Due to changes in the Drinking Water Act, all the small systems I am responsible for at work need to have the capability of having chlorinators added, if the health sample at the well head fails. Currently the systems have down hole pumps, with pressure tanks. To operate the chlorinators correctly, I need to have some kind of a tank where the chlorine has time to act on the microbes before the water is released into the pipe network that feeds the buildings. Does anyone know of any tanks that are dual purpose. The standard pressure tanks, would work if they had some way of making the first water in the first out.