weather center
Milwaukee, WI



Immediate Release
April 13, 2015
Contact: Bill Graffin, MMSD Public Information Manager, (414) 225-2077

Storm Update – April 8 & 9, 2015

(Milwaukee, WI) – The Milwaukee Metropolitan Sewerage District (MMSD) is reporting the following information to the Wisconsin Department of Natural Resources regarding sewer overflows that resulted from heavy rain April 8 and 9, 2015.

Mitchell International Airport measured record rainfall on April 9 with 3.18 inches.  Combined totals for April 8 and 9 showed 4.5 inches of rain in Mequon and 4.02 inches in the 8400 block of N. Granville Road in Milwaukee.  One inch of rain on MMSD’s service area equals 7.1 billion gallons of water.

To reduce the risk of basement backups, MMSD took emergency measures and initiated  a combined sewer overflow at about 11:00 a.m. on April 9.  The total combined sewer overflow volume  is estimated at 681.1 million gallons.  A separate sewer overflow occurred at Green Tree Road and the Milwaukee River with an estimated volume of 1.67 million gallons.  A second separate sewer overflow occurred at the 400 block of Brown Deer Road with an estimated volume of 360,000 gallons.

MMSD also took emergency steps to increase treatment capacity and reduce sewer overflows by conducting combined sewage treatment at the Jones Island Water Reclamation Facility starting at 10:30 a.m. on April 9.  The procedure is estimated to have reduced combined sewer overflows by 76.9 million gallons.  Combined sewage treatment involves pumping water directly out of the Deep Tunnel into disinfection chambers at Jones Island.  During combined sewage treatment events, the District has always met state and federal standards for fully treated effluent to Lake Michigan. 
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