MDEQ Criteria for Success in CSO Treatment

CSO controls in the Rouge River Watershed are being implemented in three phases through NPDES permits:

• Phase I elimination of raw sewage and the protection of public health for approximately 40 percent of the combined sewer area
• Phase II public health protection for the remaining combined sewer area
• Phase III meet water quality standards in the Rouge River

Under Phase I, six communities have separated their sewers. The measure of success of the sewer separation projects was whether the projects met the Michigan Department of Environmental Quality (MDEQ) criteria for construction of new sanitary sewers. Because of unique situations in some cities, MDEQ had those cities address that situation as part of the evaluation criteria.

Eight communities have constructed 10 retention treatment basins under Phase I . Each of these basins is sized for different design storms and several employ innovative technology. The facilities were intended to meet demonstrative criteria, rather than presumptive criteria. Facilities also incorporate a variety of additional features or variations in compartment sizing and sequencing in an effort to improve their effectiveness. Details on the individual CSO treatment facilities can be found at CSO Demonstration Projects.

The following NPDES permit condition established the CSO basin evaluation program:

Conduct a Retention Basin Evaluation of the effectiveness in meeting Phase II goals of the elimination of raw sewage discharges and the protection of public health, and in meeting the Phase III goals of the elimination or adequate treatment of combined sewage discharges to comply with water quality standard at times of discharge. The evaluation shall be coordinated with other Retention Basin Evaluations being undertaken by other permittees in the Rouge River Basin...

The MDEQ worked closely with Wayne County, consultants to the CSO Basin Communities, the Rouge Project, the Detroit Water and Sewerage Department and US EPA-Region 5 to develop criteria to aid in the evaluation of the Rouge River CSO demonstration basins. Those Criteria for Success in CSO Treatment were issued by MDEQ on August 11, 1998. The Criteria can be found by clicking on the following: Criteria for Success in CSO Treatment.

It is very important to note that MDEQ has concluded that all six of the CSO retention treatment facilities that have completed data collection are currently meeting the Phase II criteria of the elimination of raw sewage and the protection of public health. A June 9, 2000 Letter of Approval for Phase II Review focused on the following retention treatment basins: Acacia Park CSO Retention Treatment Basin, Birmingham CSO Retention Treatment Basin, and Bloomfield Village CSO Retention Treatment Basin. The August 7, 2000 Letter of Approval for Phase II Review focused on the following retention treatment basins: Inkster CSO Retention Treatment Basin, Dearborn Heights CSO Retention Treatment Basin, Redford Township CSO Retention Treatment Basin.

For additional and more detailed information on the performance of the CSO treatment facilities, go to technical papers and professional presentations.

Please address all comments and suggestions about the contents of this Web page to rougeweb@co.wayne.mi.us.

The Rouge River National Wet Weather Demonstration Project is funded, in part, by the United States Environmental Protection Agency (EPA) Grants #XP995743-01, -02, -03, -04, -05, -06, -08 and C-264000-01.