The corrosion aggressivity of wastes of recycled motor oils deposited in "oil lagoons" was evaluated in order to solve liquidation of these wastes. For this purpose, steel piles covered by various coatings or without any surface protection had been sunk in different parts of three oil lagoons for about five years; their corrosion attack was then determined . The results of the long-term exposition of either unprotected or surface - finished carbon steel in the actual lagoon conditions were completed with the short-term corrosion tests of several materials exposed to the waste samples from different layers of the lagoon depth profile.