Any person discharging industrial wastes into a sewer shall construct and maintain a suitable control manhole or manhole downstream from any such places or discharge to permit observation, measurement and sampling of such wastes by the commissioner or by personnel of the sanitary district as hereinafter provided. Where no manhole has been constructed or can be constructed, as in the case of some existing industries, the control manhole shall be considered to be the nearest downstream manhole in the public sewer to the point at which the building sewer is connected.
(Prior code § 17-3.5)