Turning One of the Power Sector's Toughest Wastewater Streams into a Solved Problem

A first-of-its-kind wastewater treatment system at NRG's WA Parish Generating Station has earned POWER Magazine's 2026 Top Plant Water Award — and given the electricity generation industry a working, full-scale example of how zero liquid discharge can be done inside an operating power plant.

The award recognizes newly installed technology at WA Parish that has been running since November 2025, treating “flue gas desulfurization” wastewater, one of the most chemically complex and difficult industrial wastewater streams.

As one of the largest power plants in the United States, WA Parish plays a vital role in supporting Texas grid reliability while generating enough electricity to power approximately 908,000 homes.

New wastewater discharge requirements under the EPA's Steam Electric Effluent Limitation Guidelines created the need for a practical, commercially viable pathway to zero liquid discharge (ZLD) that could be implemented without disrupting reliability — an important consideration as rising electricity demand increases the need for affordable, dependable power generation.

Wastewater from power plants can be challenging to clean because it contains high levels of minerals, metals, and other substances. After reviewing several treatment options, NRG chose an advanced wastewater treatment system specifically designed for power plants.

The system, installed by Heartland Water Technology, includes two treatment units and processes up to 50,000 gallons of wastewater daily. The units operate reliably while reducing wastewater volume by nearly 93%. The small amount of material left behind is blended into the plant's existing gypsum byproduct, allowing the facility to achieve zero liquid discharge from flue gas desulfurization wastewater.

"NRG is grateful to POWER Magazine for this recognition, and to the Heartland team for a collaboration that delivered real results at WA Parish," said Robert Patrick, SVP, Head of Development, Engineering and Construction, NRG. "This award belongs to the plant team that operates this system day in and day out. We needed a solution that was commercially proven and could be integrated into a station that never stops running — thermal evaporation met that standard, and it has performed."

For NRG, the award is a recognition of the engineers, operators, and partners who brought the system online and continue to operate it at a plant that never stopped serving the grid.