This paper suggests an approach to solve the Indian coastal water quality management problem based on waste load allocation studies and application of modelling techniques. The waste load allocation procedure suggested in this paper assists in deriving a quantitative relationship between the waste load discharged and the receiving coastal water concentrations or effects of concern as presented by water quality standards. The approach sequentially addresses the topics of hydrodynamics, mass transport, water quality kinetics and problems of bioaccumulation and toxicity.
The water quality modelling section describes the role of water quality modelling in WLA procedure. The paper also discusses the criteria and procedures for formulation of coastal zone management plans. The second part of the paper illustrates the concept with the help of brief case studies wherein simple screening procedures and the water quality modeling techniques have been applied. The first case study describes the application of the WASP model to arrive at the level of treatment required for municipal wastewater being discharged into Mumbai coastal waters so that the designated coastal water quality criteria is not violated and the degree of treatment is optimized. The second case study deals with the study of different options relating to disposal of tailings from an iron ore beneficiation plant keeping in view the impact of these tailings on marine water quality and ecology.