If the character of the sewage of any manufacturing or industrial plant or any other building or premises shall be such as to impose an unreasonable burden upon the sewers of the Downriver Sewage Disposal System, the City shall require that such sewage be treated by the person responsible therefor before being emptied into the sewer, or the right to empty such sewage may be denied, if necessary, to protect the System or any part thereof.
(1974 Code Sec. 2.115)