In a method for the hydroprocessing of renewable feeds in a hydroprocessing unit (unit A), comprising the use of sour waste water from the same or another unit (unit B), which is processing feeds containing sulfur and nitrogen, as wash water in unit A, thereby changing the pH of the waste water from unit A to lower the risk of carbonic acid corrosion of corrodible steel parts in unit A, the renewable material in unit A is directed to contact a material that is catalytically active in hydrogenating the renewable material in the presence of hydrogen, and the effluent is combined with the wash water stream which contains hydrogen sulfide and/or ammonia.