The list that follows is by no means comprehensive - so please check the main websites listed to check on the availability of other datasets.
General environmental statistical sources
Environmental information across industry sectors, emissions data, environmental protection data, fossil fuel use, oil and gas and waste data.
Public Registers Online
Allows you to conduct basic searches of the Environment Agency's public registers on water quality and pollution control, Integrated Pollution Control, radioactive substances and water abstraction and impounding.