Wisconsin Permits Capped-Pipe Chemical Treatment

From February 19, 1992 (update #12)

MADISON, Wis. - The Wisconsin Department of Natural Resources late last fall approved three more applications from Lake Michigan water utilities to chemically treat capped intake pipes for zebra mussels. The Kenosha, Racine and Cudahy water utilities all received approval to either inject chlorine, or add sodium bisulfite, into their water intake pipes prior to "capping" their lake water intake structures. All three utilities implemented these plans in late fall and early winter. Shortly after the Cudahy utility closed and chlorinated its 42-inch diameter water intake pipe in late November - relying on a smaller 24-inch diameter pipe that had not served as the city's sole intake pipe since 1975 - Cudahy residents noted a few days of a "musty, swampy, stale odor," according to utility superintendent Michael Clark. The odor - and a taste to match - was produced by increased water pressure in the smaller pipe that dredged up sediments settled in the pipe, Clark said. The problem disappeared after a few days, but another problem occurred weeks later, when the Cudahy utility experienced a blockage of the small intake pipe and had to rapidly return to using the larger intake pipe that had been closed off for 10 weeks. At Kenosha, the treatment lasted one month, and no taste and odor problems were reported as a result of the treatment. The Kenosha utility plans to treat their other intake pipe in a similar manner this spring. The contractor for the Racine utility experienced some difficulty in capping their intakes, but reported no other problems.

ID: 19920219-5.

The Zebra Mussel Update was a 4- to 8-page quarterly national newsletter published by the University of Wisconsin Sea Grant Institute from May 1990 through May 1997. The ZMU documented the spread of the zebra mussel -- an exotic nuisance mussel -- through North America's freshwater environments, especially the Great Lakes, and on efforts to control it.