Dr. Danielle Wain, Lake Science Director, 7 Lakes Alliance
This persistent hot weather has continued to worsen the water quality conditions on North Pond. Today, the water clarity, measured by Secchi Disk Transparency, was only 3 ft and there have been reports of shoreline scums from all around the lake. When the water clarity drops below 1 m (3.3 ft), the conditions are considered a potentially Harmful Algal Bloom (HAB) by the Maine DEP.
The 7 Lakes Alliance tested scums from four sites around the lake today (Sunset Camps, Fairview Lane, the dam, and Pine Tree Camp) for the most likely algal toxin that is observed in Maine (microcystin). Fortunately, all these tests have come back negative, but it is impossible to test all locations for all toxins, so, in an abundance of caution, we recommend that lake users avoid swimming in North Pond, particularly children and dogs who consume a lot of water while swimming.
Toxin production is an ongoing area of research in the aquatic sciences community. Through genetic testing done at Bigelow Lab last summer, it appears as if the most problematic algae in North Pond does not have the genes to produce toxins, which is likely why we have not detected any toxins since we started testing in 2020. But the same algae in nearby China Lake does produce toxins, so we are ever vigilant and will continue testing while the lake is blooming and after. As scum accumulations on the shoreline are the most likely places to detect toxins (not our sampling station at the deep hole), we have set up a Scum Report Form where you can let us know if you have scums on your shoreline so we know where to test.
This likely is going to be a tough year for water quality in North Pond. Once the lake starts blooming, it typically doesn’t clear up completely until the weather cools at the end of the summer, so much depends on the weather for the next couple of months. The North Pond Watershed Based Plan, approved by the EPA last year, recommends a combination of erosion control work in the watershed and an alum treatment to break the cycle of blooms on the lake. The estimate for all this restoration work is approximately $3M. 7 Lakes and the North Pond Association are working together to raise the funds to allow this work to happen. In addition to the funds already raised by NPA, 7 Lakes submitted an application for a FY25 Congressionally Directed Spending (CDS) Grant with Senator Susan Collins. After a highly competitive process, Senator Collins has decided to put forward our application for CDS as part of the appropriation bill that will be voted on in September. While there are no guarantees when it comes to Congressional approval, we are grateful for Senator Collins’ support for restoring this lake, which plays a vital role in the community. This grant for $2.3M does not cover 100% of the project and has a 20% matching requirement that will need to be raised. Although there is much to be done, 7 Lakes is optimistic that the North Pond restoration project will be as successful as East Pond.
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