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Regulation of Wastewater Discharges

In 1972, the United States Congress passed the Federal Water Act. The law authorized the U.S. EPA to delegate certain water pollution control responsibilities to any state that could demonstrate the necessary levels of expertise and authority to administer the program. Wisconsin obtained EPA delegation in 1974.

The Wisconsin Pollutant Discharge Elimination System (WPDES) permit program was established by Chapter 283.13(1), Wis. Stats. In Wisconsin, WPDES permits are issued by the DNR's Water Quality Program, with federal oversight from the the EPA. The permit program is administered by the DNR, with the Office of the Attorney General providing legal resources for the DNR in enforcement activities. The DNR is responsible for the issuance, reissuance, modification and enforcement of all WPDES permits issued for discharges into the waters of Wisconsin (except discharges occurring on Native American lands, which are regulated directly by the EPA). Wisconsin regulates discharges to both groundwater and surface water; the EPA only requires regulation of surface water discharges. No person may legally discharge to waters of the state without a permit issued under this authority.

Facilities discharging wastewater from a specific point (end of a pipe) must meet either the federal minimum requirements for secondary treatment for municipalities and technology-based categorical (or base level) limits for industries; or, the discharges must meet levels necessary to achieve water quality standards, whichever is more stringent. Land disposal systems also receive permits with limits established to protect groundwater. WPDES permits also address the land application of municipal and industrial wastewater sludge deemed safe for landspreading.

Wastewater treatment plant plan review authority exists in s. 281.41, Wis. Stats. This authority results in the required review of municipal and industrial treatment plant construction plans as well as related monitoring systems and groundwater monitoring wells. The DNR has 90 days to review the plans, which must be done before construction can legally begin.