Relative impacts of human-induced and natural wave erosion and deposition processes on large alum treated lakes: A case study on East Pond 

Location: Colby College
Sponsor: Maine Water Resources Research Institute 2022 (104b)

The use of alum treatments to bind phosphorus to control algal blooms has been expanding to larger lakes, where there is no historical precedent for success. These larger lakes can have larger wind-created waves that are more energetic, potentially moving more sediment in the lake. The team’s study aims to understand whether boat created waves (such as from wakeboarding or water skiing) or wind created waves on East Pond are decreasing the efficacy of the alum treatment on the lake bed. The team will use a mix of computer modeling and fieldwork to tease out the relative impact motorized boats may have on disrupting alum treatments in larger lakes. They will also interview and meet with local stakeholders of East Pond and visitors to the lake to understand boating and lake user preferences to inform management measures. While working with the 7 Lakes Alliance and stakeholders, the team will provide concrete evidence of the viability of using alum as a treatment for stopping algal blooms in large lakes, and develop potential guidelines for boaters to minimize their impact on the large investment the East Pond community made to protect their lake.

Research Team

• Team Leader: Dr. Alejandra C. Ortiz, Assistant Professor, Geology, Colby College
• Dr. Alison Bates, Assistant Professor, Environmental Studies, Colby College
• Dr. Danielle Wain, Lake Science Director, 7 Lakes Alliance