Before revision: Sanitary sewer backflow Backwater sanitary valves (also known as "check valves" or "backwater valves") are also often referred to as "backflow URL are intended to prevent backflow of sewage on the sanitary sewer line during a flood or sewer blockage, and have no connection with potable water.
After revision: TheySanitary sewer backflow Backwater sanitary valves (also known as "check valves" or "backwater valves") are also often referred to as "backflow URL are intended to prevent backflow of sewage on the sanitary sewer line during a flood or sewer blockage, and have no connection with potable water.