60 Years of Progress in CSO Control in Michigan

The EPA reports that approximately 860 communities are served by combined sewer systems in the United States. While the EPA started to regulate Combined Sewer Overflows (CSOs) more directly in 1994 (CSO Control Policy, 59 FR 18688,) Michigan's efforts date back much earlier. The first retention basins in Michigan were constructed the late 1950s and the State codified unlawful pollution, including the discharge of any raw sewage, in 1966. Michigan remains a leader in reducing pollution from combined sewer systems and implementing innovative approaches. Since 1988, tremendous amounts of money have been invested in CSO projects, including over $2 billion dollars using State Revolving Funds alone. This presentation will provide a timeline of Michigan's wet weather control policies in comparison to those of the EPA. Michigan's regulations/policies do not allow any untreated CSO discharges based on Michigan's water quality standards, and therefore are perceived to be more stringent than the national policies. The requirement to not allow for untreated discharges has led to construction of many innovative facilities that will also be highlighted in the presentation. There will also be discussion of some improved water quality metrics due in part to CSO treatment and control. Key projects and policies to be included are: Michigan's 1994 CSO Control Manual that created 'presumptive' and 'demonstrative' criteria for sizing of CSO storage and treatment facilities. This unique approach allowed communities flexibility in design that allowed construction of a facility smaller than the State's 'presumed' criteria, and 'demonstrate' whether the facility was capable of meeting water quality standards at times of discharge. The City of Detroit has made significant progress implementing their Long-Term CSO Control Program (LTCP) that was first submitted in 1996, though work remains to meet water quality standards. The City has spent over $1.4 billion to date to correct CSO discharges which has resulted in additional treatment capacity at the treatment plant, construction of nine treatment facilities and use of in-system storage. This work has reduced the amount of untreated CSO discharge from an annual average of 20 to 25 billion gallons per year before submittal of the LTCP to approximately 1.5 billion gallons in 2019. Oakland County's George W. Kuhn Retention Treatment Facility (constructed 1972 with a major expansion in 2006,) which provides storage for 124 million gallons of storage, and settling, screening and disinfection of additional flows. It is one of the largest screening facilities in North America. Bay City's $55 million Federal Grant Program for CSO abatement and wastewater improvements (1976-1982) that included construction of a combination of sewer separation and five storage and treatment facilities, based on cost-effectiveness for each sewer-shed. The Rouge River National Wet Weather Demonstration Project (1992-2014.) This project leveraged $350 million in Federal and additional matching funds for 88 combined/separated sewer overflow remediation projects. Saginaw's $100 million CSO Control Program, which included seven retention treatment basins and won an award in 1998 from the EPA for outstanding CSO control. Creation of an RTB best practices group where CSO facility operators from several communities in Southeast Michigan share information to optimize operation of their facilities. The addition of asset management language to NPDES permits and grant asset management funding to ensure facilities have the appropriate resources and funding to continue successful operation.