Guides
Every guide cites its sources and lists the date it was last checked. None of them can tell you whether your water is safe to drink. For that, test with a certified lab and talk to your health department.
Want it all on paper? The free Private Well Testing Checklist pulls the testing schedules, sampling tips and lab lookups from these guides into one printable page set. Download the PDF.
Buying a home with a well? Start with Buying a home with a well.
New to private wells? Start with the basics: why so many homes use wells, how a private well works, private well vs city water, and who regulates private wells.
- Buying a home with a well: inspection contingency, water tests, and which states require testing at saleWhat to put in your offer, which water tests to order by region, flow and yield tests, septic distances, well logs, sourced costs, seller questions, red flags, and a state-by-state table of home-sale well testing rules. Printable checklist included.
- How to read your well water test resultsWhat iron, manganese, hardness, sulfur (H2S), pH, nitrate, coliform/E. coli, and arsenic numbers mean, compared with EPA and state limits, with sources.
- Arsenic in well water: the best way to test, and treatment optionsHow to test a private well for arsenic, what the 10 µg/L and 5 µg/L numbers mean, and which treatment types state agencies say work (and don't), with sources.
- Iron in well water: what to test, and what to buyHow to figure out what kind of iron problem you have, and which treatment Penn State Extension and Maine CDC match to each iron level, from softeners to greensand to chlorination with filtration. With sources.
- Whole-house vs. point-of-use filters for well water: which problems need whichWhen a well problem needs whole-house (point-of-entry) treatment and when a single-tap (point-of-use) unit is enough, based on what state agencies say about each contaminant. With sources.
- Best way to test well water: state lab, county health department, certified lab, or mail-in kitThe main ways to get a private well tested, what a full panel should include, how to take a sample so the result means something, and what to do with the report. With sources.
- Nitrate in well water: testing, infants, and treatment optionsWhy nitrate matters most for babies, which wells are most at risk, why boiling makes it worse, and the treatment types state agencies list. With sources.
- How often to test a private well: CDC and state schedules side by sideYearly, every 3–5 years, or just once. A side-by-side comparison of what CDC and the health and environment agencies in NH, ME, MI, PA, NJ and Union County, NC recommend, plus the events that should prompt a test. With sources.
- Uranium and radon in well water: testing and treatmentWhat the uranium, gross alpha and radium standards are, why radon in well water is mostly an air problem, how common radon is in New Hampshire wells, and the treatment types Maine CDC lists. With sources.
- Shock chlorinating a well: when it helps, how it's done, and retestingWhen agencies recommend shock chlorination, how often it actually clears bacteria, key safety points from state and county procedures, and the retest schedule. With sources.
- How much does well water testing cost? State lab fees vs. university and private labsPublished, dated fees from state and university labs (Indiana, Florida, South Carolina, Penn State), what each test covers, and where to look up your own state's options. With sources.
- Well flooded? Inspecting, disinfecting, and retesting a private well after a floodWhat EPA, CDC and the Minnesota Department of Health say to do when flood water reaches a private well, from electrical safety and inspection to disinfection and the bacteria retest schedule. With sources.
- Why do so many U.S. households use private wells?How many American homes get water from a private well, why (rural land outside public water service areas, groundwater on the property), how the federal counts differ, and what being on a well means for the owner. Every number is sourced.
- How a private well works: drilled vs. dug vs. driven wells, aquifers, pumps and pressure tanksA plain-English tour of a household well, from the aquifer and the three well types (drilled, dug, driven) to the casing, cap, screen, pitless adapter, pump, pressure switch and pressure tank. Sourced to EPA, USGS, state health departments and extension.
- Private well vs. city water: pros, cons and costsHow a private well and a public (city) water system differ on who tests the water, who pays for what, reliability, and published cost figures for testing, drilling, pumps and treatment. Sourced to EPA, USGS, Census, state labs and extension.
- Who regulates private wells? Owners, states, counties and the federal governmentWhy the Safe Drinking Water Act doesn't cover most household wells, what states and counties usually do regulate (drilling, permits, contractor licensing, home-sale rules), what's left to the owner, and how to find your state's private well program.
Looking for local labs and contacts? See the county pages.