The quality of marine water around a sewage outfall

A major sewage outlet located close to Shuwaikh Harbor discharges raw and c reated water from the Al-Ardhiya sewage treatment plant, as well as raw sew age from a pumping station. It also receives input from Kuwait Internationa l Airport. The area has been spotted for its characteristic foul smell main ly because of stagnant water at the outlet. Therefore, samples were collect ed from eleven fixed stations at high tide and six stations at low tide to examine water quality parameters, NO3, NO2, NH3, SO4, S-2, PO4, BOD, COD, T OC and heavy metals Pd, V, Cd, Ni, Mn, Cr, Cu, and total fecal coliform. Th e results of the physical and chemical analyses for both high-and low-tide samples along with microbiological analyses indicate that the Shuwaikh mari ne area is polluted. The pollution is high near the discharge point and dec reases with distance. The data revealed a lower level of chemical pollutant s 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 move ment helps reduce pollution in the area, for improvement of the situation t o the desired level, biological wastewater treatment is suggested to remove most of the organic matter before discharge. Also, extension of the discha rge outfall pipe to the open sea area would help reduce trapping of effluen t in the coastal region and check fouling in the area. (C) 1999 IAWQ Publis hed by Elsevier Science Ltd. All rights reserved.