Water Nitrate — Benchmark Detail

Benchmark Value

0.015 mg/L

Range: 0.015 to 0.03 mg/L

Optimal Range: 0.015 to 0.03

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

Contributing Benchmarks

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

Evidence & Context

The recommended reference value is 0.015 mg/L as N.

Metric Definition:

Water nitrate concentration measured as mg/L of nitrate-nitrogen (NO3−-N) in freshwater streams.

Benchmark Definition:

Median nitrate concentration in undeveloped upland freshwater catchments representing best available condition for conservation areas.

Justification:

Derived from Queensland Government Water Quality Objectives (WQOs) and corroborated by independent scientific syntheses of pristine catchment data.

Sources (1)

Preview of Herbert River Basin Environmental Values and Water Quality ..., accessed July 27, 2025,

Herbert River Basin Environmental Values and Water Quality ..., accessed July 27, 2025, Journal

Daintree and Mossman River Basins Environmental Values and ..., accessed July 22, 2025,

View Source

Supporting Sources (20)

Additional references from the underlying research that informed this benchmark.

(PDF) Water Quality Degradation of Coastal Waterways in the Wet Tropics, Australia, accessed August 2, 2025,

Contextual Support

Requirements for graziers | Environment, land and water ..., accessed July 19, 2025,

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5.7 Nitrates | Monitoring & Assessment | US EPA, accessed August 1, 2025

Contextual Support Government

5.7 Nitrates | Monitoring & Assessment | US EPA, accessed August 1, 2025,

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A conceptual model of nitrogen dynamics for the Great Barrier Reef catchments - Griffith Research Online, accessed July 22, 2025,

Contextual Support Journal

A conceptual model of nitrogen dynamics for the Great Barrier Reef catchments - Griffith Research Online

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Daintree Rainforest Resources | Research & Monitoring | QLD - TERN Australia, accessed July 22, 2025,

Contextual Support Government

Daintree Rainforest Resources | Research & Monitoring | QLD - TERN Australia, accessed July 22, 2025,

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Dr Rebecca Bartley - CSIRO people, accessed July 22, 2025,

Contextual Support GreyLiterature

Dr Rebecca Bartley - CSIRO people, accessed July 22, 2025,

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Environmental impacts of nitrate pollution - Aquamonitrix, accessed July 24, 2025,

Contextual Support GreyLiterature

Environmental impacts of nitrate pollution - Aquamonitrix® - Nitrate and Nitrite Analyser, accessed May 11, 2025,

View Source

Improving water quality in the Great Barrier Reef - CSIRO, accessed July 22, 2025,

Contextual Support Government

Improving water quality in the Great Barrier Reef - CSIRO, accessed July 22, 2025,

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Measurement of water quantity and quality - CSIRO, accessed July 22, 2025,

Methodology Source Government

Measurement of water quantity and quality - CSIRO, accessed July 22, 2025,

View Source

Nitrate in freshwater and marine water - Water Quality Australia, accessed August 2, 2025,

Contextual Support

Nitrate - Water Quality Australia, accessed August 1, 2025

View Source

Nitrate Watch FAQs - Izaak Walton League, accessed July 22, 2025,

Contextual Support

Nitrate Watch FAQs - Izaak Walton League, accessed July 22, 2025,

View Source

Nutrient Availability in Tropical Rain Forests: The Paradigm of Phosphorus Limitation, accessed July 22, 2025,

Contextual Support GreyLiterature

Nutrient Availability in Tropical Rain Forests: The Paradigm of Phosphorus Limitation, accessed July 22, 2025,

View Source

Rainforest - WetlandInfo - Department of the Environment, Tourism, Science and Innovation, accessed July 18, 2025,

Contextual Support Government

Nutrient distribution and cycling in a subtropical rainforest in New South Wales, accessed July 19, 2025,

View Source

Preview of Relationships between land use and nutrient concentrations in streams draining a 'wet-tropics' catchment in northern Australia - CSIRO PUBLISHING | Marine and Freshwater Research, accessed July 19, 2025,

Relationships between land use and nutrient concentrations in streams draining a 'wet-tropics' catchment in northern Australia - CSIRO PUBLISHING | Marine and Freshwater Research, accessed July 19, 2025,

Contextual Support Journal

Relationships between land use and nutrient ... - CSIRO Publishing, accessed July 22, 2025,

View Source

Science in Water Quality - Reef & Rainforest Research Centre, accessed August 2, 2025,

Contextual Support

Science in Water Quality - Reef & Rainforest Research Centre, accessed July 22, 2025,

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TERN - Australia's Terrestrial Ecosystem Research Network, accessed July 30, 2025,

Contextual Support GreyLiterature

The Great Western Woodlands TERN SuperSite: ecosystem monitoring infrastructure and key science learnings, accessed May 19, 2025

View Source

Terrestrial Ecosystem Research Network TERN Australia - Queensland science, accessed July 30, 2025,

Contextual Support Government

TERN Ecosystem Research Infrastructure | School of Biological Sciences

View Source

Tour TERN's rainforest monitoring SuperSite | TERN Australia, accessed July 22, 2025

Contextual Support Government

Robson Creek Flux Data Release 2022_v2 - TERN Data Discovery Portal

View Source

Updating nitrate toxicity effects on freshwater aquatic ... - Envirolink

Direct Evidence Journal

Updating nitrate toxicity effects on freshwater aquatic ... - Envirolink, accessed July 22, 2025,

View Source

Preview of Water and Nitrogen Balance in Natural and Agricultural Systems in the Wet Tropics of North Queensland: A Review - Australian Banana Growers' Council, accessed July 18, 2025,

Water and Nitrogen Balance in Natural and Agricultural Systems in the Wet Tropics of North Queensland: A Review - Australian Banana Growers' Council, accessed July 18, 2025,

Contextual Support

(PDF) The impact of deforestation and pasture abandonment on soil ...

View Source

www.rrrc.org.au, accessed May 15, 2025,

Contextual Support Journal

Sediments and nutrients in north Queensland tropical streams: changes with agricultural development and pristine condition status (Technical Report No. 62, Australian Rainforest CRC, 2006)

View Source

Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Conservation / Protected Natural Areas
Assessment Conservation Target
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 17 Mar 2026

Notes

Lower Boundary: A lower critical threshold is not applicable; these oligotrophic, phosphorus-limited ecosystems are naturally low in inorganic nitrogen, and the benchmark itself represents the healthy baseline. Optimal Range: The optimal range is from the baseline (~0.015 mg/L) up to the 80th percentile of reference sites (~0.030 mg/L). Upper Detrimental Threshold: Concentrations persistently above 0.030 mg/L indicate a departure from the natural state. Long-term median concentrations approaching 1.0 mg/L (the chronic toxicity guideline value for 95% species protection per ANZG-deferred guidance) are considered detrimental to aquatic ecosystem health.

Related Benchmarks

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