Abstract: A waste water treatment apparatus is located between an industrial plant and a municipal sewer to treat and control the flow of waste water from the plant to the sewer. The apparatus includes an equalization basin, a water clarifier mechanism, and a flow rate control mechanism for maintaining a relatively constant water flow rate through the clarifier in spite of major changes in water level in the equalization basin. The flow rate control mechanism includes an upstanding water column and a pump for delivering water from the equalization basin to the column. The column establishes a constant liquid head for controlling water flow through the clarifier.

Abstract: A system for removing tetrachloroethylene impurity from water includes two or more adsorption columns in series flow relation. Each column has a upper layer of clay granules and a lower layer of activated charcoal granules. The liquid moves in a downflow direction through each adsorption column.