ANALYZING DISCOLORED TAP WATER FOR ELEMENTS LEACHED FROM AGING PIPES

Since the 1970’s and the formation of the Environmental Protection Agency (EPA), there has been heightened awareness of adverse health effects from lead-contaminated paints, pipes, and gasoline. Decades later, Pb-based pipes remain in buildings built before the 1970’s and can still pose health risks if Pb is leached from the pipes. Due to a pattern of visible discoloration, we investigated the chemical composition of tap water in a public building built in 1962 in Cheney, WA to make an initial assessment of pipe erosion and what elements were associated with the discoloration.

Water was collected from hot tap water upon the first sight of discoloration and analyzed using an Inductively Coupled Plasma—Optical Emission Spectrometer (ICP-OES). Results show that the discolored water had elevated concentrations of Fe, Cu, Pb, and Zn relative to less turbid water. Copper levels of some samples were over 21x higher (>28 mg/L) than the EPA Action Level of 1.3 mg/L. Some Pb levels were also higher than the EPA Action Level of 0.015 mg/L, with some concentrations being over 7x that level (> 0.105 mg/L).

Fe, the primary cause of the reddish brown color in water, exceeded the EPA Secondary Drinking Water Standard of 0.3 mg/L by 10x in some samples (or >3.0 mg/L). This study showed that Fe-rich discolored water from older pipes may be correlated with elevated concentrations of Pb and Cu that leach into the water. Cu and Pb both have serious and known health risks to the public, and this case study helps demonstrate the risks of pipe corrosion in older buildings and homes.