Water Nitrate — Benchmark Detail

Benchmark Value

No specific value — see range

Range: 0.007 to 0.015 mg/L

Optimal Range: 0.007 to 0.015

Direction: Lower is desirable ↓

Form: OptimalRange

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 7 benchmarks together — the OptimalRange form drives the primary score, while 6 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard MaximumOnly Guard Point Guard Point Guard MaximumOnly Guard OptimalRange Guard

Evidence & Context

Based on the data from reference sites in Kosciuszko National Park (typically 0.007-0.012 mg NOx-N/L), the extremely low levels in Victorian alpine peatlands (often ²60.001 mg N/L), and the ANZECC (2000) default trigger value for South-East Australian upland rivers (0.015 mg NOx-N/L), the optimal range can be defined as ²60.015 mg NOx-N/L.

Metric Definition:

Water nitrate concentration measured as NOx-N in mg per liter.

Benchmark Definition:

This benchmark defines the optimal range of water nitrate concentration reflecting natural background levels in pristine alpine and subalpine catchments.

Justification:

This range reflects observed concentrations in pristine/reference alpine sites and aligns with the ANZECC (2000) default trigger value for South-East Australian upland rivers.

Sources (4)

Preview of Australian and New Zealand Guidelines for Fresh and Marine Water ..., accessed August 5, 2025,

Australian and New Zealand Guidelines for Fresh and Marine Water ..., accessed August 5, 2025, Journal

tuvalu-data.sprep.org

View Source

Preview of Catchment Health Indicator Program Report 2021 - Upper Murrumbidgee Waterwatch, accessed August 12, 2025,

Catchment Health Indicator Program Report 2021 - Upper Murrumbidgee Waterwatch, accessed August 12, 2025, Journal

ANZECC/ARMCANZ (2000) Guidelines

View Source

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

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

Toxicant default guideline values for aquatic ecosystem protection ...

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

Nitrate in freshwater, toxicant default guideline values for protecting aquatic ecosystems

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 3 Jun 2026

Notes

No upper detrimental threshold — higher values are always better up to natural saturation. Concentrations closer to ²60.010 mg NOx-N/L represent the most pristine conditions. Maintaining nitrate levels within this very low range is crucial for preserving the natural oligotrophic state.

Related Benchmarks

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