Did the switch to chloramines cause DCs high lead levels?
Too many open questions remain to say definitively what caused the excessively high lead levels in some DC homes. I share the Committee’s hope that the expert team assembled by EPA, WASA, and the Washington Aqueduct will shed new light on these issues and recommend both short and long term solutions. As has been discussed, the primary sources of lead in drinking water are components of the distribution system itself – lead pipes, lead-based solder, and brass fixtures that contain lead. Given the difficulty and expense of removing all sources of lead, EPA’s Lead and Copper Rule is intended to minimize corrosion through appropriate treatment techniques, and prevent these metals from leaching into the drinking water. Clearly, the use of chloramines changes water chemistry, and such changes can have dramatic effects on corrosivity. The addition of ammonia at the treatment plant increases the level of nitrification in water, which can lower pH in the distribution system. Such a change requi
