US Coast Guard issues type approval for Alfa Laval PureBallast 3

Significantly, the new approval allows ships equipped with PureBallast 3 systems to take ballast water on board and discharge it only 2.5 hours later, a period known as holding time.
Until now, ultraviolet-based treatment systems have required lengthy holding times because the USCG uses different testing methods to those of the IMO. However, the introduction of the Vessel Incidental Discharge Act now enables the USCG to look again at the IMO methodology, Alfa Laval said in a statement. “If the USCG decides to accept the same testing principle used by IMO, suppliers of UV treatment systems will likely be able to reapply for USCG type approval based on the IMO testing methodology”, it stated.
The company also suggested that this latest development would give systems based on UV technology a distinct advantage over electrochlorination (EC) systems because installations based on EC technology require the use of ‘active substances’ which have to be neutralised before discharge. Reduced holding times can only be achieved by using larger amounts of neutralisation chemicals. UV treatment, however, is free of chemicals.