Polk County septic services.

Polk County administers the only septic (SSTS) program in the county; MPCA's 2025 annual report lists no separate city or township program. Your permit runs under the county's own SSTS ordinance — required by Minn. Stat. § 115.55 and allowed to be stricter than the state rules — and the county must give you a written list of any differences from those rules on request (subd. 2(c)); ask before designing. The report does not list the county as requiring a property-transfer compliance inspection; at sale, the statewide seller's disclosure still applies (subd. 6).

The dominant constraint here is seasonal soil saturation close to the surface (88.1% of rated soils), followed by water standing on the surface (48.2%). NRCS's Minnesota-specific ratings put 88.8% of rated ground in the very or extremely limited classes for a conventional below-grade trench and 67.5% for a mound -- where the trench is out, a mound is usually the design that works.