How do we dispose of waste? 

Chad Harris
October 29, 2020

Presco technician, Chad, disposing of waste water at a naturally filtering catchment pond.

Most of our cleaning processes create waste.  For example, to clean an area that is particularly soiled we put a lot of cleaning chemical down and then wash it off.  That dirty, chemically water needs to be collected and disposed of.  

We take great care to collect our waste, dispose of it responsibly and document all disposal.  

What waste do we create and collect?

We create and collect many types of waste, including:

  • liquid waste, such as water containing milk powder or chemical
  • fat from fat traps or sumps
  • hazardous waste, such as cleaning chemical, or the clean-up from a chemical bund leak*
  • contamination, such as rodent or bird carcasses, or bird faeces.

We also subcontract out oil collection.

*In a major spill of straight chemical, say 1000L or so, we would subcontract out the sucking up of the chemical, and then do the final clean up ourselves.  

How do we dispose of waste?

Our common waste is mainly disposed of in three locations:

  1. Most liquid waste without rubbish, fat or oil in it can be disposed of at a local catchment pond, which uses a natural filtering system to release safe water into the sea.   
  2. Anything with a low fat content can go to our local waste water treatment plant
  3. Anything that is compostable, biodegradable or has a high fat content is broken down at a local worm farm  

More specialised waste can be more challenging to dispose of.

If there is a high concentration of chemical in our waste, it goes through a testing process.  Once the pH is known, we can dispose of it at an appropriate site.  Our local council has facilities for disposing of waste with more extreme pH levels.  

Contamination, like rodents, is disposed of depending on the site’s facilities.  Many of the sites we work at prefer to dispose of the contamination themselves.

We recycle all waste we can.  

Oil is difficult.  The oil must be taken off the top of the waste, the water from the middle, and the sludge from the bottom.  All three parts must be separated and disposed of correctly.  Our oil goes to an oil recycling service: ExOil. The water and sludge taken by a local industrial services contractor.

How is the waste documented?

All our waste disposal is documented.  For example:

  • Waste disposed of in your site’s stormwater will be documented on your corresponding report (Confused what this means? Read this page explaining the reports we provide.)
  • Any waste disposed of with the council must have a Waste Track form.
  • Any waste disposed of at the worm farm receives a docket detailing what was disposed of, and the amount of it.


Got a question about our waste disposal?  Get in touch today at or call 0800 773 726.