Water Nitrate
Benchmark Value
Scoring Curve
The scoring engine could not generate a curve for this benchmark context. The primary form is CompositeFramework, but the benchmark data may be missing required fields (e.g., optimal range bounds for an OptimalRange benchmark). This is typically a data quality issue in the benchmark pipeline.
Evidence & Context
The ANZECC (2000) physical and chemical stressor guideline for Oxidised Nitrogen (NOx) for South-East Australia, Lowland Rivers (slightly disturbed ecosystems), as presented in Table 3.3.2 of the guidelines, is 0.020 mg/L (as N). This value appears to be the most appropriate starting point for establishing the benchmark. As calculated previously, this is equivalent to approximately 0.088 mg/L as NO3− (assuming all NOx is in the form of nitrate).
Water nitrate concentration in surface waters, measured as mg/L of nitrate (NO3−).
This benchmark represents the water nitrate concentration threshold indicating nutrient pollution risk in aquatic ecosystems within Temperate Dry Woodlands & Native Grasslands under livestock grazing. It is based on a guideline for slightly disturbed lowland rivers in South-East Australia, serving as a proxy for best available condition to prevent eutrophication.
Derived from the ANZECC (2000) default trigger value for Oxidised Nitrogen (NOx) of 0.020 mg N/L for South-East Australia, Lowland Rivers in 'slightly disturbed ecosystems' (Table 3.3.2), converted to nitrate concentration. This value is used as a proxy for the 'best available condition' under sustainable livestock grazing in Temperate Dry Woodlands & Native Grasslands due to its origin from minimally impacted reference sites and its aim to prevent eutrophication.
Sources (2)
Australian and New Zealand Environment and Conservation Council & Agriculture and Resource Management Council of Australia and New Zealand (2000). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Volume 1: The Guidelines.
View SourceHickey, C. (2002). Nitrate guideline values in ANZECC 2000. Memorandum MFE02237 prepared for Ministry for the Environment (New Zealand). NIWA Client Report: HAM2002-126.
View Source