(JESC) The Journal of Engineering, Science and Computing Issue III, Volume I, April, 2020 74 Environmental Impacts of Phosphate Rocks on the Water Quality of Rivers Abdelkader T. Ahmed, Faculty of Engineering, Islamic University, Madinah, KSA Faculty of Engineering, Aswan University, Aswan, Egypt dratahmed@yahhoo.com Mahmoud Elsayed, Faculty of Engineering, Aswan University, Aswan, Egypt engzezo1111@yahoo.com Brahim Askri National Engineering School of Gabes, Tunisia askrib@yahoo.com Abstract: One of the important natural sediment rocks impacting aquatic environment is Phosphate Rocks (PR). PR comprises from several chemical compositions such as heavy metals. Mining and transportation of PR nearby or through the rivers may expose them to pollution. Some elements such as salts and heavy metals may be leached out into the water, when PR is in contact with water due to dipping in water streams, precipitation events, or changes in water table. In this study via experimental lab work, PR leachability was investigated when it immersed in Nile River. The research work focused on evaluating the release of some constituents, including phosphors, cadmium, chromium and lead of PR on the water quality of Nile by using leaching experiments. In these experiments, the potential impact of changing conditions, such as liquid to solid ratio (L/S) and phosphate content in PR on long- term leaching of phosphor and heavy metals. Results revealed that phosphors and lead were released in high concentrations, while cadmium and chromium leached out in very low concentrations. PR leachate out 32 mg/L of phosphorus into Nile water, which it is too much more than the allowable values for natural streams, i.e. 0.5 mg/L. Therefore, if phosphate rocks are submersed intentionally or unintentionally into Nile river water, this will lead to environmental risks in the area of PR submersion. Keywords: Phosphate Rocks, leaching tests, Water quality, Nile River