Waukesha is hoping its residents will soon be getting tap water from the Great Lakes, but some environmental groups worry it could be the start of a bigger problem.

Waukesha leaders think they are close. They released another study that shows their aquifer is declining and they only have one alternative - divert water from Lake Michigan. However, that will still be a challenge.

Lake Michigan is protected under the Great Lakes Compact which prohibits any municipality outside the Great Lakes basin from taking water. But Waukesha fits the exception since it sits in a county straddling the basin.

Waukesha hopes to be the first to test that compact by diverting Great Lakes water to the city.

City leaders feel what they're doing now is unsustainable, "we're able to return 100% of the water, we're able to do it in an environmentally responsible manner. All of our other alternatives have significant environmental impacts associated with them. When you analyze all the data, when you look at all the studies and reports that have been done. Great Lakes is the only alternative for us," said Dan Duchniak of Waukesha Water Utility.