Abstract

In India, the rapid urbanization and poor waste management have heightened the risk of groundwater pollution, often from
industrial effluents and agricultural pesticides. The quality of groundwater is often assessed using the water quality index
(WQI), a non-regulatory tool that provides an overall indication of the status of water and helps identify areas needing further
study. This case study evaluates the status of groundwater of ten districts in Assam by analyzing physico-chemical parameters,
including pH, electrical conductivity, Biochemical oxygen demand (BOD), total dissolved solids, fluoride, arsenic, nitrate-N +
nitrite-N, total coliform, and fecal coliform. The data were sourced from the central pollution control board under the ministry of
environment, forest and climate change, Government of India. Year-wise variations of these parameters were critically assessed,
and WQI values were used to determine drinking water quality at each sampling site. The results revealed that all physic￾chemical parameters are found to be within permissible limits prescribed by the World Health Organization and Bureau of
Indian standard standards. In most sites, values were even below the allowable thresholds of earlier standards. Consequently,
WQI values classified as excellent and safe for human consumption. Nonetheless, the study highlights that drinking water
chemistry can change during storage or transportation due to factors such as exposure to light or seasonal variations. Thus, while
the current status of the groundwater in the study areas is satisfactory, continuous monitoring is crucial in ensuring safe and
sustainable use for drinking purposes.