A: A thick layer of shale rock restricts recharge of Waukesha’s primary water source, the deep aquifer.
This shale layer covers much of southeastern Wisconsin (including Milwaukee, Racine, and Kenosha Counties, and most of Waukesha County) as well as northeastern Illinois. The limited natural recharge of rain and snowmelt to the deep aquifer has contributed to depletion (or drawdown) of the aquifer. The depletion is also the result of decades of pumping by multiple municipal water systems and industries all across southeastern Wisconsin.
Waukesha’s leaders recognized this lack of sustainability and have examined water supply alternatives for decades. They have determined that Lake Michigan is the only reasonable water supply alternative.
The Great Lakes states that approved Waukesha’s proposal unanimously agreed, saying, “The groundwater depletion, along with the radium contamination issue, demonstrates that the deep aquifer is not a sustainable or safe source of water for the people served by the Applicant.”