Home » Online Tools » Water Quality Calculator – River, Lake & Groundwater

Water Quality Calculator

UN SDG 6.3.2 Level 1 based ambient water quality assessment.

Use national, water-body-specific or site-specific targets where suitable values are available.
Custom Target Values
Required for lakes and rivers. Water temperature is used to convert measured DO in mg/L to approximate DO % saturation.
For lakes and rivers: TON = nitrate-N + nitrite-N.
Advanced DO Adjustment
Optional. Elevation adjusts atmospheric pressure used in the DO saturation calculation. Leave at 0 m when elevation is not available.
Samples Added
0 samples
Water Quality Assessment
Samples Analyzed
–
Target Compliance
–
Status
–
–
Submit Water Quality Observation

Confidential. Email will not be displayed on the public map.
Optional. Add a publicly accessible Google Drive or other report link, if available.
Email is stored only for review/contact purposes and must not be displayed on the public map.
Methodology

For lakes and rivers, Level 1 screening uses dissolved oxygen, electrical conductivity, oxidised nitrogen, orthophosphate and pH. Nitrate and nitrite are converted to a common nitrogen basis and summed as Total Oxidised Nitrogen (TON).

For groundwater, Level 1 screening uses electrical conductivity, nitrate and pH.

DO entered in mg/L is converted internally to approximate percent saturation using measured water temperature, electrical conductivity and estimated atmospheric pressure. Elevation can optionally be entered to improve the atmospheric-pressure adjustment.

A single sampling event is reported only as target compliance. It is not labelled as an official Good or Not Good water body classification.

Default UNEP optional target values used by this screening tool are DO 80-120% saturation, EC up to 500 uS/cm, oxidised nitrogen up to 0.25 mg/L as N, orthophosphate up to 0.010 mg/L as P for rivers and 0.005 mg/L as P for lakes, and pH 6-9.

Add Sample stores each sample in the table. Analyze Water Quality evaluates all samples currently added. For two or more samples, the combined measurements are compared with their targets; at least 80% compliance is shown as Good.

This calculator is a methodology-based assessment aid, not an official national SDG 6.3.2 submission. Official reporting requires nationally defined water bodies, monitoring programmes and reporting procedures.