Four ballast water treatment system manufacturers have received the final agency action from the United States Coast Guard denying their appeals to use an alternative testing method for Coast Guard type approval of their ultra-violet (UV)-based ballast water management systems (BWMS).
In December 2015, the manufacturers were declined the use of the alternative testing method as the USCG Marine Safety Center’s (MSC) initial review concluded that the requested most probable number (MPN) method does not meet the requirements for an alternative method stipulated in the regulation.
The companies subsequently appealed to the USCG Marine Safety Center’s (MSC) decision requesting that the Coast Guard considers the MPN-based method, which evaluates the likelihood of reproduction among organisms, as equivalent to the required testing procedure.
The appeals were denied on the grounds that MSC lacked the discretion to approve a testing alternative that would change the discharge standard. In addition, the manufacturers were not able to show that their systems met the regulatory requirements for approval of an alternative test.
MPN was developed to estimate numbers of cells of a single species with well-known culturing requirements. With regards to evaluating ballast water that has thousands of different kinds of species, MPN-based methods have not been validated to date for this purpose.
The use of an MPN-based method to evaluate mixed assemblages of organisms in ballast water is being considered by the Environmental Protection Agency’s Environmental Technology Verification (ETV) technical panel.