Produced water is a byproduct, recovered during oil and gas production, that contains all fluid and gas waste brought to the surface. This fluid can contain dissolved salts and minerals, suspended solids and organics, chemicals, hydrocarbons, water entrained in the geologic oil and gas formation, and other naturally occurring constituents. Concentrations of these constituents can vary substantially between formations or basins, from near freshwater quality to saltier than ocean water. Untreated produced water can require multiple phases of treatment before being considered suitable for beneficial reuse outside the oil and gas industry, and the degree of treatment may vary based on the intended manner of reuse.

To learn more about produced water, please see information from the Environmental Protection Agency, Groundwater Protection Council, U.S. Geological Survey, and the Water and Environment Federation.

Produced water is a fluid oil and gas waste stream that has predominantly been disposed in underground injection wells or reused within the oil field. Large deep well disposal can trigger localized seismic activity, and underground space for additional water is becoming more limited in some areas. There is also concern that if not properly managed, injected untreated produced water could migrate to the surface or to sources of underground water.

Simultaneously, many parts of Texas face water shortages, particularly in arid western regions such as the Permian Basin. Researchers at the Texas Produced Water Consortium (TxPWC) are evaluating how produced water can be safely treated to remove constituents and supplement existing water supplies for applications such as industrial use, agricultural irrigation, rangeland restoration, or returned to the environment via surface discharge.

Before produced water can be safely reused, a multilayer treatment process – which typically includes pretreatment, desalination, and further “polishing” processes – is required to remove a variety of constituents. Common pretreatment treatment processes include oxidation, dissolved air flotation (DAF), and filtration. Desalination processes could be based on thermal distillation, reverse osmosis (RO), or solvent desalination.  Post-treatment polishing can include granular activated carbon (GAC) filtration and ammonia removal. After the treatment process is complete, the TxPWC describes the treated produced water as “polished desalinated produced water,” which can then be considered for beneficial applications once the quality meets regulatory permit requirements.

Recent TxPWC evaluation of pilot treatment studies in 2024-2025 found that the pilot-scale treatment systems removed more than 99% of salinity, naturally occurring radioactive materials, and organic material. More than 98% of comparable water quality parameters of polished desalinated produced water complied with TCEQ drinking water limits, and more than 89% of toxicity endpoints showed no observed toxicity in undiluted polished desalinated produced water However, meeting drinking water standards does not mean the polished desalinated produced water has been approved for drinking water; it simply provides a baseline comparison for the quality of water after going through multi-layer treatment processes. TxPWC’s water quality report demonstrates the treatment processes are highly effective at removing many constituents from the water. TxPWC is conducting research to evaluate treatment performance and water quality through ongoing research, including longer-term pilot studies, multiple growing seasons, and testing across multiple crops. Learn more in the full water quality report.

The New Mexico Produced Water Consortium (NMPWRC) also conducts studies to evaluate water quality, where they have found treated produced water samples demonstrated “no negative impact to plants, aquatic organisms, or human cell lines.” Read more about NMPWRC’s studies on their website.

When treated appropriately and permitted by applicable regulatory agencies, polished desalinated produced water could offset the usage of freshwater supplies for applications such as:

1. 1. Industrial applications
      1. Reuse within the oil and gas industry
      2. Concrete mixing
   2. Land application
      1. Crop irrigation
      2. Rangeland restoration
   3. Surface water discharge to help maintain water levels in rivers and streams
   4. Aquifer storage and recharge

It is important, however, to recognize produced water treatment and beneficial reuse is an evolving practice, and TCEQ, the main regulator, is still developing the specific standards for land application and individual discharge standards.

TxPWC was created by Senate Bill 601 of the 87^th Legislature to explore the science, technology, and feasibility of reusing polished desalinated produced water outside the oil and gas industry. As an independent research organization, TxPWC conducts rigorous science to help agencies determine appropriate water treatment standards for the protection of human and environmental health. Produced water treatment isn’t just possible; it’s happening. TxPWC is making sure it’s done safely for Texas and for the future.

TxPWC has a team of expert researchers from Texas Tech University across disciplines including plant and soil science, natural resource management, environmental toxicology, petroleum engineering, civil/environmental engineering, chemical engineering, mechanical engineering, economics, law, and agricultural communications to evaluate the safety and feasibility of produced water treatment and beneficial reuse. These experts are conducting research across six different research areas:

1. 1. Water Quality and Toxicology - Characterizes the constituents in produced water at various stages of the treatment process and conducts toxicity testing, both to support quantitative risk assessments and to inform regulatory compliance requirements for safe reuse or surface discharge.
   2. Treatment Technologies - Conducting comparative economic-driven analyses of treatment technologies for the Permian Basin produced water and identifying critical materials and minerals of interest, such as lithium, that can potentially be recovered through the treatment of produced water.
   3. Land Application – Evaluates the application of polished desalinated produced water to plant and soil and through greenhouse and field pilot studies.
   4. Surface Water Discharge – Explores the application of polished desalinated produced water to rivers, streams, and aquatic ecosystems.
   5. Energy- Produced Water Nexus - Identifies synergies to provide energy to power facilities performing treatment of produced water.
   6. Law, Policy, Economics, and Communications - Explores policy implications, economic feasibility, and public perceptions to support informed and science-based decision-making for potential beneficial reuse.

The Texas Commission on Environmental Quality (TCEQ) is responsible for permitting and regulation for discharges to surface water (g., the Pecos River) or land applications (e.g., rangeland restoration or crop irrigation) from a source that is beneficially reusing polished desalinated produced water. Any future applications (e.g., groundwater/aquifer recharge) must meet regulatory standards developed to protect human and environmental health. You can learn more on the TCEQ website. The Railroad Commission of Texas (RRC) may also permit industrial usage of polished desalinated produced water in the future.

Researchers have made significant progress in evaluating efficient treatment technologies, as well as understanding the polished desalinated produced water quality and any potential impacts of beneficial reuse on plant, soil, and environmental health. To date, some – but not all – pilot treatment systems have demonstrated the ability to yield polished desalinated produced water with no toxicity. Ongoing research focuses on understanding the scalability, economics, and potential long-term impacts from large-scale beneficial reuse.