Statistical assessment of seafront and beach water quality of Mumbai, India

The water quality of seafronts and beaches of Mumbai is under pressure and deteriorating due to discharge of partially treated sewage and wastewater through point and nonpoint sources. The objective of the study was to assess the water quality and to correlate physico-chemical and bacteriological parameters for establishing relationship, association and dependence on each other. The water quality parameters were selected as per SW II standards specified by Central Pollution Control Board, India and nutrient parameters as strong indicators of sewage pollution. Box and whisker plots were generated for evaluating spatio temporal variation of water quality which suggest influence of organic pollution mostly at Mahim and Dadar in the form of outliers and extremes. Pearson's correlations were estimated between parameters and found significant correlation with each other indicating influence of sewage on water quality. The water quality of beaches and seafronts were found unsafe for recreational purposes. The study suggested that designated water quality can be achieved by restricting nonpoint source through improvement in wastewater collection systems, appropriate level of treatment and proper disposal.