How is Groundwater Quality Classified for Drinking Purposes Based on the IWQI Index?
Groundwater quality for drinking purposes is systematically classified into five distinct categories based on the calculated value of the Indian Water Quality Index (IWQI).
The IWQI is a tool used to evaluate the overall suitability of groundwater for consumption. This index consolidates multiple water quality parameters into a single score, which then determines the water's quality class. According to the classification system, groundwater quality is categorized based on specific IWQI score ranges.
IWQI Categories and Drinking Suitability
The provided reference defines five classes for groundwater quality based on the IWQI calculation. These categories indicate the level of suitability for drinking:
- Excellent: Water in this category has a low IWQI score, indicating high quality and suitability for drinking.
- Good: This category represents water that is generally suitable for drinking, though perhaps slightly less ideal than excellent.
- Poor: Water quality begins to decline, and while possibly treatable, it is considered poor quality for direct drinking.
- Very Poor: Water quality is significantly degraded, making it largely unsuitable for drinking without extensive treatment.
- Unsuitable for Drinking: Water quality in this category is severely compromised and is not recommended for drinking.
The specific ranges for each category are detailed below:
| IWQI Range | Groundwater Quality Category | Implied Suitability for Drinking |
|---|---|---|
| 0 to 50 | Excellent | High |
| 50 to 100 | Good | Suitable |
| 100 to 200 | Poor | Low |
| 200 to 300 | Very Poor | Very Low |
| ≥ 300 | Unsuitable for drinking | None |
As stated in the reference, "The groundwater quality is categorized into five classes based on the calculation of IWQI: excellent (the values ranged from 0 to 50), good (50 to 100), poor (100 to 200), very poor (200 to 300), and unsuitable for drinking ( 300)". Values of 300 or greater fall into the "unsuitable for drinking" category.
Understanding these categories is crucial for assessing the potability of groundwater sources in areas where the IWQI method is applied.
