Water Main Flushing

The Utility Division, conducts a flushing program during the spring to maintain water quality and improve system efficiency. Hydrant flushing may occur during daytime hours, but is more likely to happen from 11 PM to 6 AM. Temporary discoloration of water may occur as iron particles are cleaned from the pipes. Although this discolored water is not harmful to your health, you should avoid use of chlorine bleach when washing clothes to avoid staining of laundry. Running the cold water tap for a few minutes is usually sufficient to restore the flow of clean water to your home. If water quality problems persist, residents should call the Utility Division at (978) 325-5600.

The City of Gloucester has typically used a conventional flushing program to maintain water quality. Conducted every spring, conventional flushing consists of opening hydrants in a specified neighborhood to flush out accumulated rust and sediment. While effective, this type of flushing does not increase the speed of water flow through the pipes enough to dislodge stubborn deposits.

Using computer mapping and water model software, the Department of Public Works (DPW) developed a unidirectional flushing program. Unidirectional flushing consists of closing specific water valves to create one way flow and then opening hydrants in a consecutive manner. This increases the speed of the water flow in the pipes. These high velocities produce a scouring action in the pipes, removing even the most stubborn deposits.

Unidirectional flushing uses up to 40% less water than conventional flushing, and allows for a better response to localized water quality complaints. Because of better sediment removal, the effects of unidirectional flushing last longer. Additionally, unidirectional flushing will test almost all of the water system valves and hydrants, identifying those in need of repair or replacement.

Spot flushing is also often used in Gloucester in areas that have a low flow or a dead end in the distribution system. This type of flushing will still be utilized throughout the entire year when weather permits.

The Water Department will return to areas, if needed, where discoloration of the water persists.