New York set its own limits ahead of the federal ones

New York State adopted maximum contaminant levels of 10 parts per trillion each for PFOA and PFOS, which are stricter than the federal limits finalised in 2024 and among the lowest state standards in the country.

The state also regulates 1,4-dioxane in drinking water, which few states do. That is not an abstract point in this state: the compound is associated with industrial solvent use and has been found in groundwater supplies on Long Island, where a very large population draws water from a sole source aquifer.

Public water systems statewide monitor against these standards and report results in their annual reports. If you are on a public supply, that report is the fastest route to knowing where you stand.

New York City is a different water system from the rest of the state

Most of the state draws on local reservoirs, rivers, and wells. New York City runs one of the largest unfiltered surface water supplies in the world, fed by 19 reservoirs and three controlled lakes across a watershed of nearly 2,000 square miles reaching up to 125 miles north of the city.

Two practical differences follow. The city's water is soft, averaging around 1.8 grains per gallon, so softening is rarely warranted on it, where much of upstate and Long Island is considerably harder.

And the city disinfects with free chlorine rather than chloramine. That matters when choosing a filter, because free chlorine is removed readily by standard activated carbon while chloramine needs a longer contact time or a catalytic carbon media. Getting that wrong is a common reason a filter disappoints.

Long Island and the sole source aquifer

Nassau and Suffolk counties sit on a federally designated sole source aquifer, meaning there is no alternative supply if it is contaminated. Everything that reaches the ground there eventually reaches the water people drink.

That geology is why Long Island has been at the centre of the state's work on 1,4-dioxane and PFAS, and why water districts there have installed advanced treatment earlier and more widely than in much of the state.

If you are on Long Island, the useful step is to identify your specific water district rather than reasoning about the county, because treatment and source wells vary considerably between districts within a few miles of each other.

Licensing in New York is local, not statewide

Unlike New Jersey, Pennsylvania, and Connecticut, New York does not license home improvement contractors at state level. It is handled by cities and counties.

Work in the five boroughs requires a Home Improvement Contractor licence from the New York City Department of Consumer and Worker Protection. Nassau, Suffolk, Westchester, and Rockland counties each run their own licensing. Plumbing is licensed separately again in each jurisdiction.

The practical effect is that a contractor legitimately licensed in one part of New York may not be licensed to work in the next county. It is a fair question to ask of anyone quoting you work here, and our current position is set out on the licensing page.

Who regulates drinking water in New York

Public water systems in New York are regulated under the federal Safe Drinking Water Act, administered by the state, and every community system must publish an annual Consumer Confidence Report describing what it found in the previous calendar year. Those reports are normally published by July 1.

Private wells sit outside that framework entirely. No agency samples them and no report is issued, so a well owner in New York is the only person who will ever test that water.

Licensing in New York

Licensed for home improvement work in each New York jurisdiction we publish. Licence numbers available on request.

Every area we cover in New York

Grouped by county. Smaller towns are served through the nearest listed area, so if yours is not here, use the closest one or send us your address.

Names shown as links have a local page with sourced water data for that town. The rest are areas we serve where the research is not yet published, so there is nothing local to read yet. Either way, send us your address.