Frequently Asked Questions

What does WSSC stand for?

WSSC stands for Washington Suburban Sanitary Commission.

What does WSSC do?

WSSC is one of the ten largest water and sewer utility companies in the nation. We provide safe and reliable drinking water to over 1.5 million customers and return clean water to our environment.

How old is WSSC?

WSSC was founded in 1918.

Who are WSSC customers?

WSSC serves the residents of Montgomery and Prince George's counties in Maryland.

What is a reservoir?

A reservoir is an artificial lake, created to store a large amount of water. This way there is always a supply of water ready to be cleaned and processed.

How many reservoirs does WSSC have and how big are they?

WSSC has three reservoirs: the Triadelphia, Rocky Gorge and Little Seneca. All three reservoirs combined can hold a maximum of 14 billion gallons of untreated water. The Triadelphia Reservoir covers approximately 800 acres. Rocky Gorge Reservoir covers approximately 810 acres. Little Seneca covers approximately 505 acres.

How deep is each reservoir?

Triadelphia Reservoir is 65 feet at its deepest point. Rocky Gorge is 120 feet at its deepest point. Little Seneca is 65 feet deep at its deepest point, right at the dam.

Why does the water go down in the summer?

In the summer, the water in the ground is soaked up by the plants and trees and does not run down to the creeks and rivers that feed the reservoirs. In the wintertime, when the trees are 'sleeping', the snow and rain run down the hills into these 'feeders' creeks and then into the reservoir.

Can I fish in the reservoirs?

Yes, you can fish in the reservoirs. If you're 16 years old, in addition to your fishing license from the State of Maryland, you need to get a special permit from WSSC.

What kinds of animals live around the reservoirs?

The are a number of usual and unusual animals and birds that call the surrounding areas home. There are rabbits, deer, foxes, Cardinals, Blue Herons, geese, and eagles, to name a few. No bears, though! There is also a wide variety of fish in the reservoirs.

How many water plants are there?

WSSC owns and operates two water filtration plants, the Patuxent River Water Filtration Plant in Prince George's County and the Potomac River Water Filtration Plant in Montgomery County.

How many wastewater plants are there?

WSSC currently owns and operates six wastewater treatment plants: Western Branch, Piscataway, Parkway, Seneca, Damascus, and Hyattstown.