U6 waste exemption: using sludge to reseed a waste water treatment plant

The U6 exemption allows you to import sludge from one waste water treatment plant to another to reseed the biological process.

Applies to England

Activity you can carry out

This can involve using sludge from one waste water treatment plant to re-seed the biological process (for example, filter bed) at another waste water treatment plant.

Activity you cannot carry out

You cannot store, treat or use septic tank or cesspool sludge under this exemption.

Type of waste you can use

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

Waste code Type of waste
190805 Sludge from treating urban waste water
190812 Sludge from biologically treating industrial waste water not containing hazardous substances

Amount of waste you can use

You can store or use up to 1,000 cubic metres at any one time at the receiving waste water treatment plant.

Key conditions

You should not use any more waste than you need to or this will be considered as waste disposal and will not be exempt.

Other things you need to know

You should store the waste in a secure place before using it so the public cannot have access to the waste and the effluent cannot enter controlled waters.

Register a U6 exemption

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

Published 28 April 2014
Last updated 5 November 2015 + show all updates
  1. Changed reference of 'dangerous substances' to 'hazardous substances' due to changes in the law.

  2. First published.