The Calculation of the discharge rate of untreated sewage is carried out according to Resolution MEPC.157(55) adopted on 13 October 2006.
Regulation 11.1.1 of the revised Annex IV of MARPOL 73/78 requires that untreated sewage, which may be discharged at more than 12 nautical miles from the nearest land, should not be discharged instantaneously but at a moderate rate of discharge when the ship is en route and proceeding at a speed not less than 4 knots, while the rate should be approved by the Administration based upon standards developed by the IMO.
Calculation of the discharge rate of untreated sewage has the following content:
