GQA Headline Indicators: Phosphate Grades for English Rivers in 2009

Over 3000 sampling sites provided information for approximately 22500 km of English watercourses in the final year of the General Quality Assessment Headline Indicator scheme. The Environment Agency's national method graded water quality based on phosphate concentrations, classifying rivers from 'Very low' to 'Excessively high' relative to other rivers. 2009 marks the conclusion of this specific assessment scheme for nutrients in England.

Use Cases

• Analyze historical phosphate concentration trends in English rivers based on the GQA grading scheme.
• Compare regional water quality relative to national nutrient baselines using the site network.
• Model the relationship between nutrient levels and river health classifications described in the methodology.

Strengths

• The scheme covered approximately 22500 km of watercourses, providing a broad spatial assessment.
• Grades were defined by specific concentration thresholds (e.g., <0.02 mgP/l for 'Very low'), enabling consistent classification.

Limitations

• Row count and column-level documentation are unknown, which limits suitability assessment.
• The data is from 2009, the final year of the scheme, and its freshness is unverified for current applications.

Provenance

Source

Environment Agency

Collection Method

National water quality indicator scheme based on a reduced network of rivers and canals.

Time Range

2009

Geography

England