What's in My Well Water? Free Well Water Testing Checker

Tell us what your water looks, smells and tastes like. Get the likely problems, how urgent they are, and the lab test to order.

If your home runs on a private well (a borehole, if you grew up in South Africa, the UK or Australia), nobody tests that water but you. The EPA's drinking water rules cover city systems, not private wells. This free checker turns the clues you can see and smell into a shortlist of what to test for.

This checker is an educational guide based on common signs. It is not a lab result and not medical advice. Only a certified lab test can tell you what is in your water. If you are worried about health effects, talk to your doctor or local health department.

Why testing matters

Most of the things that can make well water unsafe can't be seen, smelled or tasted. Bacteria from a septic system, nitrates from fertilizer, and natural arsenic in the rock all leave the water looking clear. The CDC recommends testing a private well every year for total coliform bacteria, nitrates, total dissolved solids and pH. The EPA says you, the owner, are responsible for that testing. Nitrates matter most for babies: high levels can cause "blue baby syndrome", so test before using well water for formula.

How contaminants get into a well

Groundwater picks up whatever is around and below it. Some problems come from the surface: a septic system, manure, fertilizer, or rainwater running in at a loose cap. Others are natural and come from the rock itself, like arsenic, radon, uranium, iron and manganese. Lead and copper usually come from the plumbing inside the house, not from the well.

Test more than once a year if there's a flood, a change in taste, smell or color, work on the well or septic, or new drilling or farming nearby.

Get it tested

Fix what the test finds

Buy treatment after the test, not before. The right system depends on the numbers: a softener won't remove bacteria, and a UV light won't remove iron.

How a well (or borehole) works

A well or borehole is a hole that reaches groundwater: water held in the gaps of sand, gravel or cracked rock, called an aquifer. A pipe called the casing lines the hole so loose soil and surface water stay out. A pump lifts the water into a pressure tank, and the tank keeps pressure steady so the pump doesn't start every time you open a tap.

Dug, driven and drilled

• Dug or bored wells are wide (often 2–3 ft), shallow (usually under 30 ft) and lined with stone, brick or concrete rings. They're the most likely to pick up surface water, bacteria and nitrates, and can run low in a drought.
• Driven wells (sand points) are narrow pipes hammered into sandy ground, usually 30–50 ft deep. Cheap to put in, but they draw shallow water that's easily affected by what happens on the surface.
• Drilled wells / boreholes are made by a rotary or percussion rig and can go hundreds of feet, with steel or PVC casing sealed with grout. This is the type most modern homes have and the usual meaning of "borehole".

Depth and water level

Deeper isn't automatically cleaner, but a deep, properly sealed well is better protected from surface contamination. Deep wells can instead pick up minerals from the rock: arsenic, radon, uranium, manganese or salt. The static water level (where water sits when the pump is off) rises and falls with the seasons. In a drought, or when neighbors pump hard, it can drop below the pump, giving you sputtering taps, air in the lines or sandy water.

Pump and pressure problems

• Submersible pumps sit down in the well, common in drilled wells. Jet pumps sit above ground and suit shallow wells.
• Pump clicking on and off quickly ("short cycling") usually means a waterlogged pressure tank or a failed bladder.
• Low pressure or no water can mean a dropped water level, a failing pump, a tripped breaker or a clogged sediment filter.
• No power means no water: a well pump needs electricity, so plan a backup source for outages.

Maintenance

• Check the well cap every season: it should be tight, vented and screened, at least a foot above ground, with soil sloping away.
• Keep fertilizer, pesticides, fuel and pet waste away from the wellhead. Many states require septic systems to be at least 50–100 ft from a well.
• Have the well, pump and pressure tank inspected every few years by a licensed contractor.
• Seal old, unused wells properly. They are a direct path for contamination into the aquifer.

When to test

Every year for bacteria, nitrates, TDS and pH. Every 3–5 years, a broader panel (metals, arsenic, hardness). Right away after a flood, well repair, a change in the water, or before a baby arrives. Also when you buy a home with a well.

Common well water problems

Each card shows what to look for, why it matters, how to test and the usual fix. Treatment should always follow a lab result.

How to take a water sample

1. Use only the bottles from your lab or kit, and read its instructions first. Some tests have their own rules.
2. Pick a cold tap with no filter or softener, such as the kitchen tap with the filter bypassed, or an outdoor spigot near the pressure tank.
3. For lead and copper, take the first water out of the tap after it has sat unused for at least 6 hours, usually first thing in the morning.
4. For bacteria, remove the aerator, wipe or flame-sterilize the spout if your kit says so, run the cold water 3–5 minutes, then fill without touching the inside of the cap or bottle.
5. Fill to the line, cap tightly, label it with the date and time, and keep it cold.
6. Get it to the lab quickly. Bacteria samples usually must arrive within 24–30 hours, so ship early in the week.

How to read your results

The EPA's limits for public water systems are a useful yardstick for a private well, even though they don't legally apply to it. Results are usually in mg/L (the same as parts per million). Some contaminants are shown in µg/L or ppt.

Sources: EPA National Primary and Secondary Drinking Water Regulations. In May 2026 EPA proposed keeping the PFOA and PFOS limits (with an option for water systems to have until 2031 to comply) and rescinding the 2024 limits for PFHxS, PFNA, GenX (HFPO-DA) and the PFAS mixture. Check epa.gov for the current status. There is no federal limit for hardness, hydrogen sulfide or radon in water. If any health-based result is over the limit, retest to confirm and contact your local health department.

Shock chlorinating a well (overview)

Shock chlorination puts a strong dose of chlorine into the well and plumbing to kill bacteria. It's often recommended after a positive bacteria test, a flood, or well or pump work. In outline: bypass filters and softeners, add the amount of unscented household bleach your state or county guide gives for your well's depth and diameter, circulate it until you smell chlorine at every tap, let it sit (often 12–24 hours), then flush the chlorinated water out away from your septic system and plants. Retest 1–2 weeks later.

Safety: chlorine at shock strength can burn skin and eyes. Never mix bleach with other cleaners, especially ammonia or acids. Don't drink the water during treatment, and keep the electrical parts at the wellhead dry. Shocking doesn't fix the cause: if bacteria come back, find the leak or source, or call a licensed well contractor.

Well maintenance checklist

• Every spring: test for bacteria, nitrates, pH and TDS.
• Every season: check the well cap is intact, vented and bolted, with no cracks in the casing. The ground should slope away from it.
• Keep 50+ ft clear of fuel, chemicals, manure and pet waste, and mow, don't spray, around the wellhead.
• Pump the septic tank on the schedule your installer or county recommends (often every 3–5 years).
• Watch for changes: sputtering taps, short cycling, sandy or cloudy water, or a new taste or smell.
• Every few years: have a licensed contractor inspect the well, pump and pressure tank.
• Keep records of test results, repairs and well depth in one place.
• Have unused or abandoned wells on the property sealed by a professional.

FAQ

A backup water supply that doesn't need the well

When the power goes out, the well pump stops. When a test comes back bad, you may wait weeks for a fix. Water Freedom System is a written plan for pulling drinking water out of humid air at home, built from household parts, so you have a second source either way.

Disclosure: some links on this page are affiliate links. If you buy through them, I may earn a commission at no extra cost to you. Health guidance is drawn from the CDC and EPA; this page is not medical advice.