Description: Recently, Mayor Karen Weaver of Flint, MI declared a state of emergency, based on the results released by Hurley Medical Center, confirming “what many Flint parents had feared for over a year: The proportion of infants and children with above-average levels of lead in their blood has nearly doubled since the city switched from the Detroit water system to using the Flint River as its water source, in 2014.” (Retrieved from We have been involved in Flint since April 2015, when we analyzed the original samples from Lee-Anne Walters house that first demonstrated hazardous waste levels of lead in water of the city. More information about our team, our goals and training is here: Dr. Marc Edwards, Siddhartha Roy and Anurag Mantha will be answering your questions, today. We will do our best to answer all questions in a chronological order.

Our Proof: (Please see the top right section for the AMA info)

EDIT: This AMA is no longer live. If you have any more questions, please comment and we will do our best to answer them at our earliest possible convenience. All questions so far were answered by either Sid or Anurag.

Comments: 113 • Responses: 34  • Date: 

OwMySocks34 karma

Hi, I grew up in Flint and have been following this closely for a while now. First I wanted to thank you guys so much for this, and for posting so many updates on I really think you have done a great thing here for the people of Flint. My questions:

  1. I've seen a lot of people in various comment threads putting the onus on homeowners in Flint to update the plumbing in their houses, and because the issue was corroding pipes, that the city/state is not responsible for the damage, the homeowners are. Is the plumbing in houses the main source of lead, or are there city-owned/operated pipes that have this issue?

  2. I've also seen a letter from the governor's office that states that childeren in Flint have had elevated blood lead levels in the past as well, do you know if that is the case? Do you know what a normal percentage of a city's population with elevated blood lead levels is? Do you know a good public resource for information like this? If someone unknowingly had elevated blood lead levels as a child, would they be able to tell as an adult? (Asking for...a friend...who grew up in what looks like a hot spot for high lead in water)

  3. Now that the city has switched back to Detroit water, is the amount of lead in the water in Flint homes going back down? Has the switch to the Flint river caused lasting damage to the system that might only be fixed by new pipes?

  4. While you were conducting this study, at what point did it switch from "oh here's an interesting thing to research, maybe something's up" to "oh crap, sound the alarm because this is severely dangerous"?

Thank you again, your work has been amazing.

flintwaterstudy-vt38 karma

1 - Lead can originate from lead service lines (pipes connecting mains to the home), lead solder used in plumbing in old homes, brass fixtures (from before 2014) and pipes like galvanized iron which have some lead in it. The city's water source for 50 years has been Detroit water which is very non-corrosive and also contains orthophosphate - a corrosion inhibitory chemical - and lead levels in Detroit (and in Flint until 2014) were way below the EPA's action level. So, since it is the water switch (and not practicing corrosion control treatment) that caused lead to start coming off, the decision by the emergency manager and all authorities is to blame. On a side note, the Lead and Copper Rule specifically calls for "shared responsibility" in that the lead pipes on the side of the homeowner's property are the homeowner's responsibility -- but homeowners across the country are not aware of this. But overall the lead is originating from both lead pipes and home plumbing. Not all lead is from home plumbing. LeeAnne Walters' home had plastic plumbing (everywhere) and she had hazardous waste levels of lead coming from her lead service line.

2 - Both lead paint/dust and lead in water are the most likely sources of lead. But we don't know what specifically could be the reason of high lead levels in the past. We have requested the state's data on children's blood lead and haven't received a response yet. Here is some background: We don't have data on what blood lead levels in other cities looks like. Here is some info on blood lead levels during the Washington DC lead crisis: Lead exits the human body pretty rapidly without leaving any traces behind. So, it is hard to say as an adult if you were exposed to it as a kid even if you show symptoms at a later stage.

3 - Yes, we are seeing a downward trend in lead levels in the water but the water is still not safe to drink. Please continue using lead filters. The Flint river water has caused irreparable damage and accelerated the aging of an already old and crumbling water infrastructure. The best long term solution, of course, is new pipes.

4 - We sent out 300 lead sampling kits and started getting those back in less than two weeks. Our hypothesis was a significant lead in water problem based on what we knew about Flint's water treatment from EPA's memo and testing at the Walters' home ( In the first 24 kits we received, at least 1 in 3 had significant lead. This was alarming enough! We released those results and an additional 48 kits later, we knew this was dangerous and widespread. - Sid

willsteerforORRI12 karma

Can't you just take a sample from a person's faucet, then at the connection to their house, then at the city water facility, and work your way upstream until you isolate where the lead is coming from?

flintwaterstudy-vt4 karma

Lead originates in lead service lines (pipes between water mains and your home) or any lead-bearing plumbing in the home. So, scientists usually perform what's called "profile testing" where we take consecutive water samples, map the internal plumbing of the specific home, and calculate whether the water (and the lead in it) originated from the faucet, home plumbing and/or lead service lines.

digitalreporter19 karma

What is your reaction to the announcement last week that independent Professional Service Industries Inc (PSI) was hired by the City of Flint to test at least 150 homes for not less that $45K and not more than $75K?

Why didn't your team get this contact?

A quick Google search shows that PSI has had creditably issues in the past.

Example: Lawsuit describes widespread corruption, racketeering during site work at Spanish Fort Town Center

flintwaterstudy-vt14 karma

We welcome additional testing as it is the need of the hour.

In terms of our reaction to the contract, we weren't asked to do it, so we don't have a reaction.


Just came here to say GO HOKIES!

I guess i need a question...

Do you guys ever go down to McCoy to test the water there? Just curious how it is because it is one of my favorite swim/fishing areas.

flintwaterstudy-vt7 karma

Go Hokies!!

Nope. But take a water sample next time you are there and we can test it for you.

lockd0wn10 karma

What does the team think is the most likely source of the iron?

Is personal filtration (whole house water filters) a good solution for the residents short term?

flintwaterstudy-vt14 karma

The main source of iron is the iron mains in the water distribution system.

Yes! Point of Use, NSF (National Sanitation Foundation) certified filters are the easiest way to protect oneself from lead.

1tudore10 karma

Based on the available evidence, what are the likely medical outcomes for the affected population?


How much can support for this population be projected to cost?


Looking at the reporting on exploitation of individuals with lead poisoning from housing in Baltimore, what kind of non-medical hazards can the people affected expect to face?

flintwaterstudy-vt15 karma

These are great questions! Unfortunately, these are also hard questions to answer considering we are environmental engineers and not doctors/physicians. We would not like to speculate on something we are not experts on.

However, Flint, as a city, is facing enormous challenges in terms of poverty, violence and low nutrition which all have an impact on the trajectories of the lives of their kids and lead poisoning will only make it worse.

1tudore3 karma

Ah, wrong kind of Dr. My mistake.

As environmental engineers, have you encountered or reviewed case studies where similar levels of lead poisoning occurred in a single community?

Are there contemporaneous or historical analogues we can learn from as we try to mitigate the consequences of this disaster?

flintwaterstudy-vt9 karma

There is a great book if you are interested on this topic by Werner Troesken called "The Great Lead Water Pipe Disaster." Yes, the Washington DC Lead in Drinking Water Crisis (2001-2004) is a great example of lead poisoning:

The Romans knew of lead poisoning over 2000 years ago and we know more about lead than most neurotoxins. There is no dispute regarding how bad lead exposure can be. Exposure from water is completely preventable and therein lies our big opportunity. Considering that many old cities in the US (DC, Philadelphia and New Orleans, for example) and Europe have lead pipes, there are disastrous consequences to not constantly monitoring and strengthening the Lead and Copper Rule (LCR - in the US) to ensure populations do not drink lead-tainted water without their knowledge. Public education is a huge part of mitigating consequences of elevated lead in the water. Tell people if there is a problem! Tell homes you tested if you find high levels in their kitchen tap. The LCR is being revised by the US EPA as we speak and there are efforts of watering it down and the consequences would be unimaginable if that happens. Read here: - Sid

digitalreporter8 karma

Is data being collected in Flint regarding stillborns? If not, why not?

Stillbirth rates tied to lead in drinking water

flintwaterstudy-vt10 karma

We don't know and we hope that the medical centers in Flint are making a note of this, in light of conclusive evidence of high amounts of lead in drinking water.

EDIT: Dr. Edwards has repeatedly made it known that he is ready to help in whatever way possible.

sabatoa7 karma

Has your team attempted to determine the reason that the Flint River was more corrosive than than the Detroit-sourced water? I understand that one factor was the lime softening process, and another was the lack of corrosion controls. But was or is there anything else adding to the corrosion levels of the Flint River?

flintwaterstudy-vt8 karma

Yes, along with the reasons you mentioned above, one more reason adding to the corrosivity of Flint River water is the use of Ferric Chloride (FeCl3) as a coagulant in the water treatment process. Ferric Chloride adds chloride to the water, which increases the chloride to sulfate mass ratio of the water and makes it more corrosive.

Another reason may be the use of salt for keeping the roads from freezing in the winter.

digitalreporter6 karma

Why isn't the lead toxicity in older adults being discussed?

Are Flint morgues collecting data on lead toxicity? If not, why not?

flintwaterstudy-vt8 karma

We agree that there should be a discussion on the effects of lead in adults.

However, children and senior citizens are the most susceptible population.

We do not know if Flint morgues are collecting data on lead toxicity.

myomentumisgreater4 karma

Is there a good, reasonably priced home testing kit for consumers, for testing their water for this or other contaminants? (If the same problem happens in other cities, we need to detect it sooner.)

Also: how absolutely wonderful to engage the students in the water testing project.

flintwaterstudy-vt6 karma

We would recommend taking advantage of the free water testing provided by the City. The only thing you need to be careful of is that the testing kit has bottles with small openings, so when you fill the bottle, fill it at high flow.

myomentumisgreater2 karma

I'm thinking of what the residents of other cities can learn from Flint. Looking at the test prices, per contaminant, it looks like it really adds up. Any prospect of testing becoming simpler (and less expensive) in future? (And equally or more accurate.)

flintwaterstudy-vt1 karma

The best way would be to contact one's nearest water testing lab (doesn't have to be affiliated to a water utility/agency) and ask them to run a water sample. In Flint, one such test was ~$60. And so these are expensive. Cheap water test kits from Walmart or elsewhere are typically presence-absence tests and won't give you a good estimate of how much lead is in there (and therefore, how bad the situation really is).

Roach27914 karma

Are you guys taking a break tonight to see star wars?? What is the first step to dealing with this disaster and how did the lead get there in the first place?

flintwaterstudy-vt4 karma

Ha ha. Anurag is a Star Wars geek and so he is probably going. I (Sid, here) will probably go watch something else.

Exposure to lead in water is completely preventable if the population is aware of it. Therefore, as soon as one finds out about a potentially widespread problem, the first step is public education. Go all out and inform everyone about this so that people can take action to protect themselves and their families. In the case of Flint, some families kept drinking the water for 17 months! This is unacceptable for something totally preventable. -- When you are testing for lead and find 10% or more homes with high lead (according to the Lead and Copper Rule), you are supposed to "optimize corrosion control." What that means is you modify treatment, adjust water pH, change the dose of corrosion control chemicals, etc. to ensure the lead leaching drops.

Source of lead: Lead can originate from lead service lines (pipes connecting mains to the home), lead solder used in plumbing in old homes, brass fixtures (from before 2014) and pipes like galvanized iron which have some lead in it. The city's water source for 50 years has been Detroit water which is very non-corrosive and also contains orthophosphate - a corrosion inhibitory chemical - and lead levels in Detroit (and in Flint until 2014) were way below the EPA's action level.

So, switch to Flint River's corrosive water (and not practicing corrosion control treatment) is what caused lead to start leaching into the water.

Roach27913 karma

So is everyone just on bottled water for now? Are they paying out of pocket if they are?

flintwaterstudy-vt5 karma

Free filters and replacement cartridges are being distributed to Flint citizens and we hope this support continues for at least 6-12 months so that people don't have to spend out of their pockets to buy bottled water. It will be a huge burden to bear on an already stressed population.

digitalreporter3 karma

Will boosting the volume of phosphates in the water solve the problem of lead leaching? If so, how long would it take?

Exactly, how effective is the "biofilm" in lead leaching? Can 0% "lead leaching" be achieved?

Due to the damaged lead pipes in the Flint water system will the residents ever be able to NOT use water filters?

flintwaterstudy-vt6 karma

Optimal dosing of phosphates will solve the problem of lead leaching. Detroit water has phosphates. We anticipate that it would take 1-2 months for the system to stabilize, but more testing is required to achieve a good degree of confidence.

Phosphate forms a protective coating on the inside of the pipes by reacting with the metal. This is different from a biofilm, which is a layer formed by microorganisms in the water.

0% lead leaching cannot be achieved as long as there is some lead in the system in the form of lead solder, brass fittings, lead service lines or galvanized iron or steel (which contain lead).

We recommend that the citizens of Flint keep using point of use filters at least till June 2016. As we go along, more testing will lead to a conclusive answer.

It is always better to protect oneself from the risk of lead poisoning.

whocoulditbe1133 karma

Hi! I grew up in Flint and still have family there, so thank you for the good work you are doing to help everyone understand and fix this (major) problem. I actually have a couple questions:

  1. What needs to be done to fix this is both the short and long term? Is the only FULL solution to completely replace the existing water infrastructure?

  2. Will/can the Flint River ever be a viable source of water for the city?

Thank you!

flintwaterstudy-vt8 karma

  1. Short term solution is to stay on Detroit water. The ideal long term solution is to replace the existing water infrastructure to remove all sources of lead (lead service lines, brass fittings, lead solders and galvanized iron and steel pipes). As that is a mammoth undertaking, there are measures in place in the Lead and Copper Rule, to ensure that lead does not find its way into the water (corrosion control).

  2. Flint River water is extremely corrosive and is not a "viable" source for the city.

blackblitz5 karma

Hi, I am with the company who just finished a water main leak detection survey in flint. Your long term solution of replacing the water mains will never happen, and is not viable. Even with no delays, it would take over 90 years to properly replace the pipe, even at 110% the average replace rate.

A lot of your solutions in this thread are not viable, and would never work in the real world.

Sil144 karma

What are the average sizes of the mains that run throughout the city? What about slip lining the main trunk lines that service the majority of the system to reduce lead leeching into the system? Since you say that total replacement is not an option, obviously identifying and replacing portions of the system with the highest concentrations of lead/oldest would still be an option? Of course if Flint river water is that corrosive, it is only compounds the issue. Realistically, you cannot remove ALL sources of possible lead contamination - its not possible, like you said. Brass fittings and lead solder is not necessarily a problem.

blackblitz5 karma

about 50% of the city disregarding downtown is 8-12 inch Cast Iron pipe. the problem with slip lining is that all of the house / business service corps, and all valves would need to be redrilled into the slip lining, which just in downtown is 300+ corps / valves. It would be too much of an undertaking, and would have the same timeline as complete replacement, with similar costs.

They are currently building a new transmission main that would come directly from Lake Huron, rather than take Detroit's water.

The main issue with this group, and others of the same, is that they are focusing on too large of goals, and thinking the main problem is Lead. The bottom line is the problem is more than just lead. Lead isn't the worst thing in the Flint water system, the system is the worst thing.

*Edited for correctness, I wrote this in a hurry

AndyAndrophile3 karma

Your criticisms and commentary seemed plausible and salient until that last line.

blackblitz1 karma

That is what we were told by someone at the City of Flint Water,

flintwaterstudy-vt3 karma

I (Sid, here) agree that eliminating all sources of lead is impossible.

Lead issues aside, the aged iron mains have corroded significantly too. And such pipes cannot last forever.

Finally, if there are other big issues in the current distribution system that are relevant towards safeguarding public health and saving our water infrastructure, we hope you are working diligently to fix those and will also let the public know if it concerns them.

JambaJuiceJrinker1 karma

Why is Flint water so corrosive?

flintwaterstudy-vt1 karma

Please see our response above to an earlier similar question.

myomentumisgreater2 karma

Is there a "supervisory" federal or state agency that tests occasionally to corroborate the results of a city's testing program?

flintwaterstudy-vt6 karma

While the City, and specifically, the Department of Public Works was responsible for operating and monitoring Flint’s water treatment and supply, the Michigan Department of Environmental Quality (MDEQ) is the “primacy enforcement authority” for over 1,500 community water systems (or water utilities) in the state of Michigan, including the City of Flint. MDEQ is, therefore, tasked with enforcing the federal Safe Drinking Water Act.

In layman's terms, MDEQ is the "policeman" but it doesn't do any testing on its own. It just checks what the City reports to them. Here is what they did in Flint:

myomentumisgreater2 karma

If you were to design a "second-order testing" state program, what would it cost, ballpark estimate, per city? Is this something that a sane government would do, or is there a better way to address the problem that a city's testing might not be reality-based?

flintwaterstudy-vt4 karma

According to one estimate, Flint has over 15,000 lead service lines and to the best of our knowledge, no one knows where most of them are. Prolific testing (esp. testing again and again in homes/schools/hospitals/businesses/prisons/other facilities) where we and the state found lead problems should definitely be carried out to monitor reduction in lead levels.

The Lead and Copper Rule (despite some flaws) has been in place since 1991 specifically to protect the public from being exposed to lead. The LCR requires testing and re-testing of high risk homes (known to have lead pipes) and taking a minimum number of samples periodically to detect and mitigate lead spiking in water. If the LCR was properly followed in Flint, this wouldn't have happened. We wouldn't need a "second-order testing" program then (of course, provided water utilities are not cheating on their sampling). - Sid

GovernorOfReddit2 karma

Has there been any positive things that have surprised you while working in Flint? Anything in the community that has inspired you in a city that has seen much turmoil?

flintwaterstudy-vt4 karma

Yes! The the steadfast dedication of "Flintstones" and many many allies has been a major driving force in this issue developing the way it did. Dr. Edwards has repeatedly said that Flint is a miracle, in terms of how fast things changed. This was due to the combined effort of so many heroes. Heroes, who may just have saved the next generation of Flintstones from the terrible monstrosity of lead poisoning.

peewinkle2 karma

They are merely testing the water samples from Flint; they are in Virginia

flintwaterstudy-vt2 karma

We've been to Flint four times so far. Their energy, dedication and warmth were priceless to us. In the past five months, Flint citizens have showered us with immense love and appreciation both in person and through countless correspondence via emails and social media. I'm (Sid, here) even proud that LeeAnne calls me her friend.

dandydaniella1 karma

Hi Marc, I recently heard your talk at AEESP about the Washington, DC lead contamination. I wanted to first say that attending that talk was one of the highlights of my year. You, and those that worked with you to uncover the DC water contamination, are true heroes.

I wanted to ask, how do we get ahead of lead contamination? It seems like we hear about this issues after it's already causing adverse health effects. Is there something we can do now to find lead contamination before it reaches the levels its reaching in Flint?

flintwaterstudy-vt2 karma

I couldn't agree more. I (Sid here) was at the talk too and I cannot even begin to imagine the pain and suffering the whistleblowers and scientists like Marc went (and are still going) through.

Forcefully implementing the Lead and Copper Rule and fixing its loopholes would be a good start. Continued public education should be a priority for all utilities even if they are meeting the LCR. Flint was brought to attention by residents when the agencies failed to do their job and protect the public. There probably are other Flints in the country which are not as serious but need attention and fixing. The LCR shouldn't be seen as something a utility needs to meet, but use its "intent" to protect the health of the population.

madpiano1 karma

I live in London, an old Victorian house, so my mains is a lead pipe. It's probably been here for 150 years. We have very hard water, chlorine is added (not chloramine) and no fluoride. How dangerous is that lead pipe and should I filter my water? Can I assume that due to the hard water and the pipe lying there undisturbed for so long, it has a nice coating of limescale and is safe?

flintwaterstudy-vt1 karma

We cannot comment on the safety of your water, as we haven't tested it. However, it cannot hurt to get your water tested. I'd highly recommend that as a first step.

slayer_hulk21 karma

Based on the trajectories of the same, is that lead pipe and should I filter my water?

flintwaterstudy-vt1 karma

We cannot comment on the safety of your water, as we haven't tested it. However, if you are worried about lead in water, it is better to be safe and use a filter.

BondoMondo1 karma

Why is 25ppb even an issue? The allowable level is 15ppb. How is this a "hazardous" waste level of lead in water?

flintwaterstudy-vt3 karma

Again, there is no safe level. Any lead is not good to begin with. 5000 ppb classifies as 'hazardous waste'. Sampling is Ms. Walters' home was as high as 13200 ppb.

cdsvoboda1 karma

I just finished a graduate course on aqueous chemistry, and our final exam included a case study where we modeled water samples with PhreeqC. I'm guessing it was probably some very similar techniques to what you used on this study.

Can you comment, for the layperson, in what was involved in conducting your study?

I think a lot of people hear our conclusions, but don't realize the mass amounts of work and background knowledge that go into solving these issues.

flintwaterstudy-vt2 karma

We followed the method of reporting the lead levels from the Lead and Copper Rule (LCR). This involved analyzing samples on an Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) and reporting the 90th percentile value of lead concentrations.

WitchsTitinaBrassBra1 karma

I am a student in Flint. When do you think the water will be safe to drink again?

flintwaterstudy-vt2 karma

In about 6 months, the overall lead levels in the city should come down to pre-switch levels. Keep in mind that there is no "safe" level of lead in drinking water.

WitchsTitinaBrassBra1 karma

When will water in Flint be safe to drink again?

flintwaterstudy-vt3 karma

In about 6 months, the overall lead levels in the city should come down to pre-switch levels. Keep in mind that there is no "safe" level of lead in drinking water.

TheNiceSociopath1 karma

What would be the best way to go about testing the water in my local area?

flintwaterstudy-vt1 karma

We would recommend taking advantage of the free water testing provided by the City. The only thing you need to be careful of is that the testing kit has bottles with small openings, so when you fill the bottle, fill it at high flow.

Edit: If you are not from Flint, you can still contact your Water Utility if you are worried about your water.

dirkthesexytoddler1 karma

Let's go?

flintwaterstudy-vt2 karma


Vrilmachine0 karma

With the recent trends on cancer pointing to environment more than genentics stuff like this is terrifying. We have been duped for 15 years now that bottled water was a neccesity. Amazing how we are living in a time where our parents had cleaner water and a cleaner planet.

How long has Flint leadership known about this?

BrodyApproved0 karma

What does your ideal breakfast consist of?

flintwaterstudy-vt0 karma

A very good question. I (Anurag) am not a breakfast person. Cannot comment on the others.

Metalmessiah950 karma

Tell me more about environmental engineering?

flintwaterstudy-vt2 karma

Helps fulfill your childhood dream of helping people and serving society. Gives you tools to understand, quantify and, hopefully, solve some of the world's most pressing issues. High stakes because your decisions carry power and can help or hurt millions. Most rewarding in many ways. - Sid