The Quality of Marine Water Around a Sewage Outfall

Abstract

A major sewage outlet located close to Shuwaikh Harbor discharges raw and treated water from the Al-Ardhiya sewage treatment plant, as well as raw sewage from a pumping station. It also receives input from Kuwait International Airport. The area has been spotted for its characteristic foul smell mainly because of stagnant water at the outlet. Therefore, samples were collected from eleven fixed stations at high tide and six stations at low tide to examine water quality parameters, NO3, NO2, NH3, SO4, S2, PO4, BOD, COD, TOC and heavy metals Pd, V, Cd, Ni, Mn, Cr, Cu, and total fecal coliform. The results of the physical and chemical analyses for both high-and low-tide samples along with microbiological analyses indicate that the Shuwaikh marine area is polluted. The pollution is high near the discharge point and decreases with distance. The data revealed a lower level of chemical pollutants and fecal counts at high tide than at low tide. This is mainly because of the dilution caused by incoming seawater at high tide. Although tidal movement helps reduce pollution in the area, for improvement of the situation to the desired level, biological wastewater treatment is suggested to remove most of the organic matter before discharge. Also, extension of the discharge outfall pipe to the open sea area would help reduce trapping of effluent in the coastal region and check fouling in the area.