Wis. Admin. Code NR § 210.20
All municipally owned satellite sewage collection systems shall be operated under the authorization of a general permit or an individual permit issued by the department. The department may require privately owned satellite sewage collection systems to be operated under the authorization of a general permit or an individual permit issued by the department if the department determines a permit is necessary to assure compliance with the requirements of this subchapter. General permits shall be issued following the procedures in s. NR 205.08 and shall require compliance with all applicable provisions of this subchapter. The department may issue an individual permit, including a compliance schedule for sewage collection system investigations and sewage collection system modifications, when necessary to assure compliance with the requirements of chapter.
Wis. Admin. Code Department of Natural Resources § NR 210.20