Septic System Brochure: Location
Contaminants can travel long distances in some soils. Therefore, drinking water wells should be located at least 75 feet from any part of a septic tank system.
With certain exceptions, septic tanks and drainfields must be located at least 75 feet away from the high water line of ponds, rivers and lakes. Also, the drainfield should be located so that it will not be saturated by surface water drainage or runoff from roof gutters.