Water quality assessment of Lebanese coastal rivers during dry season and pollution load into the Mediterranean Sea.

The chemical and microbiological properties of Lebanese perennial coastal rivers were studied during the dry season extending from July to September 2004. The results indicate significant levels of pollution in all eight rivers. Although many physical and chemical variables were within WHO guidelines for drinking water, coliform levels were unacceptably high indicating pollution from untreated sewage. The most polluted rivers in most categories were the Abu Ali and Antelias. With the exception of bacterial and phosphate loadings, Awali River provides the highest amount of pollution to the Mediterranean mainly due to its high water flow, although it is one of the least polluted rivers. The urgent need for controlling wastewater dumping into river streams is emphasized. The data obtained should serve as a reference point to assess the efficiency of planned wastewater treatment plants.