A Successful Collaborative Story of a Boating Club in Achieving an Innovative Treatment Solution

Stormwater Conference

New Zealand has over 100 sailing clubs accommodating approximately half a million boats over 6 meters in length (Maritime NZ, 2018). Yachting, sailing, fishing and being on the water is part of the New Zealand culture. However, many yacht clubs and marinas across the country have been and are currently discharging effluents to the waterways via stormwater with limited or no treatment. These effluents come from different chemicals such as petroleum hydrocarbon, copper, zinc and lead, which are generated during the yearly boat maintenance process of water blasting, wet sanding, cleaning, painting and anti-fouling.

This abstract highlights the impacts from boat maintenance yards on the environment and explains the way in which Weiti Boating Club (WBC), a club located north-east of Auckland with over 300 members, managed to achieve a successful low-budget solution to treat effluents’ loaded runoff from their boat yard. It recognises the success of club members in implementing a solution which was beyond what was required and for the benefit of future generations.

To uncover the key elements that made the implementation of the treatment system possible, members were interviewed. The goal of this paper is to present WBC’s member’s experience to inspire other organisations to recognise their impact on the environment, take full responsibility for their own impact, research potential effective solutions, manage budgets and work together towards the implementation of environmental projects. At a time, in which the environment is in such a fragile state, organisations need inspirational stories to make them believe that implementing environmental practices is possible, and drive for change.

Most sailors believe that their activity does not impact on the environment, as they use wind rather than fuel to power their boats. However, when looking at effluents from marinas this is not the case.

There are broadly two sources of contaminants: in-water and hardstand contaminants. According to the Auckland Regional Council Draft Marina Guidelines (2004) 5.5 grams of copper leach from an average moored 10m boat per day. A similar contaminant load comes from boat maintenance activities on land. Focusing at the boat yards, most contaminants come from water blasting, as this process removes slime and the top layer of antifouling paints. Although today anti-fouling paints are slightly less toxic to the environment as they are no longer Tributyltin based, they are nevertheless still very high in copper, zinc and organic co-biocides. Additionally, water blasting averages about 700 litres of water per boat, across various marinas and boat sizes. The same anti-fouling paints are periodically removed from a boat hull by wet sanding. Hose running while sanding, with tight water use control, uses on average 2,000 liters of water per small boat (<15m) and more for larger boats. If Auckland has half a million boats, these loads are very large. Note however, that not all boats are maintained yearly, at WBC approximately 30% of the boats are not maintained yearly.


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01 Oct 2019


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