These data are based on the UK rainfall chemistry data held on the UK-AIR database operated on behalf of Defra (http://uk-air.defra.gov.uk/). A subset of 20 sites was analysed, being those with the longest continuous data record from 1986 to 2011. Rainfall samples from bulk collectors were taken weekly or two-weekly at sites across the UK and analyzed by a central laboratory. The raw reported data contain some samples which were contaminated by bird droppings, or by wind-blown dust, and should not be used to estimate annual or long-term wet deposition at the measurement sites. Some samples were missing for other reasons, such as physical loss of the rain sample prior to analysis. Following identification and removal of contaminated sample data, the missing data were estimated, where possible, using statistical interpolation across both time and space with the GENSTAT procedure MULTMISSING. The final datasets contain the accepted and estimated data values, flagged as appropriate. The data filenames correspond to the sites as listed in the UK-AIR database (Allt a'Mharcaidh, Bannisdale, Barcombe Mills, Bottesford, Eskdalemuir, Flatford Mill, Goonhilly, High Muffles, Hillsborough, Loch Dee, Lough Navar, Preston Montford, Pumlumon, Stoke Ferry, Strathvaich, Thorganby, Tycanol Wood,Wardlow Hay Cop, Whiteadder, Yarner Wood). This cleaned dataset was prepared by Neil Cape, Ron Smith and David Leaver at CEH Edinburgh on behalf of Defra and the Devolved Administrations under the project Pollutant Deposition Processes. Full details about this dataset can be found at https://doi.org/10.5285/ada39609-ddec-4cbe-85c2-4fdd6bd774d7

This dataset provides the location details of Environmental Change Network (ECN) sites from which data are collected. There are 12 terrestrial sites and 45 freshwater sites. Sites range from upland to lowland, moor land to chalk grassland, small ponds and streams to large rivers and lakes. ECN is the UK's long-term environmental monitoring programme. A wide range of integrated physical, chemical and biological variables which drive and respond to environmental change are collated, quality controlled and made freely available for scientific research. The data form an important evidence base for UK environmental policy development. ECN is a multi-agency programme sponsored by a consortium of fourteen government departments and agencies. These organisations contribute to the programme through funding either site monitoring and/or network co-ordination activities. These organisations are: Agri-Food and Biosciences Institute, Biotechnology and Biological Sciences Research Council, Cyfoeth Naturiol Cymru - Natural Resources Wales, Defence Science & Technology Laboratory, Department for Environment, Food and Rural Affairs, Environment Agency, Forestry Commission, Llywodraeth Cymru - Welsh Government, Natural England, Natural Environment Research Council, Northern Ireland Environment Agency, Scottish Environment Protection Agency, Scottish Government and Scottish Natural Heritage.