Water Nitrate

AUS-AMR-AQU-WNI General Moderate confidence

Benchmark Value

0.44 mg/L

Direction: Higher 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 4 benchmarks together — the Point form drives the primary score, while 3 guard(s) constrain the result.

Contributing Benchmarks

Point Primary MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard

Evidence & Context

The draft technical brief for nitrate states that concentrations are often <0.1 mg/L as NO3−-N. This is equivalent to <0.44 mg/L as NO3−.

Metric Definition:

Natural baseline nitrate concentration in undisturbed freshwater systems in the Arid Mountain Ranges & Uplands biome.

Benchmark Definition:

This benchmark represents the natural baseline nitrate concentration in freshwater systems, indicating the ideal unpolluted state in the Arid Mountain Ranges & Uplands biome.

Justification:

There is no evidence for a critical minimum nitrate level required for ecosystem health; lower concentrations are better in naturally oligotrophic systems.

Sources (1)

Preview of Establishment of reference conditions and trigger values for chemical, physical and micro-biological indicators in New Zealand streams and rivers - Ministry for the Environment, accessed August 11, 2025,

Establishment of reference conditions and trigger values for chemical, physical and micro-biological indicators in New Zealand streams and rivers - Ministry for the Environment, accessed August 11, 2025, Journal

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000)

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

(PDF) Water quality parameters and population characteristics for the Flinders Ranges Gudgeon - ResearchGate

Direct Evidence

Toxicant default guideline values for aquatic ecosystem protection ...

View Source

SA Arid Lands Landscape Regional Summary 2022 Aquatic ..., accessed July 30, 2025,

Direct Evidence Government

(PDF) Effects of increasing salinity on freshwater ecosystems in ..., accessed July 31, 2025,

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Aquaculture
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 2
Effective From 19 Mar 2026

Notes

This baseline is considered the natural, unpolluted state nitrate concentration in the receiving environment. No upper detrimental threshold applies; lower values are always better.

Related Benchmarks

Other benchmarks in the AUS-AMR-AQU-WNI family.