Wastewater treatment plants in the United States discharge 365 billion gallons of water a day, and according to a group of young science wizards from Normandale Community College in Bloomington, nobody ever thought of doing something useful with it.
Until they came along, that is.
The Normandale students just returned from the national Community College Innovation Challenge, where they tied for second place among 10 teams previously selected as national finalists.
The contest, sponsored by the National Science Foundation, encourages innovation among students in science, technology, engineering and mathematics — often called the STEM disciplines.
Normandale's entry was simple in theory: Install hydrokinetic turbines to generate renewable energy from the discharge at treatment plants.
Yet as they researched the topic, the students didn't discover a single example of the technology's use in more than 16,500 U.S. treatment plants.
The students — Tim DeCesare, Sophia Flumerfelt and Naomi Nagel — estimated that their idea could save about $400 million a year nationwide and pay for itself after two years of operation. A city the size of Moorhead, Minn., could install a turbine for about $300,000, the students calculated.
"They've worked wonderfully as a team from the beginning," said Angela Foudray, the team's faculty adviser. "It's just been a joy to watch them grow as researchers and learners."
