Drinking Water Safety

Boil Water Advisories Are Spiking: 7 Alarming Facts Behind September 2026’s Wave of Warnings

Photo: Karolina Grabowska / Pexels

In one single week this September, four different US cities told residents to boil their tap water before
drinking it. Wichita, Kansas. Salemburg, North Carolina. Kalamazoo, Michigan. And a countywide advisory across
Monroe County, Indiana, home to Bloomington. That’s not a coincidence and it’s not rare, either. Here’s what’s
actually driving this wave of boil water advisories, what the warnings really mean, and why boiling isn’t
always the fix people assume it is.

🚰 Quick Answer

Boil water advisories are far more common than most people realize, with roughly 21,000 issued across the US
in just a three year stretch. Most aren’t caused by contamination at all. Water main breaks and treatment
plant disruptions account for the majority, and boiling only kills biological threats like bacteria and
viruses. It does nothing for lead, chemicals, or heavy metals that might also be in the water, which is why a
home filtration system that’s already in place matters even when the advisory turns out to be precautionary.

Key Takeaways

• •
  Four separate US cities issued boil water advisories in the same week this September, including a countywide notice covering all of Monroe County, Indiana.
• •
  A three year federal study found nearly 21,000 boil water advisories issued nationwide, and only 14 percent were tied to confirmed contamination.
• •
  The US sees an estimated 240,000 water main breaks every year, and most boil water advisories trace back to a break or a leak, not a poisoning event.
• •
  Nearly 73 percent of advisories hit places with fewer than 20,000 residents, where smaller utilities have less backup capacity when something goes wrong.
• •
  Boiling water kills bacteria and viruses, but it does not remove lead, PFAS, or other chemical contaminants, and can actually concentrate some of them as water evaporates.

What Actually Triggered This Week’s Wave of Boil Water Advisories

Look at what happened in Bloomington, Indiana, and you get a pretty clear picture of how most of these start.
A storm knocked out power at the Monroe Water Treatment Plant, which dragged down water production and let
levels drop in the storage tank. That combination pushed turbidity, basically how cloudy the water is, past
the maximum allowed level of 1.0 units. The utility called it “not an emergency” but still told the entire
county to boil water for drinking, cooking, and brushing teeth for about 27 hours.

That’s the pattern behind most boil water advisories. It’s rarely a scene out of a movie
where someone dumps chemicals into a reservoir. It’s usually something mechanical and unglamorous, a power
outage, a broken pipe, a treatment plant hiccup, that drops water pressure or lets untreated water sneak into
the system. Utilities issue the advisory as a precaution because they genuinely don’t know yet whether
bacteria got in, and boiling is the fastest way to make sure whatever’s in the water can’t make anyone sick
while they figure it out.

Why Small Towns Get Hit Hardest

Here’s something that surprises a lot of people. Nearly 73 percent of boil water advisories happen in
communities with fewer than 20,000 residents. Big cities have redundant treatment plants, deeper storage
reserves, and crews on standby around the clock. Smaller utilities, the kind running a single plant for a
whole county like Monroe County did this week, don’t have that same cushion. One storm knocking out power at
one facility is enough to trigger a countywide advisory, because there’s no backup system to lean on while
repairs happen.

That matters for anyone living outside a major metro area. It’s not that small town water is inherently less
safe day to day, it’s that the margin for error is thinner, and getting bottled water to a rural county
quickly during an advisory is genuinely harder than restocking a Kroger in a city.

What Boiling Actually Fixes, and What It Doesn’t

Boiling water for one to two minutes kills bacteria, viruses, and parasites like Giardia and
Cryptosporidium. That’s the whole point of the advisory, and it works well for that specific job. What it
does not do is remove lead, PFAS, nitrates, or other chemical contaminants that might already be in the
water for reasons that have nothing to do with the storm or the main break that triggered the advisory in the
first place. Boiling can actually make some chemical contamination worse, because as water evaporates, the
concentration of whatever’s left behind, including things like lead, can go up rather than down.

This is exactly why the EPA and the
CDC’s guidance on drinking water advisories
always distinguish between boiling for microbial safety and filtering for chemical contaminants. They’re
solving two completely different problems, and a boil water advisory only tells you which one just became
urgent, not which one might already be sitting in your tap on an ordinary day.

What to Actually Do During an Advisory

If your utility issues a boil water advisory, boil tap water for at least one full minute (three minutes at
elevations above 6,500 feet) before drinking it, using it for ice, brushing your teeth, or cooking anything
that involves water directly. Let it cool before you drink it. If boiling isn’t practical, bottled water or
water you’ve already filtered and stored ahead of time works as a substitute, though a standard countertop
or under sink filter alone is not automatically certified to remove the specific bacteria an advisory is
warning about, so don’t assume filtered equals safe unless the system is rated for microbial reduction.

Most advisories lift within a day or two once test results come back clean, the way Bloomington’s did after
about 27 hours. Utilities are required to notify residents again once it’s safe to go back to normal use.

Why This Keeps Happening More Often

Aging pipes are a big part of the story. A lot of US water infrastructure was built decades ago and simply
wasn’t designed for the population, or the storms, hitting it today. Add in more frequent severe weather
knocking out power to treatment plants, and you get more of exactly what happened in Indiana this week, a
short outage cascading into a countywide precaution. None of this means tap water is broken. It means the
system that delivers it is aging in a lot of places at once, and advisories are the visible symptom when
something in that system slips, even briefly.

Photo: Anna Shvets / Pexels

Frequently Asked Questions

The Bottom Line

Four boil water advisories hitting different states in a single week sounds alarming, and in
a way it should get your attention, but it’s not a sign that tap water across the country suddenly turned
dangerous. It’s a sign of an aging system that’s more exposed to storms, power outages, and pipe failures
than most people realize, and utilities responding the way they’re supposed to when something goes wrong.
Boiling handles the immediate biological risk during an advisory. It’s not a substitute for knowing what’s
in your water on an ordinary day, and it’s not a fix for the contaminants that don’t come with a warning at
all.

Related reading: What’s Really in US Tap Water?,
Does Boiling Water Remove Contaminants?,
Lead Pipe Replacement Deadline