Abstract: An apparatus for providing permanent decantation and separation of solvents miscible or nonmiscible in water, which are nonconductive and are absorbed by activated carbon. Water containing the solvent is passed through a decanter separator for separating nonmiscible solvent from the water solution. After flowing through the decanter separator, the solvent saturated water is gravity fed to a filter element of microscopic porosity for absorbing solvent dissolved in the water. The water is then passed through a detection cell which is connected downstream of the filter element. The detection cell includes a solvent vapor detection head connected to an electronic circuit controlling alarms. Air is bubbled through the water and the detection cell to accelerate evaporation of the solvent dissolved in the water. If any solvent is present in the air, the detection head activates visual and sound alarms.