On July 12th 2016 the US Coast Guard rejected the use of the MPN test method in type approval testing of ballast water treatment systems. However, discussions are currently ongoing with US Authorities to find a way for the USCG to accept the MPN method, and DESMI expects a conclusion on these discussions before the end of 2016.
If the discussions end with an acceptance of the MPN method, DESMI expects to receive USCG type approval for the RayClean ballast water treatment system in Q1 2017. If the discussions do not lead to acceptance of the MPN method DESMI will re-test a modified system during 2017, with an aim to receive USCG type approval in Q1 2018.
”As communicated earlier this year we have during this summer tested our RayClean BWTS with the FDA/CMFDA stain method at DHI’s landbased test facility in Denmark. Based on these tests we have concluded that the RayClean system can pass this testing, however only by testing the system exclusively in high UV-Transmittance (UV-T) water. High UV-T water is basically clear and transparent water, which is often not the kind of water found in ports around the world. See Table to the right with UV-T examples from which it can be seen that UV-T values below 0,65 are not unusual.” DESMI stated.
In IMO type approval testing of the RayClean system the so-called MPN method was used to enumerate the viable organisms, and with this method we proved that the RayClean system can handle exceptionally low UV-T values as low as just 33%, which is still today unmatched in the BWTS Industry. The reason why the FDA/CMFDA stain method shows very different results is because this method is unsuited to test the performance of UV treatment.
Source & Image Credit: DESMI