R309-545-10. Internal Features

  The following shall apply to internal features of drinking water storage tanks:

  (1) Drains.

  (a) A means shall be provided for the draining of drinking water storage tanks.

  (b) Where possible, the drain shall be separate from the outlet pipeline. If a tank drain line is provided, it shall be sloped for complete drainage.

  (c) The drain shall not discharge to a sanitary sewer.

  (d) If local authority allows discharge to a storm drain, the drain discharge shall have a physical clearance of at least 12 inches between the discharge end of the pipe and the overflow rim of the receiving basin.

  (2) Internal Catwalks.

  Internal catwalks, if provided and located over the drinking water, shall have a solid floor with raised edges. The edges and floor shall be designed so that shoe scrapings or dirt will not fall into the drinking water.

  (3) Inlet and Outlet.

  (a) To minimize potential sediment in the flow from the tank, the outlet pipes from all tanks shall be located in a manner to provide a silt trap prior to discharge into the distribution system.

  (b) Inlet and outlet pipes shall be configured to provide mixing and circulation.

  (4) Tank Floor.

  The floor of the storage tank shall be sloped to permit complete drainage of the structure.