Inland water pollution refers to the contamination of rivers, lakes, ponds, reservoirs, streams and groundwater resources by physical, chemical and biological agents that degrade water quality and render it harmful for ecosystems and human use. It is primarily the result of human activities, though certain natural processes may also contribute. The growing demand for water due to population expansion, industrialization, urbanization and agricultural intensification has significantly increased the pressure on freshwater resources, leading to widespread pollution problems. One of the major causes of inland water pollution is domestic sewage. Rapid urban growth, especially in developing countries, has led to the generation of large volumes of untreated or partially treated wastewater. Sewage contains organic matter, nutrients such as nitrogen and phosphorus, pathogens, detergents and household chemicals. When discharged into rivers and lakes without adequate treatment, it increases biological oxygen demand (BOD), reduces dissolved oxygen levels and promotes the growth of harmful microorganisms. Industrial effluents constitute another significant source of pollution. Industries such as textiles, paper and pulp, chemicals, pharmaceuticals, tanneries and metal processing discharge wastewater containing heavy metals like mercury, lead, cadmium and chromium, along with toxic chemicals, acids and alkalis. These pollutants are often persistent and non-biodegradable, accumulating in sediments and aquatic organisms. Accidental leaks and improper waste disposal practices further aggravate contamination. Agricultural runoff is a major non-point source of inland water pollution. The use of chemical fertilizers, pesticides, herbicides and insecticides in modern agriculture results in nutrient-rich runoff during rainfall. Excessive nitrogen and phosphorus enter water bodies, causing eutrophication. Livestock farming also contributes through manure runoff, introducing pathogens and nutrients into nearby streams and ponds. Soil erosion from agricultural fields adds suspended sediments that increase turbidity and disrupt aquatic habitats. Solid waste dumping into water bodies is another critical issue. Plastics, polythene bags, packaging materials and other non-biodegradable wastes block waterways and degrade water quality. In many regions, open dumping along riverbanks allows waste to be washed into rivers during rains. Microplastics have emerged as a growing concern, as they persist in water and enter food chains. Thermal pollution occurs when industries and power plants discharge heated water into rivers and lakes. Elevated temperatures reduce dissolved oxygen levels and alter aquatic ecosystems, affecting fish and other organisms sensitive to temperature changes. Similarly, mining activities contribute to acid mine drainage, where sulfur-containing minerals react with water and oxygen to produce sulfuric acid, leading to acidic contamination of nearby water bodies. The impacts of inland water pollution are multifaceted and severe. Ecologically, polluted water bodies