Water Nitrate — Benchmark Detail

Benchmark Value

0.44 mg/L

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.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard MaximumOnly Guard MinimumOnly Guard Point Guard MaximumOnly Guard Point Guard MaximumOnly Guard Point 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−. This value can be considered the ideal baseline or natural lower boundary.

Metric Definition:

Natural baseline nitrate concentration in undisturbed freshwater systems.

Benchmark Definition:

This benchmark represents the natural baseline nitrate concentration in undisturbed freshwater systems, serving as an ideal environmental health baseline in the Arid Mountain Ranges & Uplands biome.

Justification:

Represents the natural, oligotrophic baseline nitrate concentration in undisturbed aquatic ecosystems.

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 ...

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Aquaculture
Assessment Not Stated
Evidence Type ReferenceCondition

Lifecycle

Status Rejected
Version 2
Effective From 4 Jun 2026
Effective To 4 Jun 2026

Notes

No evidence for a lower critical threshold; lower nitrate is always better for environmental health in this biome. AssessmentContext defaulted to 'Not Stated' because the source document did not state one. Pipeline quarantine: Lower confidence than existing active benchmark v1 (Moderate). Rejected by operator on 2026-06-04 13:04 UTC

Related Benchmarks

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