In Dr. Antosh's opinion, some of the regulatory impetus is misplaced, because science does not have all the answers yet. For example, the increased of dissolved Phosphorous (rather than particulate phosphorous) entering Lake Erie and causing harmful algal blooms, is a mystery. Farmers or cities? Which techniques could best eliminate excess nutrients? Some have even pointed to no-till as a possible source, because nutrients are applied to the surface rather than mixed in.
Although Dr. Antosch emphesized the uncertain nature of water quality science, I believe there is enough information to act today. Several simple examples come to mind: (1) Regulations against applying manure and fertilizer in the winter, when plants are not growing and hence don't absorb any of the nutrients; (2) Existing steps to eliminate phosphorous fertilization of residential lawns; (3) Creating new wetlands to filter the runoff that does occur.