The effect of tertiary treated sewage effluents on the plant cover and the physico-chemical properties of the surface soil (environmental characteristics) before and after the Al Rass sewage plant was investigated. The data were illustrated via TWINSPAN and canonical correspondence analysis (CCA). Five sites, 1 km apart, after the discharge point and one site (control site) before the sewage plant were examined. Eleven vegetation characteristics and ten physico-chemical properties of surface soil were studied. The obtained results revealed that discharging of treated sewage effluents altered quantitatively and qualitatively the pattern of species dominance and the physico-chemical properties of the soil. Soil electrical conductivity (EC), total dissolved solids (TDS), organic matters (OM), soluble cations, and soluble anions showed increased values compared to the control (resulting in salination), whereas soil pH decreased as a result of sewage disposal. It was also noticed that the physico-chemical values of EC, TDS, Ca ++ , Mg ++ , Na + , Cl -after the sewage plant were higher than the permissible limits for agriculture recommended by FAO, whereas K + and HCO 3 -were within the recommended values.The dominance of Suaeda vermiculata Forssk. ex J.F.Jmel. after the sewage plant and its absolute absence before the sewage plant may be used as an environmental bioindicator of pollution.

A total of 132 plant samples from the aerial and underground parts of Halox-ylon salicornicum, Pulicaria undulata and Suaeda vermiculata, collected from Wadi Al Rummah, before and after Al Rass sewage Plant, were examined to assess their heavy metal contents. The results revealed highest Fe content and lowest Cd concentration in the three plant species examined. The aver-age metal concentration pattern in the aerial parts were: Fe> Mn> Zn> Cr> Cu> Ni> Pb> Cd. The concentrations of these eight elements in the aerial and underground parts were species dependant, but Mn was found to be pre-dominantly highly accumulated in the aerial parts, whereas Cu had the ten-dency to accumulate in the underground parts. The three plant species stud-ied, showed a decrease in Mn concentration and increased values in Zn, Cu, Fe, and Cr both in the aerial and underground parts after the Sewage Plant compared to their concentrations before the Sewage Plant (control.). The high accumulation of Cr in the plants examined (compared to typical concen-trations, suggested that the wild plants of the area should be used with cau-tion to feed livestock. The results also showed that P. undulata had the high-est accumulation of Zn, Cu, Ni, Fe, Mn and Cr, whereas the underground parts of H. salicornicum showed highest values for Pb and Cd.