An NBC Bay Area investigation found 30 out of 39 sewage treatment plants located around San Francisco Bay Area are at risk of flooding as sea levels rise due to climate change. Four of those plants could flood with as little as 9.84 inches of sea level rise. That’s an amount that state analysts say is a possibility by 2030. If and when that happens, toilets won’t flush, and in some cases, sewage could back up into homes, whether residents live in the hills or along the coast.