Oil/water separator

An Oil/Water Separator apparatus includes a portable container advantageously having rigid sides, including spaced apart side walls and rigid floor. Within the rigid container are defined at least two, advantageously, three chambers in an adjacent array in a downstream direction. The chambers are separated by rigid separating partitions or baffles rigidly mounted to, so as to extend between, the opposite side walls of the container. Adjacent chambers are connected in fluid communication therebetween so that influent water containing oil to be separated may enter into a first upstream reservoir chamber. The influent water is deposited into the reservoir chamber. A downstream partition or baffle separates the reservoir chamber from the downstream coalescing chamber. The first partition has an opening under a lowermost edge thereof. Water passes under the partition from the reservoir chamber into the coalescing chamber. In the coalescing chamber, mounted in the water flow path, is a coalescing pack releasably rigidly mounted between the partition and a weir partition rigidly mounted to the floor. Emulsified oil within the water flow coalesces within the coalescing pack and is separated as oil droplets flow upwardly to the water surface within the coalescing chamber. The water flow leaving the coalescing pack is directed downwardly so as to pass into conduit passing over or through a downstream weir partition so as to flow into an outlet chamber.