River and Canal Water Quality Indicators (EA)

The General Quality Assessment (GQA) Headline Indicator Scheme (GQAHI) was the Environment Agency's national indicator for water quality in rivers and canals in England and Wales.

GQAHI was designed to provide an accurate and consistent assessment of the state of water quality and how it changes over time as a national picture. There three datasets are -

• Biology - this assessment gave an indicator of the overall 'health' of rivers and describes water quality in terms of 83 groups of macroinvertebrates.
• Chemistry - this scheme measured for ammonia and dissolved oxygen in England, and for biochemical oxygen demand (BOD), ammonia and dissolved oxygen in Wales.
• Nutrients - this GQA described quality in terms of two nutrients: nitrates (mg NO3 /l) and phosphates (mg P/l) graded from 1 to 6.

Supply format: Comma delimited.

Data availability: Available under the Open Government Licence (OGL).

Other conditions may apply and these are available via the download site.

Charge: No charge.

Sample available: Data can be downloaded immediately.