At a glance
| Who regulates | Wisconsin DSPS, with counties running maintenance programs |
|---|---|
| Inspection when a home is sold | No statewide requirement found. We found no statewide rule requiring an inspection at sale. The county's maintenance records show whether the system has been serviced on schedule; ask for them when buying. |
Maintenance rules (SPS 383)
- Every system must be visually inspected at least once every three years.
- A septic (anaerobic) tank must be serviced when sludge and scum together reach one-third of the tank's volume.
- Effluent filters should be cleaned whenever the tank is serviced.
- Holding tanks are pumped when the level reaches one foot below the inlet, when the alarm sounds.
County tracking
- Since October 1, 2019, every system must be in a county maintenance tracking program.
- Counties send reminder notices when a system is due and follow up on overdue properties.
- Wisconsin has more than 750,000 septic systems, according to DSPS.
- The owner is responsible for maintenance; failing to maintain the system is illegal.
Septic tank size in Wisconsin
Set by the system design under SPS 383 and approved by the county.
Compare with other states on our tank size calculator.
Costs
We don't yet have checked Wisconsin-specific prices. National figures: pumping averages about $420–$430 (pumping cost), inspections about $550 on average (inspection cost), and a conventional system $3,000–$8,500 installed (installation cost).
Rules change, and counties and towns can be stricter than the state. Confirm with the agency above before you buy, sell or build.