Register for a free trial
Offshore Support Journal

Ballast Water Treatment Technology

Getting the best from onboard tests

Thu 16 Mar 2017 by Paul Fanning

Getting the best from onboard tests
WSS’s test kit includes the Nalfleet Ballast-Check 2 unit for detecting chlorophyll fluorescence from live algal cells

Onboard ballast water testing would seem to be the only way to remain compliant

The revision of the G8 Guidelines by IMO’s MEPC 70 with regard to self-monitoring requires that ballast water management systems (BWMSs) are to be provided with a system that monitors, records and stores sufficient data/parameters to verify correct operation for the previous 24 months. It also requires that alerts are in place to indicate when the system is shutdown or when an operational parameter exceeds the approved specification.

As with most regulation in this area, of course, this is open to a certain amount of interpretation. It does not mandate a particular type of system or dictate any technology, for instance, being vague in its stipulations. Indeed, it does not explicitly require that testing takes place at all. However, it seems reasonable to conclude from this form of words that it is making it clear that it is a shipowner’s responsibility to know whether its BWMS is compliant or not and to be able to prove it.

Realistically, the only way this can be achieved is by onboard sampling and testing, whether by use of portable or integral testing units. This has obviously put the ball firmly into the court of manufacturers to develop and market systems that mean crew can make accurate D-2 measurements on board that can give realistic confidence to both vessel operator and Port State Control.

In terms of practical experience when it comes to onboard ballast water compliance testing, German inspection company SGS has been involved in a project since 2012 that has looked at onboard testing using a variety of systems, including conducting a voyage when a number of systems were tested.

According to Gerd Schneider, SGS’s global manager of shipping services, one of the problems with this project was the vagueness of the regulation’s wording. Speaking at the Sixth IMarEST Ballast Water Technology Conference in January, he said “guidelines on sampling and analysis are quite vague and open to interpretation. Phrases like ‘sufficient sample quantity’, ‘safe and practical’, ‘manageable size’ are examples of this.”

Despite this, however, the programme has successfully carried out tests on about 450 ships, around 85 per cent of which were found to be compliant. The programme also performed 13 D-2 tests, which showed 12 to be in compliance, from which Mr Schneider concluded that “these treatment systems do seem to work.”

Where non-compliance was found to occur, it was in large part a consequence of factors distinct from the ballast water systems themselves. “The cases where we found non-compliance almost always had nothing to do with the systems themselves, but with their handling,” said Mr Schneider. “Inexperienced teams; vague sample port requirements that lead to challenging situations; valve conditions; short holding times and issues with required analysis methods were the main factors.”

In terms of portable testing systems, there is a veritable plethora available. These range from relatively simple test kits to some rather more technologically sophisticated systems.

One such is Ballast-Check 2, offered by Wilhelmsen Ship Service (WSS), which is based around a device of that name made by Turner Designs of the US for WSS group member Nalfleet. The hand-held unit is a multiple turnover Pulse Amplitude Modulated (PAM) fluorometer that provides a rapid, indicative analysis of the abundance and activity of algae in ballast water samples. The instrument is configured to provide ship operators with a rapid, indicative determination of whether treated ballast water is at risk of non-compliance with the IMO and USCG’s D-2 quality standard. Ballast-Check 2 measures algae in the 10-50um range.

Ballast-Check 2 is configured for detecting chlorophyll fluorescence from live algal cells. Light from the fluorometer is absorbed by algae, which causes the cells to fluoresce. Fluorescence emitted by the cells is detected, quantified, and displayed as a digital number estimating the abundance of algae in the sample as cells/ml. The Ballast-Check 2 has a set threshold value of 10 cells/ml and when the measured abundance of algae reaches or exceeds this, it a high risk that algae may exceeding the discharge standard.

Another system is Speedy Breedy SeaSure, a development from the original Speedy Breedy test kit. It gathers test results on microbial, phytoplankton and chemical contamination and records this in a secure ballast log that can provide a secure audit trail.

This log can be transmitted to organisations such as BWMS manufacturers, shipowners and port state control authorities. The system will assist in meeting the requirement for ships to implement a ballast water management plan, to carry a Ballast Water Record Book and to carry out ballast water management procedures to a given standard.

The first sales of these devices have been to the port state control team in China’s Shandong Province and, according to the company’s product manager Jean-Pierre Joubert, it is currently in talks with a number of other such teams.

In developing this system, Bactest partnered with Chelsea Technologies to add a test for phytoplankton. Chelsea has been designing and manufacturing sensors and systems for aquatic environments for over 50 years and offers portable and integral systems of its own.

Its FastBallast Portable Ballast Water Compliance Monitor is capable of determining the phytoplankton cell density of ballast water at the IMO D-2 and USCG discharge standards. FastBallast is available in three versions: a Discrete Sample Compliance Monitor, a Dual Function Compliance Monitor and as an Integrated Compliance Monitor.

FastBallast’s design enables a rapid and detailed analysis and is, according to the company, the only technology that can operate in flow-through mode, providing a continuous, real time update on discharge compliance.

According to Stephanie Lavelle, Chelsea Technology’s maritime manager, FastBallast’s key advantage is that, rather than using ‘multiple turnover’ technology as other testing systems do, it uses Fast Repetition Fluorometry (FRR) to achieve much more accurate results.

She told a Ballast Water Forum organised by the UK Chamber of Shipping in November that indicative tests “cannot distinguish cell size and they assume that all cells emit the same amount of fluorescence, which they don’t.” So indicative tests can only give a ‘Confident Pass’ or a ‘Confident Fail’ at extreme levels, she said, whereas FastBallast technology “can essentially give you a lab test in just eight minutes at the point of discharge.”

Recent whitepapers

Related articles





Knowledge bank

View all