What to do after a boil water advisory is lifted

How an advisory gets lifted

Indiana's environmental agency describes the test for an E. coli event: the advisory may only be lifted when two consecutive sets of samples, collected 24 hours apart, are found to be satisfactory.

That is also why something that looked like a one-day event can run longer. New York State's health department puts a typical event at 24 to 48 hours while noting it can be longer, and that how long depends on the condition that caused it, how quickly that can be corrected, and how long laboratory results take.

What follows is the sequence New York State's health department gives for your own plumbing, plus Louisiana's and Michigan's instructions for filters and for the appliances plumbed into your water line.

Flush your cold taps first

New York State's health department gives the order to work in, and it starts at the taps: run all your cold water faucets on full for at least 5 minutes each. In an apartment building, run them for longer than that.

Ice makers

Dump the ice that is sitting in the bin, then make and discard three more batches, and wipe the bin out with a disinfectant.

If the supply line running to the ice maker is more than 20 feet long, discard five batches instead of three.

Water heaters, coolers and in-line filters

Anything that holds water needs the water inside it replaced, not just the pipe leading to it. New York State's instruction is to run enough water to completely replace at least one full volume of all lines and tanks.

Run a regeneration cycle on a water softener. On a reverse osmosis unit, replace the pre-filters and check the owner's manual.

Replace your filters

Point-of-use filters are disposable and may be contaminated, so New York State, Louisiana and Michigan all say to replace them rather than keep using them — carbon filters in particular.

Louisiana adds a handling instruction that is easy to skip: wear gloves while changing a cartridge, and wash your hands afterwards.

Appliances plumbed into the water line

Coffee makers, ice machines and water dispensers should be cleaned, disinfected and flushed according to the operator's manual. That is Michigan's instruction, and the manual is what carries the specifics for your model.

Frequently asked questions

Do I need to flush my pipes after a boil water advisory is lifted?

Yes. New York State's health department says to run all your cold water faucets on full for at least 5 minutes each, and for longer than that in an apartment building. Anything that holds water — a heater, a cooler, an in-line filter — needs enough water run through it to completely replace at least one full volume of all lines and tanks.

How long should I run the taps?

At least 5 minutes on each cold water faucet, at full flow, and longer in an apartment building. That is New York State's health department's instruction, and it is the first step of the sequence: taps, then ice makers, then anything that holds a volume of water, then the filters.

Do I have to replace my water filter afterwards?

Replace it. New York State, Louisiana and Michigan all say point-of-use filters are disposable and may be contaminated, carbon filters especially, so a cartridge that was in service during the notice should be thrown away rather than kept. On a reverse osmosis unit, replace the pre-filters and check the owner's manual. Louisiana adds that you should wear gloves while changing a cartridge and wash your hands afterwards.

What do I do about the ice maker?

Dump the ice in the bin, make and discard three more batches, and wipe the bin out with a disinfectant. New York State's health department adds one adjustment: if the supply line to the ice maker runs more than 20 feet, discard five batches rather than three. Michigan adds that ice machines and dispensers should be cleaned, disinfected and flushed according to the operator's manual.

How does a utility decide to lift a boil water advisory?

By sampling. Indiana's environmental agency describes the rule for an E. coli event: the advisory may only be lifted when two consecutive sets of samples, collected 24 hours apart, are found to be satisfactory. New York State's health department describes the same dependency from the resident's side — how long it takes depends on the condition that caused it, how quickly that can be corrected, and how long laboratory results take.

Sources

New York State Department of Health — Boil Water Notices: FAQ for Residents and Homeowners — retrieved 2026-08-22
Louisiana Department of Health — What to Do During a Boil Water Advisory — retrieved 2026-08-22
City of Flint, Michigan — Boil Water Advisory FAQ — retrieved 2026-08-22
Indiana Department of Environmental Management — Boil Water Procedure Guidance — retrieved 2026-08-22

By TapWaterData Editorial