Septic system requirements in Wisconsin
What landplan.io applies when it designs a septic system in Wisconsin: the system types allowed, tank sizes, setbacks and soil loading rates, with what septic products cost there.
Updated
Design a septic system for an address in Wisconsin
Reviewed landplan.io designs by Wisconsin's own rules, which our staff reviewed against the state's regulations. Last published 5 October 2026.
Septic systems allowed in Wisconsin
The system types landplan.io permits in Wisconsin:
- Mounded Pressure System
- Drip-Line Dispersal
- SSAS Pressure Trenches
- SSAS Gravity/Flood Dosed Trenches
- Bed
- Discharging System
Septic tank size in Wisconsin
The daily design flow of a home: 150 gal/day per bedroom, at least 240 gal/day. The septic tank is sized from that flow:
| Daily design flow | Minimum tank |
|---|---|
| up to 240 gal/day | 1,000 gallons |
| 240 to 360 gal/day | 1,500 gallons |
| 360 to 600 gal/day | 2,000 gallons |
| 600 to 720 gal/day | 2,500 gallons |
| 720 to 840 gal/day | 2,750 gallons |
| 840 to 920 gal/day | 3,000 gallons |
| 920 to 1,040 gal/day | 3,250 gallons |
Septic setbacks in Wisconsin
| From | To | Distance |
|---|---|---|
| Polygon | Existing Septic Component to be Abandoned | 5 ft |
These are the values the landplan.io design engine applies in Wisconsin. Confirm a design with the Wisconsin health department or your county's before you build.
Parcel data in Wisconsin
landplan.io has parcel boundaries for 72 of Wisconsin's 72 counties: the counties where 100% of the state's people live. Type an address there and the design starts from the parcel.
Septic companies, designers and jobs in Wisconsin
- Septic companies and distributors in Wisconsin (39)
- Septic designers in Wisconsin
- Septic design jobs in Wisconsin
Where the rules come from
The regulations and documents landplan.io's Wisconsin rules are read from:
- Private Onsite Wastewater Treatment Systems (POWTS) (Wis. Admin. Code ch. SPS 383)
- Chapter SPS 384 - Plumbing Products (SPS 384.25 POWTS holding components or treatment components; SPS 384.30 POWTS materials) (Wis. Admin. Code ch. SPS 384)
- Private Onsite Wastewater Treatment System (POWTS) Inspector's Handbook, SBD-10089-P (guidance) (DSPS SBD-10089-P (R. 02/22))
- Chapter Trans 233 - Division of Land Abutting a State Trunk Highway or Connecting Highway (setback from state trunk highways) (Wis. Admin. Code ch. Trans 233 (pre-1999 Trans 233.08, printed after Trans 233.13))
- Chapter SPS 382 - Design, Construction, Installation, Supervision, Maintenance and Inspection of Plumbing (Table 382.365-4, setbacks of stormwater and clearwater subsurface infiltration systems) (Wis. Admin. Code SPS 382.365 (3) (f), Table 382.365-4)
- Chapter NR 811 - Requirements for the Operation and Design of Community Water Systems (well siting and water main separation distances) (Wis. Admin. Code ch. NR 811)
- Chapter NR 812 - Well Construction and Pump Installation (Table A, minimum separation distances between wells and contamination sources, NR 812.08) (Wis. Admin. Code NR 812.08, Table A)
- Chapter SPS 383 - Private Onsite Wastewater Treatment Systems (Register PDF, with Table 383.43-1 and the other tables) (Wis. Admin. Code ch. SPS 383)
Septic rules by county in Wisconsin
- Adams County
- Ashland County
- Barron County
- Bayfield County
- Brown County
- Buffalo County
- Burnett County
- Calumet County
- Chippewa County
- Clark County
- Columbia County
- Crawford County
- Dane County
- Dodge County
- Door County
- Douglas County
- Dunn County
- Eau claire County
- Florence County
- Fond du lac County
- Forest County
- Grant County
- Green County
- Green lake County
- Iowa County
- Iron County
- Jackson County
- Jefferson County
- Juneau County
- Kenosha County
- Kewaunee County
- La crosse County
- Lafayette County
- Langlade County
- Lincoln County
- Manitowoc County
- Marathon County
- Marinette County
- Marquette County
- Menominee County
- Milwaukee County
- Monroe County
- Oconto County
- Oneida County
- Outagamie County
- Ozaukee County
- Pepin County
- Pierce County
- Polk County
- Portage County
- Price County
- Racine County
- Richland County
- Rock County
- Rusk County
- Sauk County
- Sawyer County
- Shawano County
- Sheboygan County
- St croix County
- Taylor County
- Trempealeau County
- Vernon County
- Vilas County
- Walworth County
- Washburn County
- Washington County
- Waukesha County
- Waupaca County
- Waushara County
- Winnebago County
- Wood County
Questions
What septic systems are allowed in Wisconsin?
landplan.io permits these system types in Wisconsin: Mounded Pressure System, Drip-Line Dispersal, SSAS Pressure Trenches, SSAS Gravity/Flood Dosed Trenches, Bed and Discharging System.
What size septic tank do I need in Wisconsin?
landplan.io sizes the septic tank in Wisconsin from the daily design flow: up to 240 gal/day: 1,000 gallons; 240 to 360 gal/day: 1,500 gallons; 360 to 600 gal/day: 2,000 gallons; larger flows need larger tanks. A home's design flow is 150 gal/day per bedroom, at least 240 gal/day.
Does landplan.io have parcel data in Wisconsin?
Yes, for 72 of Wisconsin's 72 counties.