Reclaimed Water Quality Requirements for Electric Utilities

Water use for thermal cooling represents a significant percentage of total water use ranging from 81 percent to 15 percent depending on the geographic region in the United States. Reclaimed water offers some significant advantages to help meet cooling water demands in the electric power industry, allowing the existing source waters to be used for other purposes, including potable water use. The quality of reclaimed water is dependent on the background water quality used to transport sanitary waste to a wastewater treatment plant (WWTP) and on the processes used at the WWTP to remove contaminants from the wastewater. Perceptions of the water quality required for cooling purposes varies from the east coast to the west coast, with demands for low TDS and low hardness water typical on the east coast and facilities on the west coast in water constrained areas treating available water to meet their process requirements.Water quality required for various cooling process applications are examined and the ability of reclaimed water to provide reliable alternate waters for power plant cooling are addressed. Advantages in using reclaimed water to address a portion of the energy-water nexus are identified and examples provided for several power plant cooling successes. Cost in meeting cooling water treatment and transmission to the power plant are identified to assist future consideration in using new industry best practices to solve the energy-water nexus.