Environment

By Todd Neff

Forests across the Mountain West have gone orange and faded to gray. Since about the turn of the millennium, the mountain pine beetle’s appetite for lodgepole has killed off some four million acres of trees in Colorado and Wyoming alone. That the larvae of an insect the size of a grain of rice can bring such destruction is in itself a wonder of nature.

The changes go far beyond appearance, and while questions about the effects of so many dead trees on forest fires may be the most obvious, some of the beetles’ biggest impacts lie downstream. Pine beetles are shrinking the snowpack, hastening runoff and parching summer soil. The bugs have affected everything from the molecular habits of soil metals to the makeup of soil microbes. They have changed the chemistry of forest earth and increased the loads of carcinogens flowing through water treatment plants.

It’s more than a provincial concern of cabin dwellers and ski condo owners. Mountain runoff into the Colorado and Platte rivers alone sustains 30 million people and 1.8 million acres of irrigated farmland. With a warming climate, the deep freezes that once killed off pine beetles will be fewer, threatening more frequent, longer lasting epidemics affecting the region in ways science is only beginning to grasp. But science will soon catch up. A Mines-led team of hydrologists, microbiologists, geochemists, numerical modelers and social scientists is sharpening the picture of pine beetle impacts below a given dead tree and connecting how those changes trickle out to watersheds and the people who depend on them.

A five-year, $3 million National Science Foundation grant and $375,000 in Colorado state matching funds are fueling the effort. Mines Associate Professor Reed Maxwell, who specializes in hydrological modeling, serves as principal investigator. His Mines office is big and sparse. Its notable features include a high-end road bike outfitted with commuter lights, a wall clock whose arms at noon point to the cube root of 1728, and a 28-square-foot whiteboard, mostly empty on this day.

“The water quality in, say, Lake Granby has a lot to do with a watershed area that’s heavily beetle impacted,” Maxwell said. “We want to move from tree to plot to hillslope to watershed scale. That’s one of the big tasks in our grant, and we’re developing the models from scratch. They aren’t really out there.”

There are plenty of hypotheses, supported — but also contradicted — by a growing number of studies. Combined, the story goes something like this: Pine beetles kill trees, which drop their needles and load the soil with carbon as they break down. Their denuded branches let more snow into the ground, but they also stop less sunlight and block less wind, accelerating melting and runoff. The water moves through the hillslope and watershed faster. That influences how fast it reacts chemically, which in turn affects carbon balance, metal absorption and microbial makeup. At larger scales, the flow paths and speeds of rivulets, creeks and rivers change, too. The sum of the impacts shifts water quality, quantity and timing to new equilibriums, Maxwell said.

But no one knows for sure, which is why the team of eight faculty, eight graduate students and two postdoctoral researchers from Mines and Colorado State University has much to do.

If recent studies are any indication, the pine beetle plot will have many twists. Mines hydrological engineering PhD student Kristin Mikkelson spent three summers doing field work in Pennsylvania Gulch near Breckenridge and Keystone Gulch, focused on testing surface waters for copper and zinc. Dissolved organic carbon, more abundant with all the fallen pine needles, latches onto metals and keeps them mobile, boosting their soil concentrations and, one would think, the volume of metals flowing in surface waters. But while soil concentrations of metals have indeed been higher, Mikkelson said, “We’re not seeing it in the surface water.”

Another curiosity relates to municipal water quality. In a separate Mikkelson-led study, published in Nature Climate Change in October 2012, she and Mines colleagues reported that higher concentrations of organic carbon from pine needle pulses react with chlorine-based disinfectants in water treatment plants and produce more carcinogenic disinfectant byproducts. The study compared water treatment plants in five pine-beetle-impacted watersheds with four controls and linked increases in disinfectant byproducts with the degree of pine beetle infestation. The surprise, Mikkelson said, was that one class of disinfectant byproducts, known as trihalomethanes, spiked while others, haloacetic acids, didn’t.

“When we saw the jump in only the one, it was clear that the pine beetle epidemic is not only changing the amount of organic carbon, but also its composition,” she said.

Mikkelson is following up with experiments in which she percolates artificial rainwater presoaked with brown pine needles through columns of soil. “We’re measuring how that organic carbon is changing as it goes through the columns — what parts are partitioning and sorbing into the soil and which metals they’re grabbing.”

That effort complements Mines hydrology PhD student Lindsay Bearup’s work. In a Berthoud Hall lab, Bearup pulled a one-gallon Ziploc® bag from a refrigerator. Its dirt would find its way into jars, and then vials.

“I have jars and jars of dirt – really exciting!” she joked.

Bearup had collected it from a site north of Bear Lake in Rocky Mountain National Park. After hiking the eight miles in, she had filled bags of dirt beneath trees in various states of beetle impact – some green and untouched, some orange, some gray. In the lab, she had put single grams of soil into 50 milliliter falcon tubes and added chemicals to determine how organic fractions differed and what metals were present. This information, combined with water captured in a rain gauge (to determine precipitation volume and stable isotopes) and other data, may help explain the surface water metal mystery, among other things.

“I’m looking at where metals are associated with soils,” she said. “It’s interesting because organic matter is changing as trees die.”

Those changes probably affect the microbial communities in forest soils, added Jonathan Sharp, a Mines assistant professor who focuses on the intersection of microbiology, geology and hydrology. With the pine beetle work, Sharp is guiding graduate students as they work to determine microbial makeup in soil based on DNA analysis. The theory is that, as trees die, microbial ecosystems face a pulse of needles and lifeless root systems and will evolve accordingly. That, in turn, could ultimately affect the transport of metals and water quality.

“We’re trying to look from the millimeter scale all the way up to the watershed,” Sharp said.

Maxwell’s modeling work will incorporate the team’s fieldwork, as well as data from partners at the U.S. Geological Survey and the University of Colorado, to bridge these scales. One aim is to put new information in the hands of water managers and policymakers. Part of the project, Maxwell said, will involve partnering with water municipalities in Colorado and southern Nevada to help them understand how pine beetles may be affecting the quality of their inflows and how they might adjust their water treatment regimes.

“We’re seeing real water quality changes,” Maxwell said. “At best, this is going to mean an increase in water bills.”

John McCray, a co-investigator and head of Mines' Department of Civil and Environmental Engineering, says the project’s combination of field work, chemical and DNA analysis, and computer modeling could help answer questions well beyond those posed by the pine beetle.

“The processes we’re looking at really have to do with any sort of change in mountain and forest hydrology,” McCray said. “Those could be changes due to fire, development or climate change.”

It’s good that the work’s happening now, he added. “Pine beetles appear to have significant effects on hydrology and water quality, and we’ve only had a limited window in which to study this.” 

 

This article appears in the 2013-14 edition of Mines' research magazine, "Energy and the Earth."

By Taylor Polodna
The Oredigger

A group of Mines students, representing Engineers Without Borders-USA (EWB-USA), travelled down to Nicaragua to the small community of Los Gomez to complete a pedestrian footbridge over the frequently flooded Rio Ochomogo River.

The bridge had been under construction for the preceding year. The cohort included six students, a faculty mentor, and a professional mentor, ranging in majors from civil to humanitarian to chemical engineering, all of whom donated their spring reaks to helping those less fortunate than themselves. The trip marked the 4th trip to the small community over the last year in which the team was able to finish hand mixing and pouring two concrete anchors, stringing five steel cables, and laying the decking and fencing of the 42 meter pedestrian footbridge.

EWB-USA Mines is a student led campus club that focuses on sustainable development of communities outside of the US with six core values: integrity, service, collaboration, ingenuity, leadership, and service. In addition, the club participates at a local level in a variety of on-campus and off-campus events including Relay for Life, Up 'Til Dawn, and many Habitat for Humanity builds.

Barbara Anderson, a graduating senior in Civil Engineering recounts her experience toward the end of the bridge completion. "As we began putting the decking on the bridge we were able to muster a lot of community support and could tell that the community members, even the ones that didn't come to worksite, were getting excited for their bridge to be completed. Kids would walk by on their way home from school and just watch us work on the bridge for hours and, as soon as we left, would play on it. At the end of the week, we had an opening ceremony for the bridge with the whole community. It was an awesome experience to see all the people that had worked with us, fed us, and welcomed us into their homes gather together and celebrate the success of their project."

Read the rest of the story on The Oredigger website.

In an effort to develop energy self-reliance for mining operations, Colorado School of Mines Mining Engineering Professor Masami Nakagawa is leading a feasibility study for solar-wind hybrid power generation for the fourth largest silver mine in the world, Minera San Cristobal in Bolivia.

This project aims to provide sustainable hybrid power generation for the cafeteria and sleeping quarters of the Minera San Cristobal mine camp.

“This study can only supply about 1.5 megawatts of electricity -- a tiny fraction of the total energy needed for the big silver mine. What I am looking for is a ripple effect of this project to other mines to develop larger usage of renewable energy to power energy intense mining operations,” said Nakagawa, noting geothermal energy likely will stabilize complete needs by supplying base-load energy in the future.

Nakagawa, who has expertise in geothermal energy, teamed up with Mines Electrical Engineering Professor Marcelo Simoes and Kyle Bahr, a mining engineering PhD student at Mines, for a visit to the mine camp for site selection in January 2013.

“I see this project as a game-changer and I am grateful the management team of Minera San Cristobal is open-minded about sustainable mining operations and mining community development,” said Nakagawa, who is promoting a new idea in in sustainable development he is calling “Caring Energy” to empower communities.

 

A slow, persistent landslide is undermining a short section of I-70, about a mile from the highest point on the nation’s Interstate Highway System. Finding a solution is a conundrum that one Mines professor is helping to unravel.

Two summers ago on I-70, about a mile from the highest point on the nation’s Interstate Highway System, a dip in the pavement grew so large that cars were going airborne and getting tossed out of their lanes. Fortunately, no one crashed before the Colorado Department of Transportation made repairs, but drivers shouldn’t rest too easy; the Big Bump will be back.

Located about a mile west of the Eisenhower Tunnel in Summit County, the Big Bump is a perennial headache for CDOT. The dip forms in the eastbound lanes on a slope-side stretch of highway perched hundreds of feet above Straight Creek. As spring snowmelt soaks underlying layers of rock and soil, the roadbed sinks a few inches every year. When it gets bad enough, CDOT repaves to level things out, but come the following June, the Big Bump returns.

Professor Ning Lu has been working with CDOT for three years, seeking a long-term solution to the seasonal slope instability.

Professor Ning Lu has been working with CDOT for three years, seeking a long-term solution to the seasonal slope instability.

“At that point, the asphalt is now 6 to 7 feet deep,” says Ning Lu, a professor in the Department of Civil and Environmental Engineering, who refers to the slippage on I-70 as a slow-motion landslide. “CDOT keeps laying over more asphalt, but that’s just a short-term solution. With each passing year, the chance of a catastrophic event grows, and finding a long-term sustainable engineering solution is critical.”

CDOT turned to Lu, an international expert on landslides, in 2009. Since then, he’s partnered with the state’s engineers to gather baseline data about slope stability, with an eye toward developing a plan for a permanent fix.

“We started a field investigation there three years ago,” Lu says. “We put in sensors to measure embankment movement and groundwater table fluctuation in the slope over time. The main purpose of our research is to understand the configuration of the water table and soil—what type of soil is there, what’s happening with the water table.”

Lu found a clear pattern: “Stabilize, slide, stabilize, slide. But at some point, rather than 2 inches of subsidence in a year, there could be 2 feet of subsidence, and the highway would not be functional.”

That’s an outcome both Lu and CDOT hope to prevent.

Every year since the 1970s, the eastbound lane has subsided a few inches during springtime snow melt. This fissure was found after asphalt was removed for repairs in summer 2012.

Every year since the 1970s, the eastbound lane has subsided a few inches during springtime snow melt. This fissure was found after asphalt was removed for repairs in summer 2012.

Over this stretch of I-70, the eastbound lanes are built on fill excavated from the tunnel in the 1970s. There is no subsidence on the westbound lanes, which sit more directly over bedrock.

Located at 11,000 feet, winter snowfall accumulations are considerable. By early spring, drifts at the edge of the highway often stand more than 10 feet high, and a snow-laden mountainside rises another 1,500 feet to the north.

“All that snow melts within a couple of weeks in the spring,” explains Lu, adding that the topography funnels surface runoff directly toward the area of the Big Bump. “As subsurface moisture content increases, the water table rises rapidly and the slope loses stability. Our monitoring results indicate that the water table rises by as much as 30 feet within the two-week snowmelt period.” It doesn’t help that there are two springs nearby.

“We’re looking at a dynamic process that extends from the surface to the water table and the underlying bedrock,” Lu says. “Precipitation alters the stress inside a slope, and when the stress state reaches its limit along the sliding surface, there will be a landslide. Sometimes it could take a few hours. Other times it could be weeks or years.”

Searching for a sustainable solution

The highway has sunk on a seasonal basis since it was completed in the 1970s. One of the primary concerns is that this consistent movement over four decades has defined a shear plane—an interface between bedrock and the material supporting the road that gets weaker with each spring melt. “It is likely that at some point in the future, accelerated sliding is going to occur if effective measures are not taken,” says Lu.

A hydrogeologic cross-section of I-70 looking east developed by PhD student Michael Morse illustrates the possible location of a weakening shear plane under part of the highway. Boreholes are used to gather data about the elevation of the water table during spring snowmelt.

A hydrogeologic cross-section of I-70 looking east developed by PhD student Michael Morse illustrates the possible location of a weakening shear plane under part of the highway. Boreholes are used to gather data about the elevation of the water table during spring snowmelt.

Over the years, CDOT has looked at various options for permanently stabilizing the slope. One is to keep the area dry by channeling surface runoff away from the slide area and installing a network of subsurface drains. With adequate drainage, efforts could then be made to reinforce unstable soils with underground structures.

Another idea is to stack the eastbound and westbound lanes in an overhang configuration—as in Glenwood Canyon—so that both directions lie atop stable bedrock, but complex construction on this scale at this elevation would be very costly.

In addition, projects of this magnitude would necessitate closing I-70 for several months and diverting traffic over Loveland Pass, which would result in hours of delays, have a national impact on transit and shipping, and wreak havoc with state commerce and tourism. Such economic costs need to be considered along with the cost of construction.

“It would be very expensive to fix,” says Mark Vessely ’94, a former CDOT engineer who now works for the consulting firm Shannon and Wilson.

With no viable alternatives, CDOT resorted to an asphalt Band-Aid until last spring, when Vessely and his company devised plans to drill a series of shafts into the thick asphalt pad at the Big Bump and fill the holes with lightweight cellular concrete. “It reduces the weight and stress on top of the slide, and fills voids and loose soil beneath the pavement,” says Vessely. “The goal is to make some improvements and lower CDOT’s year-to-year maintenance costs, but it’s an interim measure. The long-term fix is still undecided.”

Probing the Rockies

CDOT spokesperson Bob Wilson says the department brought in Lu to help because of his insight and experience. Lu has studied landslides around the world as part of an arrangement between Mines and the U.S. Geological Survey’s Landslide Science and Engineering Partnership.

The team monitors numerous active landslide sites in Washington, Oregon, California, North Carolina and Colorado in an effort to develop simulators and modeling tools. When a major slide occurs anywhere in the world, Lu and his USGS colleagues are generally among the first investigators on the scene.

“The response team goes to take samples and data, make assessments, evaluate mechanisms, and find out how much stress and what particular type of soils were involved,” says Lu, who points out that landslides are becoming more frequent. The reason? The primary culprit is global climate change, he says. More energy in the atmosphere leads to more intense storms and precipitation.

“Any natural slope you see today is in a delicate equilibrium that has evolved over thousands of years,” Lu explains. “If you change the pattern, it’s going to alter the balance and possibly trigger a landslide.” For this to happen, the total volume of precipitation is less relevant than the intensity. “A slow rain will produce different effects on a slope than an equivalent amount of rain that falls more quickly.”

F_I-70_Hillslope_book_coverLu’s new book, “Hillslope Hydrology and Stability,” published by Cambridge University Press and co-authored with USGS colleague Jonathan Godt, offers a comprehensive set of global landslide data, along with a new hydrological and mechanical framework for predicting and analyzing the likelihood of a major slide on a given hill slope or region. It answers questions not covered in his 2004 book, “Unsaturated Soil Mechanics,” published by John Wiley and Sons, co-authored with William Likos PhD ’00, a professor at University of Wisconsin–Madison, which has become a go-to reference for civil engineers around the world. Still, he says, landslide forecasting has lots of room for improvement.

CDOT renewed the research contract with Lu and Mines Associate Teaching Professor Alexandra Wayllace for another three years. During that time, the asphalt at the Big Bump may grow another foot deeper. But Lu’s body of soil and water data will grow deeper as well and, he hopes, yield the information necessary to formulate a strong long-term solution.

What are the chances they’ll be able to finesse the problem and avoid massive disruption and expense? “Once we know more about subsurface fluid flow and stress variation patterns, we’ll be in a better position to know if conditions can be changed to stabilize the slope in a natural setting without major overhaul,” Lu says. “The key may be controlling groundwater table levels within the highway embankment. That could happen, and it could be economical and sustainable.”

Engineers at CDOT certainly hope so. “We’ve been patching this over for too many years,” says CDOT’s Wilson. “Eventually you have to fix what’s broken.”

This story appears in the Spring 2013 issue of Mines Magazine. Click to read more.

 

 

The Colorado School of Mines student chapter of Engineers Without Borders-USA has raised more than $15,000 to fund the construction of a bridge in Nicaragua.

The bridge project, located in the Carazo region, connects a rural community with access to medical facilities, food markets, and adjacent farmland that is cut off during the rainy season. The Mines group has committed to remain involved in this region for five or more years through future bridge or other development projects.

The principal donor of the project, the Alcoa Foundation, is providing a $200,000 grant to various organizations for the Building for Better program that supports engineering faculty and students at Alcoa’s academic partners in Australia, Brazil, Canada and the United States. Other donors supporting the Nicaragua bridge project include CH2MHill, Todd Wang, and Jim and Nelly Kilroy. 

The Mines chapter will travel to Nicaragua in January 2013 to begin construction of the bridge. The project will be completed before the start of the next rainy season in March. During these trips, students will investigate other sites in the region in need of bridges and will plan to design and build a bridge for a second location in the next two years.
 
The growing Engineers Without Borders-USA Colorado School of Mines Student Chapter is a student-led organization of approximately 20 students.

For more information about the project, or to donate to the cause, view their website at inside.mines.edu/ewb.

The town of Pagosa Springs, Colo., depends on geothermal resources for tourism as well as a source of renewable energy -- a recent study by Colorado School of Mines’ geophysics students will aid officials there in further developing the region’s geothermal industry.

Earlier this summer, a group from Mines, along with students from Imperial College London and RMIT (Melbourne, Australia), studied the Pagosa Springs geothermal system as part of summer field session.

“Pagosa Springs was suggested as an attractive possibility for field camp because that community had tapped its natural hot springs not only for recreation but also to provide heat for the downtown businesses,” said Terry Young, head of Mines’ Department of Geophysics.

The students characterized the local geology, conducted geophysical surveys and then analyzed their results. In early June they presented their findings, explaining the basics of geophysics and what they discovered about Pagosa Springs’ geothermal structure.

“When we contacted Pagosa Springs about conducting our field camp in their vicinity, Phil Starks, geothermal supervisor for the town, encouraged us to come and emphasized the value we could bring to the community by helping them understand their geothermal system,” Young said.

Young said the community welcomed the Mines group and they plan to return for additional field study next summer.

For photos and more information regarding geophysics field camp, see the Department of Geophysics website.

October 2011 was an exciting month, not only for Mines, the National Renewable Energy Lab (NREL) and the state of Colorado, but for solar energy in general. Coming off the purchase of Colorado-based PrimeStar Solar, Inc., General Electric (GE) announced it would build a $300 million photovoltaic (PV) production plant in Aurora, Colo. — the largest of its kind in the U.S.

It was a mix of institutions, knowledge and bright people that brought GE into the solar industry with such an investment. The backstory begins in 1996 with a Mines graduate student named Joe Beach, who is now a Mines research professor.

“The reason I came to Mines was because I was looking for ways to get into renewable energy,” said Beach. “At that time Mines was one of the few places that actually talked about it.”

In the early 1990s, the Department of Physics at Mines formed a research program in Cadmium Telluride (CdTe) technology, which is now considered one of the most cost effective thin film PV technologies available. The research began with Dr. John Trefny, who later became head of the Department of Physics and then president of the university. That research was funded by the Thin Film Photovoltaic Partnership Program, which was managed by NREL. By the time Beach started work on the program, shortly after earning his PhD, leadership had been handed off to Associate Professor Tim Ohno. It was in working with Ohno that Beach met graduate student Fred Seymour.

“I had an interest in moving laboratory research into commercial work and it turns out Fred Seymour did too,” said Beach.

Seymour and Beach collaborated to form a small business called PV Technologies, receiving two SBIR grants from the National Science Foundation and beginning work in Mines laboratories. However, they lacked manufacturing experience, and for that they turned to Russell Black and his company called Ziyax, which had expertise in large-scale deposition of thin films of semiconductors and metals on glass. They named this new venture PrimeStar Solar and began hunting for investors.

“The thing that people were just starting to realize at that time is that to have a successful PV company it takes between $500 million and $1 billion in investment,” said Beach.

GE was interested in investing in the solar market, having shopped for opportunities at other institutions in Colorado. Ultimately, however, GE approached PrimeStar and became the largest investor before purchasing the company in April 2011 and announcing its plans to ramp up production with the construction of the largest PV manufacturing plant in the U.S. PrimeStar Solar is now part of GE, and Fred Seymour is general manager of Solar Technology for GE Energy – Renewables.

“The big thing that the research here at Mines did for PrimeStar is it produced people with excellent technical skills,” said Beach, who added that the company licensed its patents from NREL, which has been active in CdTe research since the early 1980s. “You’ve got to have the right combination of engineering expertise, science expertise, entrepreneurial interest and willingness to just doggedly pursue a problem. It will make or break the transition from a laboratory technology to something that is viable commercially.”

In isolation this is a success story, yet much of the U.S. solar industry is struggling. First Solar reported its first losing quarter at the end of 2011, while Abound Solar halted production of its first-generation panel and cut roughly 180 jobs at its Loveland, Colo., facilities. California-based Solyndra filed for bankruptcy and shut its doors after receiving more than $500 million in federal government loans.

At the macro level, however, there are economic challenges at play.

“The overall PV industry problems are due to a 50 percent overcapacity right now,” said Beach. “There really isn’t a barrier to entry in the market.”

Debate continues on whether China presents unfair competition. Chinese manufacturers get extremely cheap loans and do not pay income taxes. This gives them a significant cost advantage without requiring any technology advantage, and has caused resentment and charges of dumping by some other PV manufacturers. Taking cues from the history of foreign car manufacturers in the U.S., Chinese PV companies began building assembly plants in their sales markets. This reduces shipping and working capitol costs and creates manufacturing jobs in the sales markets.

Further increasing the complexity of the issue, struggling American photovoltaic start-up companies, such as Ascent Solar (another Colorado company with ties to Mines), have been supported financially by investment from Chinese firms.

Much is to be determined in the photovoltaic energy game and, as it has in the past, Mines will play a leadership role moving forward.

"We are clearly at a challenging time in the PV world,” said John Poate, vice president for research and technology transfer at Mines. “The modern PV cell was invented at Bell Labs in 1954. CdTe is another pioneering U.S. technology. It is essential that we compete successfully in this industry, which we invented. To do this we will need a coherent national strategy to stay ahead of the game.”

This article appears in the 2012-13 issue of Energy and the Earth magazine.

Take raw sewage flowing from a major apartment complex. Send it through a 2 millimeter screen. Let a flora of microorganisms feast on it for a while. Filter it – this time through pores just 50 billionths of a meter across. Don’t touch it with a single water-treatment chemical.

That’s what the above-ground sequence batch membrane bioreactor does, and the six gallons per minute flowing out are cleaner than the effluent from most wastewater treatment plants. And unlike the massive, in-ground infrastructure just downriver of our metropolitan areas, the bioreactor is portable. The fruits of Colorado School of Mines’ Advanced Water Technology Center’s (AQWATEC) signature project could form the nodes of a next-generation network of water-treatment facilities, able to reuse water locally for things like irrigation and toilet flushing, saving pumping energy and infrastructure costs, while reducing water demand.

In the control room, Tzahi Cath, a Mines professor and director of AQWATEC overseeing this facility, lifted the lid of a vat and dipped in a Pyrex measuring cup. It looked like… water. “That was sludge a few minutes ago,” he said. “There are technologies that can make good water from almost any source.”

The AQWATEC facility, just downhill from the apartments at Mines Park, is one of many water research efforts led by Mines faculty and students. Their studies of water begin with aquifers 1,000 feet down and continue through the turbulent interface of soil and the air above. Along the way, they use tools as diverse as a managed aquifer recharge site in Colorado’s eastern plains, a wooden wind tunnel built in a converted swimming pool, and the Jaguar supercomputer at Oak Ridge National Laboratory. They aim, collectively, to ensure safe, clean water for people and the environment.

It’s critically important work. A recent United Nations report described global water challenges ranging from water supply to sanitation infrastructure. More than 80 percent of the world’s wastewater goes untreated, according to the report. Furthermore, these challenges occur amid what the UN called “unprecedented” increases in food demand, rapid urbanization and climate change, and they aren’t limited to developing countries.

“Fresh water supplies are unlikely to keep up with global demand by 2040, increasing political instability, hobbling economic growth and endangering world food markets, according to a U.S. intelligence assessment,” Reuters reported in March 2012. 

In the United States, the gap between budgets and needed upgrades to half-century-old water infrastructure is wide and growing, said Professor Jörg Drewes, a co-director of AQWATEC. “We need to come up with new ideas, to be innovative and work with the funding we have available,” Drewes said. “It’s not enough to merely replace what we have today.”

 

NSF Funds New Water Research Center

New solutions will require expertise across a broad swath of science and engineering, as well as legal, political and business realms. In 2011, Mines joined forces with Stanford University, the University of California at Berkeley, and New Mexico State University to create the first-ever NSF-funded Engineering Research Center devoted to water issues. It’s called Re-inventing the Nation’s Urban Water Infrastructure, or ReNUWIt.

Mines’ central role in ReNUWIt came in the wake of years of investment in labs and research infrastructure and the development of one of the country’s leading water-research programs, said Drewes, who is also ReNUWIt’s director of research. He is among a dozen Mines faculty involved in a 10-year effort to transform traditional models of water use to reduce consumption, recover and reuse water, cut energy use in water systems, and harness wastewater nutrients to improve urban habitats. Between the NSF and corporate partners, the program is expected to reap $80 million in research funding and enable an unprecedented degree of cross-institutional, multidisciplinary collaboration.

“The biggest benefits are really the collaboration and the long-term nature of the funding,” Drewes said. “We’re looking at how this might play out in 20 or 30 years, rather than how to help a certain utility with a particular research problem.”

The ReNUWIt projects at Mines are diverse. PhD student Ryan Holloway is working on tuning the AQWATEC bioreactor so its output varies by season. The idea is that, during the summer irrigation season, the system can be tuned so more organics and nutrients can exit for use in outdoor watering, cutting freshwater and also synthetic fertilizer use. This summer, they’ll be testing it on a half-acre plot outside the facility.

A few feet away, PhD student Dotti Ramey paints part of a microscope slide with red nail polish. Algae avoid nesting on that part, she explained. Bubbles rise through nine glass jugs backlit by squint-inducing grow lights. Hints of algae cling to bottlenecks. Outside, stainless-steel paddle wheels turn in what look like giant bathtubs. Rather than warm suds and yellow rubber duckies, the contents are cold and green. The work is part of a collaboration with startup and ReNUWIt partner BioVantage Resources, with the aim of understanding how wastewater could be used to nurture algae, which in turn treats the wastewater. The algae could be turned into useful lipids, biopolymers or even fuel.

Managed aquifer recharge is another Mines/ReNUWIt focus. This work is led by Professor Tissa Illangasekare and the Center for the Experimental Study of Subsurface Environmental Processes (CESEP). The idea is to apply concepts of rural managed aquifer recharge. This involves building ponds with very particular microbiological and subsurface features so clean water seeps back into aquifers rather than evaporating or flowing downstream to urban wastewater treatment systems. Pulling it off at a much smaller scale (think large swimming pools rather than football-field-sized ponds) demands expertise in chemistry, hydrology, biology and engineering, Drewes said.

ReNUWIt’s work extends past the physical into the managerial. Water managers keep tabs on a small number of big facilities. With an integrated network of AQWATEC-style plants enabling local reuse across a metropolitan area, managers will need tools to monitor it all and make smart adjustments. Mines Professor Reed Maxwell is working with UC Berkeley resource economist David Sunding to develop hydrologic and economic models to help quantify the costs and benefits and, ultimately, manage much more complex water infrastructures.

Dr. John McCray“It’s all about finding new ways to use and reuse water. That’s more than just science and engineering because you have to convince the politicians and the water managers, who are very conservative, to take a chance and do something in a different way,” said John McCray, a ReNUWIt investigator and director of Mines’ Department of Civil and Environmental Engineering.

Collaboration is woven into ReNUWIt’s fabric. Mines’ expertise in geology, hydrology, biology, engineering and numerical modeling is now connected with Stanford Law School’s legal and policy expertise and UC Berkeley’s economic savvy, Drewes said. The extended team has the breadth to handle the full spectrum of issues that crop up in attempts to reinvent something as fundamental as water infrastructure. Such cooperation might involve, for example, figuring out the best microbial mix to purify water captured after a storm, designing a system to enable it, and ensuring that the solution obeys water-rights law and economic logic, thereby saving money – and water – in the long run. How ingrained is ReNUWIt’s collaborative culture? PhD students in the program must have a core advisor at one of the other universities, Drewes explained.

 

Other Breakthrough Water Projects

           

  • Some of the Mines Park bioreactor’s effluent is flowing into an onsite greenhouse. Inside, a USDA-funded team led by Mines Professor Christopher Higgins is watering food crops with it, in order to study plant uptake of pharmaceutical and personal care products such as sucralose, antibiotics and other chemicals that wastewater treatment plants weren’t designed to capture.

 

  • Cath has won a $1.4 million grant from the U.S. Department of Energy to study ways to treat the “produced water” that emerges from hydraulic fracturing operations in natural gas drilling. This involves, as Cath puts it, “taking black, black water and, using membrane technologies, turning it into something usable for the next fracturing operation.” For the work, the “AQWATrailer” – a mobile lab with various filters, membranes, pumps and laboratory gizmos – will be called into action, he said. “It allows you to do things on a real scale in the field,” Cath explained. “Not many schools have this type of infrastructure.”

 

  • The same certainly goes for the wooden wind tunnel circumscribing half of what was once the shallow end of the Volk Gymnasium pool. Its loop is large enough to ride a bike through. With the breeze topping out at about 22 mph, you won’t find models of NASA hypersonic vehicles inside – though “it’ll blow-dry your hair,” quipped Mines Professor Kate Smits.

 

Smits and her team are interested in the interaction of soil moisture and the atmosphere, which remains poorly understood. The wind tunnel lets them adjust the air speed above the soil surface as well as temperature and humidity. The heart of the system is a Plexiglas soil tank sandwich 24 feet long, four inches wide and four feet deep. An array of sensors penetrates and surrounds it, including an anemometer system the Mines undergraduate robotics club built. Researchers fill the translucent tank with soil, enabling the precise assessment of basic physical processes at a scale larger than lab bench, but more wieldy than a field site. They then build real-world observations into numerical models.

 

One of her research goals is to help climate modelers sharpen their software’s accuracy in modeling evaporation rate. She’s found, for example, there is a big evaporative difference between a 1 mph wind and a 2 mph wind. But higher winds than that seem to have less of an impact, Smits said.

 

Another application of her work is to increase the ability to accurately detect landmines. The loose soil covering mines and the presence of the mine itself create different thermal and hydraulic properties in the area around the mine, as opposed to a location away from a mine, she explained. “One of the reasons I became an environmental engineer is that I love helping people and helping the environment,” Smits said. “With land mines, we can see the potential positive impact we can make by understanding the science.”

 

  • Alexis Navarre-Sitchler, a Mines assistant professor, focuses on water-related science hundreds of feet below the surface. Her team’s work aims to sharpen the understanding of how acidity affects the amount of lead and other metals in aquifer water.

 

Given the interest of carbon capture and sequestration – pumping carbon dioxide from power plants into formations thousands of feet down – it’s a hot topic. Carbonated water isn’t the problem (that’s what Perrier is, after all). But greater acidity from leaking carbon dioxide could speed up chemical reactions that release lead, uranium and other metals from aquifer rock.

 

In the lab, PhD student Assaf Wunsch bubbles CO2 through half-liter acrylic cylinders. By determining the mineral content of 23 elements in both the water and the rocks, they can see how different types of aquifers may react to carbon leakage. In related work, Navarre-Sitchler is working on models – run on the Jaguar supercomputer at Oak Ridge National Laboratory – investigating the migration of metals in aquifer.

 

Like so much of the water-related work happening at Mines, it’s science with big implications. As Navarre-Sitchler points out, “You can’t accurately understand the risks without understanding the issues.”

 

 

This article appears in the 2012-13 issue of Energy and the Earth magazine.

This is a story of humans and hardware. What happened when professors, tops in their different fields of energy research, gained campus access to a world-class supercomputer?

The story began four years ago with the institutional vision to bring a supercomputer named Ra to Mines. Dag Nummedal, director of the Colorado Energy Research Institute, and Physics Professor Mark Lusk had been working to acquire a supercomputer, and when Vice President of Research and Technology Transfer John Poate got involved, “the idea resonated campus-wide,” said Lusk.

With the horsepower of Mines leadership behind this well-timed initiative, it became a commitment to much more than hardware. Five years, one supercomputer, 10 new faculty hires, 15 classes, 60 PhD students and 120 journal publications since that original vision, Mines has become a global leader in computationally guided energy science research.

The initiative has made a huge impact on research volume, led to many important discoveries, and catalyzed interdisciplinary collaboration across campus. More than 90 percent of Mines’ academic departments are pursuing projects supported by the Golden Energy Computing Organization. As scientists from different areas come together, ideas begin to cross-fertilize and surprising synergies emerge. As Lusk notes, “Once all these people start working together under one virtual roof, good things happen.”

One of the new supercomputer hires was Amadeu Sum, a professor in the Chemical and Biological Engineering Department and co-director of Mines’ Center for Hydrate Research. He used Ra to explain the nucleation and growth of hydrates, and his work landed on the cover of Science.

On another side of campus, REMRSEC, the Renewable Energy Materials Research Science & Engineering Center, was chosen for funding by the National Science Foundation in part due to the computing power Ra could bring to the table. 

Lusk’s solar cell work with REMRSEC on multiple-exciton generation (MEG) was successful. MEG theorizes it is possible for an electron that has absorbed light energy to transfer some of that energy to other electrons, resulting in more electricity from the same amount of absorbed light.

In a cross-fertilizing leap, REMRSEC decided to look at hydrates as a way to store hydrogen. The center provided seed money to Carolyn Koh, a professor in the Chemical and Biological Engineering Department, to lead a combined team of REMRSEC solar energy scientists and Center for Hydrate Research experts. Together they developed a computer analysis to assess the potential of hydrates for hydrogen storage.

Then they began thinking of other materials that can be assembled into the cage-like clathrates. Could they build a silicon clathrate structure to store hydrogen? Using experimental facilities at the National Renewable Energy Laboratory (NREL), they determined the answer was yes.

The synergy continued. What are the photovoltaic properties of these new silicon clathrates? Can they be used to build a better solar cell? The answer, once again, appears to be yes.

In summary, hydrate engineers and solar energy physicists have founded two new facets of energy research because a world-class  supercomputing facility came to Mines. “The successes that have come from our original vision have been snapping together a Lego™ at a time,” said Lusk. “We have a cool system going now and there’s no end in sight.”

 

A New Season

Now plans are underway to purchase a new machine to become the campus flagship for high-performance computing, with Ra maintained as a set of smaller clones for less demanding projects and student training. Requests for bids have gone out to industry, and by autumn 2012 the new machine should be on campus, humming alongside its predecessor.

The next supercomputer will be a radical step forward, with at least five times Ra’s computing power and roughly 16,000 processor cores to Ra’s 2,144. Even so, it will consume just a fraction of Ra’s physical space and electrical power, thanks to technological developments over the past few years.

Ra’s successor will give a boost to many of Mines’ most ambitious efforts, and Lusk predicts the new machine will be the basis for frontier energy research for years to come. “It’s exciting to be part of this vision,” he said. “The campus now fields several big teams that do high performance computing in close collaboration with experimentalists. The original leadership has evolved into some amazing self-assemblies, and I can’t wait to see what advances come out next.”

 

Clathrate Hydrates

Illustration of hydrate nucleationResearchers have achieved the first real insight into the birth and growth of the cage-like structures known as clathrate hydrates. These materials can form naturally —for example, out of natural gas in pi/gas pipelines, where they form an “icy slush” that can accumulate in the pipelines and eventually clog the flow. Using Ra, Mines researchers have been able to simulate for the first time the molecular processes that cause such hydrates to nucleate and grow, adding – atom by atom – to each rigid molecular cage.

It’s not an easy task. Hydrates form out of disordered systems, with atoms starting out adrift and then coming together in precise ways to form a complex network of water molecules enclosing gas molecules. Simulating how that transition happens takes a lot of computing power, said Amadeu Sum. “That’s why we need to use large resources like we have on campus to do these large and long simulations,” he said.

Knowing how hydrates nucleate will help researchers better understand how to prevent/control them from forming and harness them for useful purposes as well. One impactful area for hydrates is the recovery of methane gas from natural hydrate deposits in the permafrost and ocean seafloor, and the utilization of hydrates as an energy storage medium for natural gas and hydrogen.

 

Oil and Gas

With the need for traditional fossil fuels still great, Associate Professor Paul Sava is using Ra to discover new sources of oil and gas. Active in the Center for Wave Phenomena in the Geophysics Department, Sava specializes in developing new methods for probing the earth’s interior with seismic waves. Doing so requires running simulation after simulation of how quickly waves travel through the earth, then comparing those to real-world observations to see how closely the two match.

So far, Sava’s team has been able to refine a flagship exploration technique used in industry. The Mines scientists simulate how rock from inside the planet can be squeezed (like a fluid, as industry models it) or twisted around (like an elastic) — a difference that affects the speed of passing seismic waves. Updating this knowledge allows oil and gas companies to better predict where a promising prospect might turn into a lucrative discovery. “The information relevant to them requires a big computer like this,” Sava said.

 

Hydrology

Mines’ dedication to high-performance computing has helped draw high-profile faculty to the university. “When I showed up, Ra was being unboxed,” said Reed Maxwell, a hydrologist who moved from the Lawrence Livermore National Laboratory in California.

In the Department of Geology and Geological Engineering, Maxwell uses Ra to simulate how water flows from deep within the ground to shallower levels, and also from there into the atmosphere. His computer code, dubbed ParFlow, is one of the few such models to integrate this entire hydrologic cycle. Maxwell has used ParFlow to explore all sorts of important questions, such as how agriculture draws down groundwater and how changes in hydrology affect local atmospheric patterns —for example, the wind energy potential over a particular plot of land.

Because his simulations require so much computing power, Maxwell uses not just Ra but also several other supercomputers, including ones at the Oak Ridge National Laboratory in Tennessee and at a facility in Jülich, Germany. “I always envision running on a range of supercomputers,” he said.

Most recently, Maxwell has built a high-resolution hydrological model of the entire continental United States, which covers 6.3 million square kilometers at a resolution of 1 kilometer. This simulation, which he said is one of hydrology’s “grand challenges,” is tied into leading climate models so that Maxwell can, for example, probe how water flow may affect regional climate change in the decades to come.

 

Materials

From the scale of continents down to the scale of nanoparticles, Ra’s simulations are doing it all. For Cristian Ciobanu, a materials scientist in the Department of Mechanical Engineering, Mines’ computing resources involve the very small. He works to understand the basic chemistry and physics of materials crucial for energy applications, from lithium-ion batteries to biomass to solar cells. “In all these cases, the campus facility is important,” Ciobanu says. “It’s basically a lot of computing power on site, and you can do things faster, closer to real time.”

For instance, he and his collaborators at NREL have shown that using a material as common as quartz can lead to an increase in the capacity of lithium-ion batteries over the first couple hundred cycles of charging and discharging, thus hinting at new ways to prolong battery life. Other simulations have shown that adding nanoparticles of gold or other precious metals to a particular chemical process speeds up the reaction, while also making it yield a desired reaction product, hastening the conversion of biomass into energy. Ciobanu is now running calculation after calculation on Ra to find the best possible shape and composition for nanoparticles to catalyze the biomass conversion reactions. With such information, an experimentalist can make nanoparticles that work efficiently the first time around, without having to run though the trial-and-error of testing particle after particle in real life.

For solar cells, Ciobanu has been testing how to make the perfect nanoparticles out of germanium and tin with the best electronic properties for absorbing light. Such alternative materials might be used in future photovoltaic cells, especially if they can be designed through supercomputer simulations and then tailor-made to fit those designations.

 

Photovoltaics

Lusk is also using the power of Ra to figure out how to make better photovoltaics. In 2011, he and colleagues discovered one way to beef up the efficiency with which a solar cell transforms sunlight into energy. Supercomputer simulations done at Mines suggest that in a specially designed material, a particle of light (photon) can knock loose not just one electron (its flow creates the electricity that powers solar cells) but two or more, in a process known as multiple exciton generation. The set of excited electrons would turn more of the original solar energy into useful electricity because not as much is lost to generate heat.

The race is now on to make better photovoltaic materials by exploiting multiple exciton generation and other quirky quantum mechanical properties that Lusk’s team has discovered. They use Ra to model how to best design what amounts to a new form of matter composed of quantum dots. These tiny particles, just a nanometer or two across, both help to capture solar energy and to move it through the solar cell to create useful current.

Lusk is also looking to build on nature’s own solar cell — the leaf — by co-opting its photosynthetic tricks. Nature has evolved some very clever ways of harvesting solar energy, but its solar panels don’t last very long. “We’re using the computer to unravel some of the quantum mechanical secrets that are going on all around us. And then we want to use that information to build inorganic solar cells that do the same thing better and without wearing out as easily,” Lusk said.

 

This article appears in the 2012-13 issue of Energy and the Earth magazine.

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