Drinking water quality and environmental monitoring in rural areas of district Malir Karachi

Water plays an essential and critical role in human life. Fresh water is one of the most important resources, crucial for the survival of all the living beings. Human and ecological use of water depends upon ambient water quality. The Karachi division in the southern Sindh Province of Pakistan includes a number of industries and is responsible for major contamination of freshwater resources. Contaminants like microorganisms, chemicals, toxic substances, industrial effluents, fertilizers, pesticides and municipal wastewater can make water unsafe for drinking and other domestic uses. The present work is focused on the rural areas of district Malir, Karachi where water supply schemes/systems are not available and human population use mainly groundwater directly without any treatment. Water pollution is one of the major concerns nowadays. Typically, nullahs (drainage lines), collect and carry untreated sewage which then flows into streams and rivers, resulting in widespread bacteriological and other contamination. This leads to damage to the environment and risks for human health e.g. Chronic health effects, skin lesion, circulatory problems, nervous system disorders and risk of cancer. Rural areas in Pakistan are based on scattered villages which, more often than not, lack any organized sewerage system. Therefore, the resulting sewage infiltrates into the soil and causes groundwater pollution. Keeping the focus on above mentioned problems, this masters’ thesis is designed for water sampling and drinking water quality testing in the rural areas of district Malir, Karachi(DMK). The sampling was carried out with the field team of Pakistan Council of Research in Water Resources (PCRWR), Karachi Pakistan. The drinking water samples were analyzed for different physicochemical and bacteriological parameters including, pH, electrical conductivity (EC), turbidity, total dissolved solid (TDS), alkalinity, chloride (Cl⁻), carbonate(CO₃) and bicarbonate(HCO₃), total hardness, magnesium (Mg), calcium (Ca), nitrate (NO₃), fluoride (F⁻), sulfate (SO₄), potassium (K), sodium (Na), arsenic (As), iron (Fe), total coliform and E.coli. Altogether, 35 drinking water samples were collected and analyzed. The results were then compared with WHO/NEQS limits and guidelines pertaining to quality of water for human consumption. It was revealed that out of 35 drinking water samples 14% were beyond the safe limits for physical parameters. The 60% of water samples were observed to be unfit for human consumption due to the presence of inorganic constituents beyond the safe limits prescribed by WHO/NEQS. Whereas all the drinking water samples were observed to be unfit due to existence of coliform bacteria. However, 46% of these were fecal contaminated due to presence of E.coli. Overall results indicate a critical need for better sanitation infrastructure in the area including water and wastewater treatment