Great Lakes Article:

Radioactivity, salt taint goundwater as inland areas dig ever deeper
Don Behm
Milwaukee Journal Sentinel
12/10/2002

An ongoing study of water use in southeastern Wisconsin shows that the level of a deep sandstone aquifer is dropping at such a fast pace that communities away from Lake Michigan will need to reduce their dependence on this resource for drinking water.

As wells in Waukesha, Brookfield, Germantown and other municipalities tap ever lower levels of saturated sandstone, they will encounter water containing more and more radioactivity, salt from dissolved minerals and other pollutants that must be removed.

The combination of dropping water levels and declining water quality indicates that there are limits on the use of the deep aquifer, said Robert Biebel, chief environmental engineer for the Southeastern Wisconsin Regional Planning Commission. The commission is sponsoring the aquifer performance study.

Eastern Waukesha County communities already are pumping so much out of the sandstone that historic groundwater flows have been reversed and water in and beneath Lake Michigan is now being drawn west to fill the void, said Ken Bradbury, a hydrogeologist with the Wisconsin Geological and Natural History Survey.

According to the study's preliminary findings:

Groundwater in sandstone beneath Washington and Ozaukee counties, too, is being pulled south toward Waukesha and its neighbors.

Consequently, water levels in the sandstone over a broad region are declining.

While northern Racine County sandstone is contributing water to Waukesha County wells, water in the sandstone below the southern half of Racine county and all of Kenosha county is being pulled to the south.

That water is flowing toward the well pumps supplying suburban Chicago communities away from Lake Michigan.

The amount of southeastern Wisconsin groundwater flowing toward those Illinois suburbs has doubled since 1900. Those neighbors might account for as much as 20% of the drawdown in Kenosha and southern Racine counties, Bradbury said.

Since the early 1900s, water levels in the sandstone beneath Waukesha County have dropped between 400 and 500 feet. The decline might have even been greater in the region but for Milwaukee's switch to Lake Michigan water, completed in the 1960s with construction of the Howard Ave. treatment plant.

Even so, water levels in the deep sandstone will continue to drop - as much as 100 feet by 2020 - even with moderate growth in the inland communities, according to preliminary findings of the study.

"That pace is not sustainable forever because the aquifer is not infinitely thick," Bradbury said.

Even so, long before the aquifer could be drained dry, communities will face increasingly higher costs for pumping water up from great depths and "dramatically declining water quality" with increasing levels of radioactivity or salinity, he said.

The City of Waukesha recently sidestepped a salt problem in one of its deep wells, said Jeff Detro, the city's water supply manager. Well No. 9 had been drilled to a depth of 2,266 feet years ago, but as levels dropped in the sandstone aquifer, the well was drawing water with more salt.

To avoid the salinity, the utility earlier this year completed pouring concrete into the bottom of the well, raising it to a depth of 1,725 feet. Its water no longer contains high amounts of chloride and dissolved minerals, Detro said.

Waukesha has not found such an easy fix for another set of problems - levels of radium and radioactivity exceeding federal drinking water standards.

The city has filed a lawsuit against the U.S. Environmental Protection Agency claiming that its standards are too strict. If the city loses that battle, it might need to invest as much as $67 million to remove radium and the sources of other radioactivity.

Simply switching aquifers and drilling more wells into shallower, saturated dolomite rock is not a solution available to all inland communities, according to Biebel. The regional planning commission, state geological survey and U.S. Geological Survey are working together on the regional water use study.

"If more wells were placed in the shallow aquifer, that could reduce the amount of groundwater flowing into surface streams, lakes and wetlands," Biebel said.

Aquifer storage technology - pouring treated water into wells during periods of low use, such as winter, and withdrawing it for summer's peak demand - could provide partial relief for some communities.

But a complete solution to the region's looming water woes likely will require cooperative planning among communities, he said. The study's preliminary findings convinced the regional planning commission to seek support for a first-ever water supply plan for southeastern Wisconsin.

One option - tapping into Lake Michigan - is not available for communities west of the subcontinental divide separating the Great Lakes and Mississippi River watersheds. A binational charter signed by the United States and Canada, as well as state and federal laws, restrict diverting Great Lakes water out of its drainage basin.

Restrictions on use of Great Lakes water will become even more strict, Biebel said.

Even so, there may be opportunities to expand the use of Lake Michigan water.

One example is New Berlin, which is negotiating to buy lake water from the Milwaukee Water Works. The eastern third of New Berlin lies within the Great Lakes watershed, and the community's wastewater already drains to the lake through the Milwaukee Metropolitan Sewerage District's system.

The eastern half of Brookfield and all of Germantown are in the same situation, he said.

"If some of these communities obtain water from Lake Michigan, that would reduce their use of the sandstone aquifer and conserve the groundwater supply for the future," Biebel said.

Milwaukee's two treatment plants have adequate capacity for more customers, according to a regional water supply proposal.

The Milwaukee Common Council decides if the Milwaukee Water Works sells water to other customers, Superintendent Carrie Lewis said.

Mariano Schifalacqua, Milwaukee's Public Works commissioner and a member of the advisory committee that proposed the regional water supply planning effort, agreed that there is an opportunity for more communities east of the divide to buy water from Milwaukee.

"We would discuss selling our water to others, but under no circumstances would we agree to pump water over the subcontinental divide," he said.