Pond scum, or blue-green algae, is a common sight in the Land of 10,000 Lakes. For Blue Water Ponds, a start-up company operated by two recent college graduates, pond scum is a business opportunity. The company, which won the student division of the 2010 Minnesota Cup challenge, aims to prevent summer algae blooms with a sustainable solution: barley. The company offers its services placing bales of pelletized barley into ponds in the spring and then harvests weeds in the summer to allow beneficial plants to continue growing. The treatment for the average pond hovers around $400 annually, said Ben Schurhamer, president of Blue Water Ponds.

Photo by IwateBuddy.