Friends of Lake Warner and the Mill River works on just as important an issue that rarely makes the news. Nonpoint source pollution is different. Last week, elevated E. coli bacteria forced Puffer’s Pond, fed by Cushman Brook within the Mill River watershed, to close to swimming again. As climate change drives heavier and more frequent rainfall, nonpoint source pollution does not stay flat. Brian Pearson is an Amherst resident and board chair of the Friends of Lake Warner and the Mill River.