SECTION 23-19.3.1-3

   § 23-19.3.1-3  Mandatory installation ofcheck valves. – All new residential construction that will connect to a sanitary sewer systemand any residential construction where the existing sewer connection will besubstantially altered shall have a check valve installed, that is automaticallyactivated, on the main building sewer line for purposes of protecting residentsfrom the possible backflow of, and exposure to, untreated sewage.