Raw sewage. Have you ever had it come out of your toilets, shower stalls or sinks? Though rare, some residents have experienced such unfortunate events. While the City has an aggressive maintenance program that includes cleaning and inspecting sewer mains, it is still possible that a City sewer main can plug up and lead to sewage flooding. However, by installing sewer release valves (SRV and BWV) on at-risk properties, owners can minimize their exposure to such an incident. Find out more information in this guide.