What is the Water Quality Index (WQI)?

The Water Quality Index (WQI) is a single dimensionless number that expresses the overall water quality at a certain location and time, based on several water quality parameters. It is one of the most effective tools to communicate information on water quality to policy makers and the concerned citizens. It simplifies complex analytical data into a format that is easy to understand, helping to identify if the water is safe for drinking, recreation, or irrigation.

How to Use This Calculator

To use this tool, you need results from a professional water test or a home testing kit. Enter the following parameters:

• pH: Measures how acidic or basic the water is. Ideal range is 6.5 to 8.5.
• Dissolved Oxygen (DO): Vital for aquatic life; higher levels usually indicate healthier water.
• Turbidity: Measures the cloudiness of the water. High turbidity can protect bacteria from disinfection.
• Total Dissolved Solids (TDS): Represents the total concentration of dissolved substances in water.
• Nitrates: High levels often indicate contamination from fertilizers or sewage.

Understanding the WQI Results

The calculation uses a weighted arithmetic index method. The results are generally categorized as follows:

• 0 - 25: Excellent Quality
• 26 - 50: Good Quality
• 51 - 75: Poor Quality
• 76 - 100: Very Poor Quality
• Above 100: Unsuitable for Drinking

Why Monitor Water Quality?

Regular monitoring helps prevent waterborne diseases and protects the local ecosystem. While this calculator provides a mathematical estimation based on common standards, always consult local health authorities or certified laboratories for official safety certifications regarding drinking water.