We are committed to treating wastewater in a way that returns clean water to the environment.

Historically, the wastewater industry has focused on the use of relatively high-energy treatment technologies and chemicals to protect water quality. Now, WSSC Water and other "Utilities of the Future" are moving toward ever-increasing levels of resource recovery to return high-quality treated effluent to the environment. Our initiatives include continuous improvements in energy use, nutrient recovery, water reuse, and the use of alternative energy sources.

WSSC Water operates and maintains six water resource recovery facilities. The Western Branch, Piscataway, Parkway, Seneca, Damascus and Hyattstown WRRFs are designed to handle up to 95.6 million gallons of wastewater per day; annually, they treat an average of about 65 million gallons per day. The remainder of the wastewater from our service area is treated at Washington, D.C.'s Blue Plains WRRF.


At the WRRFs, wastewater goes through physical, chemical and biological processes. In the "secondary treatment" biological process, bacteria and other microorganisms remove wastes. In the process, the bacteria grow and create new bacteria. To maintain steady treatment, a portion of these are constantly removed from the process - and we refer to this portion as the biosolids. At WSSC Water, the biosolids are thickened, dewatered, and then treated with lime to raise the pH level to stabilize them (that is, to eliminate pathogens and minimize odors). In the future, the Bio-Energy project will process the dewatered solids from the WRRFs to produce high-quality Class A biosolids and generate renewable energy.

Going down the drain

What happens to the water you use once it's gone down the drain?

Watch this interactive map to see what happens.

Last Modified: March 8, 2021, 7:20 pm EST