Abstract:
A large number of pollutants find their way into the surface water bodies due to their increased use for waste disposal. Subsequent to their disposal, the pollutants undergo a set of complex transformations as they get transported in the water body. The result of these transformations, through the process of self assimilation of the water body, is a net decrease in the level of pollutants with time. An overuse of these bodies, however, could result into significant deterioration of the water quality.
For instance, significant oxygen depletion can occur at downstream reaches of a slow moving river receiving large discharges of biodegradable organics. Similarly, sustained disposal of indadequately treated industrial waste in lake could built up the nutrient levels giving rise to an algal bloom under adverse meteorological conditions. To protect the water bodies for their abstractive and instream uses, it is necessary to control their assimilative use by means of effluent and/or surface water quality standards.
