Water Nitrate
Benchmark Value
Scoring Curve
This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context.
Evidence & Context
Sustained concentrations exceeding 0.2 – 0.5 mg/L NO3− are considered detrimental, indicating a departure from the best available condition.
Lower bound of upper detrimental threshold for nitrate concentration indicating departure from high environmental health due to eutrophication risk.
Threshold for nitrate concentration above which eutrophication risk increases, indicating ecological degradation.
Based on ANZECC (2000) regional nutrient guidelines and general eutrophication science.
Sources (1)
ANZG (2018) Australian and New Zealand Guidelines for Fresh and Marine Water Quality
View SourceSupporting Sources (3)
Additional references from the underlying research that informed this benchmark.
Hickey, C. (2002). Nitrate guideline values in ANZECC 2000. Memorandum MFE02237 prepared for Ministry for the Environment (New Zealand). NIWA Client Report: HAM2002-126.
View SourcePalaeovalley Groundwater Resources in Arid and Semi-Arid Australia - Geoscience Australia, accessed July 31, 2025,
View Sourcewebcat.niwa.co.nz, accessed May 11, 2025
View Source