With ballast water regulations maturing and shipping shifting its focus to operational compliance, the critical role of strong and robust filters within ballast water treatment systems (BWTS) is more prominent. Filtersafe head of marine Mark Riggio explains why
After several challenging years focused on securing regulatory compliance under the Ballast Water Management Convention (BWMC) and US Coast Guard’s Final Rule for ballast water treatment, shipping’s priority has shifted to operational compliance, which ensures ballast water management systems (BWMS) are compliant for the lifecycle of the vessel.
The difficulties associated with operational compliance should not be underestimated. According to SGS, around 21% of BWMS are not able to successfully complete required discharge tests during commissioning. One primary key to lowering the chances of a BWMS failure is through filter selection.
There are only a handful of filters on the market, in comparison to dozens of BWMS. Therefore, focusing on the filter is one way for owners to distinguish between a high-performing BWMS and a lower quality one.
When selecting a filter, BWTS manufacturers and shipowners should assess two key considerations. Firstly, the most important foundation for an efficient BWTS is the filter’s ability to remove large organisms and organic particles. This reduces stress on the disinfection stages of both chlorine and UV systems, reducing power and chemical usage.
Secondly, manufacturers should consider the filter’s operational performance in heavy sediment loads. It is imperative that the filter does not clog, as this would limit or even prohibit water flow through the BWTS, ultimately impacting the overall effectiveness of the entire system – and leave manufacturers open to criticism from shipowners and operators. Blocked filters can also cause operational delays during ballasting, triggering additional delays and inconvenience.
Under IMO G8 requirements, filters must prove their ability to perform effectively in water with total suspended solids (TSS) up to 50 mg/litre. However, the threshold to pass this test is relatively low and not reflective of water quality standards in some key maritime locations. For example, TSS in the Ports of Shanghai and Hamburg are twenty times higher than IMO G8 requirements for BWTS type-approval testing. This means high-quality filters that exceed IMO performance standards are critical.
Fortunately, filter performance in more challenging marine environments can be tested through the Control Union Shanghai filter test (Procedure CUW-HBR-P-2), which uses proxy mud up to and beyond 1,000 mg/L to test filter performance. Filtersafe is one of only a few filter manufacturers to achieve this standard. Furthermore, we conducted a similar inhouse ‘Filtersafe Assessment of Challenges Test’ (FACT) that measures filter functionality against real-life scenarios.
With ballast standards tightening and requirements to protect the marine environment coming ever more to the fore, BWTS manufacturers, shipowners and operators need to be confident that systems are capable of performing effectively throughout the lifecycle of the vessel across all marine environments, including those areas where water depths are shallow and quality challenges are acute. To avoid problems with a BWTS, the industry must use filter models that are strong and robust, prioritising higher performance rather than the lowest price tag.
This, coupled with a collaborative approach between all parties, can have a significant contribution to the overall success of a BWMS installation, rooting out core problems, and ensuring systems meet the needs and expectations of end users.