Well water testing in PA, NJ & DE

No utility tests a private well, so testing is up to the owner. Pennsylvania doesn't regulate private wells^[1], Delaware recommends but doesn't require testing^[2], and New Jersey requires a certified-lab test at sale and every five years for landlords^[3].

What each state recommends

State	Rule or recommendation
Pennsylvania	Test every year for total coliform bacteria, nitrate, total dissolved solids, and pH[4]. Penn State Extension's FAQ covers other tests by situation[5].
New Jersey	Private Well Testing Act: certified-lab test when a home is sold, and every five years for landlords. PFNA, PFOA, and PFOS were added on December 1, 2021[3][6].
Delaware	Test every year for nitrate and bacteria; the Division of Public Health offers free test kits and financial aid for well owners[2].

Local concerns worth adding

• Chester County, PA: 83.3% of Penn State's Chester County well samples tested for corrosivity were outside the non-corrosive range^[7]. Add pH and corrosivity. The county lists local labs^[8].
• Radon in Pennsylvania wells: 14% of 1,041 USGS-sampled wells exceeded 4,000 pCi/L^[9].
• Gross alpha in South Jersey: most often above the standard in Burlington, Camden, Cumberland, and Gloucester counties^[10].
• Arsenic in central New Jersey: highest rates in Bergen, Hunterdon, Mercer, and Somerset counties^[11].
• PFAS in New Jersey wells: 11.2% of wells tested from December 2021 through 2023 had at least one PFAS above a state standard^[3].
• Nitrate near farms in Delaware: see the Millsboro case^[12] and nitrate.

How to test, step by step

1. Choose a certified or accredited lab. Use a lab certified in your state: in New Jersey, an NJDEP-certified lab (required for Private Well Testing Act tests); in Pennsylvania, a DEP-accredited lab; in Delaware, the Division of Public Health's program or a certified lab. Chester County publishes a list of local labs.
2. Pick the tests. Start with the basics your state recommends: in Pennsylvania, coliform bacteria, nitrate, total dissolved solids, and pH every year; in Delaware, nitrate and bacteria every year. Add PFAS, arsenic, gross alpha, radon, or lead where they're known local concerns.
3. Collect the sample the way the lab says. Use the lab's bottles and follow its instructions for the faucet, flushing, and preservation. Many labs collect the sample themselves, and New Jersey requires certified sample collection for sale-time tests.
4. Get it to the lab in time. Bacteria samples have short holding times, so check the lab's drop-off window before you sample.
5. Compare results to the standards. Look at each number against the drinking water standard and the lab's notes, not just a pass or fail. Ask for the actual values.
6. Treat, then retest. Choose treatment for the problem the test found, then retest after installation to confirm it works.

NJDEP's treatment guidance advises asking for the actual numbers, not just pass or fail, before choosing a system^[13]. EPA's private well pages explain what common contaminants do^[14].

Where WÜDR fits

Our free in-home test checks treatment basics like hardness, iron, and pH so we can size equipment. It isn't a certified health test; for bacteria, nitrate, arsenic, or PFAS, use a certified lab, then bring us the report. See well water treatment.

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