4f4c4942-4343-5764-6473-313136333238 eng dataset Natural Resources Wales (NRW) 0300 065 3000 Maes-y-Ffynnon LL57 2DW enquiries@naturalresourceswales.gov.uk pointOfContact 2023-06-13 Gemini 2.2 UK Water Quality Sampling Harmonised Monitoring Scheme Summary Data AfA178 UK Water Quality Sampling Harmonised Monitoring Scheme Summary Data Crynodeb o Ddata Cynllun Monitro Wedi’i Gysoni Samplu Ansawdd Dŵr y DU 2016-10-25 publication 116328 https://naturalresources.wales 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. Natural Resources Wales (NRW) 0300 065 3000 Maes-y-Ffynnon LL57 2DW enquiries@naturalresourceswales.gov.uk owner Environment Agency (EA) 08708 506 506 Millbank Tower, 25th Floor SW1P 4XL enquiries@environment-agency.gov.uk originator Natural Resources Wales (NRW) 0300 065 3000 Maes-y-Ffynnon LL57 2DW enquiries@naturalresourceswales.gov.uk custodian notPlanned Delimited Environmental monitoring facilities GEMET - INSPIRE themes, version 1.0 2023-06-14 publication © CNC/NRW Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and NRW's copyright. It is the recipient's responsibility to ensure the data is fit for the intended purpose. Attribution statement: Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. otherRestrictions There are no access restrictions on this data. NRW may release, publish or disseminate it freely. eng environment ISO3166 Countries 2023-06-14 publication Great Britain (GBN) -5.77774100 -2.60886500 51.24082900 53.51306700 1975-01-01 2012-12-31 Natural Resources Wales (NRW) 0300 065 3000 Maes-y-Ffynnon LL57 2DW enquiries@naturalresourceswales.gov.uk distributor https://datamap.gov.wales/documents/2634 Download Data dataset The sampling network includes 230 sites, which are mainly located at the tidal limits of major rivers or at the points of confluence of significant tributaries. The information held within the HMS includes data on: Oxygen and ammonia, Nutrients, List II metals and Pesticides. Annual mean concentrations have been calculated for each HMS site. The data show the annual averages of the site means in each region, with each site given equal weight irrespective of the number of samples taken - an average of all the samples would give a greater weight to the sites at which samples are most frequently taken. In order to give an indication of the range of values at different sites within each region, figures are also given for the maximum and minimum site mean for each r egion. The data also includes for the UK average, the 10th percentile and the 90th percentile of the site means for the whole of the UK. For each determinand in each year and the 10-percentile and the 90-percentile of the site means in each region. The Environment Agency also hold and publish a copy of this dataset.