Evaluation Of The Performance Efficiency Of Selected Wastewater Treatment Plants Of Islamabad And Groundwater Quality Of The Adjacent Areas

Abstract

The escalating urbanization and industrialization in cities have led to a considerable increase in wastewater generation, posing significant challenges to water resource management. This study investigated the water quality of wastewater and groundwater in Islamabad, Pakistan, focusing on five sewage treatment plants (STPs) and their surrounding areas. The study analyzed heavy metals and biological, chemical, and physical factors. Excessive levels of pollutants (physicochemical, biological, and metals) were detected in the sewage wastewater, and groundwater beyond the limit allowed by the Pakistan EPA. The groundwater samples from different sectors showed varying levels of bacterial contamination. In some sectors, the total bacteria count exceeded permissible limits; coliform presence indicated poor water quality in others. Regular monitoring and remedial actions are necessary to ensure groundwater quality meets safety standards across different sectors. Groundwater pH values exceeded the lower limit, while EC and temperature were within limits. Some samples exceeded the permissible TDS and salt limits, and turbidity levels were high in one sample. Wastewater pH, salts, turbidity, and temperature surpassed limits but slightly decreased after treatment. All chemical parameters for groundwater were within the recommended limit of Pak EPA. Some values exceeded the acceptable limit for wastewater, including alkalinity and BOD. Groundwater heavy metals varied, with some samples exceeding acceptable limits for Mn and Fe. Some wastewater samples exceeded limits for Cr, Cd, and Mn before treatment but showed a decreasing trend after. Pb and Fe were within limits. Different sewage treatment plants showed varying effectiveness in removing pollutants from wastewater. Tele Gardens STP had high removal efficiencies, while Multi Gardens STP had lower removal efficiencies. Zaraj Housing Scheme STP was effective for removing heavy metals, but River Gardens STP showed lower removal efficiencies. CDA STP was effective in removing turbidity from wastewater. These findings highlight the need for ongoing monitoring and improvement of sewage treatment processes to maintain consistent water quality standards. The findings underscore the importance of proactive measures to mitigate the adverse effects of wastewater discharge on groundwater quality and safeguard public health and environmental integrity in Islamabad.