Event Duration Monitoring - Storm Overflows - 2020 (England and Wales)

The dataset includes Water and Sewerage Company with storm overflows in England and Wales, describing how often and for how long, monitored storm overflows discharged during 2020. The Water and Sewerage Companies in England provide this regulatory return to the Environment Agency each year to fulfil their permitted conditions to discharge from these storm overflows under the Environmental Permitting Regulations. The English data were downloaded from data.gov.uk and permit numbers were used to extract locations from the Consented Discharges to Controlled Waters database in order to extract the location of each monitoring point. Sewer Storm Overflow EDM Spill Duration Data for Wales are published as a list, and location data were provided by Dŵr Cymru/Welsh Water on request so could be included in the map without the need for any pre-processing. Some EDM returns had multiple meters on a single discharge activity, so in this case we have taken the higher of the reported spill count as the value, unless the comment indicates that the meter is not working properly in which case we nulled the value. The EDM returns Activity Reference field did not reliably distinguish between emergency overflows and storm overflows so we have included all overflows in the sewer storm overflows category. Approximately 7% of the English EDM records could not be matched to a permit number in the consented discharges database to extract a location and so have been excluded from this spatial dataset. Quality Control The Rivers Trust has endeavoured to clean, check and interpret the data, but cannot be held responsible for any missing or inaccurate data. Locations for English data have been taken from the EA consented discharge database. Points in the sea may be long-sea outfalls or they may be errors in the data. Please contact the Environment Agency with specific location queries. Water companies, citizen scientists and others are welcome to contact us to notify any known data errors on specific overflows and we will flag these in the map popups. We are providing feedback to the Defra storm overflows taskforce about how to improve transparency around sewer storm overflows, and would welcome feedback and suggestions. [e-mail]