Preliminary Assessment of Wastewater Quality near Emergency Outfalls in Kuwait Bay

Abstract

Twenty-two wastewater discharging emergency outfalls located within Kuwait Bay have the ability to pollute marine life. The quality of wastewater discharged to the sea has a direct and significant impact on the ecosystem including marine organisms, and an indirect effect on human health. The current study aims to evaluate the quality of wastewater discharged at selected sites of Kuwait Bay and to compare the obtained results with the standards of the Environmental Public Authority (EPA) for discharging treated wastewater to Kuwait Bay. Five locations were selected near emergency outfalls, and onsite field measurements for water quality were carried out, including temperature, pH, Electrical Conductivity (EC), and Dissolved Oxygen (DO). Furthermore, 15 mixed water samples (wastewater and seawater) were collected throughout November 2021 and January 2022 during low and high tides and within 1 m away from wastewater discharging outfalls. These samples were analyzed for nutrients, heavy metals, and bacteria parameters. The field results indicated the presence of slight alkalinity (pH 7.01–8.0), freshwater to saline water type (EC, 1.27 ms/cm–65.07ms/cm), oxidized environment (DO, 0.91 mg/l–5.28 mg/l). The laboratory results of water samples revealed that the concentrations of nutrients (total nitrogen, 2.0–35 mg/l) and all targeted heavy metals were detected in mixed samples for all sites in concentrations of microgram per liter and within EPA acceptable limits. On the other hand, phosphate concentration (4.2–13.6 mg/l) and the counts of microbial indicators (Fecal coliform, E. coli, and Fecal Streptococci) were high and above EPA standards, which shows the grave biological pollution that occurred at these sites. The variation in the contamination levels at the selected locations indicates the need for periodic monitoring of the quality of mixed water near wastewater emergency outlets and searching for the appropriate solutions to reduce the contaminated wastewater discharged directly into the beaches.