On Tap in the Redlands: Issue 13 – April 2017

Issue 13 | April 2017

Trade waste

Welcome to our 13th edition of On Tap! This month we feature trade waste and how Redland City Council supports businesses to safely discharge their liquid waste into sewer while ensuring we look after human health and the environment.

We have recently made significant improvements to trade waste management, including:

  • More detailed trap inspections
  • Tracking the servicing of grease traps; and the
  • Issue of Remedial Notices

What is trade waste and why do we need to be aware of it?

Trade waste is liquid waste that is produced by a commercial or industrial business, not including human waste and storm water, which is discharged into the sewer. It is sometimes known as industrial sewage or effluent.

In high concentrations, these wastes may be damaging to our employees and assets. Treatment plant efficiency may also be affected by trade waste and consequential issues may occur to waterways receiving the effluent.

Liquid wastes are produced by a variety of industrial, commercial and domestic activities and can contain a number of potentially toxic and hazardous substances, such as fats, grease, heavy metals, solvents and detergents.

Some businesses that produce trade waste include:

  • Commercial food premises, such as restaurants, cafes and fast food outlets
  • Bakeries
  • Butchers
  • Hairdressers and beauty salons
  • Hospitals and medical centres
  • Industry and manufacturing
  • Shopping centres
  • Commercial laundries
  • Automotive industries
  • Schools

Why do businesses require a trade waste approval?

Under the Water Supply (Safety and Reliability) Act 2008, only domestic wastewater from toilets and other low-level activities may be discharged into sewer. Any individual or business who intends to discharge liquid waste into the sewerage system must first seek approval from Redland City Council.

This is a simple process that can be done by completing an application form. Once Council has completed the relevant assessment, the two entities enter into a legally binding trade waste agreement.

The agreement outlines the terms and conditions by which the individual (waste generator) can safely dispose of trade waste.

What can possibly go wrong?

Depending on the type of industry, trade waste can consist of:

  • Suspended solids
  • Grease and oil
  • Surfactants

In the sewer, fats and solids may collect and cause a blockage. This may lead to an overflow from a manhole, with raw sewerage released to the environment. Council is responsible for the clean-up and the incident may lead to an environmental breach.

At the wastewater treatment plant, chemicals, fats and solids can interfere with the treatment process increasing treatment costs, and causing poor effluent and licence breaches.

The trade waste team at Redland City Council is here to ensure that these nasties don’t enter the sewerage system and end up at our treatment plants.

What is the Trade Waste Management Plan?

A Trade Waste Management Plan is a guideline for businesses to ensure effective management of commercial and industrial sewage that is discharged to the sewerage system.

The guideline includes information about the management of trade waste, including:

  • Discharge categories and volumes
  • Sewer admission limits
  • Effluent improvement programs
  • Pre-treatment processes and equipment requirements for grease traps
  • Fees and charges
  • Testing and sample collection requirements

How is trade waste managed?

The trade waste team is responsible for the development, implementation, administration and enforcement of the Trade Waste Management Plan. This includes carrying out inspections, testing, assessing and issuing trade waste approvals.

Trade waste generators are classified as either category 1 or 2 depending on the waste load imposed on the sewer.

Some businesses may be required to install pre-treatment before discharging to the sewer. This may be a grease trap, oil-water separator or DAF unit.

Special trade waste charges are included on the quarterly Rates Notice along with other wastewater charges.

What is a trap?

A trap (arrestor) is a plumbing appliance that is designed to filter fats, oils, grease, sand, sludge, food and other solids from going down the drain and entering the sewerage system. The waste is stored in a compartment so that it can be pumped out later by a waste collection company and disposed of at an appropriate site.

Trade waste - oil water separator and grease arrestor

See how a grease trap is tested

 

 To help decide how frequently a trap must be serviced, it is sampled and tested for:

  • Total Suspended Solids
  • Total Oil and Grease
Fig 1Sampling and testing shows high oil load. Increased service frequency may be required.

Fig 1 Sampling and testing shows high oil load. Increased service frequency may be required.

Trap inspections

A Council officer may inspect the trap to check that it is in good condition. If repairs are required a Remedial Notice is issued to the property owner.

A process has recently been implemented where this is done during the trap servicing, allowing a more detailed inspection to be done.

Fig 2 Dislodged baffle

Fig 2 Dislodged baffle

Corroded trap requiring replacement

Fig 3 Corroded trap requiring replacement

Fig 4Inspection shows build-up of solids reducing effectiveness of trap and reducing its life.

Fig 4 Inspection shows build-up of solids reducing effectiveness of trap and reducing its life.

Service Tracking

Since 2015, all pre-treatment devices have been registered in P&R. This allows the Trade Waste team to record and track the servicing of the traps by contractors. Council may issue a Remedial Notice to customers who are not adequately servicing traps.

How you can help?

  • Scrape your plates into the bin before washing
  • Use a sink strainer
  • The use of insinkerators is NOT encouraged
  • Don’t wash fats and cooking oils down the sink. Allow fats to cool and harden first then put in the rubbish bin.
  • Food businesses should use a recycled oil contractor and put bulk waste cooking oil in the provided container. This is a free service.
  • Never pour toxic chemicals, paints, petroleum products or solvents down the sink.
  • DO NOT flush wet wipes (even those advertised as flushable), sanitary napkins, tampons or nappies.

 

Are you contributing to Brisbane’s fatbergs?

Tipping fats and oils down the sink, or flushing items that do not easily break down, can create a build-up of congealed waste in our sewerage network, causing blockages, sewer overflows and damage to equipment.

An article published in the Redland City Bulletin reminds residents to dispose of fats and oils responsibly.

On Tap in the Redlands is produced by Redland City Council to share news about water supply, wastewater management and waste management in the Redlands.

On Tap in the Redlands is produced by Redland City Council to share news about water supply, wastewater management and waste management in the Redlands.

 

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