Minimum well clearance distance from a leach field?

• A. 50 feet
• B. 25 feet
• C. 10 feet
• D. 75 feet

Answer: (A)

The main idea is protecting a drinking-water well from septic system contamination by keeping enough distance so any effluent must travel through soil and groundwater before it could reach the well. Fifty feet is the standard minimum setback in Wisconsin codes. This distance gives a buffering layer where soil filtration and natural attenuation reduce bacteria, nitrates, and other contaminants as groundwater moves toward the well. Site specifics like soil type, depth to groundwater, and bedrock depth can change what’s needed, but fifty feet is the baseline protection. Shorter distances would leave less of a filtration path and raise contamination risk, while a larger distance isn’t required unless conditions demand extra protection.