Assessment of Drinking Water Quality within the Distribution Network of Rawalpindi

Abstract

The significance of water quality for public health cannot be overlooked. Water is vital to our existence in life and its importance in our daily life makes it imperative that thorough microbiological and physiochemical examinations be conducted on water. In recent past different studies have been conducted to indicate the deteriorating water quality and necessitate remedial measures required to ensure delivery of safe drinking water. In Pakistan, access to safe drinking water falls below satisfactory level. Among the major menaces causing agents are the pathogens that spread diseases. Coliform is adopted as an indicator organism for detecting presence of microbial pathogens, its occurrence or absence is an indicator of the quality of drinking water provided. To counter the prevalence of pathogenic contamination the most common method is chlorine disinfection. Maintenance of chlorine residue is required, at all points, to ensure the safety of drinking water. Therefore investigating concentration of its residuals present in network can be used as an excellent indicator to study microbial quality of drinking water. A comparison of low and high income areas of Rawalpindi on the basis of seasonal fluctuation (wet and dry season) was carried out. The study was basically about investigating the drinking water quality by examining the effectiveness of chlorine disinfectant against fecal indicator bacteria and assessing physicochemical parameters like temperature, pH, turbidity, TDS, conductivity and total residual chlorine. Sampling sites for this study were identified in consultation with the authorities of Water and Sanitation Agency, Rawalpindi. The results obtained regarding water quality of both areas (high income and low income) showed similar trends in both seasons. Physicochemical parameters were within permissible limits. The major findings were the difference in efficiency of chlorine which was found lower in wet season as compared to dry season, giving rise to significantly higher fecal coliform counts. While samples collected from treatment plant and waterworks reservoir were found free of contamination during both season indicating that the water is recontaminated in the distribution system after treatment due to distribution system deficiencies like low pressure, inadequate disinfectant residual, leaks and corrosion and hence needs appropriate maintenance and counteractive measures.