In fact, the Port Authority took the decision to not allow ships’ discharge of washwater from their exhaust gas cleaning systems (EGCS) following the instructions received from the General Authority of Meteorology and Environmental protection.
In light of the situation, vessels operating an open-loop scrubber will have to switch to compliant fuels when entering the area. For the records, the use of open or closed loop scrubbers, is allowed under IMO Marpol Annex VI regulation on the prevention of pollution from vessels, if the ships wish to continue burning high sulphur fuel oil.
Overaal, among others, Oman recently banned the use of open-loop scrubbers in its territorial waters.
Source: https://safety4sea.com