Season 7

[SOUND EFFECTS: Seagulls, Seaside waves, used with permission of Creative Commons Attribution License]

STEVE FRANDZEL: The idea and the practice of turning saltwater into fresh, drinkable water is old news. Really old. Aristotle mused about desalination in the fourth century B.C. Here’s what he wrote: “Salt water, when it turns into vapor, becomes sweet, and the vapor does not form saltwater again when it condenses.”

[MUSIC: “Yonder Hill and Dale,” by Aaron Kenny, used with permission of YouTube Audio Library]

In the second century, probably earlier, Greek sailors did exactly what Aristotle was talking about. They boiled seawater in bronze vessels and trapped the rising steam in sponges hanging above the cauldron. When the sponges were saturated, they squeezed the precious liquid into storage jars. Even the Old Testament mentions desalination. Kind of. When the people following Moses grumbled that they were running out of drinking water, he threw a log into a brackish spring, and, with a little divine intervention, turned it to fresh water.

RACHEL ROBERTSON: Nice intro, Steve.

FRANDZEL: Thanks Rachel.

ROBERTSON: I like how you worked in a quote from Aristotle, too. Very classy.

FRANDZEL: You could even say classical.

[MUSIC: “Symphony No. 5,” by Ludwig van Beethoven, used with permission of YouTube Audio Library]

ROBERTSON: Well, I could, but I think I’ll leave the puns to you.

[MUSIC: “Symphony No. 5,” by Ludwig van Beethoven, used with permission of YouTube Audio Library]

It’s pretty interesting, though. I hadn’t really thought about how old desalination is.

FRANDZEL: You might also be surprised to learn how widespread it is. Today, there are thousands of desalination plants in 150 countries that produce almost 30 billion gallons of fresh water every day. In the U.S. the largest desalination plant, located in Carlsbad, California, produces 50 million gallons every day. The technology is a fixture in the global effort to supply water for a huge chunk of the world’s population that struggles to find clean water. But it has a its limitations.

ROBERTSON: I knew there had to be a catch.

FRANDZEL: Well, it’s expensive – arguably, the most expensive of all water supply alternatives. Estimates generally put the cost of desalinated water at $3 to $4 per 1,000 gallons, which is a lot pricier than options like stormwater recovery and water recycling and reuse.

ROBERTSON: Okay, now that we understand the problem we can get to my favorite part -- the research! Maybe we should introduce ourselves first.

FRANDZEL: I’m Steve Frandzel.

ROBERTSON: And I’m Rachel Robertson.

[MUSIC: “The Ether Bunny” by Eyes Closed Audio used with permission of a  Creative Commons Attribution License  .]

NARRATOR: From the College of Engineering at Oregon State University, this is Engineering Out Loud.

FRANDZEL: So, earlier episodes this season have emphasized the absurdly small amount of accessible, fresh, clean water on the planet, but I think it bears repeating: Of the unimaginable volume of water on, in, and above the Earth, we humans rely on only 0.75 percent for our survival, and much of that we squander thoughtlessly -- until all of a sudden, we notice that it’s disappearing. Or just gone.

ROBERTSON: That’s why I was really excited to find out that we have a researcher here at Oregon State who is working on the age-old problem of desalination, so that more people facing water scarcity can have reliable access to clean, fresh water. His name is Bahman Abbasi. He’s an assistant professor who works at OSU-Cascades in Bend, and he just received a $2 million award from the Department of Energy. And over the next three years, he’ll be leading a team of researchers to develop a modular, portable, self-contained desalination plant. We got the opportunity to talk to him when he was in Corvallis, and one thing that impressed me was the passion he brings to his research. I asked him why this project is so important to him.

BAHMAN ABBASI: A lot of people are needlessly suffering because of water scarcity. There's a lot of water pollution. And even here in the U.S., look at Flint -- the tragedy that unfolded in Flint was a big motivator for me. In order to cut costs, the Michigan government did something inexcusable. But it doesn't have to be like this. It is really heart-wrenching when you see these people, these children, suffer, agricultural products suffer, their livelihoods suffer, when 70 percent of the planet is water. If only you could use it.

FRANDZEL: Finding a better way to use salt water is the focus of a national effort by the Department of Energy, which has committed $21 million for 14 different projects, of which Bahman’s is one. The purpose of this program is to accelerate the development of solutions that are more accessible and affordable to communities in desperate need of reliable fresh water, including areas that are not connected to the electric grid.

ABBASI: The problem is that because of climate change and climate patterns, the amount of water that is distributed between different locations is changing. A lot of wet places are getting a lot wetter, to the point of floods and a lot of undesired consequences. And a lot of the drier places are getting much, much drier. And, this change in distribution of water brings severe scarcity to certain regions. And, it is fortuitous that a lot of these regions have large bodies of saltwater, or brackish water nearby. So if we have technologies that can use seawater to produce potable water in an efficient, modular, portable way, it can solve a lot of humanities problems.

ROBERTSON: Here in the rainy Pacific Northwest, water desalination is not something we spend a lot of time thinking about. So, the question in my mind was how do they even do this? Bahman explained that there are two different approaches to desalination.

ABBASI: Very broadly speaking, there is the thermal way, by heating the water and basically distilling the water. There is the membrane-based technologies, that people force water through semi-permeable membranes, where salt is kept on one side, and clean water is allowed to pass through the membrane. So we have two routes to do it: membrane-based and thermal-based.

FRANDZEL: Among the various thermal-based desalination processes, the oldest and most common is distillation – which is how those sailors made their own fresh water supply a couple millennium ago, using the sun as their source of power.

ROBERTSON: Both methods use a lot of energy. Because oil-rich countries like Saudi Arabia have plenty of that, they use the thermal method, burning fossil fuels to heat and then distill water. Desalination plants in the U.S. tend to use a membrane-based technology called reverse osmosis, which also uses a lot of energy, and is only economically viable for really large plants because of the efficiencies of scale. And as Steve mentioned at the beginning, large plants are very expensive to build and the water they produce has to be pumped over long distances.

ABBASI: In order to solve these problems, we need to make water production very modular and portable so it’s closer to the point of consumption, so it’s not just point-sourced. You can take it where you need it. And that brings a lot of challenges. You lose the advantage of size. In a lot of engineering systems, the bigger you make them, very roughly speaking, the more efficient and cost-effective they become. So, if you shrink them, you lose a lot of your efficiency and a lot of times, a lot of your cost-competitiveness. So one of the biggest challenges was how do you shrink the size of the system without sacrificing your energy efficiency, and while maintaining your economic viability. The way that my proposed technology is different is, it is thermal-based, but efficient..

FRANDZEL: And just to break in here, under the right circumstances, Bahman’s proposed system can operate independently from the electrical grid by tapping solar power.

[MUSIC: "White River," by Aakash Gandhi, used with permissions of a Creative Commons Attribution License]

ABBASI: it is also small-scale, and modular, and portable. So, you have modules that are like half a typical desk in size, and you can stack them up and have your desired throughput, your desired production, put them in containers, and ship them around to where you need them. They don't need to be permanent installations, they don't need a lot of electricity; they're pretty much self-contained so they can produce water where it is needed.

ROBERTSON: More specifically, Bahman’s system will use high-speed air jets to atomize and evaporate incoming saltwater.

ABBASI: It's kind of like how if you blow too hard on a bowl of soup, how it just splashes all over the place, it’s the same phenomenon.

ROBERTSON: I love the imagery of that but I still wasn’t quite getting it.

ABBASI: Let me try this. Imagine you have a puddle of water, seawater, and you inject high-velocity air jets from the bottom of it. You atomize it, and in the process it gets evaporated.

FRANDZEL: Now you’re left with humidified air that’s laden with water and salt particles. Later in the process, the humid air is dehumidified by cooling it. The fresh water condenses out, and the salt is collected separately.

[MUSIC: White River, Aakash Gandhi, used with permission of YouTube Audio Library]

ABBASI: So, you can use your air as a conveyor, and you can, not easily, but you can get the humidity out of it. The point is we don't distill, we humidify and dehumidify, and that little distinction gives us a lot of energy and efficiency advantage.

FRANDZEL: One of the technological advancements in Bahman’s system will be that less energy will be required compared to other desalination systems that use humidification and dehumidification. In addition, the process will allow the heat required to humidify the air to be recovered, so very little energy is wasted. The air is recycled so that it can be used again to absorb more moisture in the humidification phase.

ROBERTSON: But how all that works is part of the technology that Bahman is still working on and hasn’t patented yet, so he has to be careful with how much he reveals.

ABBASI: People have been doing this. But the traditional systems to do this have major problems. They have a lot of fouling problems, they need air blowers, they need water pumps. And I designed ways around all of those problems in order to maintain the advantages – the energy and cost advantages – of a humidification-dehumidification process without the drawbacks of fouling and requiring a lot of electricity.

ROBERTSON: What Bahman means by fouling is that the salt gets deposited everywhere in the system and clogs things up. Shutting down the system to clean it would mean losing efficiency. This is where his modular system has an advantage. In the case of fouling, just one module can be shut down for cleaning while the rest of the system keeps producing fresh water.

FRANDZEL: And his system also addresses environmental issues. Other desalination systems produce a concentrated brine at the end of the process. It’s called waste brine and typically it’s twice as salty as seawater.

Usually, that super-salty brine is just dumped back into the sea. But that can severely harm marine life, unless it’s sprayed over a large area, which is, of course, expensive and inefficient. The final byproducts of Bahman’s system, though, will be freshwater and salt solids – no brine. That’s called zero-liquid discharge

ABBASI: So we get all the water out, and the other byproduct is just solid salt. And salt has value. You can sell it as a side revenue. And seawater has predominantly sodium chloride, table salt -- which is sellable, but cheap. But most importantly, it has magnesium chloride, which is the feedstock or the base material to produce magnesium metal. And basically, all of magnesium production in the U.S. is done from magnesium chloride, which is found in seawater. So, when we succeed – I'm not going to say "if," – when we succeed and we have this zero-liquid discharge, so just water and just salt and magnesium chloride can be separated out and be used to produce magnesium metal. It's avoided environmental cost that adds benefit and distinguishes the process from others.

ROBERTSON: Okay. And so you feel pretty confident that you can do this?

ABBASI: Oh, yes.

ROBERTSON: So, why, what gives you that confidence?

ABBASI: I've been working on this for a long time. I've been doing a lot of analyses and a lot of thinking on this. I've spent the last several years understanding what technologies have worked, and why, what technologies haven't worked, and why, and bring pieces together. It's still a research project - so there is a chance that something might go wrong. Fundamentally, there is no reason that it will not work. It will work; whether or not it will be as energy efficient as I project it to be is a matter of design and research.

[MUSIC: "Fur Elise," by Ludwig van Beethoven, used with permission of YouTube Audio Library]

ROBERTSON: As we mentioned at the top of the show, this is a story that’s just getting started, and we are planning on following this research to find out if Bahman is successful in achieving his goals of efficiency.

I want to leave you with some more of Bahman’s passion for his work which also answers the question of why we should care about desalination here in the Pacific Northwest when we still have plenty of water.

ABBASI: A lot of major achievements come about from being outward looking trying to address problems that are not directly affecting me today, but is affecting my country, is affecting the world.

I have a large proposal under review for treating fracking water. We don't do fracking in Oregon. The earthquakes in Oklahoma, it's not my business, but, I don't think about it this way. I think we should be as an institution, as academics, outward-looking, not live in our own sphere and I think it can make for a much richer society, much richer institution, and a much more successful one. I would have not been able to bring in this award without collaborations with people all over the country, coast to coast, literally. If we do this, we can be successful and build a much richer and more successful community.

ROBERTSON: This episode was produced and hosted by me, Rachel Robertson,

FRANDZEL: and me, Steve Frandzel, ...okay, let’s do that again.

[MUSIC: “Symphony No. 5,” by Ludwig van Beethoven, used with permission of YouTube Audio Library]

ROBERTSON: This episode was produced and hosted by me, Rachel Robertson,

FRANDZEL:and me, Steve Frandzel, with additional audio editing by Molly Aton.

ROBERTSON: Our intro music is “The Ether Bunny” by Eyes Closed Audio on SoundCloud and used with permission of a Creative Commons attribution license.

FRANDZEL: Other music and effects in this episode were also used with appropriate licenses. You can find the links on our website.

ROBERTSON: For more episodes, visit engineeringoutloud.oregonstate.edu, or subscribe by searching “Engineering Out Loud” on your favorite podcast app.

FRANDZEL: Bye now, and stay hydrated.

ROBERTSON: What are you most excited about for this project?

ABBASI: I'm excited by getting a good night's sleep after it's all done.

ROBERTSON: Sounds good.

[Music: “A Fistful of Dollars Theme Song” by Ennio Morricone]

JENS ODEGAARD: The wind whistles out on the dry, tumbleweed flats of the Columbia River plateau, it’s like something out of the classic Clint Eastwood film “A Fistful of Dollars.” Here, way out in the middle of northeastern Oregon god’s country, there’s a ghost town, or something close to it.

The Umatilla Chemical Depot.

Opened in 1940, the depot received its first shipment of munitions in 1941. And over the years, everything from mustard and sarin gas to TNT and another type of high explosive called RDX were stored there.

Today, all the chemical weapons have been destroyed, and the site’s officially closed down, but under the surface there’s an issue that needs resolving.

[Music: “A Fistful of Dollars Theme Song” by Ennio Morricone]

It won’t be solved by a man with no name. But there are a couple of folks who have a plan.

JACK ISTOK: Yeah, my name is Jack Istok, I’m a professor of civil engineering.

MANDY MICHALSEN: My name is Mandy Michalsen, I’m an Oregon State University graduate. My degree was in civil and environmental engineering at Oregon State, and so I worked with, Jack, of course, was my advisor, and I considered him a groundwater guru.

[MUSIC: “The Ether Bunny” by Eyes Closed Audio used with permission of a Creative Commons Attribution License .]

NARRATOR: From the College of Engineering at Oregon State University, this is Engineering Out Loud.

ODEGAARD: Hi, I’m Jens Odegaard your host. Water is an important resource everywhere, but especially out here. Though most people think of rain when they think of Oregon, the reality is that most of the clouds deposit their resources in the Coastal and Cascade mountain ranges in the western part of the state.

Irrigation, from wells tapped into groundwater that’s trapped between layers of the basalt lava flows that make up the Columbia Plateau, is what allows this eastern region of Oregon to support a thriving food packing industry, and to produce the famous Hermiston watermelons.

This brings us back to the issue that needs resolving under the surface of the Umatilla Chemical Depot. Here’s Mandy.

MICHALSEN: And so, at the Umatilla Chemical Depot, part of what they did there was to wash out munitions and sort of recycle and dispose of munitions. Compounds that are in munitions include RDX and TNT, those are acronyms, but they are chemicals that are contaminants. And, TNT in particular colors the washout water pink when it’s exposed to light. And so in order to dispose of the wastewater, they essentially dumped the pink water in unlined lagoons, and so it would absorb into the soil and infiltrate down to groundwater, and it formed a contamination plume: RDX and TNT in groundwater over time.

ODEGAARD: Mandy works for the U.S. Army Engineer Research Development Center. In this role she does a lot of groundwater cleanup including leading the cleanup at Umatilla. She brought Jack in to work with her on the project.

And together they have plenty of water to purify.

MICHALSEN: As you're dumping in the water and the aquifer’s sort of sloshing around over time, the contaminants diffuse out. I guess kind of like a tea bag. So the combined effect of the diffusion and sort of that sloshing around in groundwater, over time, made that contamination zone and the aquifer grow larger and larger.

[MUSIC: “Onward” by Podington Bear. Used with permission of a Creative Commons Attribution-NonCommercial License .]

ODEGAARD: Just how large? Well, the contaminated aquifer covers about 200 acres, is 50 to 125 feet or so below ground, and is about 15 feet thick. Here’s a visual that might help: an acre is roughly the size of an American football field without the end zones. So make a swimming pool that’s 200 football fields and 15 feet deep and fill it up with contaminated water. A lot of it.

In all Mandy estimates there are about 350 million gallons of contaminated groundwater — which is about 4 million bathtubs full. The primary method used to clean these millions of gallons is a method called pump and treat.

MICHALSEN: You could think of placing a straw through the soil down into the aquifer, and then slurping it out. So, that involved installation of extraction wells. And then above ground, there was a giant Brita filter essentially that the pumped out water was passed through, and then on the other side of the Brita filter it was clean.

ODEGAARD: This clean water was then routed out beyond where the contaminated plume extended and absorbed back into the aquifer.

The system works, but it does have some drawbacks. Here’s Jack:

ISTOK: And that technology called pump-and-treat works well when the concentration of contaminants are high because then for every gallon of water you pump, you get a substantial amount of the explosives back out of the ground.

ODEGAARD: The problem at Umatilla is that the contaminants pose a health risk at concentrations as low as even a few parts per billion.

ISTOK: You’d have to get a billion pounds of water out to recover one pound of explosives; and so if you're pumping like that, that’s not very efficient.

ODEGAARD: In other words, to tackle this problem in a timely and efficient manner, it made sense to look into another other cleanup method. A method that wouldn’t require pumping millions of gallons of water out of the ground, but rather treating the water in the ground — a method called bioremediation. Luckily for Umatilla, and for this podcast, there’s a method for trying out bioremediation, developed right here at Oregon State — a method called push-pull testing.

MICHALSEN: Jack, would you consider yourself kind of the “Godfather” of push-pull test technology? The person that's a key developer of the approach?

ISTOK: Yeah, I would think I was the developer. I don’t know my genetic heritage relationship to it, but yeah, no, I was the first one to do it, and it’s widely used now. Many people use it, of course, now, but.

MICHALSEN: Yeah. Good, because, of course, I sing your praises, haha, and tell people that all the time. The approach is really powerful, because it's elegant, it’s simple.

ODEGAARD: This push-pull method, which will be more fully explained in a minute, allows them to try out bioremediation treatment to see if it will work. Bioremediation is an unfamiliar word for many of us, but basically it means using living microorganisms like bacteria to clean something up, in this case, water. Jack explains:

[MUSIC: “Downtown” by Podington Bear. Used with permission of a Creative Commons Attribution-NonCommercial License .]

ISTOK: Mandy led a project at this site to use native bacteria in the ground that can degrade the contaminants when they’re stimulated to do so, and that’s called bioremediation. So, if you can imagine there’s a 200-acre plume and you're trying to stimulate bacteria that are living in the ground, you have to figure out what to feed them, how much to feed them, how often to feed them, where do you place those chemicals, and so on. On a big site like that, that’s difficult — there’s no easy lookup way to answer those questions. And so, at this site, we used this method that was developed at OSU called a push-pull test where we use monitoring wells across the site as test beds or as pilot testing so we can feed the organisms around one well one type of carbon, and see how well they degrade the contaminants, and quantify that process, get rates, reaction rates, so that then we can scale up to implement something over a very big site.

ODEGAARD: This method is called push-pull because scientists like Mandy and Jack push these solutions into the wells and pull out samples later to run tests and see if what they’re hoping to accomplish is actually happening.

ISTOK: Talking about Umatilla, there are these explosives, and there are some bacteria that can degrade those explosives. But if you just grabbed a handful of soil, there could be a thousand or more different species of bacteria in there, and you’re trying to stimulate the growth of just the ones you want, and none of the others. If you try to do it one by one in a laboratory setting, you can easily test out a thousand different combinations of things and find one that works, but those results may or may not apply directly to the field because the field is so big and so complicated, and so on. So what we do is we take a volume of water and add compounds to it, and inject that into a well, and then we sample that well over time and by monitoring the composition of the water we inject, we can detect that the desirable reactions are occurring; we can quantify the rates of those reactions; and that way we know that when we try to implement a treatment over a very large site, we're not going to have problems we didn't anticipate because we didn’t have enough information.

ODEGAARD: At Umatilla, Jack and Mandy found the most successful bioremediation process to be anaerobic, or without oxygen. They injected lots of sugar into the aquifer to stimulate the growth of these useful native bacteria, and as these bacteria grew and consumed the oxygenated compounds in the water — compounds like nitrate for example — they created an anaerobic environment.

Microorganisms degrade RDX and TNT, the toxic compounds, under these anaerobic conditions.

The results of this bioremediation experiment, first done as a single well test and then scaled up to a much larger portion of the site, were very promising.

MICHALSEN: You know when you looked at the plume map, it was all sort of contaminated, and now when you look at a plume map there’s a big hole in it because we essentially knocked out the source area with that approach.

ODEGAARD: In addition to bioremediation, Jack and Mandy also explored a process called bioaugmentation at Umatilla. Bioaugmentation is basically adding non-native bacteria to the aquifer to consume the toxic compounds.

MICHALSEN: The bioaugmentation pilot was also successful, and so that technology is being considered along with the anaerobic technology in a new feasibility study where it’s sort of the cost and effectiveness of one or both of those strategies is being considered officially in a regulatory context.

ODEGAARD: As Mandy mentioned, the next steps in the Umatilla cleanup are to continue testing and presenting their findings to project stakeholders who make the final call about which method or methods will continue to be used.

MICHALSEN: Yeah. Well, at this site, all of the information that was obtained through the field pilot testing that was completed is being considered officially in that regulatory context now. That’s an important step. Originally, when the remedy was established, it was identified as a pump-and-treat remedy, so that’s what folks are held to in a regulatory sense. And so, in order to change that remedy to include bioremediation, that requires activating a regulatory process, which requires time, and energy, to work, so that’s still under consideration. But, folks that managed other sites that are similar to Umatilla were very encouraged by the results that we achieved, so we’ve been working on other similar sites.

[Music: “Onward” by Podington Bear. Used with permission of a Creative Commons Attribution-NonCommercial License .]

ODEGAARD: Mandy estimates that there are 300 or more explosive-washout-lagoon type sites across the United States that could be cleaned up via bioremediation and bioaugmentation. But even more impactful is the reality that the push-pull method developed by Jack and tested at Umatilla could have a much broader reach.

ISTOK: Well, it’s designed to look at chemical reactions in groundwater and there’s many, many of those, because of course we have tens of thousands of contaminants we’ve released into the environment — all different kinds. And, you have to tailor the process to match the properties of the chemicals involved. So, if it’s a component of gasoline, you would want to pursue one set of processes.

If it’s a cleaning solvent or a radionuclide, that’s another set of processes.

[MUSIC: “Onward” by Podington Bear. Used with permission of a Creative Commons Attribution-NonCommercial License .]

ODEGAARD: This is huge, because one of our great missteps, conducted in the name of progress, or under the pressures of war-time production, or just due to flat out ignorance of the consequences, has been polluting the most essential element of life.

ISTOK: Groundwater is of course where all the freshwater is on the planet, right? And I know on the west side of the mountains here in western Oregon, we think it rains too much or something, but we should be very fortunate that it does because it keeps our groundwater recharged and full. And other places the groundwater accumulated in the past during wetter climates — so thousands of years before any of us were born — and preserving that resource for whatever use we want to put to it is important.

ODEGAARD: It’s our obligation to address these past mistakes and to do it in the most efficient way possible.

MICHALSEN: You know the government has this legacy waste and this environmental stewardship responsibility, and it's expensive. So, identifying ways to make cleanup more cost-effective and time-effective so that fewer dollars, and people resources, and so on are dedicated to that. That’s a real benefit, too.

ODEGAARD: The ultimate goal is to take sites like the Umatilla Chemical Depot and return them to a state where they are no longer fenced off, barren ghost lands haunted by the past.

ISTOK: Maybe no one’s going to build a home on the former Umatilla Chemical Depot and start pumping water to drink, but the goal is to get all these contaminants down to drinking water standards. And so it’s reclaiming the resource, it's the ultimate in recycling.

ODEGAARD: It’s this willingness to tackle these huge, millions of gallon type problems with innovative solutions that brought Mandy to Oregon State in the first place. That and some showbiz, this time of the small-screen variety.

[MUSIC: “Twin Peaks Theme - Instrumental” by Angelo Badalamenti.]

MICHALSEN: When I was younger, I was a big fan of the TV show “Twin Peaks,” which was set in the Northwest. And so I always thought, hmm, boy, it might be neat to move out west. But I had the interest in groundwater remediation and so on before, so I'm really glad that I found Oregon State and connected with Jack. He’s been a tremendous mentor and teacher, and I’m really grateful to know him and get to work with him, still. Thank you, Jack!

ISTOK: You’re welcome, Mandy.

[all laugh]

[MUSIC: “The Ether Bunny” by Eyes Closed Audio used with permission of a Creative Commons Attribution License .]

ODEGAARD: This episode was produced and hosted by me, Jens Odegaard. Audio editing was by the talented Molly Aton. Our intro music is “The Ether Bunny” by Eyes Closed Audio. You can find them on SoundCloud and we used their song with permission of a Creative Commons attribution license. Other music and sound effects in this episode were also used with appropriate licenses, and you can find those links on our website. For more episodes, visit our website: engineeringoutloud.oregonstate.edu. Also, please subscribe by searching “Engineering Out Loud” on your favorite podcast app. See ya on the flipside.

[MUSIC: Dipsy Drips, Julian Winter, used with permissions of a Creative Commons Attribution License]

OWEN PERRY: Despite global technological advances during the last century, over one in 10 people worldwide do not have access to a source of clean drinking water, according to the World Health Organization.

The Rohingya refugee camps in Bangladesh are one example of where people’s lives are threatened by lack of access to clean water. Earlier this year Jason Beaubien of NPR reported on the growing concern of aid workers for the safety of the refugees.

[AUDIO: “Monsoon Rains Could Devastate Rohingya Camps,” National Public Radio. https://www.npr.org/sections/goatsandsoda/2018/02/07/583419363/monsoon-rains-could-devastate-rohingya-camps]

JASON BEAUBIEN: The monsoon rains tend to start in April and at their peak dump 20-30 inches a month on this area. Kearny at UNHCR says the challenge is to provide basic sanitation to a population the size of Denver or Boston before the camps turn into a muddy mess.

EMMETT KEARNEY: When you are looking to developing all the water, sewage infrastructure from scratch, in the mountains, in the hills, without road access, without many materials. Tricky.

[baby crying]

PERRY: Without proper treatment, water can act as a carrier for pathogens that cause diseases such as cholera, typhoid, dysentery, hepatitis, and more.

All told, lack of clean water is responsible for the death of an estimated 1.5 million children every year.

With the pressures of population growth, climate change, and population displacement, the need for large-scale water purification is critical. This season on Engineering Out Loud, we’re focusing on efforts happening here at Oregon State University to address the challenge of providing clean water.

[MUSIC: The Ether Bunny, Eyes Closed Audio, used with permissions of a Creative Commons Attribution License]

From the College of Engineering at Oregon State University, this is Engineering Out Loud.

I’m Owen Perry. And today, we’ll talk about the work of a group of researchers in the Humanitarian Engineering program who are helping to create a novel water purification system designed for the developing world, and how they’re looking outside the engineering toolbox to make sure it’s a product that will truly make an impact.

MACCARTY: Paul Pollock and his book Out of Poverty said that 90 percent of engineering design benefits 10 percent of humanity. So we’re looking to try to use some more of the engineering design to benefit more of the bottom of the pyramid where maybe people don’t have the benefit of modern engineering so far.

PERRY: That was Nordica MacCarty, an assistant professor of mechanical engineering, who is leading the project. Longtime listeners may remember Nordica from an earlier episode of Engineering Out Loud, way back in Season 2, when she talked about her work to improve the lives of people — especially women and children in the developing world — through more efficient, less polluting cookstoves.

Here’s a clip from that episode where she spoke with my colleague Keith Hautala.

[Archival, EOL S2E3]

HAUTALA: Whenever we want to prepare a meal, or even a quick snack, we can just turn a knob and, like magic, an electric burner lights up — or a clean, blue flame, if you’re cooking with gas. You might be surprised to learn that, for nearly half of the residents of Planet Earth, this kind of luxury simply doesn’t exist.

NORDICA MACCARTY: About 40 percent of the world’s population is currently cooking with biomass to prepare their meals and heat their water and heat their homes. And this is primarily done inside. And so, you can imagine, if you've ever sat around a campfire, you know that biomass fires produce a lot of smoke. And so, being in the same time and confined space that cooking is happening, women and children are suffering severe health effects because of this necessary practice.

HAUTALA: As it turns out, indoor air pollution is actually a huge problem in the developing world, where smoke inhalation and related illnesses are among the leading killers of women and children, accounting for about 4 million premature deaths each year.

MACCARTY: To put that in relative terms, that's like the population of Los Angeles dying every year simply because they're cooking their meals to feed their families.

PERRY: In the rest of that episode, Nordica goes on to describe her work developing clean-burning, highly efficient cookstoves designed to alleviate environmental hazards of cooking over open fire.

This episode is something of a follow-up. Last time we were talking about fire; today, we’re talking about water. Well…really we’re talking about both.

Today, millions of people around the world purify their water by boiling over an open biomass-fueled campfire. In addition to the health and environmental risk, boiling water this way is a huge timesuck and also contributes to deforestation.

One company here in Oregon thinks they might be on to a solution to those problems. And they’ve partnered with Nordica and her team to make it a reality.

InStove is a nonprofit that designs institutional cookstoves for places like orphanages and schools and feeding centers in rural, low-resource communities or refugee camps.

Recently, they’ve also added a water purification system that fits inside the stove, which MacCarty and her team have helped design and test.

NICK MOSES: I’m Nick Moses, I’m a master’s student working for Dr. MacCarty also in the Humanitarian Engineering program.

PERRY: Conveniently, Nick also works at InStove.

MOSES: I’m InStove’s staff engineer so my role has sort of been an advisor, the guy that’s familiar with the system and how it works and how it can be used and tested and all those things.

GRACE BURLESON: I’m Grace Burleson and I’m in the same program as Nick.

PERRY: As part of the Humanitarian Engineering program, Nick and Grace are getting degrees in both engineering and anthropology and they are using skills from both disciplines for this project.

GRACE BURLESON: I’ve been working on it as part of my master’s thesis, which is looking at more efficient ways to improve the pasteurization, or the boiling water process, and so this product is at the center of the research for me.

PERRY: So let’s pause for a second. What is this product? What makes it so promising?

MOSES: It looks…it’s like the same size as a 55-gallon oil drum, except it’s green and it has a chimney in the back.

MACCARTY: And a pot sunken into the top of it.

PERRY: Okay, it’s a little more than a green oil drum with a chimney and a pot. At the heart of these stoves is an insulated metal combustion chamber that concentrates heat and mixes combustion gases to create operating temperatures that literally burn up the smoke. This produces a fire that is cleaner and more efficient than is possible otherwise.

The added water purifier is a gravity-fed unit that kills microorganisms by heating water to the pasteurization temperature of 71º Celsius, which is automatically controlled by an all-mechanical, fail-safe valve.

MACCARTY: InStove actually reduces the energy required to purify a liter of water by 97 percent. So, it does that by a really efficient system that uses a heat exchanger to recuperate the heat and cool the water back to room temperature before it exits the system. So, the heat is not wasted, it’s instead used to preheat the incoming water so the system uses only about a pencil’s weight of fuel to purify a liter of water and because it’s a flow-through system it can produce enough water for up to a thousand people per day at this level of efficiency.

[MUSIC: “Our Happy Place,” Maps & Transit, used with permission of a Creative Commons Attribution-NonCommercial License]

PERRY: Grace, Nick, and Nordica have done a lot of research on different ways to disinfect water, and the hundreds, if not thousands, of products out there aimed at solving this problem. There are products that distill water or use solar radiation or chlorine. But today, access to clean water is still a problem for millions of people. Why aren’t these products working?

Nick thinks he has a pretty good idea.

MOSES: Interesting how much of that work is done here and how little of it is done in context or involving people. A lot of time these products are like sold to an NGO or government and not the user or there’s sort of a missing piece of that incentive to really understand what people want and what works for them which I mean I think I’ve seen in cook stoves too sometimes but definitely notice it with all these water technologies. Engineers, we’re trained specialists, we’re the designers, the technical people, and that works if you go work at a corporation in a country like the United States because you work with people who do all those other things, who figure out the sales and the marketing and the business and the manufacturing and all the other details you need to bring a product to market or to the end user. But if you throw an engineer out into the world and have them try and design a humanitarian technology, they probably don’t have that context, that background, and on top of that they probably don’t really understand the culture and the people that they’re working with. It would be great if we could do all of those things, but the resources just really aren’t there to have all of those skill sets.

PERRY: So, for this project, it’s helpful that Nick and Grace are also both trained as anthropologists as well as engineers.

MOSES: Anthropology is kind of a good stopgap because it’s at least really reflexive and critical and helpful in understanding what pieces are missing and what people need, so even if you can’t solve every problem you can at least identify what they are and try and get help.

MACCARTY: Grace and Nick are really paving the way; they’re the first two students to graduate from the Humanitarian Engineering program with this dual master’s degree option and we’re really excited about continuing this model going forward.

[MUSIC: Dipsy Drips, Julian Winter, used with permissions of a Creative Commons Attribution License]

PERRY: There’s a theory in social sciences called the diffusion of innovations, which provides a framework for how technologies move through societies and are adopted by people. It involves understanding reasons why someone would use something, but also the barriers that keep them from doing so.

BURLESON: You never want to design something and think that that’s the solution for somebody that you don’t know. You know, 20 years ago, no one even though they needed a smartphone and that was something that companies like HP, Apple, Intel they have teams of anthropologists and social scientists trying to understand what people want and what the next big thing is going to be and then when they come out with that new technology everyone goes and buys it and wants it. And I think we have to take a similar approach in development work. You have to really think, what do people want so that when you bring them this technology you’re not convincing them and forcing anything onto them.

PERRY: This anthropological approach has proved vital to the success of the water purifier project as they began testing it in the field.

BURLESON: I was the lead on a field study in Uganda which focused on understanding cultural aspects and usability of the system within a society that is very used to boiling their water over open fires. So, trying to compare their current methods of boiling over a large stove to using this pasteurization system and kind of seeing how they liked or didn’t like this system in different ways.

PERRY: Grace used the ethnographic methods she learned from her anthropology studies to observe participants.

BURLESON: I worked really closely with this one cook who everyday had to prepare enough food and drinking water for 105 high school girls.

PERRY: Imagine, a high school dormitory in Eastern Uganda. Twice a day, a cook boils water over a smoky, open fire so that 105 girls can drink safely. Each 80-liter pot takes roughly an hour and multiple logs to boil.

BURLESON: He was really used to using a large open fire, and so I spent a lot of time watching him cook and asking him about his process of cooking and of also boiling water. And then we implemented the system and did the exact same thing. So, he used the InStove purifier and I observed him and asked him what he liked about it, didn’t like about it.

PERRY: They also measured and monitored how much fuel was consumed.

BURLESON: It was really clear the difference in how much fuel the system uses, how much wood it uses, way way less wood per amount of water that you’re producing, wood per time, and they were really excited about that, because at least this particular location they actually purchase their firewood. They use so much of it to boil water and to cook for that many people that they actually go purchase it from a local vendor rather than collecting it themselves. So, it would save them a lot of money.

PERRY: While her observations helped verify the purifier’s efficiency, they also led to some significant changes to its design. The InStove purifier was designed to boil water quickly, but also to cool it rapidly enough that you can drink it without getting burnt. The problem is, in Uganda, people really like to drink tea.

BURLESON: They drink tea at almost every single meal, and so one thing that I realized is if they use this purifier they would also have to heat up water in addition because they’re not going to just stop drinking tea. Something that InStove is looking into is can we can have a manual valve to change the temperature of the water flowing out of the system depending on if you want to drink it immediately and have it be lukewarm or if you want to have it come out a little bit warmer for tea.

PERRY: Alongside the advantages of having anthropologists on this project, another key to its success has been strong collaboration.

MACCARTY: Definitely a technology that we can implement to help bring about clean water in the developing world, but a project that certainly requires many disciplines to help succeed. Us as mechanical engineers certainly have contributed to the technical aspects, the heat transfer and the heat recovery and fluid-flow type pieces of the design, but in addition to that we’ve been working with colleagues across campus and across the world really. So we’ve been working with a Dr. Tala Navab-Daneshmand from environmental engineering, who’s been helping us to do the microbiological testing to verify that we are in fact killing the E.coli and the viruses and the other bugs that might be in the water so we can verify its performance in that regard. We’re working with Dr. Bryan Tilt in anthropology who’s advising Grace on the social evaluation pieces of the project.

PERRY: Going forward, the team is looking expand testing of the water purifier.

MACCARTY: We’re working with Dr. Molly Kile in public health who is connecting us with some of her colleagues at the Dhaka community hospital in Bangladesh where we’re about to install some of these systems in the Rohingya refugee camp.

PERRY: Recently 500 to 700,000 Rohingya people fled the genocide and violence in the country of Myanmar, across the border to Bangladesh, where enormous refugee camps have been built. With the threat of monsoons, the risk of water contamination is high.

MACCARTY: This could potentially be an ideal situation where they have a serious need for clean water and this type of system could really help to address that need. So, we need to work with those NGOs, nongovernmental organizations, on the ground to help to implement the system and train people at the medical clinics in these camps to operate and maintain the system.

[MUSIC: Sienne, Podington Bear, used with permissions of a Creative Commons Attribution License]

In these regions where the need is greatest, our understanding is often the lowest and the most lacking, so I think that’s where bringing in multiple disciplines and different perspectives is critical to making the engineering designs succeed in these sort of contexts.

PERRY: Thanks for listening. And thanks to Nordica, Grace, and Nick. To learn more about the Humanitarian Engineering program at Oregon State, visit humanitarian.engineering.oregonstate.edu.

This project is just a taste, or sip, if you will, of the some of the great work being done at Oregon State to harness science and engineering-based solutions to providing clean water to the global community. You can hear more stories about other clean water projects at engineeringoutloud.oregonstate.edu.

While you’re there, hit the subscribe button or search “Engineering Out Loud” on your favorite podcast app.

This episode was produced and hosted by me, Owen Perry. Sound design and editing was done by Molly Aton. Our intro music is “The Ether Bunny” by Eyes Closed Audio on SoundCloud and used with permission of a Creative Commons attribution license. Other music and effects in this episode were also used with appropriate licenses.

[MOVIE CLIP (Kel Wer): Water water …]

Water, water I like you, you make the earth cool and wet the trees beautiful, wild and green. Water water I like you, you make the earth cool and soft their flowers pretty sure and colorful. Water water I like you you make us happy hahaha and cheerful.

RACHEL ROBERTSON: For those of us that have access to clean water it’s easy to forget how important it is to those who don’t. That clip is from the film Kel Wer, produced here at Oregon State University. The film crew followed a group of Oregon State students to Lela, Kenya where they were working on a project to bring clean water to that rural community.

The student group is called Engineers Without Borders. There are nearly 300 chapters of the group, across the U.S. that work in 46 countries. The Oregon State club has had projects in four countries so far. In addition to the one in Kenya, they had a project in El Salvador, and are currently working in Cambodia and Nicaragua.

I’m Rachel Robertson. And yes, I did find an excuse to use a movie clip at the beginning of a podcast again.

[MUSIC: The Ether Bunny, by Eyes Closed Audio, used with permission under a Creative Commons Attribution License]

NARRATOR: From the College of Engineering at Oregon State University, this is Engineering Out Loud.

ROBERTSON: So far this season we’ve focused on what researchers at Oregon State are doing to help keep water clean around the world. But today the focus is on our students. We’ll hear from three engineering students about their experiences with Engineers Without Borders.

[MUSIC: “Amor Chiquito,” Quincas Moreira, used with permission of a Creative Commons Attribution-NonCommercial License]

It’s a story about language barriers, redesigning plans at the last minute, the importance of hydrogeologic surveys, and dancing. Yes, dancing.

RACHEL YONAMINE: It was one of the best experiences of my life.

ROBERTSON: That’s Rachel Yonamine, a civil engineering major who is currently the president of the student club, Engineers Without Borders at Oregon State.

YONAMINE: Engineers Without Borders is a nonprofit humanitarian organization that partners with both local and international communities worldwide to improve their quality of life in one way, shape, or form. We choose to do that through water projects, since it water is a basic human right. So, with that, we have two international projects: one in Cambodia and one in Nicaragua. I'm currently involved in the Nicaragua program.

ROBERTSON: Although all the students you will hear from today are in engineering, students from any major are encouraged to join, which helps to bring a diversity of skills to the projects. Not all the students go on the trips. The research, planning, and design work is done by a larger group of students in Corvallis. Rachel started with the club when she was a first-year student and has stayed involved continuously, but others join for shorter periods of time. The first step in starting a project is reviewing the applications and deciding which one the club will take on.

YONAMINE: I was actually with the Nicaragua program from its origin, which was a really exciting. I was there when they were choosing the community to work with and kind of discussing if it's something we want to take up. I've got to travel to the community twice, which was amazing and phenomenal.

ROBERTSON: As you can hear in Rachel’s voice, this is not just any engineering project. Engineers Without Borders is a chance for students to change people’s lives. It’s more than learning technical skills and project management, although that comes with the experience too. The program exposes students to situations and lessons you just can’t find in a regular classroom. A central goal of the club is to develop global awareness in our future engineers by giving them the opportunity to travel abroad, experience different cultures, collaborate with professionals, and gain hands-on, interdisciplinary experiences with international work. But I should quit talking, so you can hear the story from them.

YONAMINE: We are currently on our fourth year with the Nicaragua program. We partnered with a rural community called Los Potrerillo, so far we've installed a drilled well, we've connected piping from their well to their current distribution system. And this summer if all goes well we're hoping to implement a storage system, so they can store their water and use it all year round.

ROBERTSON: As it turns out, they were not able to return this summer due to political unrest in Nicaragua, but they hope to return either in the winter or the following summer. The first step in getting clean water to this community was drilling a well, so the main event for the initial trip was having a well driller bore the hole.

YONAMINE: A lot of research was done prior to this well drilling. It was a really big event, because we didn't know if we were going to hit an aquifer, we didn't know if the borehole was going to run dry, which means that we wasted $1,500 that the community partially pays for, as well. And luckily we did a hydrogeologic survey before, which was also a big gamble because we had to, like, invest money in it initially, without knowing if it's either even going to work. And it did. Actually, we hit probably the best spot that we could, which was amazing and we were really lucky.

ROBERTSON: The other main objective of the trip was to meet with the people who live there so they could help guide the process.

YONAMINE: We just wanted their input on what they think we should do for the future years. Like, what would be most appropriate -- is this something that they want, is this something they can maintain, etc., so that we can really get involved and make sure this project is not only feasible, but it's also sustainable on their part.

ROBERTSON: Communication with the community was the part that Rachel was pretty nervous about since she did not speak Spanish. So, I asked her how that worked out.

YONAMINE: So, there's a lot of hand motions. They knew I didn't speak Spanish so they kind of helped me work through it. And then the travel team members that were there with me definitely helped me out, too. So the learning curve was kind of exponential because I was thrown in. As long as I got some basic words, and I could like have very intense facial expressions, which I do, I was able to communicate really well with them and get the message across ... for the most part. Some parts I didn't always do that, but we worked it out eventually.

ROBERTSON: Working it out was a huge component of Rachel’s second trip to Nicaragua when they started the implementation of the project.

YONAMINE: I fully made a river-crossing design to help the pipeline go across the river to get to the highest point in the community to be gravity fed, and it turns out when we went there, we had to completely scratch the entire design.

ROBERTSON: The community nixed her idea of using wood for the quad-pod she had designed to hold up the pipeline.

YONAMINE: Wood doesn't really go well in their community and that was because it's so humid there. It would have worked because we would have been able to find good wood in the major cities; however, they didn't feel comfortable with it. And they mentioned it when we got there. So we're like, okay, that's not going to fly, because we have to make sure it's something they know will work.

ROBERTSON: The redesign used concrete columns and steel cables similar to a suspension bridge.

YONAMINE: And that worked a lot better for them, because they were familiar with it and they knew it wasn't going to go anywhere and they knew it wasn't going to deteriorate overnight.

[MUSIC: “Poppyseed,” Poddington Bear, used with permission of a Creative Commons Attribution-NonCommercial License]

ROBERTSON: I should mention that Rachel and the other students were not doing this all on their own. The student group always has a travel mentor along to oversee the process. For the Nicaragua trip, Stephen Good, an assistant professor of biological and ecological engineering, and Jim Wodrich, a senior project manager for HDR, helped her work out the new design.

Because of delays in the process, they were not able to test it before they were scheduled to leave. But during the group’s time there, they had been training the people in the community who were then able to test the system after they left. So, although Rachel has not seen the whole system operational she talked to the community members over the phone about how it is working.

YONAMINE: The community is getting a lot more water than it used to, and they also reported that they have no cases of diarrhea right now, which has never happened before, and it's a really big step for not only their community, but also for our organization.

ROBERTSON: The Nicaragua project is getting close to being finished, but the project in O’Rana, Cambodia started in 2016, two years after the Nicaragua project, so it’s not as far along. On the first trip, in 2017, the professional mentor was Paul Pedone, a retired geologist, who accompanied five students. I got the chance to speak to two of the students who were on the initial trip.

KEATON TOWNLEY: I'm Keaton Townley, I am a senior in bioengineering, and I was the program coordinator for the Cambodia program for the last year.

BRIAN BLYTHE: I’m Brian Blythe, I’m an electrical engineering major.

ROBERTSON: An interesting side note about Brian is that he was our production assistant for the podcast for the last year. And as part of that job he recorded interviews for us so he was, naturally, there for this one. It’s possible that I did not warn Brian that I’d also be interviewing him for this story… sorry Brian. That’s not the only curve ball the podcast team threw at him that he handled without flinching.
Rolling with unexpected situations was something the team in Cambodia had to deal with too – one of those fun life lessons that Engineers Without Borders provides. Here’s Brian to explain.

BLYTHE: The community submitted documentation that was like, ‘We need water, right? We have eight wells or something in the community, and we need water.’ And we show up and there's like 60 wells. The eight wells as it turns out were public wells and 60 wells were all the people that had drilled their private wells. But the problem was they had all these private wells but they all dried up during the dry season. So you could go to these private wells and they could get water during most of the year, but during the dry season either they completely dried up or the water just tasted super iron-like so no one would want to drink it. And so we're there in this community and everybody has wells but everybody's also just drinking bottled water. And so there's not a system of trash there or recycling or anything and so there's just plastic water bottles either being burned or just thrown in the gutters everywhere. So it's just like this huge ecological nightmare as you're in this community and it's like, nobody wants that. It's not like that's intentional - they just don't have any other options.

ROBERTSON: Was it kind of a culture shock to be there and see that?

TOWNLEY: Yeah, the trash I think I had gotten used to by the time just from landing into Phnom Penh, the capital. Even there, there's not a whole lot of trash service or anything going on. The whole road out to the O’Rana village it was, you know, trash everywhere.

BLYTHE: Which is really unfortunate because it's beautiful. Like, the most beautiful place in the world. Like, it's super tropical and like paradise on earth. It's heartbreaking and it's just because people don't have access to clean water.

ROBERTSON: Clearly there was a problem there that the club could help with. The issue would be how to do it right. The first trip focused on getting the lay of the land, and for this they couldn’t rely on their usual methods.

BLYTHE: You can't do like Google Street View, right? You can't really go down and look on the internet. So a lot of it was just orienting ourselves within the community and saying, “OK, where are these things actually located?” You know, where's the school relative to these houses? Where are these different public wells, and are they higher in elevation or lower in elevation? And so, we walked up and down that road many, many times, just both in doing our community surveying, and then later during the trip doing a bit of topographical surveying.

ROBERTSON: When they got home after the first assessment trip they started planning what to do.

TOWNLEY: We were hoping to use a public well that was already drilled in the community because are so many wells, it didn't seem like a good idea to put another hole in ground into that same pool of water.

ROBERTSON: What they needed was a hydrogeologic survey just like the Nicaragua project. That’s when the group hit a roadblock which caused some delay, but in the end got them two new professional mentors on the project.

TOWNLEY: There's not a lot of people in Cambodia that have that kind of technical knowledge - there are not a lot of engineering firms that will go out into the country into a rural community and do that kind of survey for us. So, we ended up doing a second year of assessment trip and went back primarily to do a rudimentary hydrogeologic survey. I connected with one engineering firm that does water projects, kind of similar to what we do. And the person I connected with ended up being one of our mentors.

ROBERTSON: That mentor was Terra Michaels, a water resource engineer who was working at Advancing Engineering Consultants in Phnom Penh at the time. She also suggested her father, Jeffrey Michaels, a civil engineer who signed up to be their official mentor on the second trip. Terra and Jeffrey helped the team perform a pump test.

TOWNLEY: We went to three different wells in the community that we had kind of identified the year before as being potential supplies for the system. And we essentially just pumped water out of it for four hours and measured the flow rate of water coming out of that well to see how much you can pump out of it, and the decrease in the water level as we pump water out to see how much taking out that water it would drop down the aquifer is what it's called in that pool of water and see if it decreases a lot. And then also measuring the water level of nearby wells to see if it's affecting other wells, and if it's affecting a lot of people or if it's just staying in one area, things like that. And so one of our other mentors from the first year is actually a hydrogeologist and so he's working with that data to see what we can expect from that aquifer and how much we can pump out of it, things like that.

ROBERTSON: OK, so you don't really know yet what you're going to do at this point.

TOWNLEY: Yeah. Nothing is entirely confirmed but we feel pretty confident that the best option would definitely be a well water to distribution system, as long as that aquifer would hold up.

ROBERTSON: The situation the group faced in Cambodia brings up another aspect of the Engineers Without Borders Program. It’s more than just bringing clean water to these communities.

YONAMINE: Something else we kind of tried to incorporate is this educational aspect in all these communities, and that's also what we do with our community meetings sometimes. We'll talk about why you shouldn't litter, why you shouldn't be drinking from the river, and so that's like a prime example. They didn't understand that drilling a new, many wells, would just run the aquifer dry, and that process was not apparent to them. So, that's why it's really important that we come in and teach them why things happen.

ROBERTSON: Connecting with the community was key to making that successful. And Keaton found some good ways to do that.

TOWNLEY: The value of having dinner with someone even if you can't really speak to them or you have to rely on like one translator and stuff can still be a really special way to connect with others. And, dancing. Food and dancing, I think, are both really good ways to that, no matter where you are, and whether you can speak or not.

YONAMINE: I want to second that. This is very true, also in the Nicaragua program.

ROBERTSON: That's funny, I was not expecting you to say that.

[all laugh]

ROBERTSON: See I told you there would be dancing. Beyond some new dance moves, the students had a lot to say about what they learned on the trip including hands-on technical skills, construction knowledge, project management … but the experience went deeper than that.

TOWNLEY: I've done a lot of thinking more about kind of the human sides of engineering and how do you make something work for real people that are going to be using it and not just, like, how do I do this math perfectly so that it's like the best solution. It's like, how do you make these projects so that they work for people, and that they'll be able to make it their own and stuff like that, which has been a lot of fun and I'm really glad I've had that experience.

YONAMINE: On a technical aspect, I learned so much, more than I could ever learn in a classroom setting.

[MUSIC: Bass improvisation by Duncan Robertson used with permission of the artist]

And then on an emotional aspect, it was incredible; these people, I can't even begin to describe how much they mean to me and how beautiful and wonderful and amazing they are. They just have so much heart and it shows through everything that they do and I'm just super blessed to be allowed to help them out and kind of create this bond with them.

ROBERTSON: What Rachel is talking about is beyond a global understanding -- it’s more than learning about how people from another culture dance, but dancing with them. Frankly, I think we could use more of that in our world, and I appreciate Rachel, Keaton and Brian for giving us a window into that experience. Our students at Oregon State often impress me. This interview was definitely one of those moments, and I’m glad I can bring you a glimpse of who they are, and how the experience being part of Engineers Without Borders impacted them.

This episode was produced and hosted by me, Rachel Robertson. Audio editing performed by Molly Aton. Our intro music is “The Ether Bunny” by Eyes Closed Audio on SoundCloud and used with permission of a Creative Commons attribution license. Other music and effects in this episode were also used with appropriate licenses. You can find the links on our website. For more episodes, visit engineeringoutloud.oregonstate.edu or subscribe by searching “Engineering Out Loud” on your favorite podcast app.

YONAMINE: This club actually ignited a passion for humanitarian work in me, so I might even apply to the Peace Corps and continue my work for a couple years abroad. But, yeah, eventually I want to come back to industry.

[SOUND EFFECTS: Dripping water, Water dripping echo, Small stream flowing, Fast-running stream, Kolubara River rapid, used with permission under a Creative Commons License]

STEVE FRANDZEL: We humans manage to foul up our precious water supply in countless ways. Fortunately, a few among us are determined to find better answers to this serious and growing problem. Like Tyler Radniecki, an assistant professor of environmental engineering. His entire career, in fact, has been about cleaning up dirty water, and that’s a pretty tall order.

TYLER RADNIECKI: Overall, our water supply in this country, it is deteriorating, the quality of that water. It’s getting worse over time. I can’t tell you if we’re in crisis mode or not, but it’s definitely going in the negative direction. Aquifers are being used up or they’re being contaminated. It’s becoming a bigger impact on the water that we do have.

FRANDZEL: That’s not a lot. Only two-and-a-half percent of the water on earth is fresh. Two thirds of that is locked in glaciers and snowfields, leaving a paltry 1.2 percent that’s easily accessible. And much of that is severely contaminated and undrinkable. So what can be done? Well, stick around and we’ll explore some unusual clean water technologies that’ll give you some reasons to be optimistic.

[MUSIC: The Ether Bunny, by Eyes Closed Audio, used with permission under a Creative Commons Attribution License]

FRANDZEL: From the College of Engineering at Oregon State University, this is Engineering Out Loud.

Dirty water comes in two flavors: Storm water runoff and wastewater. There’s a big difference, but both pose serious health and environmental risks.

RADNIECKI: Wastewater is what people think of as far as water going down the sink and the toilet of your house. Storm water, on the other hand, is when it rains, especially in cities and other areas with impervious materials, the water will hit the concrete, the roof, and it will pick up contaminants, and then it will flow over land either into a wastewater treatment plant or it goes straight into a river, and then eventually out to sea. This is an area that people have largely been ignoring as far as its impact on water quality.

[MUSIC: Harps Uplifting by Mortal Thing, used with permission of the artist]

FRANDZEL: We could go on and on about all the problems, but I think you get the picture. We’re here to talk about solutions, and Tyler has no shortage of ideas.

RADNIECKI: My research interests and goals revolve around sustainable wastewater and storm water treatment technologies. In particular, I’m interested in biological systems – so, systems that are using bacteria and plants to clean up both the wastewater and the storm water treatment systems so we can design improved treatment systems that are more reliable, that can do things faster using less energy.

FRANDZEL: In previous research, Tyler focused on water purification technologies based on titanium dioxide nanoparticles, and for that he teamed up with two Oregon companies. One is Puralytics, which makes the SolarBag water purification system. Fill the three-liter plastic bag with tainted water, set it under an open sky, and a few hours later the water’s safe to drink. It’s big with campers and backpackers, and it can be used to ensure that communities in developing nations have a reliable supply of clean water. The other company is Focal Technologies, a start-up that makes the Ray system, an eight-foot diameter lens that magnifies sunlight 200-fold and beams it into heavily polluted water.

RADNIECKI: Oh yeah. It’s a big magnifying glass. It’ll light a 2x4 on fire.

FRANDZEL: The key to both systems is that the dirty water comes into contact with titanium dioxide nanoparticles. By the way, these nanoparticles are really small. Like a tenth to a hundredth the size of bacteria, and thousands of bacteria can fit on the period at the end of this sentence. The magic happens when you add sunlight.

[MUSIC: Despite the Traffic, by Wes Hutchinson, used with permission of the artist]

RADNIECKI: When UV light from the sun hits the titanium dioxide nanoparticles, it causes a reaction that creates something called a reactive oxygen species. Essentially, you create these little molecular cannonballs, and they just attack contaminants and turn them into things such as CO2, that’s inert, that will go into atmosphere.

FRANDZEL: Tyler’s work led to performance improvements for both companies’ products. More recently, he’s been working on a pair of biologically based technologies. To get a solid idea of how each one functions, it helps to look behind the scenes of a run-of-the-mill wastewater treatment plant. Most of us don’t give them a second thought. We’re just happy they’re there, um, taking care of, um, business. When effluent from sinks, bathtubs and toilets enters the plant, it sits around in holding tanks to let the solids settle out. What’s left are dissolved contaminants, and one of the big ones is ammonia. Ammonia contains lots of nitrogen, and nitrogen is a very potent fertilizer. If too much reaches rivers, lakes and streams, it leads to a disastrous outcome called eutrophication…

RADNIECKI: …which is when you essentially fertilize a lake or a stream, and that can cause big ecological damages. That’s not good for the environment but also not good for human consumption of that water later on.

FRANDZEL: If you’ve ever seen a stream choked with algae and devoid of animals, you’ve seen eutrophication. So one of the most important jobs of a treatment plant is removing nitrogen.

[MUSIC: Harps Uplifting by Mortal Thing, used with permission of the artist]

To do that, the first step is to bubble air – lots of air – up through the water column in those holding tanks. That aeration allows bacteria to convert the nitrogen-rich ammonia into nitrate. But bubbling air takes a lot of energy.

RADNIECKI: About 60 percent of the energy at a wastewater treatment plant’s dedicated just to bubbling air through water. You convert it to nitrate, and then at that point you shut off the bubblers. So now you need a different type of bacteria, called denitrifying bacteria, that requires an organic carbon source to take that nitrate and reduce it to N2 gas, which is essentially air.

FRANDZEL: The carbon source is usually tanks of methanol, which can easily cost more than a million dollars a year for even a modest-sized treatment plant.

RADNIECKI: So that’s the traditional way to remove nitrogen from wastewater.

FRANDZEL: But Tyler’s investigating an approach that’s definitely not traditional. It’s a twist on an existing technology called anammox.

RADNIECKI: Anaerobic ammonia oxidation.

FRANDZEL: Anammox enlists bacteria that combines the ammonia and nitrite in wastewater to form harmless nitrogen in gas form, and it greatly reduces the need for aeration and completely eliminates expensive methanol from the equation. The cost savings can be huge.

RADNIECKI: The amount of oxygen, the amount of air you have to bubble through the system is reduced by about 60 percent. So wastewater treatment plants are very excited about this. They see instant cost savings if they can implement this system into their wastewater treatment plant.

FRANDZEL: But anammox requires highly trained personnel to monitor and control the process. That’s usually not an issue at big plants located in big cities. But smaller communities are constrained by tighter budgets.

[MUSIC: Doctor Talos Answers the Door, Dr. Turtle, used with permission under a Creative Commons Attribution License]

RADNIECKI: It puts it out of reach for most modest-sized treatment facilities and small-sized treatment facilities, and that’s where we want to try to take the technology.

FRANDZEL: Tyler sees a possible solution: Incorporate anammox into constructed wetlands and let the chemistry kick in and run on cruise control.

RADNIECKI: It would take this advanced technology that many of the larger cities in the country are actively pursuing to implement and put it into the hands of smaller communities, even the size of Corvallis, or smaller, that could take advantage of this technology to produce cleaner wastewater effluent but to do it more cheaply and put it into something that’s relatively simple, relatively passive, such as a wetland, and still get the same type of performance. And that’s where the challenge is – taking a very complicated technology and putting into a simpler system.

FRANDZEL: Simple, maybe, but not easy. There’s this thing called microbial invasion, when other bacteria naturally found in the wastewater try to take over.

RADNIECKI: How do you keep your anammox bacteria there and working without being outcompeted by these other microorganisms, especially in a system where you don’t have a lot of levers to control the temperature and the flow rates? It’s a very passive system. How can you sustain that anammox treatment technology in an environment that’s constantly being attacked, so to speak, by other microbes?

FRANDZEL: That’s what he plans to find out. His work is mostly at the lab scale right now, and things look promising. He’s also working with Clean Water Services, a water resources management utility in Hillsboro, Oregon, which has built some pilot-scale wetlands – about the size of a horse trough – that receive a small stream of real wastewater. If things work out and a full-size wetland is built, it’ll look much like you’d probably imagine a wetland.

[SOUND EFFECTS: Small stream flowing, used with permission under a Creative Commons License]

RADNIECKI: To me it would look kind of like a park, where you would have natural plants growing out of this system. The anammox itself would be buried underground, but there’ll be a vertical flow wetland, which will essentially be wastewater trickling over rocks. We’d be treating it, and then it would come out the other end, more than likely into a pond of some sort before eventually reaching off into a river or a creek.

FRANDZEL: On a very different technology track is FOG – F - O - G – co-digestion.

RADNIECKI: FOG is fats, oils, and greases. It’s what’s coming out of your restaurant fryer grease.

FRANDZEL: To appreciate the ingenuity of FOG, we need to zoom in on a prominent component of most wastewater treatment plants: the anaerobic digester.

RADNIECKI: You take these organic solids and you put them into a sealed reactor, essentially, so no oxygen, no air. Inside of there, a special group of microorganisms, called anaerobic bacteria, will start to break down that organic matter. It takes about 30 days.

FRANDZEL: One of the byproducts of the process is methane gas. To prevent the release of this potent greenhouse gas into the atmosphere, most plants flare it off.

[MUSIC: Doctor Talos Answers the Door, Dr. Turtle, used with permission under a Creative Commons Attribution License]

RADNIECKI: And really that’s a wasted opportunity, because you could take that same gas, that same methane, and burn it and create electricity. But the economics doesn’t make sense – to buy a generator, to burn the methane, if you’re not producing enough. And most anaerobic digesters don’t produce enough to do that.

FRANDZEL: Adding FOG, a major source of carbon, changes the entire equation and amplifies – tremendously – methane production. So much so that it becomes a valuable commodity. The wastewater treatment plant in Gresham, Oregon, has become energy self-sufficient and now produces more electricity than it consumes. In fact, they sell some back to Pacific Gas and Electric, and they added a second generator to handle the excess methane. When he learned about Gresham’s FOG co-digestion system, Tyler called them up to get a tour. And then he asked how they determined how much FOG to add.

RADNIECKI: And they just said, “Well, we just picked an amount and then we called it good. It worked, yeah, It made more gas, we’re happy with that,” and that’s where they left it.

FRANDZEL: So, they were kind of guessing.

RADNIECKI: They were completely guessing. But they were taking it on the safe side. I’m sure they were pretty nervous the first day they put in even that amount. But it seemed to work. And the reason is because they didn’t dare risk upsetting the digester.

FRANDZEL: Because that can spell disaster. If the microbial community inside the digester goes too far out of balance, the system will crash, the digester will go offline, and the sludge – which never stops coming – would have to be trucked to other treatment plants at tremendous cost.

RADNIECKI: But I can make small versions of these and I kill them off all the time and see what happens, and we definitely found differences between the food sources, although we still are working on trying to figure out exactly why this food source behaves in one way and another one behaves in another way.

FRANDZEL: Tyler has couple of things in mind. One is to gain a fundamental understanding of how the various FOG recipes, so to speak, affect the digester’s microbial community. The second objective of his research is to get a better handle on microbial resource management. It’s clear that currently the FOG process is inexact. Engineers pick a FOG source, feed it to the digester and back off at the first sign of declining performance. But that’s letting the microbes dictate the terms.

RADNIECKI: Microbial resource management, though, flips that on its head a little bit. It’s saying that if we understand the microbial dynamics in that system well enough, we can use engineering parameters, such as temperature, loading rates, things where you can twist knobs, and control flows. We can take those engineering tools and use them to shape the microbial community to perform higher, to make more gas, to recover quicker. You mold the community, you shape it into a structure that’ll perform better.

FRANDZEL: And there’s no shortage of FOG sources. Food producers up and down the Willamette Valley are clamoring to just give away their FOG for free to avoid disposal costs. But that variety is one the greatest challenges to managing the process.

RADNIECKI: FOG is not a uniform substance, it can have many different compositions depending on what kind of food products it’s coming from, and we’re very curious about how does that affect the digesters themselves? The composition of the FOG is pretty much unknown.

FRANDZEL: And methane is just the low-hanging fruit. Other byproducts of FOG include bioplastics and hydrogen.

RADNIECKI: There’s many, many possibilities if you can control these very complex microbial communities. We’re just now – in the last two years or so – starting in that direction.

FRANDZEL: I asked Tyler how he feels about the future of our clean water predicament when he’s feeling at his most optimistic and when he’s not so sanguine. On the one hand, he believes that more and more communities will come to view storm water runoff and wastewater as not just something that needs to be disappeared, but as valuable sources of energy, nutrients, and heavy metal recovery.

RADNIECKI: I think this flips the entire paradigm on its head from “This is a net cost, we have to treat this to protect our water,” to “This is a net opportunity of here are free resources coming at us if we’re smart enough to know how to use them and capture them.”

FRANDZEL: And, to tell the truth, he doesn’t get into pessimism too much, but he remembers very well someone who did.

RADNIECKI: I’ll never forget when I was an undergraduate, my advisor was very much a pessimist, and every day you’d come in – Dr. Spigarelli – and you’d come in and he goes, “So are you depressed yet? Are you depressed yet?” This was in the 90s and things weren’t looking very good. No, no, no! We can do it, we can do it. And I just always kind of had this undying, sometimes naïve, belief that between technology and the human spirit, we’ll figure this out. It’s not too late.

[MUSIC: Silver Lakes, Wes Hutchinson, used with permission of the artist]

And that’s still what drives me today. It’s not too late, we can still figure this out. Some things have gotten better and some things have gotten worse. But there’s always reason for hope. If you don’t have the hope, then we might as well just stop.

FRANDZEL: This episode was produced and hosted by me, Steve Frandzel, with additional audio editing by Molly Aton. Thanks Molly.

MOLLY ATON: You're welcome.

Our intro music is “The Ether Bunny” by Eyes Closed Audio on SoundCloud and used with permission of a Creative Commons attribution license. Other music and effects in this episode were also used with appropriate licenses. You can find the links on our website. For more episodes, visit engineeringoutloud.oregonstate.edu, or subscribe by searching “Engineering Out Loud” on your favorite podcast app. Bye now.

[SOUND EFFECTS: Toilet Flushing, used with permission of Creative Commons Public Domain]

­HAUTALA: Let’s talk about water. It’s essential for every living thing on the planet. About 60 percent of your own body weight is made up of water. You couldn’t live more than a few days without it. And yet, more than one-tenth of the Earth’s population lacks reliable access to a source of clean drinking water. Around the globe, water quality is being compromised, as communities struggle with population growth, climate change, industrial and agricultural pollution, and other pressures.

So … What are we doing about it?

NARRATOR: From the College of Engineering at Oregon State University, this is Engineering Out Loud.

HAUTALA: Welcome to a new season of “Engineering Out Loud.” For the next six episodes, we’ll be looking at some of the issues surrounding clean water – and at some of the technologies being developed right here to help ensure a safe supply of this precious resource, from Cambodia to Corvallis.

Our local listeners probably remember a water contamination scare that happened recently in Detroit Lake, near Salem, Oregon. Microorganisms called cyanobacteria caused a spike in levels of naturally occurring substances called cyanotoxins in the drinking water. This contaminated water can make people sick if they drink enough of it. I live in Salem, and I’m happy to say I survived the great cyanotoxin scare of 2018. For my wife and me, and our two dogs, it wasn’t really that much of a disruption in our routine. We just drank bottled water for a couple of weeks to be on the safe side. The dogs too. But now, every time I head to the tap, I pause for a moment and think about just how much we take clean water for granted.

[MUSIC: “Faster, Sons Of Vengeance, Faster!” by Doctor Turtle used with permission of a Creative Commons Attribution-NonCommercial License]

This past spring, thanks to a generous gift from Jon and Stephanie DeVaan, Oregon State University launched the Clean and Sustainable Water Technology Initiative. Heading up that effort is our very own Professor Lewis Semprini.

SEMPRINI: I’m Lew Semprini, I’m a distinguished professor of environmental engineering.

HAUTALA: I talked to Professor Semprini this past summer about the initiative and the work that the DeVaans’ gift has enabled.

SEMPRINI: It’s just getting started, but part of that is allowing us to develop some fellowships for recruiting graduate students to OSU. This summer, we’re starting the first undergraduate research program. We’re going to have students, undergraduates, coming, working with faculty members, in civil engineering and in environmental engineering, on various research projects that are ongoing. And then we're starting to develop a workshop in the summer to start talking about the issues of clean water technology, also a venue for students to present their research work.

HAUTALA: One goal of the Clean Water Initiative is to help Oregon State become a national leader in designing, building, and testing systems-level approaches to the problem of access to clean water. Lew Semprini has been at work on this problem for a long time.

SEMPRINI: Right. So, I started, I was at Stanford as a research associate before I came to OSU. And so, around 1986, I got started looking into in situ bioremediation, part of that position I had at Stanford.

HAUTALA: Bioremediation. That’s a broad term for any type of technology that uses living microorganisms to clean up pollution in the environment. Lew works with specialized strains of bacteria that have the superhero-like ability to break down some particularly nasty industrial pollutants known as chlorinated solvents.

SEMPRINI: So, these chlorinated solvents, one that was used quite a bit was trichloroethylene, and they are degreasing compounds. So, they were very good and used in manufacturing, cleaning. The compound perchloroethylene was used as a dry-cleaning fluid, so they’re very good degreasers.

HAUTALA: Ironically, chlorinated solvents came into use largely because of safety concerns.

SEMPRINI: Their use came about in coming up with compounds that were also not flammable. So, before that, we used a lot of chemical degreasers that were flammable in nature. So, these compounds had safety factors related to them not being flammable, and actually having excellent properties for degreasing.

HAUTALA: These chemicals did such a great job at what they were supposed to do that they were used everywhere, at thousands of sites throughout the country.

SEMPRINI: There are many sites. And, again, it’s not just a problem in the United States; it’s a problem wherever industrially these chemicals were used.

HAUTALA: The problem comes when these chlorinated solvents start to seep into groundwater after they were disposed of improperly, dumped into landfills, or stored in leaky underground tanks. If you’re not a geologist, you might remember this from an earth science class -- maybe it’s been a little while -- but there is a hundred times more water in the ground than is in all the world's rivers and lakes. It’s everywhere, filling in all the little cracks in the soil and rocks beneath the surface, and flowing through porous rock formations such as sandstone. If you went out into your backyard right now and started digging -- I wouldn’t recommend doing this without a permit -- but if you kept digging down, say 100 to 500 feet, eventually, you’d hit water.

[MUSIC: “Laid Back Fuzz,” Podington Bear, used with permission of a Creative Commons Attribution-NonCommercial License]

SEMPRINI: The other property of these chemicals is they’re denser than water, so they want to sink. So, when they leaked out of the tanks they kind of went down and migrated down through the subsurfaces, and they could go long distances until they hit something that confined their transport.

HAUTALA: When he says something that confined their transport, he means something solid like a layer of rock.

SEMPRINI: So, you could get large amounts of these solvents strung out in the subsurface, and then slowly dissolving to create these groundwater plumes that could be large in extent and had been generated over long periods of time.

HAUTALA: These plumes -- where the chlorinated solvents dissolve and spread out in the groundwater -- can cover areas measured in square miles, and they can stretch down hundreds of feet. Now, groundwater supplies about half of the drinking water in the United States. In rural areas it’s closer to 99 percent. The thing about chlorinated solvents is, while they may be great degreasers and dry-cleaning chemicals, you really don’t want to drink a big glass full of them.

SEMPRINI: Right. So, one of the big problems is, many of these compounds, they’re either known or suspected carcinogens. The EPA has put a maximum concentration levels in drinking water; like, the standard for trichloroethylene is 5 micrograms per liter.

HAUTALA: That’s 5 parts per billion, with a B. That’s like a couple of teaspoons’ worth in an Olympic size swimming pool.

SEMPRINI: But the solubility of TCE in water is 1100 milligrams per liter, so the drinking water standard is many orders of magnitude lower than the maximum amount that TCE can dissolve in water. We have very low concentrations that are needed to meet a drinking water standard but potential for plumes being much higher concentrations in the subsurface.

HAUTALA: What that means is that contaminated groundwater could potentially contain about 220,000 times the level of trichlorethylene that the EPA allows in drinking water. Are you feeling queasy yet? Grab yourself a glass of water. It gets worse.

SEMPRINI: And many of these compounds also can be transformed in the subsurface. So sometimes you can create a compound that is more toxic or has a lower drinking water standard than the compound you started out with originally. So, transformations occur – one known with trichloroethylene is the production of vinyl chloride, which is part of its transformation process. And vinyl chloride is a known carcinogen has even a lower drinking water standard than trichloroethylene.

HAUTALA: Meaning you want even LESS of it coming out of your tap. The traditional strategy for cleaning up this mess has involved pumping contaminated water out of the ground, treating it to remove the chlorinated solvents, and then sending it back underground or off to a wastewater facility for further treatment. All of that pumping uses a lot of energy, and so it’s very expensive. The strategy Lew Semprini is working on, bioremediation, has one huge advantage in that it enables treatment of the groundwater in situ, which is just a fancy Latin term meaning “on site.”

SEMPRINI: So we try and basically stimulate microorganisms in the subsurface to enhance the remediation process and try and make reactors in the subsurface to actually intercept these plumes and treat them in situ. And in this case, in enhanced or engineered bioremediation, you have to figure out how to stimulate that process in situ -- you know how to go about either taking advantage of the native microorganisms that exist there or using a process called bioaugmentation, to actually add specific microbial cultures to the subsurface, in order to enhance the remediation.

HAUTALA: Some of these specific microbial cultures come from exotic, faraway places with names like … Corvallis, Oregon.

[SOUND EFFECT:Harp Glissandos, used with permission of Creative Commons Public Domain]

[MUSIC: “Scattered Light,” David Hilowitz, used with permission of a Creative Commons Attribution-NonCommercial License]

SEMPRINI: One of the cultures we actually work with in the lab we got from, it was called the Evanite site, in Corvallis, where they used trichloroethylene. And years ago, a graduate student went down in the sediments there along the banks along the Willamette River we got some material and brought in into the lab, and we started to culture and isolate these dehalogenating bacteria from the subsurface there. We call that the Evanite culture. But many of these cultures have a common microorganism in them -- it's been called Dehalococcoides mccartyi.

HAUTALA: In environmental engineering circles, that’s how you know when you’ve become a really big deal: They name a species of bacteria after you.

SEMPRINI: It actually was named after a professor I worked with at Stanford, Perry McCarty -- the microorganism was eventually named after him. But there’s different strains of this microorganism that do different steps in this transformation process. They look a lot alike genetically, but there’s little different variations that they do various different steps in the process.

HAUTALA: The process he’s talking about is called dehalogenation, which involves breaking the chemical bonds between atoms of carbon and atoms of another type of element, called a halogen. In the case of chlorinated solvents, the halogen is chlorine. Breaking those carbon-chlorine bonds is essential in converting these solvents into less harmful molecules.

SEMPRINI: The ultimate goal is to transform them to nontoxic products. So, something like trichloroethylene, you could see if you could transform it to carbon dioxide and chloride ion, which are benign, then you've completely broken down that compound. And in other mechanisms, we’ve transformed them to compounds like ethene, which are also non-toxic. So there's different routes to try and transform these chlorinated solvents.

HAUTALA: One of these routes, of particular interest to Lew Semprini, is called organo-halorespiration. I’ll let Lew go into that a little bit.

[MUSIC: “Movin On Up ,” Podington Bear, used with permission of a Creative Commons Attribution-NonCommercial License]

SEMPRINI: This is where we take advantage of anaerobic conditions in the subsurface. So, lack of oxygen. There are some strict anaerobes. This process was discovered when we first started working at contaminated sites; we started to get some observations that trichloroethylene was the contaminant that was disposed of, but then these other contaminants start to be observed. Things like cis-dichloroethylene, vinyl chloride, even ethene. And so observations started to come in that, you know, transformations might be occurring naturally in the subsurface.

HAUTALA: So, as it turns out, there was a whole series of transformations occurring, sort of like a microscopic biochemical assembly line. Or, more accurately, a disassembly line.

SEMPRINI: And then in the lab, people began to investigate to find out that this reductive dehalogenation process was going on -- you could actually track the parent compound being degraded to daughter compounds in a successive series of transformation processes occurring. And originally we thought it was just fortuitous that other microorganisms that were anaerobes were kind of doing this. And then with time, we found out there was a specific groups of microorganisms that could actually grow on chlorinated solvents, and it became known as halorespiration. And they were actually breathing chlorinated solvents like we breathe oxygen.

HAUTALA: You heard that right. The microorganisms that grow on these chlorinated solvents and break them down technically aren’t eating them; they’re breathing them. (Their “food,” such as it is, is actually hydrogen. I know that probably sounds strange, but we’ll get back to that in a minute.) The important thing to understand here is that the microorganisms use the solvents exactly the same way the cells in our bodies use oxygen to get energy out of the food we eat.

[MUSIC: “Ray Gun - FasterFasterBrighter,” Blue Dot Sessions, used with permission of a Creative Commons Attribution-NonCommercial License]

SEMPRINI: So, trichloroethylene, they could respire that and make the daughter products. And what would happen here is they would take a chlorine ion off the molecule -- trichloroethylene is a two carbons, a double bond, and three chlorides on it, and a hydrogen -- they would take one chloride off and put a hydrogen on, and make cis-dichloroethylene, and they would be able to get energy out of that process. And it’s called a reduction because TCE is being reduced to a lower oxidation-state compound when you do that. And it keeps on going, and you could keep taking chlorides off one at a time until you get to ethylene, which has no chlorides on it, and four hydrogens. And this is a nontoxic end product.

HAUTALA: If you’re not quite able to follow all of that chemistry, the important thing to understand here is that these microorganisms can break down the chlorinated solvents into smaller and smaller molecules, until there’s nothing left but harmless, non-toxic end products. Pretty cool trick, huh? And nobody’s quite certain how they learned how to do it. At least not yet.

SEMPRINI: So, it’s been interesting in that when we look for them, we find them in a lot of places, and that's been a big question -- how did they evolve? These chlorinated solvents have not been around forever, but we have these microorganisms that could do this halorespiration and grow and get energy out of these compounds.

So, in my work, a part was the kinetics. How does this work, when you get these cultures and you're able to enrich them in the lab, looking at the various steps in the process. And by kinetics, we mean rates, the rates at which these compounds would get transformed. So I’ve done a lot or work of actually studying the kinetics of this process and figuring out when you have these multiple steps going in, how do we kinetically describe these rates of reaction?

HAUTALA: One key factor in this process is the addition of a substrate, a food source for the microorganisms to munch on while they’re busy dehalogenating solvents. As I mentioned before, nothing hits the spot quite like good old yummy hydrogen.

SEMPRINI: To generate the hydrogen that’s needed to drive this reaction, often fermenting substrates are added. And by a fermenting substrate, it’d be something like lactate, some food-grade compound, that in the ground, it ferments. And when it ferments, one of the products that’s formed is hydrogen. Okay. What happens there, though, if you add too much lactate, you could start getting into methanogenic conditions, where methane, okay, is formed in the subsurface. So, some of the energy you put in through lactate is diverted to making methane. Making lots of methane in the subsurface may not be a good thing.

HAUTALA: Spoiler alert: It’s not.

[SOUND EFFECT: Clean Explosions, used with permission of Creative Commons Public Domain]

SEMPRINI: So, there’s side reactions that go on when you carry out this process. So, some of our activities have been in the lab -- well, how do create the conditions, say, that you don’t make methane? How do you come up with very efficient systems that you take advantage and try and get the reactions that you want to happen, happen?

HAUTALA: This particular type of anaerobic bioremediation process works best when concentrations of contaminants are high. As the concentrations get lower, other types of bioremediation start to look more feasible.

SEMPRINI: When we get into low concentrations, you often wind up to do things anaerobically, you’re adding a lot of substrates, but you’re only transforming a small amount of the contaminants when you do that. So, there, oftentimes you get in that, that type of bioremediation may not make sense. So then, the other processes I’ve been studying are processes -- cometabolism. And cometabolism is an aerobic process -- we use aerobic microorganisms. And there, we try and develop the enzymes to do the transformation, by feeding a food substrate that stimulates a particular enzyme that promotes the transformation.

HAUTALA: In this approach, called aerobic cometabolism, the microorganisms aren’t really eating or breathing the solvents. In fact, they don’t really need the solvents at all. But when you feed these microorganisms the right kinds of stuff, they make these enzymes that do all the hard work of dehalogenation, really just as a kind of side job.

SEMPRINI: And these often are enzymes called monooxygenases, or dioxygenases, that are very good at oxidizing compounds. So they actually initiate the oxidation of compounds that are hard to oxidize. One micro -- groups I work with, methanotrophs, oxidize methane, and there’s an enzyme called methane monooxygenase, that initiates the oxidation of methane. But that methane monooxygenase also fortuitously oxidizes TCE, and other compounds. So in aerobic cometabolism, we try and bring up the enzymes by adding a food source that stimulates a certain enzyme system, and then you get fortuitous degradation of these compounds.

HAUTALA: “Come for the methane, stay for the TCE.” It has a nice ring to it, no?

SEMPRINI: The beauty of it is you could do very low concentrations. So, it actually, because you’re driving this with an enzyme in a food source, you could drive concentrations much below these MCL --

HAUTALA: MCL -- the maximum concentration levels.

SEMPRINI: -- in drinking water standards.

HAUTALA: Since this interview was recorded, the Clean Water workshop Lew mentioned at the start of the program has taken place, with Oregon State faculty members, graduate students, and water experts coming together right here on our campus to talk about how to preserve and expand access to clean water, and the technologies that will make that possible. For more information about the workshop and the Clean Water initiative, please follow the links on our website.

This episode was produced by me, Keith Hautala, with additional audio help from Molly Aton. Our intro music is “The Ether Bunny” by Eyes Closed Audio on Soundcloud, used with permission under a Creative Commons Attribution license. Other music and sound effects were also used with appropriate licenses. You can find the details in our show notes, which are online, along with other episodes, at engineeringoutloud.oregonstate.edu. Subscribe on our website, or by searching for “Engineering Out Loud” on your favorite podcast app.

[MUSIC: “Ray Gun - FasterFasterBrighter,” Blue Dot Sessions, used with permission of a Creative Commons Attribution-NonCommercial License]