Ballast Water treatment - points to remember

DIFFERENCE BETWEEN D-1 AND D-2 STANDARDS The difference is that D-1 relates to ballast water exchange, while D-2 specifies the maximum amount of viable organisms allowed to be discharged, including specified indicator microbes harmful to human health. D-1 standard  - The D-1 standard requires ships to conduct an exchange of ballast water such that at least 95% of water by volume is exchanged far away from the coast.  D-2 standard  - The D-2 standard specifies that ships can only discharge ballast water that meets the following criteria: less than 10 viable organisms per cubic metre which are greater than or equal to 50 micrometres in minimum dimension; less than 10 viable organisms per millilitre which are between 10 micrometres and 50 micrometres in minimum dimension; less than 1 colony-forming unit (cfu) per 100 mililitres of Toxicogenic Vibrio cholerae; less than 250 cfu per 100 millilitres of Escherichia coli; and less than 100 cfu per 100...

BALLAST WATER MANAGEMENT STANDARDS - BY IMO There are two ballast water management standards (D-1 and D-2). The D-1 standard requires ships to exchange their ballast water in open seas, away from coastal areas. Ideally, this means at least 200 nautical miles from land and in water at least 200 metres deep. By doing this, fewer organisms will survive and so ships will be less likely to introduce potentially harmful species when they release the ballast water. The D-2 standard specifies the maximum amount of viable organisms allowed to be discharged, including specified indicator microbes harmful to human health. From the date of entry into force of the BWM Convention, all ships must conform to at least the D-1 standard; and all new ships, to the D-2 standard. Eventually, all ships will have to conform to the D-2 standard. For most ships, this involves installing special equipment to treat the ballast water. IMO Member Governments, meeting in the Marine Environment ...