Blog · September 30, 2026
What Is a Well Protection Radius?
A well protection radius is a circle, often of a set footage, around a water well inside which septic fields, tanks, or chemical storage are forbidden or limited. It is a health setback. It is not a property line and not an easement unless a separate easement was granted.
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A circle around the well, not around the house
Health rules commonly require a minimum distance from a well to a septic tank, a drainfield, a property line, or a contamination source. Site plans draw that distance as a circle labeled with the radius. The circle is a regulatory setback centered on the well. It may cross a lot line. Crossing the lot line does not move the lot line and does not, by itself, give you rights on the neighbor’s land or give the neighbor rights on yours. If the circle must be kept clear on both lots, someone may also need an easement or a recorded restriction. The radius note alone is not that easement. Read whether the plat grants a well easement or only depicts a required setback. Depiction warns. An easement binds.
Shared wells and the circle
A shared well may sit on one lot inside an easement, with the radius limiting septic placement on several lots. The easement for the well and the pipes is a title burden. The radius is a health rule tied to the permit. Both can stop a drainfield. A buyer who looks only at the lot lines on a county GIS map sees neither the casing nor the circle. Platbookmapper links to that map and does not draw well radii, lot lines, or zip codes. Get the well permit, the plat, and any shared-well agreement. The agreement may assign repair costs and may locate a protection area. A measuring wheel from a wellhead you think is the well is not a survey, and opening a well cap is not a reading technique.
Building and the radius
Place septic components outside the radius the permit states. Do not slide the well symbol on a PDF to make a tight lot work. If the well was drilled in a different spot than the plan, the circle moves with the well, and the permit may need an amendment. A surveyor can locate the well and plot the radius. A phone GPS cannot hold a fifty-foot health setback well enough to risk a new field. Do not dig near the casing to see the seal. If the radius crosses your building pad, the conflict is resolved by redesign or by a written variance, not by hoping the inspector uses the GIS.
What to do next
- Find the radius on the permit or the site plan and the distance it states.
- See whether a recorded well easement exists separately from the circle.
- Keep septic parts outside the circle.
- Relocate the circle only when the well’s true location is surveyed and the permit is updated.
The mix-up to avoid
Reading the well radius as a round property line. It is a health setback. The lot line is still the lot line, and the circle can cover parts of more than one lot without transferring title.
Questions people ask
Is the radius the same number everywhere?
No. Distances depend on the state and on the components involved. A tank and a drainfield may have different setbacks. Use the number on the permit that governs that well, not a number you remember from another county.
Does the circle give the well owner the right to enter?
Only if an access easement says so. The health radius limits pollution sources. It is not a license to walk the neighbor’s yard. Stay off their land.
Find the county map
The county GIS map is the practical place to start. Find it from the Platbookmapper directory, then treat the recorded plat and deed as the documents behind the picture.
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey.