Well water or city water: what actually changes for you

The line the Safe Drinking Water Act draws

The EPA puts it in one sentence: the quality and safety of drinking water from private domestic wells "are not regulated by the Federal Government under the Safe Drinking Water Act". The CDC says the same from the other direction: the Act "focuses on public water systems. It does not cover private drinking water sources."

So the federal limits, 10 milligrams per litre of nitrate, 0.010 for arsenic, a maximum contaminant level for this and that, are rules for utilities. For a well owner they are a useful yardstick and nothing more. There is no federal requirement to meet them, and none to test at all.

EPA, private drinking water wells, page updated 25 August 2026. CDC, private water and public health, published 15 May 2024 and updated 1 September 2026.

How many households this is

Here the two agencies do not quite agree, and we are going to leave the disagreement visible rather than average it away. The EPA says around 15 per cent of the US population, more than 43 million people, rely on private wells. The CDC says about one in eight residents. Both are federal, both are current pages, and they are counting slightly different things.

EPA, private drinking water wells, updated 25 August 2026. CDC, private water and public health, updated 1 September 2026.

What you get with city water that you do not get with a well

• An annual report, by law. Community water systems must deliver a Consumer Confidence Report to customers every year by 1 July. We wrote a whole page on how to read yours.
• Someone else's testing schedule, at a frequency set by rule rather than by whether you remembered.
• A notification duty when something is found in violation of a standard.
• Treatment already applied, including a disinfectant residual that keeps working in the pipes.

And what you get with a well that the utility cannot give you: water that keeps arriving when the utility has a problem, no monthly bill, and no chlorine taste. Those are real advantages, and they are the reason the trade exists.

The part people underestimate: the power goes, the water goes

A well is a pump. The pump runs on electricity. In an outage a house on city water usually keeps pressure for a while, because the utility's system has storage and often gravity on its side, while a house on a well has exactly as much water as is already inside the house.

That is not an argument against wells. It is an argument for knowing the number. Our blackout kit page counts the drinking water already sitting in your house, and a tank water heater alone is usually more than people guess. Our 48 hour calculator gives what a household actually needs against it.

If you are on a well, the short version of the job

Test annually for total coliform bacteria, nitrate, total dissolved solids and pH, at a laboratory certified by your state. Test again whenever something changes: a flood, a repair, a new taste, a pregnancy in the house, a child moving in. Ask your health department what else is worth testing where you live, because the risk is local.

The full version, including what a test costs and the trap of sampling too soon after disinfecting, is in testing your well water.

CDC, guidelines for testing well water, 1 July 2024. EPA, protect your home's water, updated 26 February 2026.

Sources, with the date of each

• EPA, private drinking water wells, page updated 25 August 2026.
• CDC, private water and public health, published 15 May 2024, updated 1 September 2026.
• CDC, guidelines for testing well water, published 1 July 2024.
• EPA, protect your home's water, page updated 26 February 2026.
• EPA, Consumer Confidence Report information for consumers, page updated 21 November 2025.
• EPA, National Primary Drinking Water Regulations, page updated 31 August 2026.