Sustaining our environment

Pressure cleaners

Pressure cleaners use high-pressure water to dislodge dirt, algae, etc. from surfaces. Detergent or other cleaning chemicals are sometimes used to improve the efficiency of the cleaning process. A range of nozzles and attachments are used to direct the water onto the surface, including gurneys that spray water and skirted discs that glide over the surface.

More modern machines clean at higher pressure and therefore reduce the need for cleaning additives. More efficient machines use less water and can recycle and reuse water.

The information provided here does not address abrasive blasting/cleaning, which involves the addition of sand or another material to the water to physically remove the dirt. Some graffiti cleaning techniques involve abrasive blasting.

Issues of particular concern include:

wastewater running into gutters and stormwater drains
the containment and disposal of cleaning sludge
pollution from cleaning additives, materials washed off the cleaning surface, and chemicals reacting with the cleaning surface.

Be aware of your legal responsibilities

Although pressure cleaners do not work from fixed premises, they do have to comply with a range of legislation. Review the Environmental legislation and compliance overview for further information.

On-the-spot fines of $1500 for companies and $750 for individuals could be issued under the Protection of the Environment Operations Act 1997 (POEO Act) if you put anything other than clean water down the stormwater drain - even if it is accidental.

Make sure you're aware of the legal requirements before using, storing, transporting and disposing of hazardous materials (such as chemicals). The laws relating to chemical storage vary depending on the amount that you are storing. For more information contact WorkCover NSW.

Keep your knowledge of environmental protection laws up-to-date by regularly visiting What's new in law.

The drain is just for rain - What pollutants?

Pollutants that must never enter stormwater drains include:

chemicals and other additives used in cleaning solutions
materials removed from the cleaning surface such as moss, algae, grit, paint flakes, oil and grease (cleaning sludge)
compounds produced as a result of reactions between the cleaning solution and the materials removed from the face of the building or cleaning structure.

None of these should enter stormwater drains.

Plan your work: 10 Minutes Well Spent

Before you commence a job check the following:

Are there any hazardous materials such as oils and lead-based paint on the surface?
Are there localised patches of dirt or stains that can be spot cleaned first?
Is there loose material that can be swept up first?
Can you clean the surface with water only? If you need to use detergents or chemicals, use the smallest amount to complete the job.
Test an area first to determine the make-up of the cleaning sludge â€“ do the stormwater protection measures you have taken capture all the sludge?
Check the site drainage to determine which direction the wastewater will flow and whether it can be contained?
Can the wastewater (not containing chemical additives) be directed onto a grassy area or ground where it can soak in?
Are there any stormwater drains that require protecting?
Is there a risk of spray drift?

Before you leave the site, sweep up any cleaning sludge caught by your filters and bunds, and dispose into the garbage bin. Recycle chemical and detergent containers or return them to the supplier.

Roof cleaners

In addition to the checks above, roof cleaners should check the following prior to starting work:

Check for lead-based paints.
Spot test an area to ensure red oxides and other colour compounds are not washed from the roofing materials.
If possible, disconnect the downpipe and connect hosing to direct the wastewater (not containing chemical additives) to the ground where it can soak in.
When the downpipe cannot be disconnected: either plug it at the top and connect hosing to drain away the wastewater to a safe disposal area; place a filter at the top of the downpipe to collect cleaning sludge before it enters the stormwater system; or if the downpipe empties to the ground, place a geotextile sock over the end to collect the cleaning sludge. Use bunds to direct the wastewater away from the stormwater drain.
Check if there is a risk of spray drift.
Never pressure clean asbestos roofs.

Avoiding pollution

To reduce the risk of pollution through the use of water:

minimise the amount of water used by recycling and reusing the water. Use a wastewater recycling unit to clean and filter water so it may be used again.
If you cannot recycle wastewater, then direct wastewater onto the ground where it can soak in.

Detergents and chemical additives

Detergents, chemicals and cleaning sludge must never be allowed to enter gutters or wash into the stormwater drains. This includes 'natural' materials such as algae, moss and sediment.

To reduce the risk of pollution through the use of detergents or other chemical additives:

Use portable bunds to direct wastewater flow away from the stormwater drain - bunds that do not allow water to pass through are an essential item for every pressure cleaner as they direct water away from stormwater drains onto safe disposal areas.
Use a cleaning machine that recycles water.
Place a wash mat under small items to be cleaned and collect wastewater.
Direct wastewater containing detergents (not chemicals which can kill grass and pollute groundwater) onto the ground where it can soak in.
Use portable drain filters and sediment pillows to filter water before it enters the drain - these should be placed in or next to stormwater drains to catch any sediment from the washing process. After completing the job, cleaning sludge should be collected and disposed of into the garbage bin.
Carry a spill response kit to clean up chemical or detergent spills - no matter how careful you are, accidents do happen - so be prepared and carry a spill response kit. This can be as simple as sand or kitty litter to soak up chemicals, a brush and dustpan to sweep up, and a bag to package the material for safe disposal.
Ensure detergents, chemicals and waste materials are stored and handled where spillages cannot cause stormwater pollution (i.e. away from drains).
Make friends with your cleaning supplier - a good cleaning equipment and chemical supplier will keep you informed about the newest and best cleaning products and equipment. Newer equipment designs not only reduce the time taken to complete a job, but also reduce water consumption.
Biodegradable detergents - although biodegradable products are less damaging to the environment, runoff containing these products must not be allowed to enter stormwater drains. Use biodegradable alternatives wherever they are available.
Natural products are not always harmless, many 'natural' products are highly toxic. Follow the same guidelines for natural products as for other products.

Further information

DECC Environment Line on 131 555
Yellow Pages under 'Oil & Chemical Spill Recovery & Dispersal'

Page last updated: 27 February 2011