Studies on impact of release of liquid industrial waste from soda ash industry in the nearshore water of north Gujarat

Abstract

The nearshore waters of Mithapur, Porbandar and Sutrapada received 18-100 mid (million litres per day) of wastewater from soda ash manufacturing industries either through point discharges (Mithapur, Porbandar) or through submarine outfall (Sutrapada). The impacts of these wastes on the water and sediment quality of the receiving waters are discussed. Due to the density inhibited mixing the effluents tend to spread into a kilometre long milky white patch with high levels of pH, suspended solids and ammonia, along the shores on either side of the point of entry to the marine waters at Mithapur and Porbandar. Effective mixing and dispersion at Sutrapada on the contray favoured marine environmental quality closely comparable to the predisposal baseline within the natural variability of coastal waters. The sediments wherever studied did not indicate any anthropogenic contamination. It is concluded that the pollution impact was localised and the marine life in the intertidal and subtidal regions of Mithapur and Porbandar is exposed to undesirable levels of ammonia