Well water testing, radon and UV treatment

It can be in parts of Vermont, and it is a separate question from radon in air, though the two are related, because water use releases it indoors. Testing is the only way to know, and mitigation for water is different equipment from an air system.

Sometimes partially, but iron and hardness are different problems and a softener sized for hardness may not handle significant iron. This is the most common mismatch in residential treatment, which is why the test result, not the symptom, should choose the equipment.

That is a real design question, particularly on a septic system, because regular backwash adds volume and in some cases salt to a system that has to absorb it. Establish where it will go before the equipment is chosen, not after it is installed.

The Maximum Contaminant Level is the enforceable limit the state or EPA sets for public water systems, and it is the benchmark most labs report a private well against even though private wells are unregulated. A result above the MCL means the water would not be permitted to be served by a public utility, which is a clear signal to act.

Vermont's own current example is PFAS: the state's MCLs, under its updated Water Supply Rule, are 4.0 parts per trillion each for PFOA and PFOS, 10 ppt each for PFNA, PFHxS and HFPO-DA (GenX), plus a combined hazard-index limit of 1 when two or more of PFHxS, PFNA, HFPO-DA and PFBS turn up together: numbers small enough that they only make sense in parts per trillion, not the parts per million or billion most water reports use.

Note two things generally: some substances have a health advisory instead of an MCL, and some MCLs are set with cost and feasibility for utilities in mind rather than being a pure health threshold, so a result somewhat under the limit is not automatically a result to ignore, particularly for arsenic or PFAS, where health effects have been observed below the enforceable number.

Geology drives most of it, and Vermont's is specific. Arsenic occurs naturally in bedrock in parts of the state and is the most consequential common finding; uranium and gross alpha occur in certain formations; manganese is widespread enough that the state issued guidance on it; radon moves from bedrock into groundwater; and bacterial contamination usually reflects well construction, a shallow, dug or poorly sealed well, not geology.

PFAS is the exception to all of that: it has nothing to do with bedrock and everything to do with nearby land use, firefighting foam, certain landfills and industrial sites, which is why the state targets its own PFAS testing at wells near a known or suspected source rather than mapping it by region the way it does arsenic. The Vermont Department of Health publishes what has been found regionally, and your own result is the only one that decides your treatment.

You can collect the sample yourself, and for most tests that is exactly how it works: the Vermont Department of Health laboratory sells test kits, you take the sample following their instructions and return it. What you should not rely on is a home test strip for anything that matters to health. Strips give a rough hardness or chlorine reading and are useless for arsenic, uranium, nitrate, bacteria or PFAS, which are the results that actually change what you do. PFAS is not part of that standard package.

It needs its own accredited lab and its own bottle, and the sampling itself is stricter than for anything else on the panel: PFAS is used in so many everyday products, including waterproof and stain-resistant clothing, that a lab can pick up contamination from what the person taking the sample is wearing, so follow that lab's PFAS-specific collection instructions exactly rather than reusing habits from a general water test. Sampling technique matters everywhere: follow the kit's instructions on which tap, how long to run it, and how quickly it must reach the lab.

You would not know. That is the entire problem with the contaminants Vermont wells actually have. Arsenic, uranium, radon in water and manganese are colourless, odourless and tasteless at levels well above the health guidance, and gross alpha, nitrate and PFAS are the same. Bacterial contamination sometimes produces symptoms and often does not.

PFAS carries an extra wrinkle: Vermont's Department of Environmental Conservation tests private wells for PFAS only near a known or suspected source, a landfill, a site where firefighting foam was used, certain industrial land uses, as part of its own site investigations, and there is currently no state or federal requirement that any other private well owner test for it at all. Unlike a public system, nobody tests a private well on your behalf and nobody sends you a report. In Vermont the private well owner is the water utility, whether they think of it that way or not.

The Vermont Department of Health recommends testing for bacteria every year and running its Homeowner Testing Package, which covers bacteria, inorganic chemicals (including uranium, fluoride and nitrate) and gross alpha radiation, every five years, and testing when a property with a private water source is bought, sold or rented.

PFAS sits outside that entire schedule: Vermont has not set a recommended testing interval for it in a private well because testing for it is not required at all, so it gets ordered separately, on its own timeline, when there is a specific reason to: proximity to a known or suspected PFAS source, or simply wanting the answer. Test additionally after any work on the well or pump, after flooding, if a neighbour's well shows a problem, and whenever the taste, colour or odour changes. If there is or will be an infant in the house, test nitrate before instead of after. That is the one with an acute risk.

The landlord is responsible for providing safe, potable water, which in practice means the landlord should be testing. A tenant is entitled to ask for recent results, and a landlord who has none is not in a strong position. If you are a tenant with a concern, request the results in writing, and if none exist, a Health Department test kit is inexpensive enough that testing yourself and presenting the result is a practical route to getting something done.

PFAS will not show up in that basic result, though. It has to be ordered separately from an accredited PFAS lab, and it is worth asking for specifically if the property sits anywhere near a landfill, an old fire-training area or other likely source. Report anything above a health standard promptly and in writing.

Treatment equipment warranties are only as good as correct sizing: a claim on a softener or filter sized to the wrong test result, or no test result at all, is likely to be denied as an installation or application issue, not a defect. The warranty protects the equipment, not a bad sizing decision.

Treating symptoms, taste, smell, staining, without testing for what actually matters. The contaminants most worth knowing about in Vermont well water have no taste, smell or color at all, PFAS is the clearest current example, since it comes from a nearby source instead of anything the water itself gives away, so equipment chosen by symptom alone can miss the one thing that mattered.