All measurements, tests, and analysis of the characteristics of waters and wastes to which reference is made in this chapter shall be determined in accordance with "Standard Methods for the Examination of Water and Sewage" and shall be determined at the control manhole provided for in § 50.35 or upon suitable samples taken at the control manhole. In the event no special manhole has been required, the control manhole in the public sewer to the point at which the building sewer is connected shall be used.
('83 Code, § 2.5(i))