EA Water Quality

EA Water Quality

The Environment Agency Water Quality Archive API provides access to water quality monitoring data across England, covering rivers, lakes, groundwater, and coastal waters.

Data Model

• Sampling Points — ~65,000 monitoring locations with geographic coordinates, status, type, and regional classification.
• Observations — Individual measurements at sampling points: chemical concentrations, biological indicators, physical parameters.
• Determinands — ~8,000 measurement types (pH, dissolved oxygen, ammonia, heavy metals, pesticides, etc.).
• Samples — Collection events at a sampling point on a specific date.
• Samplings — Groupings of samples by purpose and campaign.

Key Patterns

• Use limit and skip for pagination (max 250 per page).
• Sampling point IDs (notations) look like AN-011262, MD-009632 — region prefix + number.
• The API returns JSON-LD by default. All tools request application/ld+json.
• Results are in member array with totalItems count and view for pagination links.
• Filter observations by determinand code (integer), date or dateFrom/dateTo ranges.
• Geographic search uses latitude/longitude/radius (km) OR easting/northing/radius.

Gotchas

• No standard JSON: API only accepts application/ld+json or application/geo+json, not application/json.
• BNG coordinates by default: Geometry uses British National Grid (EPSG:27700) unless Accept-Crs header specifies WGS84.
• Large dataset: 65,000+ sampling points, 8,000+ determinands. Always use filters and limits.
• Date format: ISO 8601 dates only (YYYY-MM-DD).
• Compliance flag: Use complianceOnly=true to filter for regulatory compliance samples only.