CCA Texas Position on Desalination

As coastal communities in Texas increasingly turn to desalination of both brackish groundwater and saline surface water to meet growing freshwater demands, CCA Texas supports responsible, science-based practices that protect the health of our state’s coastal ecosystems, fisheries, and water quality.

Desalination Sources

Desalination is becoming more common across the Texas coast, using technologies like reverse osmosis to remove dissolved ions (salt) and produce freshwater from two primary sources:

• Brackish groundwater, drawn from deep aquifers with moderate salinity levels (typically 1,000–10,000 mg/L TDS), and
• Saline surface water, such as seawater from bays, estuaries, or the Gulf (typically 10,000–35,000 mg/L TDS). For reference, Gulf seawater is - 36,000mg/L.

While desalination offers a valuable source of freshwater for municipal and industrial needs, it also generates a concentrated waste stream, commonly referred to as concentrate, brine, or reject water. Regardless of the terminology, the method and location of discharge are critical considerations. When released into bays and estuaries, this waste stream often presents significant ecological risks. As such and at a minimum, comprehensive permitting and rigorous, site-specific evaluation under the Texas Commission on Environmental Quality’s (TCEQ) Texas Pollutant Discharge Elimination System (TPDES) and the federal Clean Water Act are essential to ensure environmental protection.

Environmental Concerns

Surface discharge of desalination effluent, whether from brackish groundwater or seawater, raises serious concerns for the health of coastal ecosystems. While both types of desalination use similar treatment processes, the effluent they produce varies in concentration, chemistry, and volume:

• Seawater desalination produces high-volume brine nearly twice as salty as the original intake water, often exceeding 60,000 mg/L TDS. When discharged into shallow or poorly flushed bays, this hypersaline waste can smother benthic habitats, reduce oxygen levels, and exceed the salinity tolerance of critical species.
• Brackish groundwater desalination typically produces effluent with lower volume and salinity than seawater desalination; however, it often contains naturally occurring but potentially harmful constituents—such as arsenic, boron, and radionuclides—depending on the geochemistry of the source aquifer. Even at reduced salinity levels, this concentrate can negatively impact sensitive estuarine species and habitats, particularly when discharged into low-energy environments with limited flushing. Moreover, many proposed discharge sites for brackish desalination projects are located in historically freshwater streams and creeks, where ecosystems may be especially vulnerable to changes in water chemistry.

Regardless of source, desalination waste streams can:

• Exceed salinity tolerances for many fish and invertebrates, causing stress, displacement, or mortality.
• Degrade riparian zones, oyster reefs, seagrass beds, and other vital habitats for aquatic species.
• Alter the natural ecological balance, particularly in semi-enclosed or nutrient-stressed bays.

While some proponents argue that discharge waste streams could dilute hypersaline conditions in isolated systems, these cases are highly specific and temporary. The long-term risks to water quality, marine life, and ecosystem stability far outweigh any short-term benefits.

CCA Texas Recommendations

CCA Texas remains guided by its mission to protect sustainable coastal fisheries and preserve the habitats that support them. In line with recommendations from the Harte Research Institute and other coastal experts, we urge the following for all desalination projects in Texas:

• Prohibit surface discharge of brine into rivers, streams, or estuaries—particularly in shallow, semi-enclosed, or poorly flushed bay systems. These waters cannot absorb concentrated waste without suffering long-term ecological damage.
• Prioritize deep-well injection into geologically isolated underground formations, ensuring zero risk of contamination to freshwater aquifers or groundwater-dependent ecosystems.
• Support offshore discharge only when deep-well injection is not feasible—and only after rigorous modeling demonstrates no significant impact to marine life or water quality.
• Mandate strong environmental review for all proposed discharges, including:
• Site-specific hydrologic and salinity modeling that accounts for seasonal and climate variability.
• Baseline and post-discharge biological assessments to monitor impacts on habitats and species.
• Public transparency and engagement with affected stakeholders, including fishing, conservation, and coastal communities.
• Require comprehensive, peer-reviewed science before any discharge is approved. This includes establishing baseline ecological conditions and benchmark hydrological studies to inform site suitability and cumulative risk.
• Invest in long-term monitoring and adaptive management, guided by independent academic institutions such as Texas A&M University–Corpus Christi’s Harte Research Institute and University of Texas Marine Science Institute.

Conclusion

Texas must find new water solutions—but not at the cost of our bays and estuaries. These ecosystems support not only fish and wildlife, but entire coastal economies. According to the 2022 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation, Texas’s saltwater fishery generates an estimated $4.2 billion in annual economic impact. That value is rooted in healthy estuarine habitats, clean water, and balanced salinity—all of which are threatened by irresponsible desalination discharge.

CCA Texas believes we can meet our water needs without compromising coastal health, but only if we commit to desalination practices that avoid estuarine discharge and prioritize offshore or deep-well solutions. We will continue advocating for policies that are grounded in science and protective of the people, places, and fisheries that define the Texas coast.

Our bays are not disposal sites. They are nurseries, livelihoods, and legacies. Let’s keep them that way—for this generation and the next.