UMass Magazine Online




	UMass Amherst scientists in a real-world lab: David Ahlfeld, Klaus Nüsslein, Richard Yuretich, Sarina Ergas and Allan Feldman. (photo by Ben Barnhart)

FRED FLINTSTONE IS JOUNCING ALONG an icy, rutted back road through the rural town of Rowe, Massachusetts, not far from the Vermont border. He’s riding the outside of a maroon, eight-seater van full of UMass Amherst faculty and students. Each of the van’s front doors is emblazoned with the word “Geosciences” above a whimsical logo of the cartoon caveman balanced atop a globe, jauntily shouldering a rock hammer.

The yabba-dabba Stone Age hero and the thoroughly modern UMass research team are bound for the site of the long-abandoned Davis Mine, located about 40 miles north and west of campus. Until an economically calamitous (but happily non-fatal) cave-in more than 90 years ago, the mine was a mainstay of Rowe’s economy. Nowadays, this part of town is pocked with the cellar holes of defunct houses, and second-growth forest has staked its claim to much of the land along these unpaved back roads.

Before the mine collapsed and its shafts filled with groundwater, it was a lucrative source of raw material for sulfuric acid, one of the world’s most widely used industrial chemicals. From 1882 until 1911, miners pulled 100 tons a day of iron pyrite from the ground in Rowe. Popularly known as “fool’s gold,” this glittering mineral is of no use whatever if you’re looking for precious metal to fashion into coins, bullion or jewelry. But pyrite can be processed to yield substantial quantities of sulfide, which can in turn be used to manufacture sulfuric acid. (The mine also yielded smaller but nevertheless financially significant amounts of copper.)

During its 29-year working life, the Davis Mine pumped thousands of tax dollars into the town’s coffers, and became a local tourist attraction as well. Visitors could climb an observation tower above the main shaft for a panoramic view of the bustling operation, which featured on-site blacksmith and butcher shops, a steady traffic of horse-drawn ore and coal wagons and the town’s first electric lighting. The annual payroll amounted to $100,000, and local farmers made extra income supplying the mine with timber and firewood, while selling fruit, vegetables and dairy products to the workers.

The mine’s collapse damaged more than the local economy. The flooded shafts produced an effluent stream that contaminates the environment to this day. Replete with acid and heavy metal pollutants, this water from the mine trickles over a rusty-orange creek bed and into Davis Mine Brook.

The acidic flow dissolves minerals along the stream channel and in the subsurface soil, thereby releasing soluble ions of iron, zinc, copper and other metals into the water. From the brook, this tainted water flows into the Mill River, then into the Deerfield River and eventually into the Connecticut. Progressively diluted in its passage from tributary to tributary, the dead mine’s outflow is ecologically insignificant by the time it reaches the big river. Closer to the source, however, the pollution has a formidable impact, eliminating fish and insect life from the mine’s namesake brook. State environmental officials have identified Davis Mine Brook as the only lifeless stream in the Deerfield River watershed.

Fortunately, the news is not all dire. Scientists have been studying the abandoned mine site for many years, and have found encouraging evidence that the soil and water are carrying out their own natural detox program. Some of this environmental repair is due to minerals that neutralize the water’s acid content. Some is the product of what scientists call bioremediation, changes for the better brought about by biological activity. In this instance, the credit goes to microscopic bacteria acting on various pollutants to eliminate them or render them less harmful.

Furthermore, nothing in the water or soil at Davis Mine site is as dangerous as the uranium, cadmium and the like at larger abandoned mines, so cleanup needs are less urgent here. For now, UMass scientists are using this environment of relatively mild pollution as a real-world laboratory in which to explore solutions that could someday help to advance cleanup efforts at more dangerous toxic locations.

Because the natural cleanup under way in Rowe has important implications for other pollution sites around the world, UMass researchers studying the Davis Mine ecosystem have received a $1.59 million grant from the National Science Foundation’s Biocomplexity in the Environment program. The interdisciplinary team carrying out the federally funded research project includes five UMass professors from four departments. Microbiologist Klaus Nüsslein is studying the bacteria populations involved in bioremediation. Geologist Richard Yuretich is focusing on the chemistry of the site’s rocks and soil. David Ahlfeld from the department of civil and environmental engineering is analyzing the site’s intricate surface and underground flow patterns, while Sarina Ergas of the same department is measuring the rates at which various microorganisms are performing their bioremediation work.

Education Professor Allan Feldman, a specialist in science education, is coordinating the research participation of high school and middle school teachers who are taking a hand in the Davis Mine project and using the experience to enhance scientific learning in their classrooms. And as if to underline the international importance of this environmental research, the UMass team is also collaborating with the Williamson Research Centre for Molecular Environmental Science at Manchester University in England, where researcher Jonathan Lloyd is studying bioremediation at a mine in Wales.

This chilly, snow-covered morning in early April finds just two professors, Nüsslein and Yuretich, accompanied by graduate and undergraduate students in microbiology, geology and civil engineering bound for an area near Davis Mine Brook where they’ll be drilling deep holes, gathering rock and soil samples and inserting subterranean equipment to collect groundwater at various depths.

The actual drilling is being done by professionals from Westminster-based American Drilling Services, Inc., operating a portable rig that rides on massive tank treads to negotiate the difficult terrain. They’re already setting up for the day when the Fred Flintstone van pulls into a purely imaginary parking space alongside some trees that crowd right up to the edge of the narrow road. While the guys with the rig prepare a patch of snow-covered earth for today’s first drilling, the two professors with their retinue of students set off on a slipping and sliding downhill trek through the wintry woods that surround the abandoned mine shafts.

Reaching the bottom of a steep slope and turning to follow the course of the mine’s effluent creek, the UMass science crew encounters a multitude of scary signs warning of the danger that lurks in the site’s deep, water-filled pits and shafts. One sign in particular is notable for the eloquent, in-your-face simplicity of its message: YOU COULD DIE HERE.

A few more minutes of hiking bring the bundled-up team of death-defying researchers to the spot where the mine’s outflow creek empties into Davis Mine Brook. Bootprints along the path announce that they have walked this way before, and sled tracks in the snow bear witness to the loads of research supplies they have hauled in on previous visits.

On a rise above the brook, the equipment for today’s work is spread out in a kind of controlled disarray. Hoses snake from the drill rig down to the brook. Even on a harsh New England spring day that still feels an awful lot like winter, the drill will overheat dangerously unless a pump cools it with a steady flow of water. Cartons full of sterilized jars are stacked beside a tank of compressed nitrogen. Nüsslein explains that the jars will serve as receptacles for the soil samples that the drill carves out of the ground beside the brook. Underground bacteria living in the soil fare poorly when exposed to oxygen, so the jars will be filled with nitrogen to help preserve the microorganisms.

Coils of translucent white plastic tubing lie here and there on the snow, ready to be cut into lengths and fitted with various attachments to form what the researchers call “wells.” The tubing measures only about two inches in diameter, far narrower than a well from which a farm family might draw water by the bucketful. But the slender plastic wells assembled here will serve essentially the same purpose, fetching underground water to the surface. Equipment cartons are packed with supplies of special conical devices for the well bottoms, caps for the tops, filters to screen out dirt and black plastic cuff gizmos that clamp around the tube to punch the holes that create groundwater collection ports. Sacks of clay pellets wait to be poured down the drill holes for sealant purposes once the wells have been properly prepped and inserted.

Yuretich shows off a cross section of the well tubing. The interior is divided into seven channels, a central circle surrounded by six wedges. The central channel is for sampling water from the bottom of the drill hole, with the help of the conical attachment that blocks off the other channels at that end of the tube. Each of those black cuffs, spaced at five-foot intervals along the well, cuts an access hole in one of the six perimeter channels. Researchers can then use the well to collect groundwater samples from seven different depths without the labor-intensive tedium of drilling one 35-foot hole, one 30-foot hole, one 25-foot hole and so on. “Our goal,” Yuretich says, “is to look at the different characteristics of the groundwater at different levels so we can get a three-dimensional picture of what is happening in the subsurface. Trying to design a system that effectively samples the different levels is always a challenge. This is one way that seems to be the most cost-effective and time-effective.” (Since some drill holes will be less than 35 feet deep, he adds, some of the wells will not be using all seven channels.)

The drillers finish boring the latest groundwater sampling hole. As they withdraw a heavy length of metal pipe from the ground, one of the students flips open a shallow wooden box about five feet long with the interior partitioned into three narrow chambers. The drillers wrestle their pipe into position above the box and strike it with clanging hammer blows to dislodge the cylindrical mass of rock and dirt inside. The three-chamber box can hold up to 15 feet of geological samples. Unlike the soil samples bound for the microbiology lab, these don’t have to be bathed in nitrogen to preserve their bacteria.

With a combination of delicate precision and sweaty, muscular effort, the drillers swing their earth-penetrating equipment away from the hole, fix it in position on the rig and prepare to slide the plastic well into place. “It’s hard work when you want to tickle an exact answer out of the environment,” Nüsslein observes. When this phase of the research project is complete, which will be the work of several days, the team will have installed nine wells at strategically chosen points around the brook.

Among their many contributions to the bioremediation study, these wells will help to map the site’s underground flow patterns. By pouring a non-toxic chemical tracer into the mine’s effluent creek, then testing well-water samples to determine where that chemical turns up downstream, researchers will be able to chart the polluted water’s movement through the subsurface environment.

Some of the water and soil samples collected here will find their way to the civil and environmental engineering lab of Sarina Ergas, where she will construct experimental replicas of the mine site, thin plastic columns filled with Davis Mine rock and soil samples. She’ll then pump acidic and metal-polluted water through the columns and measure changes in the water’s chemistry as it interacts with the minerals and the microorganisms. Her colleague David Ahlfeld will be using a variety of experimental and fieldwork data to construct models of a different kind. A hydrologist who specializes in mathematical modeling, Ahlfeld will produce computer simulations of the groundwater’s activity.

Once this latest well has been installed, one of the drillers mounts the driver’s seat and begins the slow process of jockeying the drill rig’s tonnage down a slope and across the brook. As the vehicle inches along, its giant treads gouge and churn the snow. If the weather were more springlike, Yuretich points out, those treads would be chewing up the landscape instead. “To do this in the snow causes somewhat less disruption,” he says. “We can take care of our research business with minimal impact.”

The next order of business will be to hook up the drill to a device called a split spoon sampler (it’s a metal tube that splits apart lengthwise into two half cylinders) and gather a batch of material for Nüsslein’s nitrogen jars. As the drill rig maneuvers among the trees, laying its deep tread marks, students and professors get their equipment ready. On a folding table set up in the snow, they set out a measuring tape and some sterile jars with foil seals still in place. Somebody checks the nitrogen tank and fastens a thin plastic hose to its outlet valve.

Somebody else has already begun measuring a length of tubing for a new well, carefully marking the spots where each channel will be perforated. That next well may be installed before the end of today’s work, or it may not be completed until tomorrow. At the moment, there’s a bit of a lull in the action. Students are chatting with one another, posing occasional questions to the professors, nibbling on fruit, energy bars and other snacks, shifting from foot to foot to keep warm as they wait for the next stage of the day’s work.

Things slow down like this periodically throughout a day at the mine. There was some waiting around this morning while the drillers got rid of ice jams in their coolant hoses. Another pause came when the well was assembled and good to go but the drill hole was not yet ready to receive it. Now the students and professors have a few minutes of cooling their heels – literally in this case – while the rig sets up in its new position and gets started on the next round of drilling. “We stand around waiting for something to happen,” Yuretich chuckles, “then all of a sudden all hell breaks loose.”

Sure enough, when the impromptu break ends, it vanishes in a puff of zero-to-60 acceleration. One student comes pelting up the hill with part of the split spoon sampler in his hands, a half cylinder of metal cradling a cylindrical chunk of soil. “Here he comes!” cries another student as she peels the foil from a sterile jar and holds out the container toward the nitrogen tank. The hose from the tank slips into the jar and a hand hovers by the valve ready to start the flow of gas. The runner lays the soil sample on the table, where somebody has stretched a length of measuring tape. As Nüsslein snaps a picture, Yuretich jots some quick notes on an aluminum clipboard, recording a few geological observations. Wielding a narrow trowel, somebody scoops a section of the sample into a jar as the nitrogen flows. A lid is swiftly screwed into place, and the foil comes off another jar. In short order, the tabletop sports a row of sealed, nitrogen-swathed samples.

A student finishes labeling the final jar as Nüsslein picks up the first one and peers at its contents through a field microscope, a pocket-sized tool that looks like the scrawny cousin of a jeweler’s loupe. This is just a cursory inspection, a preliminary look out here in the field. Back on campus there will be plenty of time to scrutinize the soil and its resident bacteria with a full complement of lab equipment, time to unlock all the bioremediation secrets the Davis Mine site has to offer.

The research project officially got under way last September, and is planned as a five-year study, so in all likelihood, many of its discoveries lie ahead. Already, Nüsslein and his colleagues have identified bacteria with physiological characteristics that had never been observed in any previous study. “In microbiology,” Nüsslein says, “if you go to a new extreme environment, you will always find new species.” The newly discovered species in Rowe has evolved survival traits suited to life in a diverse soup of heavy metal ions. Water and soil bacteria can typically tolerate one or two heavy metals without toxic effect, Nüsslein says, but in the Davis Mine environment, “We have found microbes that are tolerant of five or six different heavy metals.” The hope is that knowledge about these organisms might prove useful in cleaning up toxic residue at gold and coal mining sites around the world, where the pollution is often far worse than at a relatively small sulfide operation in the foothills of the Berkshires.

The environment plays by its own rules, and human scientists do their best to guess what the results are all about. Given what they’ve discovered in the first few months of the Davis Mine project, researchers have every reason to be looking forward to the journey from here to 2007. This week, in the first of the project’s five Aprils, the UMass team will be out here by the brook every day, getting some authentic environmental science under their fingernails. Other times, they may go as long as a month between visits to the site. This past winter, as the snow piled high on this part of the state, they held a lot of team meetings in warm buildings on campus to share ideas and lay plans for the five-year study. After this week’s intensive fieldwork, they’ll have long hours in the lab sorting through all the data from the groundwater wells and the soil jars. This is a different kind of riches from the earth, a mother lode of knowledge about environmental health and natural pollution remedies. This is the new wealth from the mine that once produced 100 tons a day of fool’s gold.

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