Sewer Overflows in Wisconsin

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Over the past 25 years, Wisconsin communities have invested $3.9 billion in improving sanitary sewage collection and treatment systems they own and operate. These improvements range from the replacement of failing on-site disposal systems by small rural communities to the massive Water Pollution Abatement Program in the Milwaukee area. These projects have resulted in significant improvements in the quality of the state's waters.

Due to expanding populations, an aging of this important infrastructure, and several unusual rainfall events in parts of the state, there has been significant public, legislative and media interest in the number of sewage overflows reported in 1999 and 2000. This report contains information that will be used by the Department of Natural Resources in moving forward with actions that seek to prevent, to the maximum extent practicable, the discharge of untreated sewage to state waters.

This report contains information about sanitary sewer and combined sewer systems in the state. It also contains data on the frequency and location of sanitary and combined sewer overflows, and provides additional detail on the sewerage system owned and operated by the Milwaukee Metropolitan Sewerage District. * Most importantly, the report contains a series of recommendations for actions to be taken by the Department, by communities across the state, by the Milwaukee Metropolitan Sewerage District (MMSD) and by the communities served by the MMSD. These recommendations can be summarized as follows:

1. The Department must implement improved systems for tracking and follow-up on reports of sanitary sewer overflows (SSOs). Rules and compliance activities that were developed over the years have produced a patchwork of requirements that need to be consolidated and refined for the sewerage systems in operation in the state. Any new or revised rules must include uniform standards for the design of sewage conveyance and treatment facilities. The Department must create a comprehensive system that will assure:
1. Sewage collection systems are maintained, operated and managed to prevent the entry of groundwater infiltration and stormwater inflow to the extent practicable and
2. Infiltration and inflow that enters sewage collection systems does not cause or contribute to SSO.
2. The Department must initiate an outreach program to assure that all communities submit timely reports about SSOs from their sewer systems as required by their WPDES permits, and become more aggressive in correcting the root causes of overflows, particularly excessive infiltration and inflow.
3. Communities in the service area of the Milwaukee Metropolitan Sewerage District must, together with the District, identify and remove the sources of infiltration and inflow to their sanitary sewers so they do not overflow directly to surface waters and, further, assure that the downstream capacity of the District's conveyance, storage and treatment systems are not exceeded.
4. The Milwaukee Metropolitan Sewerage District must continue to improve the operation of its conveyance, storage and treatment facilities to maximize the amount of combined and sanitary sewage that is captured, stored and treated before discharge to surface waters. MMSD must also work with its contract and service communities to design and implement cost-effective ways to significantly reduce the excessive infiltration and inflow that currently enters local sewers that are tributary to the District's system. In addition, MMSD must prepare a new facilities plan for the period 2010 to 2020 that identifies projects that are needed to upgrade conveyance, storage and treatment to assure SSOs are prevented and CSOs are minimized. Water quality impairments are caused by many different sources of contamination. Control of any one source of contaminants will not, by itself, address all the water quality problems in a particular river or lake. It is important that the Department continue to investigate these impairments using an integrated, multidisciplinary approach to assure water quality improvements are achieved in a comprehensive manner, using a watershed approach to manage the quality of our waters.

 

Sewer Overflows In Wisconsin Report 266 Kb
Appendix A 8 Kb	Appendix B 12 Kb	Appendix C 15 Kb
Appendix D 12 Kb	Appendix E 1173 Kb	Appendix F 49 Kb
Appendix G 4203 Kb	Appendix H 12628 Kb

If you have comments regarding the Sewer Overflows in Wisconsin report, please contact Duane Schuettpelz schued@dnr.state.wi.us. If you would like a hard copy of this report sent to you, please call (608) 267-7694.

Last Revised: Thursday July 27 2006