After months of news coverage talking about Flint, Michigan’s devastating state of emergency for finding lead in its drinking water, USA Today covered President Obama’s trip to Flint with this bit of relief to say: “if you’re using a filter, if you’re installing it, then Flint water at this point is drinkable.”
Flint’s switch to the Flint River as the city’s main water source caused the corrosion of lead into the water systems. Scientists have been hard at work figuring out how to solve the medical issues arising in Flint and improve water treatment systems around the world.
Where has this crisis taken us? We looked into the reality of the ever-evolving process of water treatment, and the science behind its past, present, and future.
The quality of our water is a major part of our country’s future. (Credit: Thinkstock)
How is our water treated?
Water treatment depends on the source—things change depending if the water is taken from lakes, rivers, or groundwater.
“For a river, the main thing would be to remove the solids from the water, or what we call turbidity, that have run off the surface,” said Dr. David Sabatini, David Ross Boyd Professor at the University of Oklahoma, Associate Director of the Institute for Applied Surfactant Research, and Director of Water Technologies for Emerging Regions (WaTER) Center.
“We need to destabilize those particles so that they can clump together and be big enough to settle out of the water, so systems use coagulation and flocculation, which are processes to make those particles clump together more easily and settle out more readily.”
Water treatment goes through multiple stages of filtration before it’s cleared to be used again. (Credit: Thinkstock)
Next, the water goes through sedimentation, which removes larger particles from the water, and later a sand filter, which removes the majority of what’s left behind.
“Those particles can make the water look cloudy or murky, which makes it undesirable, but they also may harbor pathogens or microorganisms which make us sick,” Sabatini explained, noting cholera and typhoid fever as just a few of the water-borne pathogens these particles could be carrying.
For those pathogens, Sabatini described the next treatment phase as a disinfection process using chemicals such as chlorine to remove pathogens. “Chlorine, similar to what we put into a swimming pool to make sure the pool water doesn’t harbor pathogens of concern, or different forms of chlorine together with other molecules like ammonia, would be traditional disinfectants,” he explained.
When treating ground water or river water, scientists must also address localized contaminants dissolving into the source water from the geology surrounding it. “There may be iron or manganese that needs to be removed for aesthetic reasons, and there may be things like arsenic, chromium, or fluoride that are in the water which may cause health concerns,” he said.
As a current resident of the Oklahoma City area, Sabatini used his home as an example: “in Central Oklahoma we have naturally occurring arsenic in our groundwater, and since arsenic is a health concern, it needs to be removed from the ground water for health reasons more so than aesthetic reasons.”
So how do we know when it’s safe to drink?
Never fear: at the Environmental Protection Agency (EPA), there are certain standards and health-based requirements treated water must meet for it to be considered public drinking water.
“The EPA has two levels of standards—primary and secondary,” Sabatini explained. “Primary is based on health concerns (pathogens, arsenic, etc). The water is required to have no more than a certain level of those compounds in it for health-based reasons, so it needs to be treated.”
“Secondary standards for things like iron are not a health-based concern, but are standards for what the general populous would find acceptable and desirable. Since it’s not health-based, secondary standards are not enforced to the same level and degree as the primary standards are,” he continued.
So for Flint, how exactly did the lead get into their drinking water?
The issue surrounding Flint’s water crisis is twofold. “Part of the issue was that the water went from being what we called depositing to being corrosive,” Sabatini continued. “The water was laying down a layer of hardness on the pipe, and over time the pipe was getting slightly smaller and smaller because of the deposits coming out of the water and the hardness sticking to the pipes. Corrosive water attacks the pipe, slowly dissolving the deposits.”
Beyond the water’s corrosiveness, the second part of the issue derives from the origin of the lead. While the lead was not a function of the source water, Sabatini explained that rather it was a function of the pipe, either in the pipe’s material or the possible lead soldering used to join the pipes.
Lead in the pipes started to seep into Flint’s water supply, causing much of the damage seen throughout the community. (Credit: Thinkstock)
“There was a time before we realized the lead, either the lead in the pipe or the lead soldering used to join the pipes, was a health concern,” he said. “When lead paint was first made, we didn’t realize the health risks, but over time those health risks became apparent. Over time we’ve encountered and addressed the lead paint issue, and, in the same way, pipes with lead that previously were used for water systems turned out to create an apparent health issue.”
Many older cities in America and abroad used lead pipes when they were first installed. In 2004 The Washington Post found evidence of high lead levels in the DC water supply. It’s very possible that there are many “ticking time bombs” under our cities that could be the next Flint.
Does this mean water pollutants have caused issues in the past?
Before scientists realized the importance of treating water, there were many outbreaks of water-borne diseases. In mid-1800s London and Chicago, historians account for large portions of each city’s population dying due to these water-borne diseases like cholera and typhoid fever which only decades later were discovered to be introduced through water.
“The number one reason we treat water is to prevent deaths,” Sabatini explained. “In London and Chicago in the 1800s we didn’t even know water was a cause for the outbreak, so we weren’t treating the water for those things at the time.”
London’s growth in the 1800’s caused many health issues including water safety concerns. (Credit: Museum of London)
Modern water supplies aren’t free from health issues. “In Milwaukee, WI there was an outbreak of cryptosporidium, another pathogen that was discovered more recently,” he explained. “As opposed to 150 years ago, we’re talking about 25 years ago. Cryptosporidium was just an emerging pathogen of concern that hadn’t been widespread or prevalent, and all of a sudden it was making its appearance, causing scientists to realize that while chlorine is a good disinfectant, we need to use a UV light or ozone to tackle some of these newer pathogens of concern.”
And, going outside of the United States, the issue is still prevalent in many parts of the world. In countries that have 8-15 percent infant mortality rates where one in seven children die before the age of five due to water-borne diseases, the threat of untreated water is still very much a part of everyday life.
“We don’t realize from which we’ve come,” Sabatini said when speaking about his work with the WaTER Center. “There’s people living in that very situation today, and we have a moral obligation to help those less fortunate than ourselves.”
So what’s next for domestic and foreign water treatment?
Flint was not the only city with a water problem—either in the United States or in the world—which proves one thing: water treatment is an ever-evolving process.
Nanobots could be part of the future of water treatment. (Credit: Thinkstock)
At the WaTER Center, students, professors, and scientists are researching the future of water treatment for a world in which water is becoming a limited resource through both advanced technologies and nature itself.
“With the new field of nanotechnology on the rise globally, we’re looking into ways where we can take advantage of what we learned in nanotechnology as it applies to drinking water treatment,” Sabatini explained. “At the same time, one of the things we’re doing at the WaTER Center is working in Africa and Southeast Asia where people are living at a dollar-per-day without the resources we have and looking for low-cost, in-country materials we might be able to use that might provide a more cost-effective manner of water treatment more accessible to their income level.
“Our hope is that as we’re looking at these cheaper solutions, nature may teach us some things that could help us treat our water more effectively. We’re operating at both ends of the spectrum: let’s take advantage of the most recent advanced technologies, but let’s also, in resource-constrained settings, look at less expensive techniques that might help guide our high-tech approaches.”
While the Flint water crisis appears to be coming to a close, scientists understand the need to continue learning about and adapting water treatment to avoid these issues in the future.
In one such case, researchers are looking into water reuse as a more economically-priced solution to the world’s current water needs.
Developing new water access and treatment techniques is critical for development in developing and third-world countries. (Credit: Thinkstock)
“In addition to withdrawing water from one source and using it, treating it, and discharging it back into the environment, the idea is to capture some of that water we treated and treat it to an even higher level to reuse it,” he concluded.
“In cities looking to supplement their current water source with a new water source, rather than moving water from 20, 30, 50, or 100 miles away, which can be quite expensive, they can look closer to home and say, ‘well, here’s this water supply right here already in our grasp. Instead of waving goodbye to it, maybe we should look into using it.’”
With a resource as vital to our survival and existence, the rising need for both water treatment and solutions to our water-sourcing concerns is becoming a more and more relevant conversation among scientists.
“We tend to take water for granted because it’s so readily available,” Sabatini continued. “As water becomes a more limited resource, we’re going to have to resort to improved technologies and increased treatment costs. I think we need to prepare ourselves to pay more and more for water ,but if you really put it into context, as vital as water is to our very survival and existence, we should be willing to pay more for it than we are.”
But still, as Flint has gained country-wide support for its crisis and now has the ability to drink its water once more (President Obama himself took a sip of it during his speech, indirectly proving this point), domestic and foreign scientists are reminded of how much more research is needed to continue providing the world with one of its most valuable resources.
“It’s very exciting at the WaTER Center to be able to help prepare students and partner with students in addressing those issues and creating a better future for those less fortunate and for all of us,” Sabatini concluded.
“Rising water lifts all ships, so if America can help other countries improve, bring stability, and increase peace around the world, we are fulfilling our global responsibilities.”
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Image credit: Thinkstock
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