The 75 feet between a drinking well and a septic system, and what it does to a small lot

The distances

Under Chapter 64E-6 of the Florida Administrative Code a private potable well must be at least 75 feet from any part of an onsite sewage treatment system: the tank, the drain field and the pipes between them. A non-potable irrigation well needs 50 feet. Public supply wells need considerably more. The measurement is taken from the well to the nearest component, not to the middle of the field.

Why the rule exists

A drain field treats effluent by passing it through soil. On sandy ground around Jacksonville that treatment depends on distance and time, and a shallow well too close to a field can draw water that has not had enough of either. The setback is the margin that makes a private well and a private septic system safe on the same lot, which is the arrangement most rural and many older suburban properties here live with.

What it does to a small lot

Draw the 75-foot circle around an existing drain field on a quarter-acre lot and it often covers the whole lot. Add the property line setbacks and the driveway and the number of places a new drinking well can legally stand can be zero. The options then are a deeper well at a location that does work, a redesigned drain field, an irrigation well at the shorter setback with the house on utility water, or a variance, which is slow and not guaranteed.

Why the two trades belong together

When a well contractor and a septic contractor each site their own work without the other, the homeowner discovers the conflict at inspection. A crew that does both measures once, plans once and files both permits with a single site plan. That is the practical argument for the name on the truck.