Current Status of Pollution in Major Rivers and Tributaries of India and Protection-Restoration Strategies

The increasing global population is causing much damage to the ecosystem’s natural balance, especially the “lifeline” of any landmass and rivers. But with gradual civilization and industrialization, this serendipity of riverine systems is being compromised. Since the past century, people are trying to understand the scientific role of any river ecosystem along with the source of pollution, either geogenic or due to anthropogenic acts. Reports have shown the involvement of uncontrolled industrial effluent discharge, untreated or partially treated household sewage and release, and disposal of hot water from nuclear thermal plants are the main reason for pollution. The Ganga-Yamuna has average Pb, Cd, Cr, Ni, Cu, and Zn concentrations within a range of 2690, 1310, 1090, 1120, 2000, and 15,320 μg/L and 2553, 1101, 3627, 851, 4791, and 3518 μg/L, respectively. Due to several inter-elemental chemical interactions of river beds or sediments, natural polluting toxic elements get released from complex compounds and dissolved in the aqueous phase, becoming bioavailable to the phytoplankton and zooplankton from where such pollutants get biomagnified in higher trophic level in the food chain. The prescribed biological oxygen demand (BOD) of river water has been prioritized as threat category 1 if found ≥30 mg/L with coliform microbial populations of 2500 MPN/100 mL. This chapter focuses on such studies, with state-wise analysis of the Indian subcontinent, which pointed out the recent river pollution status, in a concise way along with a brief discussion on the available mitigation strategies for river pollution.