Evaluation of Seasonal Variations in Water Quality and Microbial Contamination of the Kallada River, Kerala
Athira UR, Rincy A, Jensy RF, Rajani V and George A
DOI: 10.5281/zenodo.21598840
ABSTRACT
The Kallada River, a major west-flowing river in Kerala, serves as a critical source of drinking water, irrigation, fisheries, and ecological support. Increasing anthropogenic pressures, including sand mining, agricultural runoff, sewage discharge, pilgrimage activities, and riparian degradation, have adversely impacted its water quality. This study evaluated the physicochemical and bacteriological characteristics of the Kallada River at eight sampling stations during pre-monsoon, monsoon, and post-monsoon seasons from November 2022 to July 2023. Water samples were analyzed for temperature, pH, total dissolved solids (TDS), electrical conductivity, alkalinity, hardness, free carbon dioxide, nitrate, phosphate, sulfate, sodium, potassium, and total coliform counts using standard analytical procedures. Results indicated seasonal variations in water quality parameters, with most physicochemical parameters remaining within permissible limits established by Indian standards. However, elevated phosphate concentrations and exceptionally high total coliform counts reflected significant anthropogenic contamination. Site 1 consistently exhibited greater deterioration in water quality, primarily due to intensive human activities associated with the Sabarimala pilgrimage. Pearson correlation analysis revealed significant relationships among physicochemical parameters across seasons, underscoring the influence of nutrient enrichment, runoff, organic matter decomposition, and mineralization processes. Although the river water generally meets criteria for Class C surface water, it is unsuitable for direct consumption without treatment and disinfection. Continuous monitoring and implementation of effective management strategies are necessary to safeguard the ecological integrity and water quality of the Kallada River.
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