Risk areas for contamination

High risk areas

Some activities and equipment in marinas have a particularly high risk of backflow because of the types and quantities of possible contaminants or the likelihood of conditions occurring which allow backflow. These include:

• filling of boats' drinking water tanks
• refuelling and general water loading points
• dry docks, especially those involving maintenance work on plumbing systems
• facilities used for emptying and cleaning chemical toilets
• emptying and cleaning of on-board sewage storage tanks
• water supply standpipes and hoses, especially on pontoons
• pressurised water wash systems and equipment
• fire hose reels and below-ground fire hydrants outlets

Other contamination risk areas

Water supplies can become contaminated through other means. Water pipes must not be installed in ground which is contaminated. Possible contaminants in marinas include fuel and lubricating oils, paint thinners, toxic chemicals (for example, anti-corrosion or antifouling compounds) and sewage. Hydrocarbons such as fuel oil and other organic chemicals like paint thinners or brush cleaners can permeate through plastic pipes and leakage or disposal of these must be safeguarded. Care must be taken where above or below-ground pipes may be subject to contamination after installation, avoiding for example, installation of pipes close to fuel storage tanks or outlets. Cross connection can occur between water supply pipes and pipes containing other liquids (such as pressurised seawater, river water or foul water), and the Byelaws require that pipes should be clearly identified to distinguish between them.