Wis. Admin. Code Department of Natural Resources NR 210.21

Current through October 28, 2024
Section NR 210.21 - Sanitary sewer overflows and sewage treatment facility overflows
(1) PROHIBITED OVERFLOWS. Sanitary sewer overflows and sewage treatment facility overflows are prohibited and may not be approved by the department nor authorized in a permit issued by the department. If applicable to an overflow event, permittees shall provide information that will enable the department to determine whether any of the following conditions exist:

Note: When used without qualification in this chapter, the word "overflow" includes both sanitary sewer overflow and sewage treatment facility overflow.

(a) The sanitary sewer overflow or sewage treatment facility overflow was unavoidable to prevent loss of life, personal injury, or severe property damage.
(b) There were no feasible alternatives to the sanitary sewer overflow or sewage treatment facility overflow such as the use of auxiliary treatment facilities or adequate back-up equipment, retention of untreated wastes, reduction of inflow and infiltration, or preventative maintenance activities.

Note: When evaluating feasibility of alternatives, the department may consider factors such as technical achievability, the relationship between the control of storm water and the control of infiltration and inflow into the sewage collection system, costs and affordability of implementation and risks to public health, the environment, and welfare of the community served by the sewage collection system.

(c) The sanitary sewer overflow or the sewage treatment facility overflow was caused by unusual or severe weather related conditions such as large or successive precipitation events, snowmelt, saturated soil conditions, or severe weather occurring in the area served by the sewage collection system or sewage treatment facility.
(d) The sanitary sewer overflow or the sewage treatment facility overflow was unintentional, temporary, and caused by an accident or other factors beyond the reasonable control of the permittee.
(2) DEPARTMENT RESPONSE. If a prohibited sanitary sewer overflow or sewage treatment facility overflow occurs, the department may, in addition to the factors provided in sub. (1), also consider the following factors in any enforcement action or response:
(a) The permittee's activities in implementing a capacity, management, operation, and maintenance (CMOM) program, or a functionally equivalent program, that meets the requirements in s. NR 210.23.
(b) The status of preparation of a system evaluation and capacity assurance plan, or a functionally equivalent plan that meets the requirements of s. NR 110.10(4), that may be required under s. NR 210.24.
(c) The status of implementation of an approved system evaluation and capacity assurance plan, or a functionally equivalent plan that meets the requirements of s. NR 110.10(4), that may be required under s. NR 210.24.
(d) The status of planning or implementation of specific actions that conform to an approved facilities plan under ss. NR 110.08, 110.09, and 110.10 and that meet the requirements of this chapter and s. NR 205.07(1) (u).
(e) The status of planning or implementation of specific actions required by a WPDES permit, or other legally binding document, to construct or implement projects that will address the cause of the sanitary sewer overflow or sewage treatment facility overflow.

Note: The department may initiate enforcement action under s. 283.89, Stats., for any sanitary sewer overflow or sewage treatment facility overflow.

(3) PERMITTEE RESPONSE TO OVERFLOWS. Whenever a sanitary sewer overflow or sewage treatment facility overflow occurs, the permittee shall take all feasible steps to control or limit the volume of untreated or partially treated wastewater discharged, and terminate the discharge as soon as practicable. Remedial actions shall be implemented consistent with an emergency response plan developed under s. NR 210.23(4) (f). Remedial actions may include the following:
(a) Interception and rerouting of untreated or partially treated wastewater around the point of failure, if that failure is in the sewage collection system.
(b) Use of vacuum trucks or other appropriate mechanisms to recover as much of the wastewater discharged as possible and properly dispose of such wastewater and wash down water.
(c) Cleanup of debris at the overflow site.
(d) Adequate sampling to determine the amount, characteristics, and impact of the overflow.
(4) PERMITTEE REPORTING. Permittees shall report all sanitary sewer overflows and sewage treatment overflows as follows:
(a) The permittee shall notify the department by telephone, fax, or email as soon as practicable, but no later than 24 hours from the time the permittee becomes aware of the overflow.
(b) The permittee shall, no later than five days from the time the permittee becomes aware of the overflow, provide to the department the information identified in this paragraph using department form number 3400-184. If an overflow lasts for more than five days, an initial report shall be submitted within 5 days as required in this paragraph and an updated report submitted following cessation of the overflow. At a minimum, the following information shall be included in the report:
1. The date and location of the overflow.
2. The surface water to which the discharge occurred, if any.
3. The duration of the overflow and an estimate of the volume of the overflow.
4. A description of the sewer system or treatment facility component from which the discharge occurred such as manhole, lift station, constructed overflow pipe, or crack or other opening in a pipe.
5. The estimated date and time when the overflow began and stopped or will be stopped.
6. The cause or suspected cause of the overflow including, if appropriate, precipitation, runoff conditions, areas of flooding, soil moisture, and other relevant information.
7. Steps taken or planned to reduce, eliminate and prevent reoccurrence of the overflow and a schedule of major milestones for those steps.
8. A description of the actual or potential for human exposure and contact with the wastewater from the overflow.
9. Steps taken or planned to mitigate the impacts of the overflow and a schedule of major milestones for those steps.
10. To the extent known at the time of reporting, the number and location of building backups caused by excessive flow or other hydraulic constraints in the sewage collection system that occurred concurrently with the sanitary sewer overflow and that were within the same area of the sewage collection system as the sanitary sewer overflow.
11. The reason the overflow occurred or explanation of other contributing circumstances that resulted in the overflow event. This includes any information available under sub. (1), including whether the overflow was unavoidable to prevent loss of life, personal injury, or severe property damage and whether there were feasible alternatives to the overflow.

Note: A copy of form 3400-184 for reporting sanitary sewer overflows and sewage treatment facility overflows may be obtained from the department or accessed on the department's web site at http://dnr.wi.gov/topic/wastewater/documents/3400-184_ssoreportform.pdf.As indicated on the form, additional information may be submitted to supplement the information required by the form.

(c) The permittee shall identify each specific location and each day on which a sanitary sewer overflow or sewage treatment facility overflow occurs as a discrete sanitary sewer overflow or sewage treatment facility overflow occurrence. An occurrence may be more than one day if the circumstances causing the sanitary sewer overflow or sewage treatment facility overflow results in a discharge duration of greater than 24 hours. If there is a stop and restart of the overflow at the same location within 24 hours and the overflow is caused by the same circumstance, it may be reported as one occurrence. Sanitary sewer overflow occurrences at a specific location that are separated by more than 24 hours shall be reported as separate occurrences.
(d) A permittee that is required to submit wastewater discharge monitoring reports under s. NR 205.07(1) (r) shall also report all sanitary sewer overflows and sewage treatment facility overflows on that report.
(e) Satellite sewage collection system permittees shall submit reports required under this subsection to all owners of sewerage systems which receive wastewater from the satellite sewage collection system.
(5) PUBLIC NOTIFICATION. A permittee shall notify the public of any sanitary sewer and sewage treatment facility overflows consistent with its emergency response plan required under s. NR 210.23(4) (f). Such public notification shall occur promptly following any overflow event using the most effective and efficient communications available in the community. At minimum, a daily newspaper of general circulation in the county(s) and municipality whose waters may be affected by the overflow shall be notified by written or electronic communication.
(6) NOTIFICATION OF DRINKING WATER SYSTEM OWNERS. The department may require the permittee to notify the owner of a drinking water intake located in a surface water receiving any sanitary sewer overflows and sewage treatment facility overflows. Such conditions shall be included in the WPDES permit.

Wis. Admin. Code Department of Natural Resources NR 210.21

CR 12-027: cr. Register July 2013 No. 691, eff. 8-1-13.