Guidance
U7 waste exemption: using effluent to clean a highway gravel bed
The U7 exemption allows you to use effluent from water and waste water treatment plants to clean highway gravel beds where high-quality water is not needed.
Applies to England
Activity you can carry out
You can clean sealed gravel beds that capture highway run-off using effluent from water and waste water treatment plants.
Activities you cannot carry out
You cannot:
- use effluent that does not comply with the discharge consent issued to the water treatment works or waste water treatment works that it came from
- clean highway gravel beds that do not have sealed drainage
- clean gravel beds that are not part of a highway drainage system
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 |
|---|---|
| 190899 | Effluent only |
Amount of waste you can use
You can use up to 10 cubic metres of effluent in any 24 hour period.
Key conditions:
Key conditions are that:
- the gravel bed must have sealed drainage so that effluent can only enter groundwater or surface water through a lawful discharge or collect in a sealed sump
- you must collect all effluent used or produced during the cleaning operation, and remove it to be treated at an appropriately authorised site
- any effluent you use must comply with the discharge consent issued to the water treatment works or waste water treatment works that it came from
- you should not use any more waste than you need to or this will be considered as waste disposal and will not be exempt
Register a U7 exemption
You need to register this exemption with the Environment Agency if you meet the requirements: