Like clean water? Then you'll love Rep. Bart Stupak. Swimming in sewage just isn't this fun. For the last year, Stupak has been fighting a U.S. EPA proposal that would allow inadequately treated sewage to be "blended" with fully treated waste during rain and snow events. The messy mix would then be released into the nation's rivers, lakes, and coastal waters. If blending is permitted, Stupak warns, people will get sick, beaches will close, and tourism and fishing will suffer. Not only that, taxpayers will bear the cost of cleanup down the road. "It doesn't make sense," the Michigan Democrat …