The Historic UK Water Quality Sampling Harmonised Monitoring Scheme (HMS) data contains statistics for a series of water quality sampling sites including annual means, maximum and minimum values for each region for specified determinands from 1975 onwards. The Harmonised Monitoring Scheme (HMS) was established to provide an archive of water quality data for the UK. It is used to provide information for international obligations, including the long-term trends of some determinands and the estimation of riverborne input of selected determinands to the sea.
