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Flint: Bitter lessons learned

Facts about the water quality crisis in Flint, Michigan are in the paper almost every day and the chemistry and toxicology of what went wrong, at first blush, appear to be fairly straightforward and easy to understand. Prior to 2014, Flint received its drinking water from Lake Huron, as administered by the Detroit Water and Sewerage Department. That water was low in salinity and also contained an orthophosphate corrosion inhibitor. When the water supply was switched to the Flint River, as administered by the Flint Water Treatment Plant, the salinity increased eight fold and despite the corrosive nature of the water, no corrosive inhibitors were added to protect Flint’s water delivery system.

There were two major consequences associated with the subsequent pipe corrosion. First of all, the corrosive action of the salty water caused iron to leach from delivery pipes, turning the water a rusty red. The iron in turn bound up the disinfectant (chlorine) that was added to the water, thereby negating its antibiotic potency, causing outbreaks of water borne bacterial diseases. At the same time, the corrosive action of the water also caused lead pipes to leach lead into the water supply. For some unlucky tracts of houses, the lead concentration dramatically increased. Lead is a dangerous neurotoxin particularly in children, and elevated blood lead levels are a serious concern as they are associated with impaired IQ and an increased likelihood for anti-social behavior.

Flint River in Flint MIchigan
The Flint River circa 1979. By U.S. Army Corps of Engineers, via Wikimedia Commons

The science underlying Flint’s drinking water issue, as delineated above, is fairly easy to understand. However, the issue is more complicated than that, in that the causes of the lead toxicity are deeply rooted and the remediation may prove to be vexingly complicated.

The lead tragedy in Flint is yet another body blow to a city that is already reeling from urban decay. At its heyday, Flint was a town of 200,000, with more than 80,000 of the residents being employed by General Motors. GM has pulled out of Flint, lock, stock and barrel, with the corporation currently employing only 5% of the employees that it did during the boom years. The economic collapse has caused an exodus from the city, as it has lost over half of its population. The loss of the tax base, in turn, has led to a concomitant lose in infrastructure, and the services to the citizens of Flint, have been compromised.  Since 2008, the city’s police force has cut by half the number of sworn officers. Similarly, since 2005, approximately 5,000 homes, representing 10% of the city’s properties, have been demolished. Flint is a city that is falling apart from the inside out. 

The collapse of a city’s infrastructure puts its residents at risk. Abandoned real estate can lead to greater risks of violence and bodily harm, just as a reduction in a city’s tax base can lead city officials to make regrettable infrastructure decisions. In Flint, the issue may be less about "how did this happen," but more about what components of an already weakened community infrastructure will collapse first, and what will be the consequences?

Symptoms of lead poisoning (raster)
By Mikael Häggström, via Wikimedia Commons

The failure of the drinking water system in Flint has touched the hearts of the American people and aid, much of it in the pragmatic form of bottled water, has poured into the city. The aid is well directed, as it is imperative that children within Flint do not drink lead-laced water, for the only truly safe concentration of lead in drinking water is none at all. The federal government’s action level for lead, the concentration at which remediation in deemed necessary, is 15 parts per billion. Fully 10% of tested households in Flint have been found to have lead levels exceeding 25 ppb. Children cannot safely drink this water, therefore swift and immediate action was, and continues to be, necessary. 

It may also be important to recognize that the lead pipes in Flint have been used for decades, and the lead issue was only realized when the water source was switched to the salty Flint River.  The reason why lead pipes could be used with minimal intoxication for so long is that an inner scale or patina forms on the pipes over time entombing the metal ions, the lead and iron, preventing them from leaching into the water. The corrosive nature of Flint River water damaged the patina, and allowed these ions to be liberated. While it is true that the patina would redevelop over time if the water source was switched to a less corrosive one, such as the deep water of Lake Huron, it is much too late for that now. The only real recourse is to dig up the lead pipe and replace it.

In Flint, there is a house on McClellan Street that holds the distinction of having the highest levels of lead in its tap water. The concentration was found to be 1,000 ppb, over 65 times higher than the government’s action levels. Given the severity of the lead issue at this household, it was one of the first to have its delivery pipes dug up to be replaced.  But there was a surprise. The water lines entering the house on McClellan Street were made of copper, not lead. Clearly, the lead in the tap water at this house was not coming from lead pipes, but may have been coming from the solder that was holding the copper pipes together. The house on McClellan Street clearly illustrates that putting the lead genie back into the bottle may prove to be much more difficult than it first appeared.

The tragic collapse in Flint’s water delivery system cannot be dissociated from the social and economic realities of the city. At its heart, the lead issue in Flint is more complex, and the solution may prove to be more difficult to develop, than it would first appear. Sadly, this may be the bitter lesson that Flint has to teach us.