The International Maritime Organization (IMO) adopted the Ballast Water Management (BWM) Convention to prevent the transfer of invasive aquatic species via ship ballast water. The D‑2 standard, which entered into force in 2017, requires that all discharged ballast water meet strict microbiological limits after treatment.
To achieve compliance, a ship must install an approved Ballast Water Management System (BWMS) and demonstrate that the residual concentration of viable organisms does not exceed 10 colony‑forming units per 100 mL (CFU/100 mL) in the final effluent. Regular inspections and performance monitoring are mandatory to verify ongoing compliance.
Operators use a simple compliance check: if the measured residual concentration (C_{res}) is less than or equal to the threshold (10 CFU/100 mL) and the installed BWMS is listed on the IMO‑approved inventory, the vessel is considered D‑2 compliant.
What is the purpose of the Ballast Water Management Convention?
When did the D-2 standard enter into force?
What must ships do to comply with the convention?
How is compliance with the D-2 standard verified?
What are the consequences of non-compliance with the Ballast Water Management Convention?
Can ships discharge ballast water without treatment?
What types of organisms are targeted by the Ballast Water Management Convention?
Results are for informational purposes only and do not constitute professional advice.