TORONTO - Ontario has "a number of concerns" with a Wisconsin city's request to draw water from the Great Lakes in what would be a precedent-setting move if the plan was approved.

Waukesha, a city of about 70,000, has asked the Great Lake states for permission to divert water from Lake Michigan because its own aquifer is running low and the water is contaminated with high levels of naturally occurring cancer-causing radium.

Under a current regional agreement between eight U.S. states and Ontario and Quebec, diversions of water away from the Great Lakes-St. Lawrence River basin are banned, with limited exceptions that can be made only when certain conditions are met.

Waukesha -- in seeking to become the first such exception to the ban -- argues that although it's located outside the boundary of the Great Lakes basin, it is part of a county straddling that geographical line and should be allowed access to the lakes' water.

It also promises to return treated water to Lake Michigan.

But Ontario has taken issue with the plan in a technical review of the diversion application put forward by Waukesha and the Wisconsin department of natural resources.