Maintenance of vessels on slipways and dry docks
Slipways and other hardstand areas that are used for cleaning, repairing and maintaining vessels need pollution control measures to prevent pollution of the environment.
｡?rovide slipways with a permanent catch drain, located above the high water level. The drain collects residues and then directs any paints, waste liquids and solids to a collection pit via a silt trap. The collected contaminated wastewater must not be discharged to the environment. You should contact your local wastewater (sewerage) organisation about pre-treatment and a trade wastewater agreement.
｡?o any slipway work (including hull blasting and wet rubbing) above the catch drain so that any wastes drain into it.
｡?und and grade the maintenance area so that any pollution can be contained and collected.
｡?ake collection pits large enough to hold the first flush of contaminated stormwater or the expected volume of wastewater from wet cleaning processes, whichever is greater.
｡?o not use high-pressure liquid cleaners (using water, detergents, solvents, caustic or acids) where untreated wastes can enter waterways.
｡?on't do any surface preparation (sanding, grinding, scrubbing and washing down) where it may contaminate stormwater, the foreshore or the water.
Keeping clean stormwater away from dirty work areas
｡?revent stormwater from entering any areas where it may become contaminated. You can do this with drains or rollover bunds (refer to information sheet 9, 'General Information'.)
｡?here possible, cover or roof work areas to prevent the contamination of stormwater and to minimise the collection of rainwater.
｡?nstall a first-flush stormwater collection system that will capture the first 10 mm of rainfall over the entire catchment area. Direct this first flush into a holding tank and dispose of it to the sewer. Make sure you have a proper trade waste permit from your local wastewater or sewerage organisation. For more information on first-flush systems, call Pollution Line, Tel: 131 555.
｡?ollow a regular maintenance program to ensure the effectiveness of measures designed to minimise pollution of the stormwater system.
CASE STUDY
Solutions to Pollution on the Georges River
A marina on the Georges River is doing its bit to improve water quality in the catchment. All maintenance work, including hull cleaning and painting, is done on the slipway that has a permanent catch drain located above the high water level. The drain collects all paint flakes, marine growth and other debris from boat maintenance and prevents these pollutants from entering the river The catch drain is cleaned out regularly
