Drinking Water Quality Assessment Of Defence Housing Authority Phase II, Islamabad, Pakistan

Abstract

The present study was conducted to assess the water quality of filtration plants situated in Defense Housing Authority 2, Islamabad, Pakistan. Total of 66 samples were analyzed for physicochemical, heavy metals and micro biological contamination. The results before and after filtration were obtained in the following order. pH ranged before treatment (7.25-8.38) and after treatment (6.72-8.35), EC ranged before treatment (461-678) μS/cm and after treatment (462-711) μS/cm, TDS ranged before treatment (340-545) mg/l and after treatment (351-568) mg/l, Chloride ranged before treatment (11.74-85.26) mg/l and after treatment (11.15-88.52) mg/l, Sulfate ranged before treatment (7.36-16.8) mg/l and after treatment (7.99-19.21) mg/l, Total Hardness ranged before treatment (125-287) mg/l and after treatment (124-311) mg/l, respectively. The results were compared with PAK-EPA standards. It was found that pH, TDS, EC, chlorides, total hardness an sulfates were within the permissible limits. The heavy metal such as Cd, Pb, Ni, Cr Fe, Zn, Mn and As were also tested in the same samples and results showed Cd, Pb, Ni, Cr were above the permissible limits in some samples while Fe, Zn and Mn were within the permissible limits. Arsenic was not detectable in the samples. The microbial analysis of the samples collected before from storage tanks in F1, F2, F6, F8, F9, F11 showed the presence of E. coli. Samples collected after filtration from F1, F4, F8 and F10 showed the presence of E. coli. The reason for higher number of bacterial colonies might be due to inadequate maintenance of water. These results suggest regular maintenance and monitoring of the filtration plants.