On April 18, high school students in Yakima, Wash., helped collect runoff samples from a low-impact development demonstration project. The project — funded in part by a grant from the Washington State Department of Ecology — compares pervious asphalt, pervious concrete, and permeable pavers. All three demonstrations have a layer of crushed stone or sand beneath them, along with a plastic liner and underdrain system connecting to collection vaults that redirect stormwater to infiltration trenches. Officials are looking at pollutant removal, along with pavement durability. They have found that permeable pavement may help remove metals. Read more.