Wisconsin Administrative Code
Department of Natural Resources
NR 800 - Environmental Protection - Water Supply
Chapter NR 810 - Requirements for the operation and maintenance of public water systems
Subchapter I - General Operations
Section NR 810.19 - Discharge of system or backwash water

Water discharged to the ground surface or storm sewers as part of flushing the distribution system, draining or disinfecting reservoirs, or as part of operation of a water treatment facility shall comply with the applicable general permit to discharge under the Wisconsin pollutant discharge elimination system (WPDES) as per the provisions of ch. 283, Stats. Discharge directly to a surface water is prohibited unless specific approval is obtained prior to the discharge.