Water Quality Index Calculator

The ISQA (Simple Water Quality Index) is a numerical value that represents overall water quality based on five key parameters: temperature, BOD, TSS, dissolved oxygen, and conductivity. Higher values indicate better water quality.

The ISQA is calculated by first determining individual index values for each parameter, then using the formula: ISQA = Temperature Index × (BOD Index + TSS Index + DO Index + Conductivity Index).

BOD (Biological Oxygen Demand) measures the amount of oxygen consumed by bacteria and other microorganisms while decomposing organic matter in water. Lower BOD values indicate better water quality.

Dissolved oxygen is essential for aquatic life survival. Higher DO levels indicate healthier water that can support fish and other organisms, while low DO levels suggest pollution or excessive organic matter.

Total Suspended Solids (TSS) measure particles floating in water that make it cloudy or turbid. High TSS levels can indicate erosion, pollution, or poor water treatment, affecting both water quality and aquatic ecosystems.

Conductivity measures water's ability to conduct electrical current, which relates to dissolved salts and minerals. Moderate conductivity is normal, but very high or low values can indicate pollution or other water quality issues.

Generally, higher ISQA values indicate better water quality. Values above 80 typically represent excellent quality, 60-80 is good, 40-60 is fair, and below 40 indicates poor water quality requiring attention.

Testing frequency depends on the water source and use. Drinking water should be tested annually, while surface waters may need monthly or seasonal testing. Areas with known contamination risks should be tested more frequently.