The scheme was established in 1974 by the Department of the Environment with much of the initial planning and implementation undertaken by the Water Research Centre.
Before inclusion of any location in the survey, homogeneity testing was carried out to characterise quality variations laterally and vertically within the river section chosen.
In addition laboratories who were to undertake the analysis of samples were identified and a comprehensive AQC exercise was conducted to ensure comparability of data derived from the monitoring programme.
[2] The scheme was originally intended to operate for 10 years from 1974 to 1984 to provide data to the Department of the Environment to permit the identification of national trends in water quality.
[citation needed] It was formally discontinued in 2013,[4] however in England many of the monitoring sites continue to be surveyed to describe long term water quality trends.