Peoria Water TTHM Notice: What It Means and What to Do

Peoria’s water notice: what TTHMs are, how worried to be, and what actually fixes it

If you live south of Bell Road in Peoria, you got a letter. The city’s water system exceeded the federal limit for total trihalomethanes, or TTHMs, with a July reading at the monitoring station near 71st and Olive avenues that came in slightly above the standard. Goodyear sent the same kind of letter in May. In two decades of practicing medicine I have learned that these notices produce two bad reactions: panic, and shrugging. Neither is right. Here is the honest version, and a concrete way we can help.

Credit where it is due: the city is not hiding anything

TTHMs are not a contaminant someone dumped in the water. They form when chlorine, which keeps your water free of the bacteria that actually kill people, reacts with natural organic matter. Levels climb in the summer because heat speeds the reaction, which is why Arizona utilities see their highest readings in July and August. The federal limit is 80 parts per billion, measured as a running annual average at each site, not a single sample. Peoria reported the exceedance because the law requires it and because you have the right to know. The city has said the rest of the system is within the standard and that there is no danger unless exposure is long-term. That statement is accurate as far as it goes.

The honest evidence check

Here is what “long-term” means. Disinfection by-products including trihalomethanes are associated in the research with cytotoxic, mutagenic, and carcinogenic effects, with the best-documented signal being bladder cancer risk over years of exposure, and a weaker signal for reproductive and developmental effects in pregnancy. Exposure is not only from drinking: TTHMs are volatile, so showering and bathing add inhalation and skin contact. A single summer slightly above the limit does not meaningfully change your lifetime risk. Living in a home where the water runs high every summer for decades might. The right response is proportionate: not fear, but a permanent, cheap fix.

Two things you should also know. First, bottled water is not systematically safer than tap; a 2025 analysis found contaminant mixtures across private, public, and bottled supplies alike, and it costs many times more. Second, you can over-purify. In an animal study, fully demineralized water was associated with worse offspring outcomes than filtered tap water that kept its minerals. The goal is to remove the toxicants and keep the minerals.

What actually removes TTHMs

Activated carbon does. The refrigerator filter you have not changed in two years probably does not. The certification to look for is NSF/ANSI Standard 53 with a listed claim for trihalomethane (TTHM) or VOC reduction. Standard 42 alone covers taste and chlorine, not TTHMs. Reverse osmosis systems certified to Standard 58 with a carbon stage also work. The EPA points consumers to these NSF listings rather than to any brand. Filters that carry the right certification and are widely available include:

Pitcher: Epic Pure pitcher (NSF 42, 53, 401) or Brita with the Elite filter, not the standard filter. Least expensive, no installation, filter every 2 to 6 months.
Faucet mount: PUR PLUS faucet filter. Ten-minute install, covers cooking water too.
Under sink: Aquasana AQ-5200. Highest capacity, filters last about six months, the option most of our patients end up with.
Reverse osmosis: APEC RO-90 or similar NSF 58 system with a carbon stage. Broadest removal, but it strips the minerals out along with everything else — read the next section before you buy one.
Shower: a carbon shower filter reduces the inhaled and skin fraction. Certification is thinner in this category, so treat it as a bonus, not the fix.

Whatever you buy, confirm the box or listing says NSF/ANSI 53 with TTHM or VOC reduction, and put the filter-change date on your calendar. A saturated filter protects no one.

Remineralization: who needs it, who doesn’t, and what not to put in your water

This is where a lot of well-meaning advice goes sideways, so let me separate the two situations cleanly.

If you bought a carbon filter, you do not need to remineralize anything. Standard 53 cartridges are designed to pull out health-related contaminants, not minerals, and they leave calcium and magnesium essentially intact. A community study that measured what actually comes out of home systems found pitcher and faucet filters produced mineral levels comparable to unfiltered tap water. The certification number is not what determines mineral loss; the technology is. If someone is selling you remineralization drops to go with a pitcher filter, they are solving a problem you do not have.

If you bought reverse osmosis, remineralization is worth doing. RO membranes reject 90 to 99 percent of dissolved ions, and that is indiscriminate. In the same community study, RO systems produced by far the lowest mineral levels of any home method, with median calcium around 2.3 parts per million and magnesium under half a part per million, against tap water that carries many times that. Two consequences follow. The first is taste: dissolved mineral content is the main driver of how water tastes, and stripping it shifts the perception from fresh toward flat and slightly bitter, which is the real reason most people stop using their RO system. The second is nutritional, and here the evidence is suggestive rather than settled. Studies have correlated drinking-water mineral content with serum calcium and magnesium in children even after accounting for diet, and one eco-epidemiological study of Chinese schoolchildren on very low-mineral RO water reported less height gain and more dental caries. That is an association in one population, not a proven cause, and I will not oversell it. But the fix is a cheap cartridge, so there is no reason to run the experiment on your own family.

The way to do it is a purpose-built post-filter stage: a calcite or calcium-magnesium remineralization cartridge that installs after the membrane. Calcite adds calcium and restores alkalinity; look for a cartridge that supplies magnesium as well, since calcite alone does not. Widely available options include an inline remineralization cartridge for RO systems or a complete RO system that includes a remineralization stage. One maintenance note that gets skipped: remineralization media reintroduce nutrients into the water, which raises its bacterial growth potential, so change that cartridge on schedule the same way you change the membrane.

What not to do: adding pink Himalayan salt or sea salt to your water. This one is everywhere online right now and it does not hold up. Remineralization is about restoring calcium and magnesium. Both of those salts are overwhelmingly sodium chloride, with calcium and magnesium present only as trace constituents, so what you are actually adding is sodium — counterproductive for anyone with high blood pressure, heart failure, or kidney disease, which describes a large share of the people most motivated to filter their water in the first place. Worse, unrefined sea and rock salts have been shown to carry trace heavy metals including lead, along with polycyclic aromatic hydrocarbons. You would be reintroducing exactly the class of contaminant the filter just removed. And for what it is worth, calcium and magnesium are absorbed far more efficiently from food than from water, so a plate with leafy greens, nuts, legumes, and dairy does more for your mineral status than anything you stir into a glass.

Our offer: $150 toward your care for filtering your water

We would rather you spend a hundred dollars on a filter than a thousand on a problem later, so we are putting money behind it. Buy any NSF/ANSI 53 certified water filter, bring the receipt to your first visit, and we credit $150 toward your care at Integrative Medical Partners. One credit per household, applied at the office, details confirmed when you book. It applies whether you come in for hormones, weight loss, aesthetics, or just to find out where you stand.

Measure, don’t guess

The people who should take this notice most seriously are the ones the city’s own letter names: anyone pregnant or trying, young children, older adults, and anyone immunocompromised. If that is you, or if you have been drinking unfiltered Peoria water for years, the useful move is not worry, it is a baseline. Liver and kidney markers, a complete blood count, and a look at the rest of your labs tell us far more than the notice does. If you have been on RO water for years, magnesium status is worth checking too, and that is a lab, not a guess. Related reading: signs of magnesium deficiency and what masquerades as it, the six daily habits that carry the most weight, and fatty liver and how to reverse it.

Text us at 480-219-2624 to schedule, or call. Quick response, real scheduling, no phone tree.

To Health and Wellness,
Dr. Ty Tallman

References

City of Peoria, 2026 — public notification of total trihalomethane exceedance, southern system.
Environmental Pollution, 2020 — disinfection by-products in drinking water: occurrence, toxicity, and abatement.
Food and Chemical Toxicology, 2000 — epidemiology of chemical contaminants of drinking water.
Environmental Science and Pollution Research, 2022 — water toxicants, health concerns, and remediation.
Environment International, 2025 — shared contaminant mixtures in private, public, and bottled water.
Water Research, 2023 — performance of NSF/ANSI 53 certified filters.
Journal of Dentistry, 2024 — home filtration and its effect on fluoride and mineral concentrations.
Water Research, 2016 — sensory quality of reverse osmosis water followed by remineralization.
Environment International, 2018 — low-mineral direct drinking water, height growth, and caries in schoolchildren.
Scientific Reports, 2025 — serum minerals in children consuming reverse osmosis versus non-RO water.
Water Research, 2018 — bacterial growth potential in remineralized reverse osmosis permeate.
Environmental Science and Pollution Research, 2020 — trace elements and hydrocarbons in unrefined sea and rock salts.
Heliyon, 2024 — mineral composition of Himalayan and other specialty salts.
PLoS One, 2014 — reproductive outcomes in rats given five types of drinking water.
Reviews of Environmental Contamination and Toxicology, 2008 — risk of waterborne illness via drinking water in the United States.
Pediatrics in Review, 2017 — environmental risks to children and point-of-use treatment.
Wilderness & Environmental Medicine, 2019 — clinical practice guidelines for water disinfection.