Porterville Municipal Code Art. II Plumbing Code

Where any part of a building, which is being serviced or served by the sewer system, is lower than the sewer line which serves the building, the owner shall install a check valve or back sewer valve in order to prevent sewage from entering or flowing into such lower area or portion of the building being served by the sewer line.

The check valve shall have a cast iron body, with bearing parts of noncorrosive metal or material, and be so constructed and installed in order to ensure a positive mechanical seal and remain closed except when discharging sewage or waste. Valve access covers shall be of the bolted type, with gaskets, and every valve shall be installed in an approved manner so as to be readily accessible at all times and shall strictly conform to the specifications of the Plumbing Code. (Ord. 627 § 1)

The public health and safety requires that all nonconforming connections or uses now existing in buildings or structures be remodeled or improved and check valves or back water valves be installed in order to comply with the sanitary provisions and requirements of the City, and section 7-7 of this article shall apply to all existing or hereafter installed plumbing connections. (Ord. 627 § 2)