City of San Francisco is one of the exceptional ones since it secured the best water from Hetch-Hetchy many generations ago, and the worst that is likely to ever happen is bad pipes, and possibly contaminants in the specific areas that saw military use(i.e. Hunter's Point, Treasure Island, Presidio). Other towns in the Bay Area have something bigger to worry about, OTOH, even tech workers at the major SV campuses. The South Bay is dotted with industrial Superfund sites and there are a lot of unknowns about when and where they'll leak out.