Halfman, Students Assess Owasco Lake – Hobart and William Smith Colleges \
The HWS Update

Halfman, Students Assess Owasco Lake

In the recently completed study, “Owasco Lake, New York: Water Quality & Nutrient Sources, 2014 Findings,” Professor of Environmental Studies John Halfman and student researchers Genevieve Moralez ’15, Katherine Coughlin ’16 and Nicolette Andrzejczyk ’16 identify links between degraded water quality, harmful algal blooms, and phosphorus deposits entering the Owasco Lake through tributaries.

“The water quality degradation in 2014 is attributed to the heavy May rains throughout the region, and the input of nutrients from the unfortunate disposal of animal manure on frozen ground,” Halfman articulates in the study’s findings. In addition to the run-off manure from farms, which enters streams and is deposited into the lake, the study attributes the increase in phosphorus levels to erosion.

In January, Halfman presented the findings to the Owasco Lake Watershed Management Council. The project was funded by the Owasco Lake Watershed Association, and Cayuga County Legislation, due to growing regional concern for water quality in the Finger Lakes.

The high phosphorus levels explain the appearance of toxic blue-green algae in the lake in recent years. While increasing levels are problematic for every lake in the region, water quality in Owasco Lake has declined dramatically this past year and is easier to analyze because of its smaller size.

Implementing best management practices (BMPs) — such as vegetation buffers — to prevent non-point sources of nutrients, Halfman explained to the management council, would help catch, trap and slow the progress of sediment that often contains phosphorus, while the county’s septic system inspection plan and mitigation measures at the wastewater treatment plants also help mitigate phosphorus levels.

Halfman collected water samples weekly last spring and fall for analysis in the lab and continued the process throughout the summer, when he was assisted by student researchers. The team gathered data from the lake itself and its tributaries, and from a newly acquired water quality monitoring buoy that collected water column profiles of a variety of data every 12 hours, which “provided a more robust view of water quality in the lake by detecting algal blooms and other events missed by the monthly samples,” they wrote in the report. The samples were filtered and combined with reagents in the lab before analysis by spectrophotometer for nutrient and other concentrations.

“Working with Professor Halfman this past summer was an amazing opportunity that allowed me to apply material I learned in classes to real world problems,” says Andrzejczyk. “The hands-on research throughout the Finger Lakes allowed me to learn several water quality monitoring techniques and analyses, both in the field and in the lab.”

Ultimately, Halfman and student researchers conclude, BMPs should be implemented, “where necessary, to reduce nutrient and sediment loading from agriculturally-rich watersheds, while at the same time monitoring downstream of these remediation projects to assess their effectiveness.”

But because “water quality is a watershed-wide issue” and “everyone benefits from a cleaner lake,” they recommend that the financial burden to install the BMPs must not “be placed solely on the farmer and other landowners…everyone should help support the remediation effort.”

The full 2014 report on Owasco Lake’s water quality and nutrient sources is available here.