For more than a decade, Professor of Biology Tom Mozdzer and students have studied various aspects of Lake Vickers, the water retention pond on Bryn Mawr’s campus named for former president Nancy Vickers, as part of his ecology class each fall.
This winter, with funding from a generous donor, Mozdzer and Environmental Studies major Kate Ervin ’25, began investigating the effects of winter road salting on the pond.
Mozdzer and Ervin have found that the lake isn’t just experiencing quick pulses of increased salinity, as they originally hypothesized. Instead, road salt from repeated winter storms has resulted in sustained levels of salinity, which they think may be causing certain plants and animals to have trouble surviving in and around the lake.
“With every single snowstorm, the pond is getting saltier," Mozdzer says. "Technically, it's no longer freshwater, and it has been brackish since January 7."
Mozdzer and Ervin started their research in December, a day before the first snowstorm of the season. They initially set up two water quality monitoring stations, one in the pond’s shallow basin and one in the primary basin, and a few weeks ago, they added a third station on Mill Creek behind Batten House. To better understand the changes in the pond, they also installed a weather station at the pond, collecting environmental data, including temperature, rainfall, wind, and barometric pressure.
“These data are necessary to prove the effectiveness of future conservation and sustainability strategies on campus," says Mozdzer. "By first understanding the scope of key ecological indicators—for example, road salt—we can begin to investigate strategies to lessen the effects of salinization on campus and beyond."
Together, Ervin and Mozdzer are collaborating to recommend plant species that can not only tolerate the high levels of salt entering the pond during winter but could also function to effectively remove excess nutrients in the spring and summer. These efforts aim to improve the pond's water quality, ultimately benefiting Mill Creek, into which the pond drains.
Created in the 2001–02 calendar year as part of the construction of the Ward building, Lake Vickers takes in stormwater from 70 acres in and around campus, with the majority (50 acres) being off campus.
“Given the hydrological footprint, it is likely that most of the road salt we are measuring is coming from the township and is not generated from campus,” says Mozdzer.
Bryn Mawr College has a history of implementing novel solutions to improve sustainability both on and off campus. Lake Vickers was initially designed to control the flow of stormwater into Mill Creek, a tributary of the Schuylkill River. As a result, many of the College’s neighbors have seen improvements, including Mozdzer himself, who moved downstream of the College several years ago.
“According to my neighbors, our homes used to have serious water issues during heavy rains," he says. "Fortunately, given the College’s innovative management of stormwater, I haven’t seen a drop of water in my sump pump basin, suggesting that Lake Vickers is doing its job both on and off campus!”
Moving forward, Mozdzer wants to focus additional efforts on determining whether and when the salt from Lake Vickers is entering Mill Creek.
“Unfortunately, we didn’t get the third water quality station in time to catch this year’s major snowstorms, but this is something we plan to evaluate next winter. While we really don’t know how salty Mill Creek was this winter, we do know that the salinity of the water leaving the pond to Mill Creek was less salty than the inflow suggesting that the College might be helping ameliorate the acute effects of intense salt reaching Mill Creek.”
The small investment in Mozdzer and Ervin’s project has generated cascading opportunities on and beyond campus. Data from the sensors will also create new opportunities for students taking ecology next year as they continue to study the limnology of Lake Vickers and the ecology and health of Mill Creek.
The Biology Department has plans to have students work with and visualize these data from Lake Viker's in Biological Exploration (B111) next year. Associate Professor Don Barber from Geology and Environmental Studies intends to implement these data into the Environmental Studies Curriculum in ENVS201. In addition, Angie T. Quiroz '26, Fiona Shen '27 and Lucy M. Cambefortare '25 are working with staff from Library & Information Technology Services to create a data visualization interface that could be applied with partners at the Discovery Center in Philadelphia as part of the Praxis course, DSCI B310 Data in Action: Non-Profits and Data.
Ervin got involved with the current project after doing an ecology lab in the fall on the stratification, or the process by which layers of water separate due to differences in temperature in the pond.
“This experience has definitely shown me the complexities of science, such as getting funding, ordering parts, working with a team of people to paint a picture of what is going on, and also trying to balance getting data in on time,” says Ervin.
For first-year students coming to Bryn Mawr next year, Ervin advises jumping right in when they get to campus.
“Don’t be afraid to put yourself out there and do things that seem scary, such as staying here for the summer to do research or moving to Germany for an internship," Ervin says. "If there was one thing I would have done differently, I would have taken advantage sooner of all the amazing opportunities in our Environmental Studies and Biology departments.”