Plumbing
PFAS: The Forever Chemicals In Your Water
Rich Jordan · August 21, 2026 · 8 min read
Plumbing
Rich Jordan · August 21, 2026 · 8 min read
This is the first deep dive in our series on what is actually in your tap water. We are starting with PFAS because it is the one where the evidence is strongest, the regulation is moving fastest, and the gap between what a treatment plant does and what your family drinks is widest.
Per- and polyfluoroalkyl substances are a family of thousands of synthetic chemicals built around a carbon-fluorine bond. That bond is one of the strongest in organic chemistry, which is exactly why these compounds are useful and exactly why they are a problem.
They make cookware nonstick. They keep grease from soaking through fast food wrappers. They make carpet and jackets shed water. They are the active ingredient in the aqueous film-forming foam that fire departments and military bases have used on fuel fires for decades.
And because that carbon-fluorine bond does not break down under normal environmental conditions, they accumulate. In soil. In groundwater. In fish. In us. That is where the nickname comes from. Not marketing - chemistry.
The single most useful study here is the U.S. Geological Survey's 2023 national survey. Researchers sampled tap water at 716 locations across the country, from private wells to large municipal systems, and tested for 32 different PFAS compounds.
The headline finding: at least 45% of U.S. tap water contains one or more PFAS.
What the USGS found
A few things about that number are worth sitting with.
In April 2024 the EPA finalized the first enforceable national drinking water limits for PFAS. Maximum contaminant levels were set at 4 parts per trillion each for PFOA and PFOS, with a hazard index approach governing mixtures of PFHxS, PFNA and the GenX chemicals.
Four parts per trillion is roughly four drops in a thousand Olympic swimming pools. Setting a limit that low is a statement about how the agency read the health data.
Then in May 2026, the EPA proposed two changes:
I want to be straight with you about how to read that, because this is the moment where my industry usually starts selling fear.
The underlying health science did not change. What changed is the compliance timeline and the scope of what is federally enforceable. Public water systems face real costs and real engineering constraints in meeting a 4 ppt standard, and the extension is a response to that. It is a legitimate policy argument. But if you are a homeowner, the practical translation is simple: the date by which your utility must act moved further away, and four compounds may end up with no federal limit at all.
New Hampshire, Maine and New Jersey did not wait for the federal government, and their standards are not identical to it.
New Hampshire set its own maximum contaminant levels in 2019 and wrote them into statute in 2020: PFOA at 12 ppt, PFOS at 15 ppt, PFHxS at 18 ppt and PFNA at 11 ppt. New Hampshire was among the first states in the country to regulate four PFAS compounds at once, driven in part by the contamination around Merrimack and the surrounding Souhegan Valley.
New Jersey was the first state in the nation to set an enforceable limit on PFNA, and has adopted MCLs of 14 ppt for PFOA, 13 ppt for PFOS and 13 ppt for PFNA. New Jersey's PFAS program is one of the most established in the country, which is not a coincidence in a state with the industrial history it has.
Maine ran an interim standard of 20 ppt for six PFAS compounds, alone or combined, and in December 2025 adopted the federal 2024 standards into its drinking water rules, with the new limits taking effect in April 2027.
| Compound | Federal (2024 rule) | New Hampshire | New Jersey |
|---|---|---|---|
| PFOA | 4 | 12 | 14 |
| PFOS | 4 | 15 | 13 |
| PFHxS | Hazard index, proposed for rescission | 18 | No state MCL |
| PFNA | Hazard index, proposed for rescission | 11 | 13 |
Maine ran a 20 ppt interim standard for six compounds combined and adopted the federal standards in December 2025, effective April 2027.
Two practical consequences follow from that.
First, a state limit that is higher than 4 ppt is still a limit. Your utility is accountable to it, and if you are on a public system you can read the results. Every community water system publishes an annual Consumer Confidence Report, and PFAS results are in it.
PFAS are persistent in humans the same way they are persistent in the environment. Half-lives for some compounds are measured in years, meaning your body clears them slowly enough that ongoing low-level exposure accumulates.
The health associations in the research literature include:
The EPA's own assessment describes PFOA and PFOS as likely carcinogenic to humans. That is the agency's language, not an advocacy group's.
Conventional municipal treatment is a sequence built for a different problem: coagulation and flocculation to clump particles, sedimentation to drop them out, filtration to catch what is left, and disinfection to kill what survives.
PFAS are dissolved, extremely stable and very small. They pass straight through that sequence. Chlorination does not touch them - the carbon-fluorine bond does not care. Conventional filtration does not catch them because they are not particles.
Removing PFAS takes one of three technologies:
Municipal systems that have installed these are the ones meeting the low limits. Many have not installed them yet, and the compliance extension means many will not for years.
Under-sink reverse osmosis is the right first move. It is the most effective household technology against PFAS, it treats the water you drink and cook with, and it is not an expensive project. If you do exactly one thing after reading this, do this one.
A whole-house carbon filter helps but is not a substitute. Activated carbon at the point of entry reduces PFAS along with chlorine, chlorine byproducts and many organic compounds, and it treats shower and bath water. It is generally less thorough on PFAS than reverse osmosis, and its performance depends heavily on media volume, contact time and replacement discipline.
The strongest setup is both. Whole-house carbon for everything, under-sink reverse osmosis for drinking water.
Pitcher filters mostly do not. Standard carbon pitcher filters are designed for taste and odor. Some products are certified for PFAS reduction and some are not, and the certification is the only thing that tells you which is which. If you are relying on a pitcher, look for NSF/ANSI 53 or 58 certification specifically naming PFOA and PFOS.
Get the water tested. Not a regional estimate, not a national average - your tap, your house.
If you are on a public system, start by pulling your utility's Consumer Confidence Report, which is public and free, and see what they report for PFAS. If you are on a private well, there is no report and testing is the only way to know.
From there the decision is straightforward: what did the test find, and what technology removes it.
Tell us what you need - we’ll confirm your appointment and get your home back to comfortable, fast.
HOW QUICKLY CAN WE SERVE YOU?