Water Nitrate

AUS-TSR-URB-WNI General Moderate confidence

Benchmark Value

0.015 mg/L
Direction: Lower is desirable ↓
Form: Point

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 5 benchmarks together — the OptimalRange form drives the primary score, while 4 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard MinimumOnly Guard Point Guard MaximumOnly Guard

Evidence & Context

The WQO for Oxidised Nitrogen (NOx) in the lowland fresh waters of the Black River Basin is 0.015 mg/L (as N).

Metric Definition:

Oxidised Nitrogen (NOx), which is the sum of nitrate (NO3²2) and nitrite (NO2²2), used as a proxy for nitrate concentration in well-oxygenated surface waters.

Benchmark Definition:

This benchmark represents the Queensland Government's official water quality objective for oxidised nitrogen in lowland freshwaters of the Black River Basin, indicating a high-health state in a managed tropical landscape.

Justification:

Derived using the ANZG referential method, based on the 80th percentile of data from the least-disturbed reference sites in the region, representing a high level of ecological health.

Sources (1)

Preview of Townsville basins - Queensland Environment Department, accessed August 2, 2025,
Townsville basins - Queensland Environment Department, accessed August 2, 2025,

Environmental Protection (Water and Wetland Biodiversity) Policy 2019 - Schedule 1 (referencing WQOs for Black River Basin)

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Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Preview of Black ross (townsville) - water Quality improvement plan
Black ross (townsville) - water Quality improvement plan
Contextual Support Journal

Black ross (townsville) - water Quality improvement plan

View Source
Preview of Land-use effects on water quality in an intensively managed catchment in the Australian humid tropics | Request PDF - ResearchGate, accessed July 30, 2025,
Land-use effects on water quality in an intensively managed catchment in the Australian humid tropics | Request PDF - ResearchGate, accessed July 30, 2025,
Contextual Support Journal

Land-use effects on water quality in an intensively managed ...

View Source

Context

  • Region Australia
  • Biome Tropical & Subtropical Rainforests
  • Land Use Urban & Developed Use
  • Assessment Pristine Reference
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 17 Mar 2026

Notes

This benchmark is a robust, scientifically-derived regional guideline, but not a direct field measurement from a best-practice urban site due to a documented lack of such data.