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Liquid trade waste

Liquid trade waste means all liquid waste, other than domestic sewage, produced by a business, industrial or commercial activity, that is discharged to the sewerage system. It excludes domestic waste from a hand wash basin, shower, bath or toilet.

Due to its concentration levels, liquid trade waste may need pre-treatment before it is discharged into the sewerage system.

Liquid trade waste includes liquids from:

  • businesses and commercial premises such as cafes, restaurants, hotels, service stations, mechanical workshops, supermarkets, beauticians, and butchers
  • industrial premises
  • community and public premises such as schools, hospitals, nursing homes, pools, and universities
  • any of the above activities carried out at residential premises
  • trade activities, eg, mobile carpet cleaning
  • septic tank waste, chemical toilet waste
  • waste from marine pump-out facilities and established sites for the discharge of pan contents from portaloos, caravans and mobile homes to the sewerage system.

Why liquid trade waste management is needed

By controlling liquid trade waste discharges, Council, together with the operators and owners of businesses, are helping to protect the environment and public health, as well as reduce costs. The benefits of controlling liquid trade waste include:

  • protecting river systems by reducing the amount of problem substances reaching treatment plants
  • preventing harmful substances from damaging the sewer, disrupting the sewerage treatment plant process or contaminating land and water
  • reducing sewerage overflows and blockages by controlling the amount of grease discharged into the sewer
  • creating a safer workplace for people who work in and around the sewer
  • improving wastewater quality reaching the sewage treatment plants, allowing our treatment processes to work more effectively and efficiently and not be harmed by sudden shocks of toxic substances.


Pre-treatment is any activity that removes contaminants from wastewater (eg, grease and oil) before it is discharged to the sewerage system.

Pre-treatment equipment may include devices such as sink screens/strainers and grease arrestors that are installed in businesses where the activity produces oily and fatty wastes such as a restaurant or takeaway food outlet.

The installation of appropriate pre-treatment processes and devices should be specific to the activity being carried out. This is necessary in the management of trade waste because it assists in reducing the concentration levels of substances discharged from business activities to levels that the sewerage system can effectively transport and treat.

Apply for approval to discharge liquid trade waste

Discharging liquid trade waste without approval is an offence.

If you intend to carry out a business activity that generates and discharges liquid trade waste into Council's sewerage system, you will need to complete a Liquid Trade Waste Application to get Council approval under Section 68 of the Local Government Act 1993 (the Act). This applies to both new and existing trade waste dischargers.

How to apply

Application can be made by either the owner of the premises, or the tenant who carries out an activity on the premises. However, the tenant must have the property owner's written consent in order to apply for approval.

You can apply for Council approval by completing the application form:

Substances you can't discharge

Clause 3.2.2 of the Liquid Trade Waste Management Guidelines 2021 prohibits the discharge of certain substances into Council's sewerage system:

  • organochlorine weedicides, fungicides, pesticides, herbicides and substances of a similar nature and/or wastes arising from the preparation of these substances
  • organophosphorus pesticides and/or waste arising from the preparation of these substances
  • per and poly-fluoroalkyl substances (PFAS)
  • any substances liable to produce noxious or poisonous vapours in the sewerage system
  • organic solvents and mineral oil*
  • any flammable or explosive substances*
  • discharges from chemicals and/or oil storage areas and 'bulk fuel depots'
  • natural or synthetic resins, plastic monomers, synthetic adhesives, rubber and plastic emulsions
  • roof, rain, surface, seepage or ground water, unless specifically permitted (clause 137A of the Local Government (General) Regulation 2021)
  • solid matter*
  • disposable products including wet wipes, cleaning wipes, colostomy bags, cat litter and other products marketed as flushable
  • any substance assessed as not suitable to be discharged to the sewerage system
  • liquid waste that contains pollutants at concentrations which inhibit the sewage treatment process – refer to Australian Sewage Quality Management Guidelines, June 2012, WSAA
  • any other substances listed in a relevant regulation
    *In excess of the approved limit (refer to Table 6 of the Liquid Trade Waste Management Guidelines 2021).