Slipway and Jetty Cleaning and Maintenance
Maintenance wastes can enter harbours from the cleaning of jetties and slipways. Debris and wastes produced could contain a mixture of contaminants including oils, oil emulsifiers, paints, solvents, detergents, bleach and antifouling paint scrapings. The dilution of wastes in the harbour waters means that in most cases any possible adverse effects will be only localised and temporary. However, there may be a problem where wastes are washed into enclosed waters, such as docks, or areas with low tidal flushing.
Government has produced guidance on the cleaning of slipways and harbour infrastructure. The Health and Safety Executive is the authority responsible for the approval of chemicals in biocidal products containing active substances with the intention of destroying algae.
In the SEMS Annual Survey, Solent harbours report that they try to avoid using harmful chemicals and use plain seawater or environmentally sound cleaning materials when undertaking cleaning operations. The Green Blue initiative recommends that you do not use chemicals to remove weed and algae from slipways, use a stiff brush or a high pressure hose instead.
A marine licence is not required from the Marine Management Organisation for cleaning a slipway, although an Environmental Permit may be required to discharge into surface or ground water.
Potential impacts from this activity include the following:
- Abrasion/disturbance of the substrate on the surface of the seabed
- Changes in suspended solids (water clarity)
- Increase the presence and spread of Invasive Non-Native Species
