August 12 – 18, 2022Vol. 24, No. 10

East Pond Alum Update

by Mel Croft

Those of us who spent careers in the sciences learn quickly the burden of proof in the sciences is demanding. The best way to solve complex problems is to employ smart, knowledgeable, creative people, and then gather as much data as possible to develop solutions. A great example is the alum treatment in East Pond.

When I arrived on East Pond in 2007, the cause of the lake’s frequent algae blooms was not well understood until a lot of smart people, including Dr. Whitney King from Colby College in partnership with what is now the 7 Lakes Alliance, stepped in to tackle the problem, which turned out to be high levels of phosphorus in the lake’s sediment. After much scientific analysis, an alum treatment was proposed, with extensive work to determine the proper amount, placement and cumbersome mechanics of such a huge and costly project.

The alum was applied in 2018, and we’ve enjoyed beautiful, clearer water for the past four summers. According to 7 Lakes Alliance Lake Science Director Dr. Danielle Wain, the average water clarity in East Pond in 2021 was 17 feet, an impressive 6 feet deeper than before the treatment. Prior to the treatment, we would not invite guests to visit us on the lakes after mid-July when the water began to turn an ugly green. By August, the lake often erupted into a fully stagnant, smelly bloom.

Dr. Wain stresses that “alum is one of many tools in our lake management toolbox. After many years of study, it was determined to be an effective solution for managing the algae blooms in East Pond, which has a small watershed and few streams that bring phosphorus into the lake. Alum treatments only reduce the existing phosphorus in the lake, and do not prevent future phosphorus pollution from entering the lake. Only protecting the watershed and reducing erosion can do this.”

Dr. Wain also points out East Pond remains one of the largest lakes treated with alum in the United States. It is the fifth largest lake in the 7 Lakes region.

Recognizing the key role erosion plays in dumping phosphorus into the lake, I volunteer as the coordinator for the LakeSmart program on East Pond to help individual shorefront owners do their part to stop erosion at their doorstep. As Benjamin Franklin said, “An ounce of prevention is worth a pound of cure.” There are a lot of happy people on East Pond, and we want to keep it that way!

Mel Croft is an East Pond resident, a retired geologist, and a 7 Lakes Alliance Board member.

©2022 by Summertime in the Belgrades. All rights reserved.