Keep Finding and Fixing Sewage Contamination in Milwaukee,
Says EPA
Milwaukee Riverkeeper has been working with the University of Wisconsin-Milwaukee School of Freshwater Sciences’ Professor Sandra McClellan and her lab since 2008, monitoring and identifying sources of sanitary-sewage contamination of the stormwater systems in targeted areas of the Menomonee and Kinnickinnic River watersheds. But the work is hardly finished. So it is good news that the EPA Great Lakes Area of Concern Program has issued a new $468,000 grant that will extend the collaboration through 2014 and 2015.
The Riverkeeper and University lab staff will continue to collect one dry-weather and three wet-weather samples from stormwater outfalls at bacteria “hot spots” in both watersheds. Samples are tested for E. coli, enterococcus and, using DNA analysis, a human-specific strain of bacteroides. The grant will also allow testing of surface waters to better understand the flow of bacteria from local rivers. The purpose is to find and eliminate the sources of sewage contamination in local rivers, which, along with associated viruses and pathogens, are threatening public health and keeping local waterways from the “fishable, swimmable” goals of the Clean Water Act.
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Sewage contamination from three area rivers – the Menomonee, Kinnickinnic and Milwaukee – is a major cause of Lake Michigan beach closings in Milwaukee. Bacteria loads in local streams greatly exceed what would be expected simply from stormwater runoff, and these loads have increased over the past two decades while other water-quality measures have improved – which indicates that bacteria is coming from leaking and failing sewage infrastructure.
Analysis of data from 2008 to 2013 shows that approximately 150 of the 308 stormwater outfalls that were sampled multiple times produced at least one positive test for human-sewage contamination. In 23 outfalls, human bacteria were found in every sample. Given the huge extent of the problem, the partners are focusing their efforts on outfalls with consistently high results for human bacteria, and on pipes that flow in dry weather, a sure indicator that they are constantly discharging sewage to area waterways.
Kinnickinnic River Stormwater Sampling Results 2013 (Highest Human Bacteroides Counts Per Outfall)
The data that is collected is helping Milwaukee and surrounding municipalities to better plan and conduct diagnostic testing of failing stormwater sewer systems, using such methods as dye testing and smoke testing, and then to repair the damaged infrastructure. In the past year, six projects have been undertaken to repair some of the worst conditions. The team is also working with the Milwaukee Metropolitan Sewerage District to locate broken pipes and illicit connections that contribute to contamination.
“Total Maximum Daily Load” pollution-reduction plans targeting bacteria in the three rivers are being drafted and will likely be approved by this summer. In addition, a new stormwater permit for the Menomonee River watershed – one of only four in the United States – requires all the municipalities it serves to develop a common protocol for targeting sources of human sewage contamination to the stormwater sewer systems.
An original version of this article appeared in the Summer 2014 issue of WATERKEEPER Magazine. For more visit www.waterkeeper.org
