Abstract: Method and apparatus are provided for treating salt water. In the method, a feed water is run through a skimmer unit to form de-oiled water. The de-oiled water is passed through an electrocoagulation unit to form electrocoagulated water. A precipitating agent is added to the electrocoagulated water and stirred to form a water/floc mixture. A polymeric coagulation enhancing agent is added to the water/floc mixture with mild stirring and coagulants in the mixture are permitted to settle. A partly clarified water from the mixture is drawn out from a level above the settled coagulants. The partly clarified water is run through at least one settler and coagulants are removed from the bottom of the at least one settler. A clarified salt water stream is withdrawn from the final settler. The necessary equipment can be mounted on a trailer. The trailer can be provided with a stairway and catwalk to facilitate safe inspection.