Assessing Hydro-Geochemical Parameters And Toxic Metals Of Surface Water In East Kolkata Wetlands For Suitability Measures

Abstract

Surface water, one of the most vulnerable components of the environment, plays an essential role in domestic, agricultural and industrial applications. However, rapid urbanization and industrialization have significantly altered the concentrations of physical, chemical and toxic metal parameters in water resources. This study focuses on the East Kolkata Wetlands (EKW), a unique ecosystem sustained by wastewater, offering numerous environmental and economic benefits. The primary objectives of this study are to assess the pollution load, including physico-chemical parameters and toxic metal contamination, and to analyze its spatial variation across the EKW. For this investigation, 13 water samples were collected from various points across the study area during the pre-monsoon and post-monsoon seasons. Concentrations of the physico-chemical parameters and toxic metals of the samples were analyzed following the APHA (American Public Health Association) standardized methods. Additionally, inverse distance weighted (IDW) interpolation, heavy metal pollution index (HPI), and water quality index (WQI) were used to identify suitable sites for domestic use. The findings indicate that the water in EKW ranges from neutral to alkaline, with TDS levels exceeding permissible limits, while concentrations of toxic metals, including arsenic (As) and mercury (Hg), generally fall within the permissible limits and lead (Pb), cadmium (Cd) and chromium (Cr) exceed in some areas limits set by WHO and BIS standards. Areas near the Leather Complex and Dhapa dumping ground exhibit significant contamination from toxic metals and overall pollution. In contrast, other parts of the study area meet the criteria for domestic water use. The findings have broader implications for wetland management practices in other urban areas where wastewater-fed systems are prevalent, aligning with global priorities on water quality and sustainable urban development.