Sanitary Sewer Extensions Bans

The Department of Natural Resources (DNR) cannot approve proposed extensions of sanitary sewers that would connect to a sewerage system that cannot adequately convey or sufficiently treat existing wastewater flows. The sewer extension ban rules are in s. NR 110.05, Wisconsin Administrative Code. In addition, the Department of Commerce (Commerce) cannot approve new private interceptor main sewer, or building sewers serving more than 54 drainage fixture units, if the municipality is subject to a sewer ban under s. NR 110.05. The Commerce ban rule is in s. Comm 82.20(4)(c), Wis. Adm. Code. The 54 drainage fixture criteria normally allow one and two family dwellings to be connected to an existing municipal sewer.

Any community that becomes subject to a sewer extension ban will receive a notification letter from the DNR. The ban is triggered by significant violation of WPDES discharge effluent limits at a wastewater treatment plant, or by excessive bypassing of untreated or partially treated wastewater out of the sewerage system. The bans are applicable to extensions of new sewer. Existing sewers may still be repaired or replaced as necessary.

The sewer ban regulations are intended to restrict the amount of wastewater that is discharged to over-loaded or inadequate wastewater treatment facilities and thus minimize untreated or poorly treated wastewater discharged to waters of the state. This also reduces the potential for waterborne disease outbreaks due to bypassing of untreated wastewater. The sewer extension review policy influences municipalities to take corrective actions and implement prevention programs regarding their wastewater treatment systems. In this manner, the policy protects the state's water quality.

The sewer ban program has been in effect since 1976. The majority of wastewater facilities in Wisconsin are well operated and meet their discharge limits. Typically only 1 to 2% of all municipalities in Wisconsin are under a sewer ban at any point in time.

Specific Criteria:

Sewer extensions cannot be approved by the DNR if there is a total of more than 3 months of violations of the monthly average limitation for either Biochemical Oxygen Demand (BOD5) or Total Suspended Solids, or both, in the previous 12 months. Solely for purposes of sewer ban determinations, a "violation" is defined as 1.3 times the effluent limit for BOD5 and 1.2 times the effluent limit for total suspended solids. These effluent limits will be listed in the specific community discharge permit.

Sewer bans are also imposed on sewerage systems that experience "Category 1" bypassing. Bypassing events are classified by DNR as either Category 1 or 2, as defined in s. NR 110.05(2), Wis. Adm. Code. Many factors are considered in the classification process. In general, a bypass that occurs during dry weather or during a storm event with a probable recurrence frequency of less than 5 years, may be classified as Category 1.

Sewer Extension Ban Exceptions:

There are exceptions contained in s. NR 110.05(5), Wis. Adm. Code. Sewer extensions serving charitable or humanitarian institutions, or sewers eliminating a threat to public health or safety, may receive approval. Also, revisions to previously approved sewer extensions resulting in no wasteload increases may be approved as long as the original approval was less than four years prior to the revision request. When exceptions are approved, there may be limitations imposed on the number of building connections allowed.

Removal of Sewer Bans:

When the problem is corrected, and a satisfactory record of operation is obtained, the ban is removed. A satisfactory record of treatment for purposes of s. NR 110.05, Wis. Adm. Code, means that there are less than 4 months of violations over a previous 12-month operating period. A ban may also be lifted if a corrective action is implemented and results in 4 consecutive months of compliance, thus demonstrating a trend for expected continued compliance. The specific factors that allow the lifting of a sewer ban are discussed in detail in s. NR 110.05(3), Wis. Adm. Code.