Most Bay Area cities are trying to staunch the flow of trash into the bay through storm drains, but some cities are leading the pack. Richmond has already reduced 80 percent of its trash entering storm drains, thanks to a mix of trash bans, trash-filters and community projects. “The City of Richmond has made a lot of progress,” said Allison Chan, associate director of policy at the nonprofit Save the Bay, an advocate of reducing trash pollution. “Of the cities…