Automotive trade wastewater

Compliance, savings and sustainability go hand in hand

Removing solids, oils and grease from your wastewater at the source helps reduce the number of blockages and overflows on your property, in our system and in the environment. Whether you’re a mechanic, a panel beater or a car detailer, or you run a car wash or service station, we can help you to save water, save money and do the right thing by our waterways.

Your business requirements

Automotive businesses must have a connection agreement. So before you start operating your business and installing your pre-treatment, go to Sydney Water Tap in and apply to discharge trade wastewater into the wastewater system. Simply follow the steps in the approval to discharge commercial trade wastewater process.

Before we can give our approval, your business will have to meet our requirements, which will probably include:

  • in-sink and in-floor bucket traps
  • an authorised oil water separation system with a minimum 500L collection pit and pump
  • appropriate backflow prevention.

You must use only pre-treatment equipment we’ve listed, and size it to meet your future anticipated maximum hourly wastewater flow rate.

Protect waterways, and add to your bottom line

All wastewater enters our system as biosolids, recycled water or treated wastewater. We're equipped to handle it. But discharging solid materials and grease in your trade wastewater has consequences. It has the potential to damage your property’s plumbing and our wastewater system. Blockages smell bad, cause overflows and are expensive to fix. Wastewater overflows have a huge impact on our waterways.

By managing your resources and disposing of waste responsibly, you can help protect Greater Sydney’s waterways – and maybe even add to your bottom line.

Tips for managing waste

Motor oil, radiator fluid, brake fluid, battery acid and fuel can leak from damaged vehicles.

  • Oils and batteries to be stored in bunded area that does not discharge or drain to pre-treatment.
  • Wipe up spills immediately.
  • Use trays to collect drips from the car.
  • Don't drain neat fuel or neat oil to a pit that’s pumped to your pre-treatment system.
  • Collect and store brake fluid, motor oil and fuel in drums for off-site removal.
  • Collect and store used radiator fluid for off-site removal.

  • Use a dry process where the work area is not connected to the wastewater or stormwater systems and the workshop operates without a floor drain or wash bay.
  • Wipe up spills straight away using sawdust, cotton waste or other oil absorbent material.
  • Seal the floor so that it can be mopped or swept – don't use a hose.
  • Install bunds to repel rain and stop liquid waste from escaping to the wastewater or stormwater system. Make sure the car is completely inside the bunded area before starting work.
  • Install a bund around oil storage areas and include a blind pit to collect drainage from the lowest point within the bund.
  • Store batteries in a bunded area on top of a plastic pallet. Waste and spills in this area should drain to a blind pit.
  • Collect and store radiator waste, waste oils, fuels, solvents, paints and degreasers in separate containers for off-site removal and disposal.
  • Remove batteries off-site for recycling as soon as possible.

  • Use a pressure cleaner and quick break detergent to wash large parts and engines.
  • Ensure used chemical baths are collected and disposed of off-site.

  • Minimise wastewater by using a bucket of water to hand rub panels and vehicle bodies.
  • Use a dry powder guide coating system or vacuum dry rubbing system.
  • Pump out contaminated water from the spray booth water curtain and remove it off-site. Do not discharge this to our wastewater system.
  • Store all paints and thinners in a suitable flammable-liquid storage container within a bunded area.
  • Install a mesh screen in the collection pit to prevent tape, plastic clips, abrasive paper and other objects from entering the pit. This will also protect the pump used with the oil separator.

  • Tyre black, upholstery cleaners and shiners contain chlorinated hydrocarbons and flammable solvents. Buffing polishes may contain ammonia and petroleum hydrocarbons.
  • Spot clean first.
  • Minimise the use of chemicals to clean and detail vehicles.
  • Choose biodegradable cleaning products.
  • Ensure car wash areas have bunds and grates to contain the wash water. Recycle water where possible.

  • Use a dry process where the work area is not connected to the wastewater or stormwater systems and the workshop operates without a floor drain or wash bay.
  • Wipe up spills straight away using sawdust, cotton waste or other oil absorbent material.
  • Seal the floor so that it can be mopped or swept – don't use a hose.
  • Wash the floor with a quick break detergent and pressure cleaner and hose in the direction of the collection well in the wash area.
  • Use bunds (barriers) to prevent wash water from leaving the wash area.

What's in your wastewater

Commercial trade wastewater from motor trades contains petroleum hydrocarbons, solids, metals and chlorinated solvents and phenols. These chemicals can affect workers’ health and safety, damage our wastewater system, affect our treatment processes and limit our ability to produce good quality recycled water and biosolids. Some can even cause explosions.

By producing less waste and following the requirements of your connection agreement, you can minimise the impacts of your automotive trade wastewater.

Pollutants and impacts from motor trades businesses


Possible effects

Petroleum hydrocarbons
Diesel, petrol, solvents, liquefied petroleum gas, engine oil, grease and degreasers contain petroleum hydrocarbons.

  • Release flammable or explosive gases at the premises or in our wastewater systems
  • Are toxic to aquatic life

Road grime, underbody mud and engine grit

  • Deteriorate mechanical equipment such as pumps and valves
  • Form deposits in the wastewater pipes and cause overflows
  • Accumulate in pumping stations, causing blockages
  • Cause overflows on your site

Leaded petrol, radiators, engine parts, catalytic converters, batteries and the residue from chemically cleaning engine blocks contain lead, zinc, copper, nickel and aluminium.

  • Contaminate wastewater by-products
  • Interfere with wastewater treatment processes
  • Are toxic to humans, animals and plants

Chlorinated solvents 
Decarbonising solutions and degreasers contain chlorinated solvents.

  • Are toxic to humans
  • Damage plastic drainage fittings

Find out more about saving water
See our water efficiency tips for business to learn how to monitor and manage your water use and check out our special offers from WaterFix Small Business and WaterFix Commercial.