Prince William Water's drinking water sources, including the Potomac River, Occoquan Reservoir, Lake Manassas, and the Bull Run/Evergreen Well System, do not contain any lead.

A source of lead in drinking water can be household plumbing. In 1986, lead was banned from use in pipes and solder for drinking water systems. In older homes, where lead is present in the service lines, plumbing fixtures and solder connections, it may leach into the water after the water sits for long periods of time.

The water Prince William Water purchases from Fairfax Water and the City of Manassas is treated with a corrosion inhibitor, which is added to help prevent lead from leaching from household plumbing into drinking water.