Water Nitrate

AUS-TDG-LVG-WNI General Moderate confidence

Benchmark Value

0.7 mg/L
Thresholds: Lower: —, Upper: 0.7
Direction: Lower is desirable ↓
Form: MaximumOnly

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context. The scoring engine uses 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.

Evidence & Context

A water nitrate level of 0.7 mg/L as NO3−​ (based on the 95% species protection toxicant guideline, as per Hickey's clarification) represents a significant upper detrimental threshold for aquatic ecosystem health.

Metric Definition:

Water nitrate concentration indicating ecotoxicity risk to aquatic species.

Benchmark Definition:

This benchmark represents the upper nitrate concentration threshold above which aquatic species are at risk of toxic effects in Temperate Dry Woodlands & Native Grasslands under livestock grazing.

Justification:

Based on the Hickey (2002) review interpretation of the ANZECC (2000) nitrate toxicant guideline for 95% species protection.

Sources (1)

Preview of Memorandum - Nitrate guideline values in ANZECC 2000, accessed August 8, 2025
Memorandum - Nitrate guideline values in ANZECC 2000, accessed August 8, 2025 Journal

Hickey, C. (2002). Nitrate guideline values in ANZECC 2000. Memorandum MFE02237 prepared for Ministry for the Environment (New Zealand). NIWA Client Report: HAM2002-126.

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Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of Australian and New Zealand Environment and Conservation Council & Agriculture and Resource Management Council of Australia and New Zealand (2000). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Volume 1: The Guidelines.
Australian and New Zealand Environment and Conservation Council & Agriculture and Resource Management Council of Australia and New Zealand (2000). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Volume 1: The Guidelines.
Direct Evidence Journal

Australian and New Zealand Environment and Conservation Council & Agriculture and Resource Management Council of Australia and New Zealand (2000). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Volume 1: The Guidelines.

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Context

  • Region Australia
  • Biome Temperate Dry Woodlands & Native Grasslands
  • Land Use Livestock Grazing & Pasture
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 25 Mar 2026

Notes

This value serves as a key ecotoxicity threshold indicating potential harm to aquatic biota.

Related Benchmarks

Other benchmarks in the AUS-TDG-LVG-WNI family.