Vanguard Magazine

www.vanguardcanada.com AUGUST/SEPTEMBER 2017 27 Approved oil content monitor (OCM). Treated bilgewater that is discharged to ocean water is typically required to have 15 ppm oil or less; inland waters require 5 ppm or less. The discharge of streams such as black- water and greywater is also problematic, since they contain high levels of nutrients such as phosphates and nitrates. For mari- ners, blackwater generally refers to sew- age and there is no requirement in most cases for treatment of greywater prior to discharge despite its high nutrient content. However, some vessels do choose to treat both blackwater and greywater even if it is not mandated. The excessive release of nutrients into bodies of water can lead to eutrophica- tion, characterized by an explosive growth of algae (algal bloom), which subsequent- ly depletes the water of oxygen leading to devastating effects on marine species. A high proportion of inland and coastal waters in North America are affected to some extent by eutrophication due to nutrients coming from various sources, many of which are more important than ship discharges. A variety of marine sewage treatment plants are available for ships, but the design and operation of these is challenging due to various factors, including high strength of wastewater, intermittent and variable production of wastewater, ship motions, and inclusion of various cleaning products and fluids which are not well tolerated by biological systems. Unlike OWSs, there is no requirement to monitor the effective- ness of the sewage treatment prior to dis- charge. Marine regulations In order to minimize pollution of the oceans, the International Maritime Or- ganization (IMO) developed MARPOL 73/78, which is the most important in- ternational marine environmental conven- tion. Close to 100 per cent of the world's shipping tonnage are state parties to the convention, which includes Annexes I-VI that regulate different forms of pollution. Ships that are flagged under countries that are signatories to MARPOL (including Canada) are subject to its requirements wherever they operate. Although MAR- POL does not apply to defence vessels or other ships used by government for non- commercial activities, there are widespread efforts to respect the regulations through the use of appropriate equipment and prac- tices whenever possible. In some areas of the ocean, the potential for environmental damage due to oceano- graphical and ecological factors, and/or intensity of traffic is so great that designa- tion as a "Special Area" subject to special regulations is required. For example, any discharge of oil or oily mixtures is prohib- ited in Antarctica. Recently, due to global warming melting sea ice across the Arctic, shipping routes once thought impossible are opening up, leading to rapidly growing international interest and traffic in this area. As a result of this, and after years of consultations and effort, IMO adopted the Polar Code (In- ternational Code for Ships Operating in Polar Waters) 3 . The Polar Code entered into force on January 1, 2017. Discharges of oil or oily water are prohibited, sew- age (blackwater) may be discharged under specified conditions, and greywater is not regulated. Nations, and even selected jurisdictions E ENVIRONMENTAL STRATEGY OPERATIONS Master Corporal Chris Brewer watches Corporal Maxime Morasse shape berms for the award-winning waste water treatment system at Canadian Forces Station Alert.

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