Measuring the quality of drinking water is important as it directly affects public health. However, relying on just index to decide whether to drink tap water or not in your country may be misleading as there are various factors that can affect water quality.
The Environmental Performance Index (EPI) is published by the Yale University. Their methodology: Based on each country's score on Yale University's Environmental Performance index. The index assigns each countrya score that rates the quality of local drinking water based on the number of age-standardised, disability-adiusted life-years lost per 100.000 persons (DALY rate) due to exposure to unsafe drinking water. Higher scores indicate safer drinking water. In my opinion, using the EPI index could be misleading when it coms to measuring water quality for the following reasons:
- Limited scope: The EPI only considers a few indicators related to water quality. These indicators do not provide a comprehensive picture of water quality as they do not consider other important factors such as the presence of toxins or contaminants in water sources, public pereception, aging infrastructure and cultural norms.
- Incomplete data: The EPI relies heavily on the availability and quality of data, and in many countries, especially developing ones, there is limited data on water quality. This can result in an incomplete and potentially misleading assessment of water quality in those countries.
- Lack of consideration for regional differences: Water quality can vary significantly within a country, especially in large countries with diverse geography and ecosystems. The EPI does not account for these regional differences and may provide an inaccurate overall assessment of water quality.
- Dynamic nature of water quality: Water quality can change rapidly over time due to natural factors such as weather patterns or human activities such as agricultural practices. The EPI only provides a snapshot of water quality at a given time and may not reflect changes over time.
While the EPI can provide a useful tool for assessing a country's overall environmental performance, it may not provide an accurate reflection of water quality. It is important to supplement the EPI with more comprehensive assessments and local data when evaluating water quality in a given country.