Components Testing - Effects of Changing Disinfectants and Other Water Quality Parameters on Lead and Copper Release

摘要

New and used meters and stop valves were provided by participating utilities (SeattlernPublic Utilities and DC Water) and tested using local tap water to measure leaching of lead andrncopper upon exposure to changing disinfectants (free chlorine to chloramines and vice versa) andrnother controlled water quality conditions (pH, alkalinity, phosphate). The tests were conductedrnby a “fill, stand, dump, and refill” procedure. Components were tested at the same time, in thernsame facilities, and using the same water quality as pipe loop testing that was conducted as partrnof this research project. Results showed that high lead and copper levels were measured initiallyrnfrom both new and used components, but levels declined rapidly during baseline tap waterrnconditions. In the absence of phosphate, lowering pH and/or switching from chloramines to freernchlorine resulted in higher metals levels. The lowest lead and copper levels were measured whenrnphosphate was present. After an initial period of conditioning, results from components testingrnprovided supporting data consistent with copper alloy pipe loop testing results.