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Where can I legally put a well?

Planning a new well? Pick your state and check your planned spot against the minimum legal distance from your septic tank and drainfield — the separation that keeps your drinking water safe.

Your Lot

Check your well location

Your state Each state sets its own minimum separation distances.

Planned well → septic tank Distance in feet from your planned well to the septic tank.

50 ft

Planned well → drainfield Distance to the leach field / drainfield (where the septic effluent soaks in).

100 ft

Your result

Most states require your well to sit at least 50 ft from the septic tank and 100 ft from the drainfield. Pick your state for its exact minimums.

These are state minimums — your county is often stricter

The distances here are each state's baseline rule, pulled from its health department or well code. Many counties and local health districts require more, and a few features (slope, soil, well depth, water table) can push the number higher. Always confirm with your local health department before you drill — and a licensed driller pulls the permit and confirms the siting as part of the job.

Why It Matters

Why the distance is the law

It protects your water

A septic drainfield releases treated wastewater into the soil. Too close to your well, and bacteria or nitrate can reach your drinking water before the ground filters it out.

Tank vs. drainfield differ

A sealed septic tank can sit closer (often 50 ft) than the drainfield (usually 100 ft), because the drainfield is where effluent actually enters the ground.

It gates your permit

Most states won't permit a well that's too close, and a failed setback can stall a home sale or build. Getting it right up front saves a costly re-drill.

Sources: per-state minimums verified from each state's health department, environmental-quality department, or well/septic code (46 of 51 confirmed against the state's own code; a few from reputable secondary citations — flagged in the result). Figures are statewide minimums for a conventional single-family system; local rules and site conditions can require more. Not legal advice — confirm with your local health department.

Next steps

Before you act on this number.

Well regulations and permits hub The wider framework these distances sit inside.
Permits by state Who issues the permit where you are.
Testing guide What to test for if a source is close.

Common questions

Reading this properly.

Usually the strictest one that covers you. A state minimum sets the floor, and a county or local health department frequently requires more. Lot lines, slope and soil type can all change the answer, so confirm with the authority that issues your permit before siting anything.

More than the septic tank. Drainfields, sewer lines, livestock yards, fuel tanks, and in some jurisdictions property boundaries all carry their own separation distances. The tank is simply the one people remember.

Often not — older wells are frequently allowed to remain where they are. But that grandfathering usually ends the moment you replace the well or alter the septic system, and it never makes the water safer. If separation is tight, test more often.

Siting a new well? Get a licensed driller.

A licensed driller confirms the placement against your local rules, pulls the permit, and drills it right the first time. Get up to 3 free quotes from licensed well drillers near you — direct contact, no referral fees.

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Well & Septic Setback Checker — Where Can I Put a Well?