T18 waste exemption: using flocculants to remove water from waste

The T18 exemption allows you to treat waste by using flocculants to remove water so that clay or water-based paints can be recovered.

Applies to England

Types of activity you can carry out

These include:

  • removing water from clay effluent produced from manufacturing ceramics to recover the clay and/or water
  • recovering water-based paints from wash water

Types of activity you cannot carry out

You cannot:

  • use this exemption if you are planning to dispose of the waste, for example by discharging it to a sewer
  • treat hazardous waste

Types of waste you can treat

The waste codes are those listed in the List of Wastes (LoW) Regulations. You need to make sure your waste fits within the relevant waste code and description.

Waste code Type of waste
010409 Clay effluent from the manufacture of ceramics
080120 Water-based paint wash water

Quantity of waste you can treat

You can store or treat up to 30,000 litres at any one time.

Key conditions

The waste must be stored in a container with secondary containment.

What else you need to know

You must not discharge dirty water to controlled waters or sewers without the correct consent. See Discharges to surface water and groundwater: environmental permits.

Register a T18 exemption

You need to register this exemption with the Environment Agency if you meet the requirements.


Hazardous waste – see How to classify different types of waste.

Secondary containment – a bund or any other system for preventing waste that has leaked from its main container from escaping from the place where it is stored or treated.

Published 28 April 2014