"So, we get the benefit of basically utilizing energy from the sewer that would have just been wasted or not used at all," Fangman said. "And then keep not only greenhouse gases but also water conservation for the system."

While this technology is quite new to the U.S., Fangman says it's been used in Western Europe for more than a decade and in Canada for at least five years. The facility in Denver will serve as a model for systems that can be created in metro areas all over the country.