Controlling Lead and Copper Rule Water Quality Parameters

The Lead and Copper Rule (LCR), enacted in 1991, was implemented to reduce exposure to lead and copper at consumers' taps. Water suppliers were required to initiate treatment that would reduce corrosion in the distribution system and thereby limit the release of lead and copper. The LCR required the supplier to initiate this treatment, called optimized corrosion control treatment (OCCT), and to monitor for certain water quality parameters (WQPs) to demonstrate that the OCCT was in place. The intent of this study was to determine how well WQPs can be controlled at actual water treatment plants and in distribution systems. In general, the data analyzed in this study demonstrated that utilities can successfully control these parameters within certain ranges, but variability does occur. The use of control charts for monitoring and responding to demonstrated variability of these WQPs is also presented. The value of control charts in observing trends and reacting to variations where appropriate is described.