The Unintended Consequences of migrating to Flint River water

The City of Flint had been purchasing drinking water from neighboring Detroit for almost half a century. With rising water costs rooted in an acute fiscal crisis, the city’s Emergency Manager decided to stop this practice. Instead, the city decided to treat the nearby Flint River for potable use beginning April 30 of last year (2014). This was a temporary move until Genesse County (where Flint is located) and other Michigan counties finished building a ‘Karegnondi Water Authority (KWA) pipeline in 2016. The Flint River basin has suffered from poor water quality for a number of years and the water is difficult to treat. The most recent consumer confidence report further acknowledges that on a scale of 1-7, with 7 being most at risk for contamination, the Flint River is a 7.

Immediately following the switch, consumers started noticing a drastic reduction in tap water quality. Initially it was taste and odor problems. Flint residents have described their water to be blue, yellowish, and even sewerage-like, with unpleasant odors. Discolored water caused by metallic rust, released from unlined cast-iron pipes or iron service lines carrying the water with increasing corrosion occurring along their lengths. Microorganisms like sulfate-reducing bacteria living in the rusty pipes can produce the smell of rotten eggs (i.e. hydrogen sulfide) and render the water acidic.

Figure 2: Exemplary pictures looking into Flint drinking water pipes, showing different kinds of iron corrosion and rust (Photo: Min Tang and Kelsey Pieper)
Figure 1: Exemplary pictures looking into Flint drinking water pipes, showing different kinds of iron corrosion and rust (Photo: Min Tang and Kelsey Pieper)

There were also health concerns associated with multiple violations of the National Primary Drinking Water Regulations, most notably due to Coliform bacteria and Total Trihalomethanes (TTHMs). High levels of coliforms indicate likely fecal (i.e., sewage, poop) contamination of the potable water supply. The Flint River has significant sewage input, and if the treatment plant does not completely remove the bacteria and other dangers posed by the sewage, high coliforms and public health risks can result. The TTHMs are formed when naturally occurring organic compounds (i.e., decaying leaves and grass and plants) present in the water react with the free chlorine, which is added to destroy the fecal bacteria that may be present in the Flint River water (see Dr. Joan B. Rose’s guide to TTHMs in Flint Water). High TTHM levels are a health concern and are suspected to cause a wide array of health problems with long term exposure.

There are also serious concerns with high levels of lead leaching in the water from lead pipes that connect homes to the cities water mains via the service line connection, and also from lead plumbing (i.e., lead solder, leaded brass). See Figure 3 for a detailed schematic. Lead is the best-known neurotoxin and can cause severe learning, neurological and developmental disabilities in both fetuses and children under the age of seven. A Flint household with lead levels measured at 397 parts per billion or ppb by the city (the action level from the EPA is 15 ppb) had a child with increased blood lead level after the switch to Flint water. The high blood lead in the child is even more disconcerting given that the family was not directly drinking Flint water, and the harm therefore arose from either back contact (or indirect ingestion — incidentally consuming water while bathing or from washing dishes, for instance)  or consumption of highly filtered water (two filters were in use). Flint River is very corrosive for iron and lead materials, compared to the water previously purchased from Detroit. Orthophosphates that are commonly added to corrosive waters to minimize lead leaching from aged water distribution pipes made of or containing lead, but water from the Flint River is so corrosive that use of orthophosphate might not provide the normal benefits and might actually make things worse.

Figure 1: Potential Sources of Lead Contamination in tap water of homes, schools and other buildings (Triantafyllidou 2011)
Figure 2: Potential Sources of Lead Contamination in tap water of homes, schools and other buildings (Triantafyllidou 2011)

Clearly, the dramatically increased corrosivity of the Flint River water versus previously purchased from Detroit, and the relatively high contamination of the water from Flint River, has created significant challenges for the Flint Water Department and the City to address. It is possible, that no matter how competent and effectively this source is treated, that Federal Regulations for bacteria, chlorine levels, lead and TTHMs considering Flint’s old water pipe system cannot be met. This issue will be a key subject of our research.

Primary Authors: Ni Zhu and Siddhartha Roy

Acknowledgements: Dr. Marc Edwards, Dr. Brandi Clark, William Rhoads

4 thoughts on “The Unintended Consequences of migrating to Flint River water

  1. Another source of high concentrations of lead in Flint drinking water could have come from the very method of treating Flint river water prior to distribution. According to a study by the Centers for Disease Control:

    “Changes in water treatment and disinfection practices can substantially undermine lead corrosion control (60). In the mid-1990s in the District of Columbia (DC), high levels of free chlorine were used to decrease coliform bacteria in water, a process that inadvertently changed the type of lead mineral coating in the water lines to one with very low solubility in the background pH of the DC drinking water. When the free chlorine was replaced with chloramines, the transformed highly insoluble lead scale minerals were no longer stable and dissolved. Therefore, a substantial level of lead was released from the lead service lines into drinking water at the tap (61). ”

  2. I had no idea Marc Edwards was involved in the District of Columbia’s high levels of lead in drinking water study 13 years ago. The CDC study only referenced his name once and if you try to read the paper on the EPA website you get an error saying the page cannot be found. Mr. Edwards started this page and was the one who responded to Mrs. Walters request for help. He is a true hero in every respect.

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