Comparative Study of Ground and Surface Water Quality Assessment Using Water Quality Index (Wqi) in Model Colony Malir, Karachi, Pakistan

Abstract

This study covers the evaluation of the quality of ground water and surface water using water quality index (WQI) for drinking purpose of Model Colony, Karachi, Sindh, Pakistan based on parameters physical, chemical, biological and heavy metals. The ground water samples were collected through boring wells and surface water samples were collected from (KWSB) Karachi Water and Sewerage Board’s water supply system from different locations of study area. Four different locations were selected for collection of water samples using sterilized plastic bottles (1.5L capacity) from 9C, Kazimabad, Abbasi market, and Surti Society. Sampling was done in the evening time (05:00 pm PST). The results were compared with the WHO guidelines. It is concluded that some parameters like Lead and Fecal Coliform (E. coli) are found above from WHO guidelines, some like Arsenic, pH, Turbidity, Total Alkalinity as (CaCO3), Calcium, Chloride, Hardness (CaCo3), Magnesium, Nitrate, Potassium, Sodium, Sulphate and TDS are found below from WHO guidelines. For Water Quality Assessment Weighted Arithmetic Index method is used. WQI categorizes the both sources of water of Model Colony as good quality water. The mixing of sewage water which may infiltrate from the river channels and nala surrounding the study area, results in decreased quality of water. Calculated value of WQI revealed that the ground water with WQI= 25.60 and surface water with WQI= 29.38 are grouped into good category of water quality which indicates that it is unfit for drinking purpose. However, it can be used for the domestic, irrigation and industrial use. However, it can be used Over all public opinion was recorded through checklist at Model Colony causing various health ailment problems. The survey shows that persons found having diseases like Diarrhea 90%, Hepatitis-A 15%, Skin 70%, Eyes problem 45% and Typhoid 65%.