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Set separation distances from wells, water and buildings

Separation distances protect drinking water and watercourses from sewage. Your local code sets the legal minimum, but greater distances give better protection.

How

1. Get your local separation table and plot every well, spring, stream, pond, building and property line on your site plan.
2. Example, Minnesota (USA): septic tanks, drainfields (small systems), non-portable privies, greywater dispersal areas and constructed wetlands must be at least 50 ft (about 15 m) from a water-supply well. For a well with less than 50 ft of watertight casing, the drainfield, privy and greywater distances double.
3. Example, Nebraska (USA): 50 ft from a well to a septic tank and 100 ft (about 30 m) to a drainfield.
4. Example, England: ground discharges must be at least 50 m from any well, spring or borehole used for drinking or food production, and not inside groundwater source protection zone 1.
5. Example, California (USA) greywater irrigation fields: 100 ft from water-supply wells and from streams and lakes (50 ft if the greywater is filtered), 2 ft from buildings.
6. Place your well uphill and as far as practical from all sewage and greywater areas. Coordinate with the water module before fixing either location.

Do these first

• water-1

Sources

1. Isolation Distances from a Well. Minnesota Department of Health, accessed 2026-11
2. Setback Distance From Septic to Drinking Water Well. Extension.org (Cooperative Extension), accessed 2026-11
3. General binding rules for small sewage discharges (SSDs) with effect from 2 October 2023. UK Government (Environment Agency, England), accessed 2026-11
4. Laundry to Landscape Graywater System Design Guidelines. County of Santa Cruz Environmental Health, accessed 2026-11

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