Water Nitrate

AUS-TMS-CON-WNI General Moderate confidence

Benchmark Value

0.1 mg/L

Range: 0.03 to 0.1 mg/L

Thresholds: Lower: —, Upper: 0.1

Optimal Range: 0.03 to 0.1

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

Based on available scientific information and national guidelines, a reference benchmark value for water nitrate in Conservation / Protected Natural Areas within Australian Tropical Monsoonal Savannas, representing the 2best available condition, 2 is proposed as < 0.1 mg/L as Nitrate-Nitrogen (NO3 2 BN).

Metric Definition:

Water nitrate concentration expressed as milligrams per liter as Nitrate-Nitrogen (NO3 2 BN).

Benchmark Definition:

This benchmark represents the maximum desirable concentration of water nitrate in Conservation / Protected Natural Areas of Australian Tropical Monsoonal Savannas, reflecting the best available condition to maintain naturally low nitrate levels in these oligotrophic freshwater systems.

Justification:

The < 0.1 mg/L NO3 2 BN value, while scientifically grounded as a general indicator for undisturbed freshwaters in the region, is not specifically derived from comprehensive, multi-site studies focused exclusively on Conservation / Protected Natural Areas within Australia's Tropical Monsoonal Savannas. There is a well-documented paucity of long-term, publicly accessible water quality data for northern Australia, particularly concerning baseline or reference conditions in these specific ecosystems.

Sources (2)

Preview of Diatom–water quality thresholds in South Australian streams indicate a need for more stringent water quality guidelines | Request PDF - ResearchGate, accessed May 11, 2025,

Diatom–water quality thresholds in South Australian streams indicate a need for more stringent water quality guidelines | Request PDF - ResearchGate, accessed May 11, 2025,

Validating species sensitivity distributions using salinity tolerance of riverine macroinvertebrates in the southern Murray–Darling Basin (Victoria, Australia) - Canadian Science Publishing

View Source

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

Toxicant default guideline values for aquatic ecosystem protection ...

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Supporting Sources (50)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Discharge-driven seasonal pattern of ionic solutes, suspended sediment and water clarity for a tropical savanna river in northern Australia - ResearchGate, accessed May 14, 2025,

(PDF) Discharge-driven seasonal pattern of ionic solutes, suspended sediment and water clarity for a tropical savanna river in northern Australia - ResearchGate, accessed May 14, 2025,

Contextual Support Journal

Environmental Water Requirements of Vallisneria nana in the Daly River, Northern Territory1 | Request PDF - ResearchGate

View Source

Deriving guideline values using reference-site data - Water Quality Australia, accessed August 12, 2025

Direct Evidence Government

Water Quality Guidelines Home - Water Quality Australia

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Litchfield Savanna BASE Contextual, Soil Physico-Chemical Data ..., accessed May 20, 2025,

Contextual Support GreyLiterature

Litchfield Savanna BASE Contextual, Soil Physico-Chemical Data ..., accessed May 20, 2025,

View Source

Preview of Simultaneous exposure to nitrate and low pH reduces the blood oxygen-carrying capacity and functional performance of a freshwater fish | Conservation Physiology | Oxford Academic, accessed May 20, 2025,

Simultaneous exposure to nitrate and low pH reduces the blood oxygen-carrying capacity and functional performance of a freshwater fish | Conservation Physiology | Oxford Academic, accessed May 20, 2025,

Contextual Support Journal

View Source

Surface water chemistry monitoring protocol to assess ... - DCCEEW, accessed May 20, 2025,

Contextual Support Methodology Source

Surface water chemistry monitoring protocol to assess ... - DCCEEW, accessed May 20, 2025,

View Source

Toxicant default guideline values for aquatic ecosystem protection ...

Direct Evidence

Toxicant default guideline values for aquatic ecosystem protection ...

Toxicant default guideline values for aquatic ecosystem protection ...

Direct Evidence

Toxicant default guideline values for aquatic ecosystem protection ...

Toxicant default guideline values for aquatic ecosystem protection ...

Direct Evidence

Default guideline values - Water Quality Australia

View Source

tuvalu-data.sprep.org, accessed May 20, 2025,

Contextual Support