Status and Variations of Ecological Parameters of Domestic Sewage Inflow at Niccopark and Vanivihar Wetlands of Bhubaneswar, India

Abstract

To assess the status of water quality of municipal wastewater and to quantify the sewage flow in two important locations of Bhubaneswar City, Orissa, viz., Vanivihar and Niccopark wetlands, composite samplings at hourly intervals were carried out for 96 hours in every three months during 2003-05. In general, the inflow of wastewater at both the sites was maximum during 9-11 am, and the variations were in line with the probable water use pattern of the surrounding community and time of travel from different sources. However, the variations in rainy season sampling were largely influenced by the rainfall pattern. At Vanivihar, the nutrient load during pre-monsoon, monsoon and post-monsoon season were 11.72, 7.55 and 9.58 mg/l as total inorganic nitrogen and 2.05, 3.46 and 2.67 mg/l as phosphate, while the BOD5 level was 132, 103 and 126 mg/l, respectively. The mean population of total coliforms were 7.6, 5.71 and 5.27 x 105 CFUs/100 ml; faecal coliforms 3.59, 2.69 and 2.73 x 105 CFUs/100 ml; faecal streptococci 2.83, 2.78 and 2.29 x 105 CFUs/100 ml; and Salmonella 0.88, 0.76 and 1.6 x 105 CFUs/100 ml during pre-monsoon, monsoon and post-monsoon samplings, respectively. The corresponding levels of different parameters at Niccopark were 13.86, 8.68 and 11.1 mg/l; 2.58, 3.72 and 4.19 mg/l; 145, 109 and 134 mg/l; 7.87, 6.94 and 4.23 x 105 CFUs/100 ml; 4.35, 3.8 and 2.85 x 105 CFUs/100 ml; 4.02, 2.6 and 2.4 x 105 CFUs/100 ml; 1.1, 0.83 and 1.01 x 105CFUs/100 ml. Record of high concentration of nutrients, organic load and microbial pathogens in two sampling sites throughout the sampling period indicated that water drained into the downstream is heavily contaminated.