Water Nitrate — Benchmark Detail

Benchmark Value

0.01 mg/L

Range: 0.007 to 0.012 mg/L

Optimal Range: 0.007 to 0.012

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 8 benchmarks together — the OptimalRange form drives the primary score, while 7 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary UpperThreshold Guard MaximumOnly Guard Point Guard MaximumOnly Guard MinimumOnly Guard MaximumOnly Guard UpperThreshold Guard

Evidence & Context

The benchmark of ²640.010 mg NOx-N/L is derived from consistently low median concentrations (ranging 0.007-0.012 mg NOx-N/L) observed at multiple upstream control and reference sites within Kosciuszko National Park 1, representing high ecological health in minimally disturbed alpine catchments.

Metric Definition:

Water nitrate concentration measured as NOx-N in minimally disturbed alpine and subalpine aquatic ecosystems.

Benchmark Definition:

Water nitrate concentration as NOx-N representing best available natural condition in alpine/subalpine protected areas.

Justification:

Based on multiple well-documented reference/control sites within Kosciuszko National Park and supported by other alpine regions indicating naturally very low nutrient levels.

Sources (2)

Characterising alpine peatland water quality on the Bogong High Plains, Victoria - Threatened Species Recovery Hub Journal

Characterising alpine peatland water quality on the Bogong High Plains, Victoria - Threatened Species Recovery Hub

View Source

NSW alpine resorts environmental performance report 2020–21 Journal

NSW Alpine Resorts Environmental Performance Report 2020–21

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Toxicant default guideline values for aquatic ecosystem protection ..., accessed August 8, 2025

Regulatory Framework Journal

Toxicant default guideline values for aquatic ecosystem protection ...

View Source

Context

Region Australia
Biome Alpine and Subalpine Complex
Land Use Conservation / Protected Natural Areas
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 17 Mar 2026

Notes

The benchmark is more stringent than the ANZECC (2000) default trigger value for SE Australian upland rivers (0.015 mg NOx-N/L) and reflects the pristine nature of these protected alpine areas. RangeFixup applied 2026-03-21 22:21 UTC: OptimalRangeHigh: 0.015 → 0.012; UpperBound: 0.012 → 0.015 [Migration] Original wider evidence range: 0.007 – 0.015 (retained OptimalRange: 0.007 – 0.012)

Related Benchmarks

Other benchmarks in the AUS-ASC-CON-WNI family.