China Changes Regulations on Waste Water Discharges as Sulphur Cap Approaches

CHINA – WORLDWIDE – With the sulphur cap deadline, which will see the percentage of the element allowable in marine fuel cut from the current 3.5% limit reduced to a maximum of 0.5% on 1 January 2020 fast approaching, a rumour that China has banned the use of open-loop scrubbers has been doing the rounds.

Open loop scrubbing systems utilise the natural alkalinity in seawater for neutralising the SOx in exhaust gases, producing sulphuric acid. The resultant waste water must then be treated to conform to MEPC 184(59) criteria before it can be discharged into the surrounding sea.

It seems that translation errors have led to the current confusion with regard to revised Chinese regulations. The domestic emission control area (DECA) regulations were revised with effect from last week but currently, according to sources, the banning of waste water discharges remains within the inland ECAs, port waters under coastal DECAs and waters in Bohai Bay. It is however likely that these areas may well be soon extended.

Should that be the case it will mean a complete ban within most of China’s territorial waters as these are comprehensively covered by emission controlled areas. Chinese authorities accepted the use of vessels equipped with suitable scrubbing technology if they are operating on fuel high in sulphur provided all the regulations were complied with.

Shipping owners association BIMCO has encouraged its members to pay attention to the following points from the new DECA regulations:

• Ships that need to switch to low sulphur fuel must make a fuel switch plan and keep it on board. The switch timing, ships position, fuel sulphur content - before and after switching – as well as fuel tank data and consumption details must be properly recorded on the ship’s Engine Log. BIMCO reads this as in line with IMO requirements for entering and leaving ECAs in accordance with MARPOL Annex VI.
• The discharge and disposal of water pollutants generated by ships using exhaust gas cleaning systems (scrubbers) must meet the requirements of relevant regulations. It is prohibited to discharge wastewater generated by open-loop scrubbers within the inland emission control areas, port water areas of coastal emission control areas and Bohai Bay water areas.
• A yet to be decided ban on wastewater generated by open-loop scrubbers within the whole of China’s domestic emission control area will be announced in due course.
• It is prohibited to discharge exhaust gas wash water residues into any current DECA water or burn them on board.

Open loop scrubbers are the most popular of the three available types, the others being closed loop which utilises water treated with additives before recycling the liquid internally, and hybrid scrubbers, which as the name suggests operates by combining both technologies. Critics of open loop systems say they simply exchange poisoning the air for polluting the sea.

The Port of Singapore in November unilaterally banned the discharge of processed water from open loop scrubbers whilst the Port of Helsinki has dealt with waste of all types by offering a service to allow discharge into shore based facilities. This has meant that around 90% of cruise ships which call there discharge sewage, ballast water and treated scrubber water in this way with the possibility to dispose directly into the city’s sewage system for subsequent treatment.

Photo: All discharges from ships need to conform to international standards whether from scrubbers, ballast tanks or any other source.