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.

Ontario's objections

The Province of 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.

"The Government of Ontario has identified a number of concerns relating to Wisconsin DNR's explanation of how Waukesha satisfies the 'straddling county' exception," wrote Jason Travers, director of the natural resources conservation policy branch at Ontario's ministry of natural resources.

The province also found that the potential impacts of the proposed diversion on Great Lakes water quantity had not been sufficiently assessed.

"Based on Ontario's analysis of the proposal, additional information regarding wastewater return flow and water quality discharge standards is required to evaluate aspects of the proposal," Travers said.

Opponents in the basin

Waukesha's proposal has raised worries among American and Canadian communities around the Great Lakes, with a number of opponents warning that the diversion could set a dangerous precedent for other communities facing water shortages.

Ontario's review tackled that issue and found that while Waukesha itself doesn't have adequate supplies of potable water, it's not clear if surrounding communities, which would be included in the diversion effort, are also without adequate supplies of water.

"The Government of Ontario is concerned with the potential precedent that would be set if the proposal were to be approved without adequate demonstration that all communities in the defined service area have met each criterion of the standard," Travers wrote.

Ontario's review also acknowledged that Waukesha's proposal was likely just the beginning of similar future requests.

"The issue of increasing radium concentrations in public groundwater water supplies is occurring up and down eastern Wisconsin and is therefore not restricted to just Waukesha," it said. "The Waukesha water diversion proposal is only one part of a bigger water demand scenario that the province of Ontario should be prepared to address in the future."

Ontario has weighed in on Waukesha's proposal because it, along with Quebec, is part of the regional agreement known as the Great Lakes-St. Lawrence Basin Sustainable Water Resources Agreement, which was signed to protect waters in the basin.

While its review will be considered by its fellow Great Lakes states at a meeting in mid April, Ontario and Quebec will not, however, be part of a final vote by eight state governors on Waukesha's proposal that will determine the issue.

The Great Lakes support 33 million people, including nine million Canadians and eight of Canada's 20 largest cities, according to the federal government.