Cross-border sewage continues to exacerbate the environmental crisis along the Tijuana River Valley and Imperial Beach, but San Diego County officials say the air is safe for now. In other news, Vice President Kamala Harris's presidential campaign unveiled an ad this week featuring some of former President Trump's senior officials who now say he’s unfit to be president. We hear from conservative pundit Bill Kristol on why he thinks the former president is a danger to democracy. Plus, as part of an ongoing KPBS series on San Diegans who volunteer in unusual ways, we hear from two women in Lemon Grove who want to transform the city into a bee pollinator city.