While the roll-out of the IMO 0.50% sulphur cap was a relatively smooth affair, regulations for ballast water management have been far more troublesome
The sulphur cap mandate was generic and there were specific pathways to achieve it, with well-defined trade-offs in potential cost savings to the ship owner; differences in national mandates had relatively less bearing on the alternative fuel choices.
For ballast water management systems (BWMS), the technological pathways are far more diverse, with a lack of clarity on performance under various operating conditions. Furthermore, the five-year phase-in period to gain experience has been complicated by Covid-19 and calls by shipowners for deadline extensions.
Steve Candito, chief executive for ballast water treatment system manufacturer Ecochlor, says there are more than 60 systems that have IMO type approval. Currently, 38 have USCG type approval, among them about 15 use ultra-violet (UV), 15 are electro-chlorination, and eight are other treatment technologies including de-oxygenation and chemical injection systems.
To treat ballast water, the Ecochlor system has a two-step process, first using filtration, followed by treatment with chlorine dioxide (ClO2). It is effective in all water types and conditions without having to adjust operating parameters for salinity, turbidity or temperature, says Mr Candito. No treatment or neutralisation is required prior to discharge, he adds.
Among the grey areas in the global regulatory framework is that the US is not a party to the IMO mandates. This has resulted in several areas where there is a lack of harmony between the requirements in the US and IMO mandates. The US Vessel Incidental Discharge Act (VIDA) helped to bring in some harmony, in that it facilitated UV systems by allowing organisms that cannot reproduce to still meet the requirements.
“Restrictions on ballast water exchange within the US contribute to a lack of harmony”
“Restrictions on ballast water exchange within the US, such as in the Great Lakes and the west coast, are another contributor to a lack of harmony,” says Mr Candito.
The IMO Ballast Water Management Code (BWM Code) came into effect in October 2020.The testing protocol laid down further requirements for type approval for makers, says Mr Candito. Prior to the BWMS Code, manufacturers could test their BWMS in only two different salinities, but received an approval for all three water types: fresh, salt and brackish water. Under the new requirements, manufacturers must test in all three salinities to receive approval for all three.
“A BWMS that has not been tested in all salinities will have their limitations included within the type approval certificate,” says Mr Candito.
The BWM code also requires specifications on high and low values for critical operating parameters and any limitations are detailed on the type approval certification. Mr Candito says Ecochlor systems, for example, are approved for 50 – 16,000 m3/hr.
Commission testing for the operation and efficacy of BWMS is on the horizon. Some countries have already mandated this testing at commissioning.“Commission testing would ensure crew familiarity with the operation of the systems as well as confirm the BWMS is working as expected in the treatment of ballast water,” explains Mr Candito. This testing was to be made mandatory by IMO in October 2021, but the deadline has now been extended to June 2022.