When the temperature drops in Prince George’s and Montgomery counties, the chances of water main breaks rises about 60% compared to warmer months. Break can leave hundreds of people without service and can also cause serious traffic problems, so WSSC takes winter preparations very seriously. WSSC has teams of skilled contractors on standby, along with trucks, heavy equipment, and the latest technology ready to roll for the coldest season.
There is a relationship between water temperature and breaks. A sudden temperature drop provides a kind of shock to the pipes. Most of WSSC water comes from the Potomac River which feeds the WSSC Potomac Water Filtration Plan, and when air temperatures drop the water in the Potomac River drops too. It takes a day or two, but an increase in breaks and leaks soon follow. The river also brings the colder water from higher elevations to the west. Even a 10-degree change in the air or water temperature can dramatically increase stress on a pipe, including underground pipes. Water temperature below 40 degrees F can also cause pipes to become more brittle, and above ground pipes can freeze when the air temperature hits freezing or below. That leads to increased external stress. The Patuxent River, and the two reservoirs formed behind Brighton and T. Howard Duckett dams, provide about 30% of the water for WSSC customers via the Patuxent Water Filtration Plant. But the reservoirs are deeper than the Potomac River, and the temperatures don’t change as fast. Therefore we have fewer breaks and leaks in areas served by the Patuxent Plant.