information can be reviewed in the Water Data Interactive (WDI) map-based Web browser. In the browser, select the Groundwater Database application. For areas of the state without water quality data, geophysical well logs will need to be interpreted or direct measurements obtained from oil and gas operators.
How does water become brackish?
Some water is naturally brackish because groundwater dissolves minerals as it percolates through the aquifer. Some aquifers contain more evaporite minerals (salts deposited when seawater evaporated) than other aquifers, so the salinity of the groundwater is greater. In general, the longer the water is in contact with the aquifer minerals, the longer the groundwater has to dissolve some of those minerals.
What is the salinity range of groundwater in a designated BGPZ?
Between 1,000 and 9,999 milligrams per liter (mg/L) total dissolved solids concentrations.
Can BGPZs be designated in very saline groundwater zones (10,000 to 35,000 mg/L TDS)?
No. The TWDB considers slightly to moderately saline groundwater to be brackish groundwater. Therefore, BGPZs are only designated in brackish portions of aquifers.
Can I develop a brackish groundwater source outside of a BGPZ?
Yes. While brackish groundwater production is not limited to the area of a designated BGPZ, statute requires the TWDB to designate BGPZs in areas of the state with high potential for long-term brackish groundwater production and the lowest risk of adverse impacts. Groundwater withdrawals and well permitting are subject to groundwater conservation district rules, where applicable.
Is a BGPZ’s production volume separate from the MAG volume?
Yes. Texas Water Code § 36.1015(l) states that groundwater conservation district rules regarding permits within a BPGZ must provide that the production authorized from a designated BGPZ is in addition to, or separate from, the amount of modeled available groundwater.
What is House Bill 722?
House Bill 722 (86th Texas Legislature) is codified in Texas Water Code § 36.1015. The provisions of Texas Water Code § 36.1015 provide a common framework for permitting and regulatory certainty for those pursuing a brackish groundwater project within a designated zone.
Does House Bill 722 expedite the permitting of brackish wells inside of a BGPZ?
Texas Water Code § 36.1015(e)(7) states that groundwater conservation district rules adopted for brackish groundwater withdrawal from a BGPZ must provide greater access to brackish groundwater by simplifying procedure, avoiding delay in permitting, saving expense for the permit seeker, and providing flexibility to permit applicants and the district.
What are the benefits of having a designated BGPZ in my groundwater conservation district (GCD)?
BGPZs are areas designated by the TWDB as areas with high potential for long-term brackish groundwater production with the lowest risk of adverse impacts. The data, analysis, and technical information provided through TWDB BRACS studies and BGPZ designations provide valuable resources to stakeholders, including GCDs and potential brackish groundwater development project sponsors. The TWDB also provides a technical review of and report on permit applications to GCD. Groundwater conservation district (GCD) rules adopted for brackish groundwater withdrawal from a BGPZ must provide greater access to brackish groundwater by simplifying procedures, avoiding delays in permitting, saving expense for the permit seeker, and providing flexibility to permit applicants and the district (Texas Water Code § 36.1015(e)(7)). These rules provide a common framework for permitting and regulatory certainty for those pursuing a brackish groundwater project within a designated zone.
Does the permitting process for brackish groundwater apply to a GCD without a BGPZ?
A GCD located over any part of a designated BGPZ may adopt rules for permits within the BPGZ. Texas Water Code Chapter 36 allows districts to make and enforce rules for aquifers under their jurisdiction, which may include brackish parts of those aquifers. The permitting process described in Texas Water Code § 36.1015 provides a common permitting framework for BGPZs with which all GCDs must comply.
Can a BGPZ be amended?
Yes. See the BGPZ Amended guidance document for details.
Would a brackish groundwater permit application for a location outside of a BGPZ that is currently being amended be placed on hold while the BGPZ is amended?
A decision made in this scenario would be at the groundwater conservation district’s discretion.
What kinds of projects are eligible for a permit from a groundwater conservation district in a BGPZ?
Groundwater conservation district rules for permits in a BGPZ apply only to a permit for a municipal project designed to treat brackish groundwater to drinking water standards or for an electric generation project.
If a BGPZ is designated in an area without a GCD, would a GCD need to be created as a result?
There is no requirement that a groundwater conservation district must be created in an area with a designated BGPZ.
Are BGPZs limited to zones hydrologically isolated from other zones of the associated aquifer?
Will production from BGPZs impact other zones of the associated aquifer?
Will production from BGPZs result in increased salinity to any zone of aquifer?
The TWDB designates BGPZs in parts of aquifers that are separated by hydrogeologic barriers sufficient to prevent significant impacts to water availability or water quality in any area of the same or other aquifers, subdivisions of aquifers, or geologic strata that have an average total dissolved solids concentration of 1,000 milligrams per liter or less at the time of zone designation.
The potential for impact due to brackish groundwater production is addressed in Texas Water Code § 36.1015, which states that the rules adopted under this section must require implementation of a monitoring system recommended by the TWDB to monitor water levels and water quality in the same or an adjacent aquifer, subdivision of an aquifer, or geologic stratum in which the designated BGPZ is located.
Will production from BGPZs contribute to subsidence?
Subsidence is the lowering in elevation of the land surface caused by groundwater production. For a project located in a designated BGPZ in the Gulf Coast Aquifer, groundwater conservation district rules adopted for BGPZs must require reasonable monitoring of land elevations by the district to determine if production from the project is causing or is likely to cause subsidence during the permit term.
Whom can I contact at the Texas Water Development Board for more information about BRACS or BPGZs?
If you have any questions about the BRACS program, please contact Kristie Laughlin (512-475-1748) or Mark Robinson (512-463-7657).