A Homeowner's Guide to Testing Private Well Water

Your Well, Your Responsibility

If your home is served by a private well, you are your own water utility. You drill it, you maintain it, and you test it. No government agency monitors your well water quality. No annual report arrives in the mail. No inspector checks your results.

More than 43 million Americans — roughly 15% of the U.S. population — rely on private wells for drinking water. The EPA does not regulate private wells under the Safe Drinking Water Act. That responsibility falls entirely to the homeowner.

This is not a reason to panic. Millions of families drink safe, clean well water every day. But it is a reason to test — regularly, systematically, and with an understanding of what you're looking for.

Why Well Water Is Different

Municipal water systems are required to test for dozens of contaminants, report results to regulators, and notify customers of violations. Private wells have none of these requirements at the federal level. Some states have enacted their own well water regulations — requiring permits for drilling, mandating testing at the time of sale, or setting standards for landlords — but the patchwork is inconsistent and often limited.

The geology around your well, the agricultural activity in your area, the age and condition of your well casing, and the depth of your water table all affect what contaminants might be present. A neighbor's well that tested clean five years ago tells you very little about your own water today.

About 1 in 5 sampled private wells contain at least one contaminant at levels that exceed health-based guidelines. The most common problems are bacterial contamination, nitrates, and naturally occurring minerals like arsenic and radon — none of which you can detect by sight, smell, or taste.

What to Test For

The EPA recommends that all private well owners test annually at minimum. Here are the core contaminants to include in every annual test:

*Additional tests based on your location and situation:*

• Arsenic: Naturally occurring in many regions, particularly the Southwest, New England, and parts of the Midwest. Colorless and tasteless. A known carcinogen with no safe level of long-term exposure.
• Radon: A radioactive gas that dissolves into groundwater in certain geological formations, particularly granite-rich areas of New England and the Mid-Atlantic. Inhalation during showering is the primary exposure route.
• Iron and Manganese: Common in well water. Not typically a health hazard at normal levels, but causes staining, taste problems, and appliance damage.
• Hardness: Calcium and magnesium content. Not a health risk, but affects soap use, appliances, and plumbing.
• Lead: Can leach from well pump components, pressure tanks, or household plumbing even if not present in the groundwater itself.
• PFAS: If you live near a military base, airport, industrial facility, or area with known PFAS contamination, test specifically for PFAS. Many standard well water panels do not include PFAS.
• Volatile Organic Compounds (VOCs): If you live near gas stations, dry cleaners, industrial sites, or areas with underground storage tanks.

How Often to Test

Every year, at minimum: Test for total coliform bacteria, E. coli, nitrates, pH, and total dissolved solids. Annual testing catches problems early, before they become serious.

*Test immediately if any of the following occur:*

• Flooding or heavy rain near your well. Surface water can carry bacteria and contaminants directly into your well casing.
• Your well was recently repaired or serviced. Any work on the well can introduce contamination.
• You notice a change in water taste, odor, or appearance. Sudden changes are a warning sign.
• A new baby is in the home. Infants are especially vulnerable to nitrates. Test before using well water for formula or food preparation.
• A neighbor reports contamination. Groundwater contamination can spread.
• There is known agricultural, industrial, or mining activity nearby. Runoff and leaching can affect wells over time.
• You've never tested your well. If you moved into a home with a well and have no testing history, test comprehensively before relying on the water.

Types of Tests Available

Basic well water test kits (at-home): Available at hardware stores for $20–$50. These typically test for coliform bacteria, nitrates, pH, and hardness. They are useful for quick screening but are not as accurate as certified lab analysis and do not cover the full range of contaminants.

Certified laboratory testing: The most reliable option. You collect a water sample using a provided kit, mail it to an accredited lab, and receive a detailed digital report. A comprehensive well water panel from a certified lab typically costs $100–$300 and covers 50–100+ parameters including bacteria, heavy metals, nitrates, VOCs, and more.

State health department programs: Many states offer free or subsidized well water testing through their health departments or environmental agencies. Contact your state's department of environmental quality or department of health to ask what's available in your area.

For a comprehensive certified lab analysis of your well water, our partner Healthy Hydration offers a water quality check that provides professional results with plain-English explanations and filtration recommendations.

What to Do If Your Results Are Bad

Bacteria detected: Do not drink the water until the problem is resolved. Common responses include shock chlorination of the well (a process of disinfecting the well with a high concentration of chlorine), followed by re-testing. If contamination recurs, the well casing may be compromised and require professional inspection.

Nitrates above 10 mg/L: This is the EPA's MCL for nitrates. Do not use this water for infants under 6 months or for preparing infant formula. Point-of-use reverse osmosis systems effectively remove nitrates. Boiling does not — it actually concentrates nitrates.

Arsenic detected: If arsenic is above the EPA's MCL of 10 ppb, install a certified point-of-use reverse osmosis system or an arsenic-specific adsorption filter. Whole-house treatment for arsenic is expensive; most families address it at the drinking water tap.

Lead detected: Identify whether the lead is coming from the well itself or from household plumbing. A certified reverse osmosis system or NSF/ANSI 53-certified filter will remove lead at the point of use.

PFAS detected: If PFAS are present above EPA health advisory levels, a reverse osmosis system is the most effective treatment option. Granular activated carbon (GAC) filters also reduce PFAS but with less consistency than RO.

A Simple Annual Testing Schedule

The Bottom Line

Owning a private well means owning the responsibility for your water quality. The EPA won't test it. Your utility won't test it. No one will send you a violation notice if something is wrong. Annual testing is the only way to know what's in your water — and it's the single most important thing a well owner can do to protect their family.

If you're not sure where to start, our free ZIP code water report can give you a sense of what contaminants are common in your area, and our partner Healthy Hydration offers a professional water quality check that covers the full range of well water concerns.

FranklyH2O provides water quality education based on publicly available EPA data and peer-reviewed research. This article is for informational purposes only and does not constitute medical advice.