Affiliate disclosure: Private Well Guide (privatewellguide.com) earns a commission from some links on this page, at no extra cost to you. We don’t test water or products ourselves. Recommendations here come from EPA, CDC, state agencies and extension services.
Health note: This is general information, not medical advice. Your local health department knows which contaminants are common in your area. Ask them before you choose a panel, and use a state-certified lab.
Lab tests cost money, and “test for everything” panels can cost several times more than a basic one. Both CDC and EPA say the same thing: test for the baseline every year, then add tests based on the specific risks around your well.
Step 1: The baseline every well needs
Test at least once a year for these four (CDC, EPA):
- Total coliform bacteria. If positive, labs typically also test for E. coli or fecal coliform, which point to contamination from human or animal waste.
- Nitrate. CDC says all well owners should test for nitrate at least once a year.
- pH. Corrosive water can pull lead and copper from plumbing.
- Total dissolved solids (TDS). A general measure of dissolved minerals.
Your health department or a certified lab can usually run this panel. Tap Score vs Your State-Certified Lab vs DIY Strips
Step 2: Add tests based on what’s around you
EPA’s list of conditions and the tests they call for:
| If this applies to you… | …consider testing for |
|---|---|
| Recurring stomach or intestinal illness in the household | Coliform bacteria |
| Plumbing or service lines that may contain lead | pH, lead, copper |
| Radon in indoor air, or a radon-rich region | Radon |
| Corroding pipes or plumbing | Corrosion, pH, lead |
| Intensive agriculture nearby | Nitrate, nitrite, pesticides, coliform |
| Coal or other mining nearby | Metals, pH, corrosion |
| Gas drilling nearby | Chloride, sodium, barium, strontium |
| Dump, junkyard, landfill, factory, gas station or dry cleaner nearby | Volatile organic compounds (VOCs), TDS, pH, sulfate, chloride, metals |
| Gasoline or fuel-oil odor, or buried fuel tanks nearby | VOCs |
| Objectionable taste or smell | Hydrogen sulfide, corrosion, metals |
| Stained fixtures or laundry | Iron, copper, manganese |
| Salty taste, seawater, or a heavily salted road nearby | Chloride, TDS, sodium |
| Scale, or soap that won’t lather | Hardness |
| Treatment equipment wearing out quickly | pH, corrosion |
| You need a softener for hardness | Manganese, iron |
| Cloudy, frothy or colored water | Color, detergents |
CDC adds a list of chemicals to ask your health department about: VOCs, lead, arsenic, mercury, radium, pesticides and herbicides.
Step 3: Test at least once for your area’s natural contaminants
Some contaminants come from the rock and soil, not from anything you or your neighbors did:
- Arsenic. USGS estimates about 2.1 million people may use wells with arsenic above 10 µg/L. Arsenic in Well Water: Where It Comes From and How to Remove It
- Uranium and radium. These are regulated for public water at 30 µg/L (uranium) and 5 pCi/L (combined radium) (EPA). Connecticut’s public health department notes that uranium results can vary from season to season and suggests retesting whenever a result is above 10 µg/L.
- Radon. Wisconsin DNR notes that you can’t know your well’s radon level without testing. Radon in Well Water: Should You Test?
Neighbors’ results can differ from yours, so test your own well.
Situations that call for specific tests
- Pregnancy or an infant in the home: nitrate. EPA suggests testing early in pregnancy, before bringing a baby home, and during the baby’s first six months (EPA fact sheet). Nitrates in Well Water: Health Risks, Limits and Fixes
- Older home or brass fixtures: lead. Lead in Well Water: Testing Your Pipes, Pump and Fixtures
- Near a military base, airport, industrial site, or firefighting-foam use: ask your state about PFAS. PFAS in Private Wells: Testing and Treatment
- A fuel or chemical spill nearby: VOCs (EPA fact sheet).
What you can usually skip
- Tests with no link to your situation. In CDC’s words: “spend time identifying potential problems as these tests can be expensive.” EPA’s fact sheet says to “limit them to possible problems specific to your situation.”
- Re-running one-time geology tests every year. Once you have a baseline for arsenic or uranium, follow your health department’s advice on how often to recheck. Annual retesting isn’t usually the default. Recheck sooner if your water or surroundings change.
- Hardness and iron as health tests. They matter for plumbing and appliances. Penn State Extension notes that iron and manganese generally carry aesthetic standards; manganese has an EPA health advisory above 0.3 mg/L. A cheap DIY strip can track hardness between lab tests.
Building your panel
| Your situation | Suggested starting panel |
|---|---|
| Any well, every year | Coliform (+ E. coli), nitrate, pH, TDS |
| First test on a new-to-you well | Baseline + arsenic, lead, iron, manganese, hardness, plus local add-ons from your health department |
| Farm country | Baseline + nitrite and the pesticides your health department suggests |
| Radon or uranium region | Baseline + radon, uranium, gross alpha/radium |
| Near fuel or industry | Baseline + VOCs (and PFAS if your state recommends it) |
Mail-in lab kits bundle many of these tests. Tap Score’s Essential Well Water Test, for example, lists heavy metals, minerals, hardness, nitrate, nitrite and coliform bacteria including E. coli Tap Score: Essential well water test →. Compare it with what your county lab offers. Best Well Water Test Kits 2026: DIY Kits vs Mail-In Labs
FAQ
Is a “comprehensive” panel worth it?
For a first test on a well you’ve just bought, a broad panel gives you a useful baseline. After that, a targeted annual panel is usually enough.
Should I test before or after my softener or filter?
Test raw (untreated) water to learn what’s in the well, and treated water to confirm your equipment works. New Jersey’s home-sale rules, for example, require testing untreated groundwater.
Sources
- CDC, Guidelines for Testing Well Water: https://www.cdc.gov/drinking-water/safety/guidelines-for-testing-well-water.html
- EPA, Protect Your Home’s Water: https://www.epa.gov/privatewells/protect-your-homes-water
- EPA, Home Water Testing fact sheet: https://www.epa.gov/sites/default/files/2015-05/documents/epa816f05013.pdf
- EPA, National Primary Drinking Water Regulations: https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations
- USGS, arsenic estimate: https://www.usgs.gov/news/national-news-release/study-estimates-about-21-million-people-using-wells-high-arsenic
- Connecticut DPH, Uranium in Drinking Water: https://portal.ct.gov/-/media/departments-and-agencies/dph/dph/environmental_health/what-you-need-to-know-about-uranium-in-drinking-water-pdf.pdf
- Wisconsin DNR, Radon in private well water: https://dnr.wisconsin.gov/topic/Wells/radon.html
- Penn State Extension, Iron and Manganese: https://extension.psu.edu/iron-and-manganese-in-private-water-systems
- NJDEP, Private Well Testing Act: https://dep.nj.gov/privatewells/pwta/