National Water Quality Instrumentation Service (NWQIS)

The National Water Quality Instrumentation Service (NWQIS) is responsible for testing, building, calibrating, deploying and maintaining multi-parameter water quality equipment across England. They offer both handhelds, used for spot sampling, and real-time monitors that can be deployed in situ and report live data via telemetry at a specified interval frequency. The data from these devices relates to the physical chemistry of the watercourse with the ability to measure; depth, temperature, conductivity, salinity, pH, ammonium, ammonia (derived), turbidity, dissolved oxygen (% saturation and mg/L), chlorophyll, blue-green algae, fDOM (fluorescent dissolved organic material) and nitrate.

The equipment is calibrated monthly and can be used to rapidly respond to pollution events as well as monitor the general health of a watercourse and determine the effects of agriculture, treatment works, dredging/sediment flow, saline intrusion, works occurring in/near the watercourse and many other factors that may affect water quality. The equipment is mainly deployed in freshwater systems but is also used to monitor some saline environments including estuaries and (more recently) marine environments.

The data obtained is of evidential quality and is checked every day by a team of experts whom provide updates, decide what needs actioning and assist with data analysis.

NWQIS’ biggest customer is the EA, they provide equipment for different regions based on a pre-determined service level agreement (SLA). Equipment is also deployed for non-SLA projects (e.g. external investigations in collaboration with the EA) and commercial customers (e.g. water companies).

The link below contains all the NWQIS data that has been granted public access (non-commercial and not sub-judice), this includes both active investigations and sites that are either temporarily or permanently closed:

Hydrology Data Explorer - Explore

This website includes data from other DEFRA groups (such as Hydrometrics) but the work of NWQIS can be identified by selecting only the Water Quality stations.