Septic System Permit (POWTS)

Required for installing, replacing, or modifying private onsite wastewater treatment systems (POWTS) in Wisconsin. Regulated under SPS 383 (formerly Comm 83) and administered at the county level. All POWTS installations require a licensed master plumber, a soil evaluation, and a state-certified inspector. Wisconsin transitioned from the older 'septic system' terminology to 'POWTS' (Private Onsite Wastewater Treatment System).

Verified 2026-02-01
Typical Fee Range
$200–$800
flat
Typical Timeline
2–6 weeks
From application to approval
Inspection Required
Yes
One or more inspections required
Jurisdiction Level
County
Issuing authority level

When Is a Septic System Permit (POWTS) Required?

  • New septic system (POWTS) installation
  • Replacing or upgrading an existing septic system
  • Connecting to or modifying an existing POWTS
  • Property with a failing septic system that needs replacement

When Is a Septic System Permit (POWTS) NOT Required?

  • Routine septic tank pumping and maintenance
  • Properties connected to municipal sewer

Related Permits You May Also Need

Well Permit
Required for constructing, reconstructing, or abandoning private water wells in Wisconsin. Wisconsin DNR regulates private wells under NR 812 and requires all well construction to be performed by a licensed well driller. County agencies typically administer well permits and coordinate inspections. Well location must meet minimum setback distances from septic systems, property lines, and potential contamination sources.
→
Residential Building Permit
Required for new single-family homes, duplexes, and multi-family dwellings in Wisconsin. The state enforces the Uniform Dwelling Code (UDC) statewide through DSPS, but municipalities issue permits and conduct inspections locally. Plans must comply with SPS 320–325 for structural, energy, and safety requirements.
→
County Sanitary Permit
Required by some Wisconsin counties as a prerequisite for building permits on properties with private sewage systems (POWTS). The county sanitary permit verifies that the property has an adequate and code-compliant private sewage system to handle the proposed use. This may overlap with or be combined with the POWTS/septic system permit in some counties.
→

Required Licenses

The following professional licenses may be required to obtain or work under this permit type in Wisconsin.

Frequently Asked Questions — Septic System Permit (POWTS)

Who permits septic systems in Wisconsin?

County agencies administer POWTS (septic system) permits in Wisconsin under authority delegated by the state. The county reviews soil evaluations, issues installation permits, and conducts inspections. A certified soil tester must evaluate the site, and a licensed master plumber must perform the installation.

How much does a septic system cost in Wisconsin?

The permit itself costs $200–$800. The complete installation typically costs $8,000–$25,000 depending on the system type, soil conditions, and site complexity. Conventional gravity systems are less expensive; mound systems and advanced treatment systems cost more. A soil evaluation ($500–$1,500) is required before the permit can be issued.

How often does a septic system need inspection in Wisconsin?

Wisconsin requires POWTS maintenance inspections every 3 years. Conventional septic tanks should be pumped every 3–5 years depending on household size and usage. Some advanced treatment systems require more frequent maintenance. Counties maintain maintenance tracking programs and will notify property owners when inspections are due.

For Professionals

Managing permits across multiple jurisdictions?

Get fee changes, requirement updates, and deadline alerts for every municipality you work in. Built for contractors, expeditors, and compliance teams.

No credit card required. Free for up to 3 locations.