There have been several instances where water purified from seawater by reverse osmosis has caused accelerated corrosion of carbon steel pipes. Therefore research was undertaken to determine the corrosion rate of 1010 carbon steel in water with different contaminants with and without aeration and at different velocities. The results show that in high purity deionized (DI) water with oxygen the corrosion rates were initially very high but dropped rapidly within a few hours to <100µm/yr. In jet impingement of DI water with oxygen the corrosion rates dropped even lower approaching zero because the steel passivated. Water analysis from offshore Gulf of Mexico platforms showed that reverse osmosis units would typically leave behind contaminants of NaCl and Na2SO4. Adding contaminants to the DI water increased the corrosion rate proportionally. The water contaminated with 351 ppm NaCl and 26 ppm Na2SO4 experienced no passivation of the steel. In jet impingement with this water containing oxygen there was accelerated corrosion of the carbon steel at ~5000 µm/yr. The corrosion mechanism was not erosion corrosion but rather accelerated pitting of the carbon steel under a thick brown/black layer of rust. If the oxygen was removed the corrosion rates decreased to ~600 µm/yr.