The problem of lead in the water in Washington, D.C. could occur (or may already be happening) in a number of other U.S. cities.
Higher temperature, low-pH, and dwell time of water in contact with these components are among the factors that tend to increase the lead concentration in water seen at the tap. Strategies which may be employed by municipalities in dealing with lead in their distribution systems include chemical addition, or intentionally coating pipes with a precipitate or film layer, which acts as a barrier between water and the offending lead source - thus significantly reducing corrosion rates. Once introduced, these strategies can prove very effective at keeping lead corrosion to a minimum.