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Check separation distances between systems

Drinking water must be kept away from sewage, fuel, chemicals and animals. Check your plan against your local legal setbacks, which vary widely between countries and regions.

How

1. Get the official setback table from your health, environment or building regulator. The EPA notes that most US states set a minimum horizontal distance between septic systems and wells.
2. Example (Mississippi, US): septic tank at least 50 ft from a well, septic drain field at least 100 ft, and at least 100 ft recommended from livestock yards, fuel tanks and pesticide storage.
3. Example (Ireland, Kildare County Council guidance): wastewater system at least 30 m from a well, more if the well is downslope; fuel tanks at least 30 m; slurry spreading at least 25 m; animals fenced at least 3 m from the wellhead.
4. Increase distances in sandy or gravelly soils, where the well is downslope or downgradient, and where groundwater is shallow.
5. Keep the well out of flood-prone areas and grade the ground so surface water drains away from the wellhead.
6. Measure and dimension every critical distance on the master plan.

Do these first

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Sources

1. Septic Systems and Drinking Water. US Environmental Protection Agency, accessed 2026-11
2. Protecting Your Private Well. Mississippi State University Extension, accessed 2026-11
3. Private Wells: protecting your well (leaflet). Kildare County Council, Ireland, accessed 2026-11

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