The Environment Agency (part of DEFRA) are responsible for dealing with large scale fly-tipping (of a lorry load or more) leaving the smaller incidents to Local Authorities.

These statistics issued by DEFRA however exclude incidents dealt with by the Environment Agency.

The reason is simple – they have given up prosecuting fly-tippers

See:

Environment Agency only prosecuted 1 fly-tipper in 2 years

Environment Agency fail to prosecute large scale fly-tippers