Because the source water in Oakwood, Ohio, is extremely hard, the city installed ion exchange softening at one of two main well fields. Believing the ion-exchange softening process to necessarily make a more corrosive water than conventional chemical softening, the Ohio EPA required the city to determine the impacts the softening would have on internal corrosion. USEPA joined the city to expand the city to result in a better understanding of the use of pilot systems and monitoring at the tap for prediction of the corrosion of lead, copper, and iron in water systems. Tables summarize the metals concentrations in the tap samples. The average lead, copper, and iron concentrations in the tap samples were not significantly different before and after softening. Part of this observation may be attributed to the fact that so many of the houses have water softeners on the cold water lines.