Engineering interns work to balance the triple bottom line — social, economic, and environmental needs — for an island research community.

By Sharon Tregaskis

At home, flush the toilet and it’s easy to forget the waste ever existed. At Cornell’s Shoals Marine Lab, the situation is a bit more complicated—and transparent. On this rustic island research station six miles out to sea in the Gulf of Maine, there is no municipal system to take care of details. Instead, a diesel-powered generator runs the pump that pulls water from the ocean and into the tank of each toilet. Another pump powered by that same diesel generator draws fresh water from the island’s only well—or through a reverse osmosis desalinator that converts seawater into something potable—and into the bathroom faucets. On the other side of the equation, every drain on this 95-acre island empties into a three-tank wastewater treatment facility—also powered by that diesel generator. At season’s end, island staff carry the treated solid waste out to sea and dispose of it in compliance with an overboard discharge permit issued by the State of Maine. Here, every flush—and every kilowatt that makes one possible—counts.

The concept of scarce resources strategically deployed isn’t news to anyone who’s set foot on an island surrounded by miles of ocean. But for four engineering undergrads who spent a month this summer as interns at Shoals, the implications of a closed loop system became abundantly clear. Leslie Campbell ’08 CE, Nicole Ceci ’08 GS, and Yuan “Clara” Yuan ’07 OR, together with University of New Hampshire senior Lisa DiMiano, put Appledore Island’s engineering systems under the microscope as the first participants in Integrated Island Engineering Sytems for Sustainability, an internship supported through a grant from the Saquish Foundation, founded by Charles Werly ’27. “We’re a perfect test-tube for engineering,” says station manager Ross Hansen, who supervised the interns. “Because it’s an island, you can get your hands around things—what comes in and what goes out—get a real-world experience. It’s a perfect place for students to get immersed.”

Shoals Marine Lab was founded as a place for immersion—in marine ecology. Operated in partnership by Cornell and the University of New Hampshire since 1973, Shoals offers undergraduates at the two campuses the opportunity to hear about the object of their study in a lecture, and moments later reach into a tidal pool or lean over the side of a boat to pull that creature from the water for closer examination. Over the last three decades, the seasonal lab has expanded to offer experiential learning for high school and graduate students, families, and professional scientists. Every summer, close to 3,000 visitors take the forty-five minute boat ride from Portsmouth, N.H., to take classes, conduct field studies, band birds, and explore marine life.

When sustainability leapt to the top of Cornell’s academic priorities, Shoals administrators saw an opportunity to extend such immersion experiences to undergraduates and faculty for whom marine ecology holds limited appeal. “Shoals offers a nice meeting point for many of these issues in sustainability,” says lab director Willy Bemis, a Cornell professor of ecology and evolutionary biology. “The chance to bring together students from different backgrounds—from life sciences, engineering, sociology, history, natural resources, conservation—in one convenient place lends itself to the kind of intense thinking necessary to define what the future of sustainability might be, both in a curricular sense and more society-wide.”

Throughout the summer, the four engineering interns grappled with the very real challenge of defining sustainability—a loose concept sometimes known as the “triple bottom line” that balances concern for the environment with contemporary and future human needs and cost consciousness—in the context of Shoals Marine Lab’s engineering systems. Frequently, that balancing act meant discarding an environmentally attractive solution because of cost or implementation difficulties, or recognizing that a legacy system might be operating inefficiently, but that its replacement would break the bank. “When you’re doing day-to-day operation or day-to-day maintenance, it’s so easy to lose sight of sustainability,” says Yuan, an operations research major. “The incentive structures aren’t there to really be sustainable—it’s all money, money, money, and net present value. It was very educational for me to see that happen, to participate in the process myself. I can stand on my soapbox and tell other people to be sustainable all I want, but until I’m actually in the position of being an engineer and having all these practical considerations…. It was very educational.”

Over the course of four weeks, the all-female quartet delved into the intricacies of the island’s fresh and saltwater systems, analyzed the wastewater treatment plant and possible alternatives, detailed the lab’s electrical supply and demand, mapped and labeled the tangle of wires and pipes that crisscross the island, and investigated strategies for increasing efficiencies and decreasing ecological impacts. “We really didn’t know much about the operational side of a lot of the systems that we were working with,” says Campbell, who pursued the internship to test her interest in environmental engineering. “We spent entire days just following wires, figuring out where the power comes from, where it goes, how it’s all being used.”

Beyond mapping a system cobbled together over thirty years—in some cases reaching the heights of elegant simplicity and in others rivaling Rube Goldberg for sheer complexity—the students gained hands-on expertise to complement the theoretical foundation they’d already acquired through problem sets and homework assignments in Ithaca. “We had to teach ourselves a lot being out there,” says Campbell. “We spent so many hours in the library, just looking up resources, trying to figure out how systems work, what different parts do. Every system has its specific equipment and methods. It was really hard to get our heads around each system and then take the next step to say ‘What do they need to do with that system? How can it be improved? How can it really work out there?’”

Hansen coordinated visits from the local utility company, a purveyor of composting toilets, a renewable energy systems consultancy, and faculty from UNH and Cornell. “Half of every internship is work and the other half is learning,” says Ceci. “When people would come in from industry or professors would come talk to us, they’d try to start teaching us the physics background and we’d say ‘No, we’ve had that. We just don’t know what the system does.’”

By summer’s end, the team could speak authoritatively not only about how leach fields might be incorporated into the island’s wastewater treatment system, but about wet-stacking (the piston-clogging result of running a diesel generator at sub-optimal levels) and a wealth of technical details related to the island’s three generators. “I’d only been exposed to the theoretical, small-scale circuitry stuff, which just isn’t that interesting to me,” says Ceci of her previous experiences in electrical engineering. “Actually being out there and working on the entire system was really, really interesting. That’s just not an experience everyone else gets. There’s no class on this campus that says, ‘Go follow the entire grid.’”

They also inventoried the island’s plug-in appliances and their electrical loads, measured per capita consumption of power and water over the course of each day and throughout the summer, and analyzed more than 300 samples taken as part of a rhodamine dye test for evidence of leaks in one of the wastewater treatment plant’s holding tanks and a nearby body of water affectionately known as “Lake Titikaka.” They even managed to get faculty, staff, and students participating in the island’s other programs to tally the number of flushes at each toilet. “I felt like a real engineer,” says Yuan. “The wastewater dye test—sampling the tanks and measuring them later—it felt like we were doing real work.”

For lab administrators, committed to making Appledore a sustainable campus while minding a tight budget, the interns provided crucial insights into the current state of affairs and what it will take to decrease the island’s reliance on fossil fuels and other inputs. “People knew there were issues in terms of capacity, age of the systems, and sustainability, measured in terms of cost, fossil fuels,” says John Foote ’74, who recently chaired an ad hoc planning group for Shoals charged with optimizing the island’s programs and operations. “No one really knew with certainty what was going on. People had intuitive opinions, and a sense of the situation, but no one could say ‘we’re maxing out at 27 kilowatts,’ or something like that. To get to the next step, we had to take a baby step, measuring the situation.”

As they measured the situation, the students also began forming opinions—about which appliances demand too much electricity for too little value (the ice maker in the dining room, says Ceci) and how best to deal with human waste (composting toilets, say all four). Ultimately, any recommendation they offered had to fit with all of the island’s systems, as part of an integrated whole. “There’s clearly a connection between water usage and electrical usage because we have to pump water around,” says Bemis. “But finding those ties and realizing those interconnections is a really important part of the learning experience and one that takes place at every level—at the student level, at our own staff level, and so forth.”

Early in their time at Shoals, wastewater became a high priority for the interns. The lab’s overboard discharge permit expires in 2009, and lab administrators anticipate revisions to its terms—if the permit is renewed at all. Their second day on the island, the interns themselves were horrified to learn that Shoals, an academic unit dedicated to the study of marine life, would dispose of any human waste—even treated and in accordance with state permits—in the ocean. And then the rhodamine dye test revealed a slow, steady leak from one of the holding tanks into Lake Titikaka. The quartet devoted some 32 pages of their 76-page final report to the topic, and became expert on a wealth of innovative wastewater treatment strategies, including sand filtration systems, alternative leach fields, and solar aquatic treatment systems that use plants, snails, and fish in progressive tanks to clean wastewater. “We spent this whole internship questioning and knowing there are other ways to get things done,” says Campbell, “learning that just because an approach is unconventional doesn’t mean it’s not going to work.”

Simultaneously, the group developed increasingly stringent standards for which solutions might be successfully implemented at the lab. Incinerating toilets—which do exactly what you might imagine—were dropped from consideration because of their high energy requirements. The hope of simply replacing the flush toilets in each building with their composting counterparts also fell by the wayside, due to space constraints imposed by the bedrock foundation on which most of the buildings sit. Instead, the students recommended the construction of centralized outbuildings outfitted with composting toilets and possibly powered by a handful of solar panels being offered to Shoals by the university.

“I’d like to see Appledore become a laboratory or example that could be looked to by not just other island communities up and down the coast of Maine, but also coastal communities,” says Foote, who attended the team’s final presentation as part of an alumni panel including UNH grad and retired utility executive Mike Dalton; Tom Johnson ’76; alternative energy consultant Abigail Krich ’04 BE, M.Eng. ’06 EE; and Cornell sustainability coordinator Dean Koyanagi ’90. “The ideas that were being presented were ‘out of the box,’ but completely intriguing and caused me to think differently about what solutions are possible.”

Ultimately, says Foote, Shoals’ engineering interns have laid a solid foundation for the lab’s long-term efforts to become energy and resource efficient. “In addition to being very bright and knowledgeable,” says Foote, “the students had perceptive insights into how things work and how they don’t work and really inventive ideas about how to make Appledore an example of sustainability. The future is very exciting.”