Since 1 January, 2007, auxiliary diesel engines and diesel-electric engines must use fuels with a sulphur content at or below 0.5%, and the threshold will be reduced to 0.1% on 1 January, 2010.

The regulations do not apply to a ships’s main propulsion systems – use of these fuels must commence within 24 miles of the California coast.CARB regulations impose significant new record-keeping requirements on ships with regard to the use of lowsulphur fuels and there are substantial penalties for non-compliance.

Cold ironing is not an option here because the vessels have to be compliant as soon as they are within the 24-mile limit.

Ships can, however, employ alternative methods of compliance – such as scrubbing technology, says a spokesman for Krystallon, the BP/Kittiwake joint venture  that has developed the Krystallon seawater scrubber.

The company believes seawater scrubbing technology could have an important part to play as ports come under increasing pressure to reduce air pollution. In November, the new sulphur emission control areas (SECAs) for the North Sea and English Channel will come into force.

“That will be a historical milestone,” says the Krystallon spokesman. “Ports have never faced anything like that before.And there is talk about where the next SECA will be – probably the Mediterranean.” Emissions from ships are the big issue right now and that encompasses what happens while vessels are in port, says Philip Roche, a shipping lawyer at Norton Rose.“It isn’t like vessels come into port and turn their engine off. So ports like Dover, for example, are quite hot spots for diesel pollution, especially with ferries coming in and sitting there burning fuel into the air while vehicles are loading.

“Consultation is going on at the moment over the English Channel and North Sea SECAs; when they are introduced you will only be able to burn low-sulphur fuel in these areas and that will apply to all the ports and facilities attached to those seas. All the ports will have to be able to provide bunker supplies of lowsulphur fuel.”

Mr Roche says cold ironing is going to become increasingly high-profile in many ports. “Obviously if you can turn the generator off, there is a huge improvement, especially in the big ports.

“I think there will be a large move towards providing these facilities – but it isn’t just a case of running a cable along the jetty.This involves a high level of investment because of the high voltage involved and the need for proper junction boxes, etc.”

Another big topic is waste reception, according to Mr Roche. “At the moment regulations require ports to have waste reception facilities. But there has been a recent case where a ship decided it was too difficult or expensive to discharge all the sludges in a European port, so did it off the Ivory Coast. “There is going to be pressure on providing these waste reception facilities at reasonable cost, so that ships are happy to use them and don’t wince when they have to pay for them.”

And then there is a ballast water issue, another hot topic, says Mr Roche. “There have been a few ship accidents recently where ships have been trying to transfer ballast water at sea and got into trouble. Now the feasibility is being examined of chlorinating it, heating it, or bombarding it with ultra violet light so that when it is piped out all the microbes, larvae and eggs of invasive species are wiped out and the water is sterile.

“That doesn’t impact on ports directly but of course ports have the problem that until that technology is in force, what are people doing with ballast water?”