Sustaining our environment

Stormwater management

What do you need to know about stormwater?

When it rains the water from your business drains directly into creeks, rivers, beaches or harbours.  This water runoff is often called stormwater. 

Stormwater must not contain any substances from your business activities.  If pollutants such as oil, grease, detergents or other substances leave your site when it rains it can be harmful to the environment and may be considered a pollution offence. It is also considered water pollution if washwater, spilt liquids or any substance from your site enters stormwater drains or street gutters.

Wastewater or stormwater?


Wastewater (sometimes called trade wastewater) is any water used or contaminated as a result of your business's activities. Wastewater from businesses may contain pollutants such as sediment, particles and chemicals. Wastewater must not enter the stormwater system. It should be discharged to the sewerage system or to storage tanks. Refer to Trade Wastewater, for advice on wastewater disposal.

Stormwater is rainwater that flows across outside surfaces into stormwater drains or directly into waterways. Stormwater should not contain pollutants.

What can you do to stop stormwater pollution?

  • Do not allow anything other than clean rainwater to enter the stormwater drains on or near your premises.
  • Prevent any washing water from entering stormwater drains. Confine your cleaning and washing to a contained or bunded area where the wastewater is directed to the sewer.
  • To direct wastewater to the sewer you need a trade waste permit from your local water organisation (Sydney Water, Hunter Water or your local council). Alternatively, collect the wastewater, treat it and reuse it. (Refer to 'Trade Wastewater', for information on applying for a trade waste permit.)

Cleaning your work area

  • Keep your premises clean to stop unintentional pollution of the stormwater system. Your customers and staff will also appreciate a clean and tidy work area.
  • Do not hose the workfloor or forecourt unless all the water can be collected or directed through an approved trade waste system. Do not allow any contaminated water to enter the stormwater system. 
  • If you cannot hose without getting dirty water into gutters or stormwater rains, there are other cleaning options:
    • Sweep or vacuum the area.
    • Use absorbent material to remove most of the grime and then use some solvent on a rag to remove the rest.
    • Paint the workfloor with a nonslippery paint to prevent it from absorbing oil.

Dismantling of parts and vehicles

  • Do all dismantling where liquids might be present on a designated vehicle exchange area that is sealed, bunded and roofed and set up for draining.
  • Drain all waste liquids, such as oil and coolants, into trays and then pour them into storage containers. Doing this thoroughly and immediately reduces the handling of waste liquids and eliminates the danger of injuries as a result of chemicals on the  floor. Never allow waste liquid to drain or spill onto the floor. 
  • Make sure that all waste liquids are stored in containers in a bunded, sealed and covered area.

Degreasing of engines and parts

  • You can degrease engines in the workshop if you have a wash bay approved by Sydney Water, Hunter Water or your local council, or if you have some other means  of storing or treating the wastewater. Do not degrease engines outside the workshop, or where any run-off can enter the soil or stormwater system.
  • Do not degrease parts outside the workshop, or where any run-off can enter the oil or stormwater system. Biodegradable products are allowed in the sewer but not in the stormwater system. An alternative method of degreasing is to wipe parts with rags.
  • Cleaning parts using solvents such as kerosene, should be carried out in dedicated parts cleaners.  These should be located within a bunded area. 
  • Consider ways to minimise solvent use, for example by susbstituting with water based washing that uses biodegradable products or investigating the applicability of ultrasonic cleaners.

Degreasing hands

  • Degrease your hands over a sink that is connected to the sewer. Do not degrease them where the water can run into the gutter or a stormwater drain. Where there is no sewer, pour the wastewater into a large drum for disposal by a licensed waste contractor.

Storage of wastes and contaminated parts

  • Store all contaminated parts (e.g. radiators and engine parts) inside or in a covered, sealed and bunded area, even after they have been drained, to prevent residual oil from leaking into the stormwater system.
  • All wastes that are stored for collection need to be kept out of the rain - either undercover or in a container or skip with a lid.  Rain water that comes into contact with wastes (both liquid and solid wastes) can carry pollutants from the wastes to the environment. 
  • Liquid wastes need to be stored in a bunded area to prevent spills from escaping and causing water pollution.  Ensure that containers are sealed, stored upright and collected as soon as possible.

What the law says

Environmental laws require that you do not pollute waters or the land, as described in Environmental Legislation.  Any spills or pollution that cause material harm to the environment must be reported to the appropriate regulatory authority - either DECC or local council.  DECC may be contacted by calling the DECC Environment Line on phone: 131 155.

Further information

  • Your local council
  • DECC Environment Line, phone 131 555
  • Yellow Pages - look under 'Water Treatment Equipment' and 'Environmental & Pollution Control Consultants

Page last updated: 27 February 2011