What you need to know about trade waste pretreatment in Tasmania

Cleanawater on 3 April 2020

Tasmania Water (TasWater) is the entity responsible for wastewater treatment in Tasmania. They operate 112 sewage treatment plants and have 177,000 connections to a network of sewer mains stretching for 4,700 km.

The policies of TasWater are governed by the Water and Sewerage Industry Act 2008 (Industry Act). Their primary regulator in terms of trade waste is the Environment Protection Authority (EPA). The Act specifies that no person may discharge anything to the wastewater system in Tasmania without the consent of TasWater.

Cleanawater offers trade waste pretreatment solutions that satisfy the requirements of TasWater.

TasWater trade waste policy

Any business seeking to discharge trade waste to the TasWater sewer network should first familiarise themselves with the Trade Waste Policy. The policy describes TasWater’s approach to managing wastewater, compliance requirements, pretreatment as well as pricing.

TasWater adopts a risk-based approach to issuing trade waste licences. Acceptance criteria and charges may vary from customer to customer based on the risk associated with their trade waste, and its potential impact on the downstream wastewater treatment plants. TasWater uses four risk categories to differentiate between different types of trade waste:




Low volume or strength trade waste dischargers that pose minimal risk to the wastewater system.


Low to medium volume trade waste dischargers that require pretreatment at the source. There are 3 subcategories (a, b and c) based on a technical and commercial assessment of the risk of accepting the trade waste.


Dischargers who pose a medium risk to the wastewater treatment systems of TasWater through volume, composition or quality.


Dischargers who pose a high risk to the wastewater treatment systems of TasWater through volume, composition or quality.

Category 3 and 4 trade waste dischargers must enter into a contract with TasWater. Their costs depend on volumetric discharge and mass loading.

Pretreatment requirements for trade waste in Tasmania

Wastewater treatment plants have limitations in terms of their capacity and their ability to process high volumes of pollutants. As a result, TasWater specifies pretreatment requirements for individual trade waste dischargers to protect the treatment plants. They treat each application on its own merits. Some sewage catchment areas may have more stringent requirements than others because of the downstream infrastructure. It is important to note that TasWater reserves the right to approve the pretreatment solution of each discharger. Customers must seek their approval before installation.

Some standard pretreatment solutions required by TasWater for different industries are as follows:

  • Grease arrestors for commercial kitchens, and other businesses that serve hot food.
  • Oil water separators for motor trade activities like refuelling depots, mechanical workshops, service stations and vehicle washing.
  • Baffled settlement pits for various types of wash down bay.

Cleanawater trade waste pretreatment solutions

Meeting the trade waste requirements for TasWater requires an understanding of the regulations and the technology behind pretreatment solutions. Cleanawater offers pretreatment solutions that satisfy TasWater and help businesses with trade waste compliance. Two pretreatment solutions for the Tasmanian context are as follows:

1. Oil water separators

Companies that have the potential for oil residue in their trade waste may need an oil water separator to obtain a trade waste permit. Oil water separators work on the principle that oil is lighter than water. They allow enough residence time for oil suspended in the trade waste stream to separate and float to the surface. Internal structures help accelerate the accumulation of oil into droplets. Clean trade wastewater is discharged from the separator while oil collects for disposal. Cleanawater supplier Vertical Gravity Separators and Coalescing Plate Separators.

2. Wash bays

A structured wash bay solution ensures the treatment of water before discharge to the TasWater sewage system. Wash bays capture the water and prevent it from flowing into stormwater drains. Wastewater processing includes removing solids in a silt trap and oil in an oil water separator. Capturing the water also makes recycling possible, which benefits the environment and saves on the cost of potable water. Cleanawater offers portable and permanent wash bay solutions.

Talk to Cleanawater for expert advice

Contact Cleanawater for commercial wastewater treatment solutions and advice in Tasmania. Our technical experts understand the requirements of TasWater and can guide you through the process of permit application and compliance. Our pretreatment solutions meet the standards set by TasWater and help our customers with their obligations for environmental duty of care.

Contact Cleanawater to find out more about our wastewater treatment solutions.