ENVIRONMENTAL CODE OF PRACTICE
Boat Washdown, Cleaning & Maintenance
Overview
There are several pieces of legislation that affect boat wash
down and maintenance facilities. Much of this comes under the
Water Resources Act (1991)
regulating any polluting matter entering controlled waters. The
waste products of the wash down or boat maintenance may also be
classified as hazardous depending on their concentration and will
need to be disposed of as necessary under the appropriate waste
regulations. The facility provider has a duty of care to carry out
under the same regulations.
The concern with boat wash down occurs when antifouling
scrapings are allowed to enter the water in large concentrations.
There have been cases where high levels of contaminants arising
from landside activities have meant that maintenance dredged
material cannot be deposited at sea due to historically high levels
of contaminants such as TBT, leading to potentially expensive
landside disposal. This is a classic example of storing up problems
for the future, so it makes sense to prevent such materials
entering the water. Since the banning of TBT in 1987, copper
biocides are now the most commonly used alternative for antifouling
paints. However, it is now thought that certain species are copper
sensitive with even low levels of copper compounds being toxic to
them and the use of copper based antifouling has even been banned
in some European countries. However, it is recognised that the
potential for impact is greatest where concentrated copper
scrapings are allowed to enter the water, rather than the slow
leaching process of the antifouling from the boat hulls.
Antifouling products themselves are also covered by a variety of
different regulations. As hazardous substances, they are covered by
Control of Substances Hazardous to Health regulations (COSHH) and under the Control of Pesticides
Regulations 1986 they are subject to legal requirements and
approval by Government Ministers. The Health and Safety Executive
(HSE) administers this approval process and it is the duty of the
user to comply with the conditions of use printed on the product’s
label. The Biocidal Products Regulations (2001) is now in force in
the UK and covers the use of biocide products.
Discharge Consents
If you want to discharge sewage or trade effluent directly into
surface water, such as rivers, streams, canals, groundwater or the
sea you will almost certainly need to apply for a discharge consent
or 'consent to discharge'.
By issuing and reviewing consents, the Environment Agency can
regulate the quality of the discharges in England and Wales to help
protect water quality, the environment and human health.
The EA assess every application for potential impacts on
water quality, taking into account the views of members of the
public and other interested parties who may be affected by the
proposals.
Depending on the environmental risk associated with the
discharge , the EA may monitor the discharge and/or the receiving
water.
The cost of the consent will be determined on a number of
factors including the type of water course you are discharging
into, the volume of the discharge and the content of the
effluent.
For more information, visit the Environment
Agency's "Charging
for discharges" webpage.
Boat wash down
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. The following
guidance is recommended.
Use of scrubbing piles
In most cases scrubbing piles are located on the foreshore where
the owner of the boat carries out the work. In most cases the
facilities simply allow the water from cleaning the vessel to run
straight onto the surrounding mud with little capacity to collect
any residue paint. In these cases, simple actions can be taken to
avoid pollution:
1. Sufficient water pressure should be used to remove the
fouling whilst leaving the paint layer intact, any pigmented runoff
indicates the water pressure is also removing a layer of paint and
should be reduced
2. When removing old antifouling paint layers, lay a plastic
sheet beneath the vessel or other suitable methods to collect the
paint scrapings and dispose of these appropriately.
Wash down ashore
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 recirculation. This may include a treatment facility
incorporating settlement and filtration, to remove particulate
matter and recycle ‘clean’ 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.
In-water scrubbing facilities
Experiments have been undertaken around Europe to evaluate the
effectiveness of mechanical cleaning as an alternative to biocidal
antifouling products. The results are not conclusive but boats
without antifouling may need to be cleaned every two weeks in order
to keep the hulls free from organisms and weed. This process is
also promoted using non toxic paints to ensure that prevents
pollutants entering the water.
Whilst the use of traditional antifouling paints may not be
appropriate for use with these systems, as they are not designed to
receive the high level of abrasion provided by the brushes used in
these systems, new coatings which are biocide free are being
developed. The replacement of the use of biocides with mechanical
scrubbing has to be welcomed provided that the non-biocide boat
coatings, which are used with the system are environmentally
acceptable. Further research is required in order to better
understand the environmental implications of these systems and the
Environment Agency is seeking further details on the toxicity of
the paint so that it can make a better assessment of the
environmental implications of these systems.
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.
The Green Blue's "Green Directory" lists a
range of products which can be used as an environmentally friendly
alternative.
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. Go to Waste
Management for details of how to determine whether the waste is
hazardous or non-hazardous and the implications of this.
Water efficiency
Large quantities of water can be used in boat cleaning and wash
down. Leaving hoses running can be costly and can be easily
avoided.
Trigger operated spray guns fitted to hoses will help stop
wastage, and save money - when the hose is not being used, it will
automatically stop flowing. The flow from a small wash down hose is
around 1m / hr (almost 13 baths). Hoses are often left running when
not in use, and the amount of water lost over the period of a week
will usually cover the cost of the spray gun and its
installation.
The use of such guns on jetty and pontoon hoses will also reduce
the amount of water wasted when boat owners fill their boat water
tanks. Without spray guns, once tanks have been filled, hoses are
left running until the boat owner has walked back to the tap and
turned it off.
It is also possible to recycle the wash water from a boat wash
down area. This will dramatically reduce the amount of water
needed, and lead to savings on water bills. For details of
companies who can provide equipment for this type of recycling,
contact Envirowise.
The Green Blue Fact Sheets
The Green Blue have also produced some fact sheets on the
following related topics