Flint, MI, is currently suffering from a "perfect storm" attributable to out-of-control corrosion of its aging potable water distribution system. The hypothesis is that these circumstances will also create severe chemical/biological health risks for Flint residents, including elevated levels of lead and opportunistic premise plumbing pathogens in drinking water. Preliminary data collected has revealed extraordinarily high levels of lead, with average concentrations over 20 minutes of water use exceeding 2,000 ppb (> 200 times the World Health Organization allowable levels for lead in potable water).
The main objectives of this research are to: 1) compare levels of chlorine, iron, fecal indicator bacteria, opportunistic premise plumbing pathogens, and corrosion-inducing bacteria present in water mains of a distribution system with uncontrolled corrosion (Flint) versus surrounding cities/counties still using non-corrosive water, 2) profile opportunistic premise plumbing pathogens occurrence in hot and cold potable water systems at these same locations, and 3) determine if there is evidence of elevated lead in Flint homes, and, if so, forensically determine the links to iron corrosion in the distribution system. The elements of the "perfect storm" currently include: under-appreciation of the role of corrosion control in sustaining urban potable water systems and increased corrosion due to higher chloride in Flint's new source water. The high rates of corrosion occurring in Flint are releasing high levels of iron to water and consuming chlorine disinfectant, which our most recent laboratory testing has indicated will increase lead release to water and growth of opportunistic premise plumbing pathogens in cold and hot water plumbing systems. The unfortunate but unique opportunity offered by Flint's current situation, provides an ideal opportunity to field test our recent discoveries regarding potentially adverse consequences of iron corrosion on chemical/microbiological water quality at field rather than laboratory scale. The general results and approach used herein can inform residents and managers of other U.S. cities, who will soon be dealing with similar problems associated with failing potable water infrastructure exacerbated by increased chloride in water due to excessive use of road salt and rising sea levels.
