New York is testing out a new water scrubber at one of its wastewater treatment plants in Queens. Meet the algal turf scrubber--two 350-foot slides covered in green algae. Water flows down the slides, algae grows naturally, and then helps clean water that is sent over it. John McLaughlin, Director of Ecological Services for the New York City Department of Environmental Protection (DEP), and Peter May, restoration ecologist for Biohabitats, explain how the scrubber works, and where the harvested algae goes.