Chlorination and water quality monitoring within a public drinking water supply in Rawalpindi Cantt (Westridge and Tench) area, Pakistan

Abstract

Concern over the presence of fecal coliform in public drinking water supplies has been expressed in recent years in Pakistan since it has been regarded as pathogenic organism of prime importance in gastroenteritis. Two major drinking water distribution systems in the Cantt area of Rawalpindi district covering the Westridge and Tench areas was monitored over a 2-month period to determine the prevalence of fecal coliform and chlorine residual. The collected samples were examined for total chlorine, free chlorine residual, chloramines, total coliforms, fecal coliforms, and turbidity. The drinking water quality monitoring in the distribution network was performed by collecting samples from water source, overhead reservoir, and residential taps. In the Westridge area, total chlorine varied from the lowest value of 0.27 mg/L at Station # W-5 to the highest value of 0.42 mg/L at Station # W-2, total coliforms varied from 1.1 to 3.6 most probable number (MPN)/100 mL with presence of Escherichia coli in all samples, total dissolved solids (TDS) ranged from 199.5 to 205 mg/L, conductivity fluctuated between 399 and 411 microS/cm, and turbidity varied from 0.43 to 0.73 NTU. In the Tench area, the value of total chlorine ranged from 0.14 mg/L at Station # T-7 to 0.55 mg/L at Station # T-1. Total coliform varied from 3.6 to 5.1 MPN/100 mL and fecal coliform were detected at all the stations except at Station # T-1. TDS ranged from 201.4 to 257 mg/L, conductivity varied from 343 to 513 microS/cm, and turbidity ranged between 0.66 and 1.55 NTU. It is recommended to the respective agencies to ensure that the chlorine residual is available at consumer end.

Drinking water quality monitoring and surveillance for safe water supply in Gangtok, India

“…Chlorine residuals of drinking water have long been recognized as an excellent indicator for studying water quality in the distribution network (Lienyao et al 2004;Hashmi et al 2009). To assess the water quality at consumer end with respect to residual chlorine and bacterial quality and enroute contamination in the distribution network, 13 representative sampling points were selected, out of which 11 sampling points belonging to Selep WTP and two sampling points to VIP complex WTP, receiving water from different reservoirs.…”

The Challenges of Water Pollution, Threat to Public Health, Flaws of Water Laws and Policies in Pakistan

“…In Pakistan contamination of drinking water with industrial wastes and municipal sewage coupled with lack of A. Jabeen et al water disinfection practices and quality monitoring at treatment plants is the main cause of the prevalence of waterborne diseases [31]. Around 62 percent of Pakistan's urban and 84 percent of its rural population does not treat their water, resulting in 100 million cases of diarrheal diseases registered in hospitals, with 40 percent of deaths attributed to drinking polluted water.…”

Combating Accidental Microbial Episodes by Back-Ground Chlorine Residuals in a Scaled-up Distribution Network (Rig) Using a Central Composite Design (CCD)

“…1 reduces to Eq. 2 based on p values depicted in Response Table III, as given under: Ln (CFU/mL) = 11.90 -0.66 A +2.32B -0.11C -0.50 D+1.62E-0.41E 2 (2) The equation describes the effect of most influential factors very well, depicting the microbial episode as the main factor in the failure of distribution system and a main causative agent in the spread of water borne diseases. The other factors are pipe length, flow rate and background chlorine residuals and time.…”

“…Surface run-off, cross-connection and the leakage of sewage disposal systems as well as septic tanks" wrecked or leaking pipes, back siphonage from a plumbing fixture or cross-connection into a water supply line and intermittent water supply are some other reasons behind the bacterial nemesis of the drinking-water industry, especially in developing countries [2].These external contamination events can act as a source of inoculum, introducing nutrients and resulting in the decrease of residual disinfectant concentrations within the distribution system, causing degradation of water quality. A poorly maintained distribution system can act as a vehicle for S. Rasheed and I. Hashmi are with the Institute of Environmental Sciences and Engineering, School of Civil and Environmental Engineering, National University of Sciences and Technology, Islamabad, Pakistan (e-mail: sajidarasheed@iese.nust.edu.pk, imran.hashmi@iese.nust.edu.pk).…”