Assessment of Wastewater Drainages in Urban and Rural Region of Allahabad (Uttar Pradesh, India) through Water Quality Index (WQI)

Water quality index (WQI) is a dimensionless number that combines multiple water quality factors into a single number by normalizing values to subjective rating curves. Conventionally it has been used for evaluating the quality of water for water resources such as rivers, streams and lakes, etc. Factors included in WQI vary depending upon the designated water uses of the water body and local preferences. Some of the factors include dissolved oxygen (DO), pH, biological oxygen demand (BOD), chemical oxygen demand (COD), total coli form bacteria, temperature, and nutrients (nitrogen and phosphorus), etc. These parameters are measured in different ranges and expressed in different units. The WQI takes the complex scientific information of these variables and synthesizes into a single number. The WQI can serve as a simple first step tool in these efforts of evaluating the effects of the conservation practices in improving and/or sustaining the quality of water in the watershed. By regularly monitoring the physical and chemical makeup of water quality, it is possible to detect changes (both good and bad) and implement response measures to mitigate detrimental change before a situation worsens. At the same time, water quality monitoring data can be used to track response to management regimes aimed at improving water quality.