Required Septic System Setbacks
Table 1 - OAR 340-71-220 Minimum Separation Distances
| Items Requiring Setback |
From Sewage Disposal Area Including Replacement Area |
From Septic Tank and Other Treatment Units, Effluent Sewer and Distribution Units |
- Groundwater Supplies
|
100' |
50' |
- Temporarily Abandoned Wells
|
100' |
50' |
- Springs:
- Upgradient:
- Downgradient:
|
50'
100'
|
50'
50'
|
- Surface Public Waters:
- Year Round (Perennial)
- Seasonal (Intermittent)
|
100'
50'
|
50'
50'
|
- Intermittent Streams:
- Piped (Watertight not less than 25' from any part of the on-site system):
- Unpiped:
|
20'
50'
|
20'
50'
|
- Groundwater Interceptors (GWI)
- On a Slope of 3% or Less:
- On a Slope Greater than 3%:
- Upgradient:
- Downgradient:
|
20'
10'
50'
|
10'
5'
10'
|
- Irrigation Canals:
- Lined (Watertight Canal):
- Unlined:
- Upgradient:
- Downgradient:
|
25'
25'
50'
|
25'
25'
50'
|
- Cuts Manmade in Excess of 30 Inches (Top of Downslope Cut):
- Which Intersect Layers that Limit Effective Soil Depth Within 48 Inches of Surface:
- Which do not Intersect Layers that Limit Effective Soil Depth:
|
50'
25'
|
25'
10'
|
- Escarpments:
- Which Intersect Layers that Limit Effective Soil Depth:
- Which do not Intersect Layers that Limit Effective Soil Depth:
|
50'
25'
|
10'
10'
|
- Property Lines:
|
10' |
5' |
- Water Lines:
|
10' |
10' |
- Foundation Lines of any Building or Structure:
|
10' |
5' |
- Underground Utilities:
|
10' |
-- |
This does not prevent stream crossing of pressure sewer effluent sewers.
