Ballast Water Standard D-2

Ballast Water Performance Standard D-2 under the BWM Convention — performance limits on viable organisms in discharged ballast water. The standard caps viable organisms ≥ 50 µm at less than 10 per cubic metre and viable organisms 10–50 µm at less than 10 per millilitre, plus indicator microbe limits. Compliance is met by an approved ballast water management system (BWMS) using filtration and either UV irradiation or electrochlorination. Type approval is under the IMO BWMS Code and the US Coast Guard regime; in-service compliance is verified by sampling.