SURVEY AND ANALYSIS OF GROUNDWATER CONTAMINATION IN WASA SUPPLIED WATER WITHIN HOTSPOT AREAS OF RAWALPINDI CITY

Abstract

With the advent of 21st century, rapid industrialization and population growth has resulted in deterioration in quality of natural water reservoirs at global level, thus imposing high human health risks. Accordingly, the accessibility of safe drinking water to common public has become one of the major challenges in developing countries like Pakistan. The major aim of current research was to collect groundwater samples from four zones of Water And Sanitation Agency (WASA) in subdivision of Rawalpindi city (also termed as Rawal Town). Furthermore, eight physicochemical parameters and one microbiological analysis were conducted across 20 hotspots (populated) areas covering forty-six Union Councils (UC) devised by Tehsil Municipal Administration (TMA), Rawalpindi. The results indicated that only 1% of total samples exceed threshold turbidity limit in UC 37, while 5% of total samples for hardness and 7% of total samples for alkalinity in UC 14 were found above national and international standards of water quality namely Pakistan Standard for Drinking Water Quality (PSDWQ) and World Health Organization (WHO) permissible limits respectively. However, other physicochemical parameters including pH, electrical conductivity (EC), total dissolved solids (TDS), chlorides and dissolved oxygen were found within allowable levels for all studied areas. In contrast, fecal contamination was observed for all water samples, as indicated by most probable number test, rendering it unfit for human consumption. Pearson correlation matrix was developed to monitor the relationship between water quality parameters with results indicating strong correlation between “EC with TDS”, “pH with hardness and alkalinity” and “chlorides with EC” at p value less than 0.05. At the end, water quality index (WQI) was developed with results showing excellent rating at UC 29 “Khurram Colony” and UC 30 “Chah Sultan” and poorest rating at UC 37 “Dhoke Dalal” across all studied sample sites. Overall, our findings revealed that microbial contamination in drinking water pose a serious threat to residence of Rawalpindi city and needs special attention to ensure public health safety