Survey of bacteriological surface water quality (Nahr Ibrahin River, Lebanon)
The Nahr Ibrahim catchment area is classified as an international heritage site. Along the Nahr Ibrahim River, solid and liquid effluents have an important impact on bacterial contamination. Physico-chemical and bacteriological parameters were studied at nine sampling sites located along the Nahr Ibrahim River from its source to its estuary. Total bacteria, total coliforms, fecal coliforms and fecal streptococci were studied during dry and wet weather periods. During these periods, the studied parameters revealed an important influence of the type of soil and leaching on the bacteriological composition of the river. Furthermore, the origin and the degree of temporary bacteriological contamination were identified. A multivariate statistical approach demonstrated that the effect of site location masked the effect of sampling date on the degree of bacteriological contamination. Downstream river sites were characterized by nitrate and bacterial pollution whereas upstream sites showed only by bacterial contamination.