Like magic! Just kidding, though we wish. It'll basically be comprised of three layers, each one taking out smaller and smaller contaminants. This will alleviate the burden on any one material and extend the life of each. The first two layers, which do most of the heavy lifting, will be a combination of textiles, membranes and particulates. The third layer is planned for non-chemical disinfection, since we want to return the water to the river in better shape than we found it. Plus, swimming in chlorine is no fun.