Reverse osmosis, Multi-Stage flash / effect distillation In Saudi Arabia 
Introduction
I. Seawater Desalination process
1- Reverse Osmosis (RO)
2- Multistage Stage Flash Distillation (MSF)
3- Multi Effect Distillation (MED)
II. The negative impact caused by the desalination technologies.
1- Environmental effect
2- The high cost of desalinated products
III. Conclusion
a- Recommendation