Gloucester switches its water disinfectant for the fall. Here is what you may notice at the tap

Gloucester's tap water may smell of chlorine for the next few weeks. The Department of Public Works began flushing the city's water mains on Wednesday, Oct. 14, to switch the disinfectant in the pipes from monochloramine to chlorine, according to a notice the city posted the same day.

What is happening

Most of the year, Gloucester's water is treated with monochloramine, a disinfectant made from chlorine and ammonia. Each fall, the DPW switches the pipes over to plain chlorine for a while, then switches back. The city describes it as preventive maintenance: chlorine kills bacteria in the pipes that, the city says, are harmless to drink but can cause bad tastes and smells and make it harder to keep enough disinfectant throughout the system.

The DPW is flushing targeted parts of the system to move chlorine through the pipes. After two to five weeks, it will switch back to monochloramine and flush the whole system again. The city did not post a street schedule or an end date.

What you may notice

• A chlorine smell. The city says a chlorine odor may be noticeable while chlorine is in use, and it goes away once the system is back on monochloramine.
• Discolored water. Flushing can stir up the normal flow in the pipes. If your water looks discolored, the city recommends running the cold water.
• Problems that do not clear. Call the DPW at (978) 325-5680 and ask for spot flushing.

Still in a drought

The city's water use restrictions are still posted: no lawn sprinklers or automatic irrigation, outdoor watering only with a handheld hose or watering can before 9 a.m. or after 5 p.m., and no washing driveways, sidewalks or patios. The state still lists the region at Level 2, Significant Drought, as of Oct. 9. Read what the drought level means.

Earlier coverage: Gloucester opens a dumpster at the DPW for old trash carts and recycling bins (Oct. 13), the other DPW notice this week.