Cleaning & maintenance

Boat cleaning

On-water boat cleaning of topsides and decks is common and detergents are often used. It should be remembered that it is illegal to allow polluting matter to enter the water. Soaps, detergents and bleaches should be used with caution and sparingly ensuring that only small residues enter the water. This is also applicable to the cleaning agents used in galleys and sea-toilets, which will drain or flush into the water. There are an increasing number of ‘environmentally-friendly’ cleaning products on the market and these should be used wherever available.

Boat maintenance

The concern with boat wash down occurs when antifouling scrapings are allowed to enter the water in large concentrations.

Removal of vegetation and other organisms which may be attached to the hulls of boats is common practice in boatyards and marinas as well as clubs and at publicly available facilities. Scrubbing piles are the most commonly used taking advantage of sufficient tidal ranges, whilst hauling the boat out of the water may be preferred by some when additional maintenance is required. More recently systems have been developed to scrub hulls whilst the boat remains in the water. In all of these systems care must be taken to avoid allowing polluting matter to enter the waters.

If the vessel is removed from the water similar measures must be taken to avoid any polluting matter entering the water or surface drains. In order to tackle fully the issues associated with using water to remove antifouling ashore, you will need a means of collecting and storing the effluent prior to its disposal or treatment. This is likely to require a designated wash down area with an impermeable surface and a system of channels or bunds to direct the effluent to a central drain. Once collected, the effluent can be filtered in order to separate the antifouling particles from the wash down water. This will allow the water to be recycled & used again. By minimising the quantity of water used during wash down the waste requiring disposal will also be minimised.

The contaminated effluent (which will contain dissolved antifouling as well as solid pollutants such as paint particles) should be collected and disposed of appropriately. There are three options:

1. Disposal to the foul sewer may be possible with the prior arrangement of the local sewage provider. You should contact your local sewage provider for more information and to discuss whether this would be an acceptable option to both the sewage provider and yourself.
2. An alternative option is to have the sealed storage tank emptied and the effluent removed and disposed of at a waste site which is suitably licensed to accept this type of waste (this will usually require the use of a suitably licensed waste contractor).
3. The third option is to carry out on site treatment and possible re-circulation. This may include a treatment facility incorporating settlement and filtration, to remove particulate matter and recycle ‘clean’ water. Any discharge from such a facility would require consent from the Environment Agency under the terms of the Water Resources Act 1991 (as amended by the Environment Act 1995). You should contact your local environmental agency for further information about whether such a discharge would be deemed acceptable. In considering whether a consent would be appropriate, the agency will need to be satisfied that the treatment facilities proposed will result in an overall reduction in the polluting load currently discharged and will be effective in enabling the quality of the effluent to achieve the quality criteria of the consent. It will also depend on the quality, nature and location of the receiving water.

It is likely that all systems will generate a degree of settled particulate matter within the storage sump, which will need to be classified as hazardous or non-hazardous and disposed of at an appropriately licensed waste disposal facility. We recommend where companies are unsure of whether the waste is hazardous or not, independent analysis should be undertaken.

Physical removal of coatings

Physical removal includes scraping and blasting, both techniques that will generate material and residues. It is recommended that all scraping and blasting is carried out in a dry dock or in a wash-down area with provision for the retention and collection of waste water and debris. Various techniques are available:

• Vacuum systems suck debris directly into a bag that will save time on clearing up.
• Plastic Blast Media (PBM) allows re-use of abrasives, which will reduce the volume of waste disposal and could save you money.
• Shot and slurry blasting materials are toxic and must be disposed of by a suitably licensed waste contractor as hazardous waste - do not swill used blast material into the marina basin or into the drainage network.
• Consider the feasibility of using hand scraping as an alternative. In the future, the higher labour costs of scraping by hand may be offset by savings in waste management costs.

These residues may contain toxic material such as flakes of antifouling paint and particles of the blast material and should be collected and stored in a sealed tank prior to being removed and disposed of at a waste site which is suitably licensed to accept this type of waste. See Chapter 7 in the Environmental Code of Practice on Waste Management for details of how to determine whether the waste is hazardous or non-hazardous and the implications of this.