Getting to the Bottom of Lake Pollution

Story posted June 01, 2009

Emily Kimball
Peter Lea's Geology 100 student Emily Kimball '09 shows off a sample of Androscoggin Lake water.

There was a time when government major Catherine Jager '09 wondered what she had gotten herself into. It was the middle of winter and she was helping to haul a sled laden with an ice auger two miles across Androscoggin Lake.

"It was right after a snow storm and it was freezing," Jager recalled. "And there we were getting ready to drill a hole through the ice."

Catherine Jager
Catherine Jager '09, facing, describes her research at the Leeds town meeting.

Her wintry trek was just one part of data gathering undertaken by students in Environmental Geology and Hydrology, a 100-level service-learning course taught by Associate Professor of Geology Peter Lea. Within the semester, other students took lake water samples, cored sediments to determine pollution trends, and developed statistical data models.

Jager's adventure paid off in the spring when she and her classmates became the star attraction at a public meeting in the nearby town of Leeds, which borders the lake. The students gave poster presentations of their data to town residents and members of the citizen-based Androscoggin Lake Improvement Corporation.

Their work has become a central part of a community-state effort to protect the environmentally threatened lake.

Students at the lake
Students take measurements from the Androscoggin Lake dam.

"This is the only lake in the state that gets floodwater from a Class C industrialized river—the Androscoggin—and as a result it has impaired water quality," noted Lea, who is one of several Bowdoin professors working on research related to the Androscoggin River. "We're trying to get a better sense of what's going on in the system. We hope to be able to measure and quantify contamination levels, water flow, and sedimentary history to pass on to community members and the Maine DEP, which is the main body charged with overseeing its protection."

The lake is home to a large river delta with an unusual ecosystem, including the only recorded occurrence of cattail sedge in Maine, a rare plant. The delta is periodically submerged when water from the Androscoggin River back floods into Androscoggin Lake.

"After the river got industrialized in the early 1900s the floodwaters started bringing nasty stuff with them into the lake," noted Lea. A dam was built in the 1930s to curtail flooding, however, the lake had major algal bloom in 1999, which indicates a high level of phosphorus in the water.

Lea and student in boat
A student researcher, left, uses a Vibracore apparatus to get core samples of lake sediment.

To better pinpoint the cause of the bloom, Lea and his students are combining their new data with archival field notes on lake water quality taken over a 30-year period by volunteers from the Androscoggin Lake Improvement Corporation. Among the members of the community group is Jack Mahoney, an octogenarian who wrote fastidious field notes and observations in a journal over several decades.

Bowdoin student Duncan Masland '11 entered Mahoney's measurements into a spreadsheet program to develop detailed graphs of lake temperature, oxygen and transparency over time. Mahoney was on hand at the town meeting to see his handiwork on display.

"It was really neat to meet him," noted Jager, adding: "People do a lot of community service at Bowdoin, but what is amazing about the geology department is the amount of improvising and fun involved. You work up to your knees in cold water, you take data for organizations on weekends, you gotta push a car out of a snow bank. Every time we went on a trip it was always an adventure."

Sampling efforts were supported by community course liaisons funded by the Joseph McKeen Center for the Common Good, a program designed to enhance connections between Bowdoin's academic programs and the surrounding community.

Students at lake


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