Our sampling of 252 homes demonstrates a high lead in water risk: Flint should be failing to meet the EPA Lead and Copper Rule

Over the weekend, we analyzed all samples shipped to Virginia Tech from Flint to date. Flint residents have already returned an astonishing 84% of the sample kits we sent out (252 out of 300 samples). We will continue to analyze water samples as they are returned. However, mathematically, even if the remaining 48 samples returned have non-detectable lead, our conclusion will not change — FLINT HAS A VERY SERIOUS LEAD IN WATER PROBLEM.

Forty percent (40.1%) of the first draw samples are over 5 parts per billion (ppb). That is, 101 out of 252 water samples from Flint homes had first draw lead more than 5 ppb. Even more worrisome, given that we could not target “worst case” homes with lead plumbing that are required for EPA sampling, Flint’s 90%’ile lead value is 25 ppb in our survey. This is over the EPA allowed level of 15 ppb that is applied to high risk homes. This is a serious concern indeed. Several samples exceeded 100 ppb, and one sample collected after 45 seconds of flushing exceeded 1000 ppb.

We now advise Flint consumers to heed EPA information that advises consumers on how to avoid adverse health effects from exposure to excessive lead in drinking water. The main concern is related to water used for drinking or cooking. With the exception of one home that we sampled which had astronomical levels of lead, the levels of lead detected in Flint were safe for bathing, showering, toilet flushing and watering lawns/gardens.

Until further notice, we recommend that Flint tap water only be used for cooking or drinking if one of the following steps are implemented:

  • Treat Flint tap water with a filter certified to remove lead (look for certification by the National Sanitation Foundation (NSF) that it removed lead on the label), or
  • Flush your lines continuously at the kitchen tap, for 5 minutes at a high flow rate (i.e. open your faucet all the way), to clean most of the lead out of your pipes and the lead service line, before collecting a volume of water for cooking or drinking. Please note that the water needs to be flushed 5 minutes every time before you collect water for cooking or drinking. For convenience, you can store water in the refrigerator in containers, to reduce the need to wait for potable water each time you need it.

We do not issue this warning lightly, and note that our concern is based on several lines of evidence. First, scientifically, we predicted based on past research that the Flint River water chemistry would create a serious lead in water problem. Second, we confirmed the very high corrosivity of the Flint River water for lead in our laboratory testing at Virginia Tech. Third, for some reason that no one has yet explained to us, the Flint River water was introduced into the pipe distribution system without any measures (or even a plan) to reduce its corrosivity. We are therefore very perplexed by recent MDEQ assertions that the situation in Flint is normal. Finally, we have the results of our survey of 252 homes conducted with the assistance of Flint consumers. Because of the very serious and permanent health damage that arises from lead exposure, we feel that this problem requires immediate public health warnings and intervention– we provide that for Flint consumers in this report.

Another mystery that must be examined very carefully in the days and weeks ahead: How is it possible, that Flint “passed” the official EPA Lead and Copper Rule sampling overseen by MDEQ? In our experience, following the EPA site selection criteria targeting homes with the highest risk for lead, the MDEQ sampling should have found much worse results than our sampling. Instead, MDEQ is asserting that the lead levels in Flint are much lower. Hence, we call on the U.S. EPA and others, to conduct a detailed audit of the 2014 and 2015 LCR sampling round overseen by MDEQ in Flint, to determine if it was conducted consistent with requirements of the law.

Primary Author: Dr. Marc Edwards

Samples Analysis: Dr. Jeffrey Parks, Anurag Mantha

Acknowledgements: Siddhartha Roy

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