Androscoggin Lake: Algal Bloom Response

Latest Updates

30 Mile will update this webpage as information becomes available

6/15/2026 – Funding and monitoring update

On June 10th, Wayne voters attending Town Meeting approved Wayne supporting  this project with $15,000. Thank you to everyone who came to vote!

6/3/2026 – Algal Bloom Forum

Thank you to everyone who attended the Androscoggin Algal Bloom Forum in person or online. If you weren’t able to attend, the presentations and Q&A have been recorded and are available to watch (or rewatch) at http://youtu.be/C9z3WJVmZzs. We are working to update our Q&A page to reflect new questions as soon as possible.  

Forum summary: 

Sara York, 30 Mile’s Water Quality Specialist, reviewed progress made since the previous forum in November; 

  • Organized the Androscoggin Lake Steering Committee: 8 people representing Wayne, Leeds, ALIC, 30 Mile, businesses, lakefront owners, and lake users that will guide four work groups (science, government, fundraising, communications).
  • Secured funding: Maine Outdoor Heritage Fund, ALIC, 30 Mile,  the Town of Leeds, With pending funding from the Town of Wayne and Maine DEP
  • Hired consultants: Ecological Instincts (Jen Jesperson) for watershed planning and VHB Engineering for the Dead River dam peer review study.

Jen Jesperson of Ecological Instincts, the hired environmental consultant for this project, spoke about the work she will be doing to complete the nine-element watershed-based management plan. This plan is essential for understanding current causes and sources to develop scientifically sound lake and watershed restoration strategies. She highlighted; 

  • Androscoggin Lake has sensitive sediment chemistry and is above the phosphorus threshold where it becomes more likely to sustain algal blooms. But there is still potential for recovery. 
  • Phosphorus levels being investigated include external loading such as runoff from the watershed (roads, driveways, agriculture, septic systems, the Dead River backflushing), and internal loading (phosphorus released from lake bottom sediments when oxygen is depleted). 
  • Watershed modeling and analysis will be completed to determine the major sources of phosphorus, their relative contributions, and how much needs to be reduced. 

Sara York, reviewed the data collection to be completed and utilized this season; 

  • Updated lake bathymetry mapping (depth/volume map)
  • Sediment core sampling (10+ locations)
  • Monthly/bi-weekly plankton sampling to identify cyanobacteria species and abundance
  • Dissolved oxygen surveys across lake to determine if anoxic conditions impact phosphorus in shallow areas
  • Storm runoff sampling from tributaries
  • ADCP instrument and gauges on the Dead River to measure backflushing events and water levels
  • Peer review of 2000s-era Dead River dam studies
  • Updating septic records for a septic system loading analysis 

To help support this work, you can donate to the “Keep It Blue” campaign here.

6/1/2026 – Funding and monitoring update

In May, the Maine Outdoor Heritage Fund (MOHF) Board voted unanimously to fund the 30 Mile River Watershed Association’s grant application for work on Androscoggin Lake. This $25K grant will support an environmental assessment to identify the causes of the algal blooms and management strategies to protect public health. Project partners include Maine DEP, ALIC, and the towns of Wayne and Leeds.

Work has already begun this spring with intensified data collection that will continue throughout the summer and fall, including sediment sampling (10+ locations), plankton sampling, stream sampling (10+ locations), dissolved oxygen transects, and recording backflushing events of the Dead River. Data collection will be conducted by 30 Mile staff, and supported by trained volunteers and Maine DEP. This data will inform the work to be completed by Ecological Instincts, which will include phosphorus loading analyses, watershed modeling, and more, all leading toward developing a U.S. EPA-approved Nine-Element Watershed-Based Management Plan (required for certain grant eligibility). Completing this extensive, science-based work will help us better understand the factors causing the blooms and evaluate potential solutions to help prevent them. 

 

5/1/2026 – Androscoggin algal bloom Work Groups update

The Androscoggin Lake Steering Committee’s four Work Groups (science, government, communications, and fundraising) have been assigned and have conducted initial planning meetings. Over 30 volunteers signed up and will be participating in a wide variety of tasks. Work over the next month will include applying for grants, finalizing data collection methodologies, planning summer events, reviewing ordinances, and building relationships with local, state and federal representatives. Work with the technical team, which includes lake science experts, DEP staff, engineers, and 30 Mile staff, is also underway, with an immediate focus on the Dead River. 

The next public forum is planned for Wednesday evening, June 3rd, 2026, at the Wayne Community Church. Jen Jespersen of Ecological Instincts, the consultant hired to conduct the data analysis, modeling, and planning for remediation efforts, will be speaking about their progress to date. Additional forum details will be available soon. 

At their April town meeting, the Town of Leeds approved $5,000 to support this work. The request for funding from Wayne will be voted on at June’s town meeting. 

Updates, FAQs, and additional information on Androscoggin Lake’s algal blooms can be found at 30mileriver.org/androscoggin-bloom. 

The Androscoggin Lake Steering Committee represents Wayne, Leeds, ALIC, 30 Mile, businesses, lakefront owners, and lake users – all working together to provide a forum for meaningful citizen dialogue and discussion to foster a realistic and timely action plan to restore the health of Androscoggin Lake.

 

Donate to Keep It Blue!

Quick Links

30 Mile will update this webpage as information becomes available-
please check back for more updates!

Questions? Contact Sara, Water Quality Specialist at sara@30mileriver.org

Past Updates

Background

Androscoggin Lake experienced a severe cyanobacteria bloom during 2021, 2023, 2024, and 2025. Near-bloom conditions were documented in 2022. Maine Department of Environmental Protection (Maine DEP) defines a “lake-wide algal bloom” when water clarity <2 meters (~6 feet) depth at the deepest point in the lake (monitoring station #1). 

What you need to know:

  • The blooms in Androscoggin Lake have consisted of cyanobacteria (formerly called blue-green algae)
  • Cyanobacteria can bloom when there’s too much phosphorus in the lake.
  • Some species of cyanobacteria can produce toxins under certain conditions
  • Not all cyanobacteria blooms are toxic
  • Areas where the algae have concentrated, forming dense scums or accumulations, should be avoided by humans, pets, and livestock
  • Avoid swallowing lake water while swimming, and do not allow pets or livestock to drink lake water
  • Avoid using lake water for household uses, cooking, or drinking
  • Shower and wash swimsuits after swimming

    What causes algal blooms?

    Cyanobacteria rely on three things: light, temperature, and nutrients. When it rains, phosphorus enters the lake via stormwater runoff that is delivered from the land in the watershed surrounding the lake. Phosphorus is a naturally occurring nutrient found in soil, fertilizers, pet and livestock waste, and septic systems among other sources. It is found in very small amounts in the lake water, but is found in very large amounts on land in the watershed surrounding the lake. Every time it rains, water flows over the land and flows downhill – into the ditches, streams, and Androscoggin Lake. When too much phosphorus enters the lake, excess algae growth occurs.

    Another important source of phosphorus is the sediments at the lake bottom. In the summer months, low oxygen levels in the deep waters of the lake can cause a chemical reaction to occur in the sediment. This reaction causes the sediment to release phosphorus into the water — a phenomenon known as “internal phosphorus loading”. To learn more, please read Androscoggin Lake’s 2023 Water Quality Report here: https://30mileriver.org/androscoggin-lake/. 

    For more information about algae blooms and cyanobacteria, please visit Maine DEP’s informational webpages via the following links:

      Algal Bloom Information

      What are cyanobacteria?

      Cyanobacteria are a type of algae. Formerly called blue-green algae, cyanobacteria are aquatic bacteria that are able to photosynthesize. Originally called blue-green algae because dense blooms will turn the water green, or blue-green in color, cyanobacteria are a natural and important part of the lake ecosystem, and can be found in all lakes all over the world. However, when nutrient (phosphorus) concentrations are high enough and conditions are just right, their population can explode. The result is what we call a “cyanobacteria bloom” or “algal bloom.”

      What kind of cyanobacteria is it?

      The species of cyanobacteria have been identified as Dolichospermum (formerly known as Anabaena), a common bloom-forming species in Maine lakes. Microscope photos (right, courtesy of R. Windecker) show the filamentous algae consisting of multiple bead-like cells of three distinct cell types. Dolichospermum can produce toxins under certain environmental conditions.

      Is the water toxic?

      We do know that the species causing this bloom has the ability to produce toxin. We are collecting water samples for toxin analysis by US EPA, however test results are not immediate. 

      Maine DEP has been testing for cyanotoxins in Maine lakes for decades. Of all the toxin samples Maine DEP has collected, there were only a few open-water samples that exceeded EPA’s Drinking Water standard for the algal toxin microcystin for infants and non-school-age children. None of the samples exceeded the standard for school-age children or adults.  No open water samples have exceeded EPA’s Recreational Standard – even when collected from lakes with blooms that are chronic and severe. 

      However, Maine DEP has detected very high concentrations of the algal toxin microcystin in down-wind algal scums that can accumulate along shorelines.  This is why we advise everyone to stay away from any concentrated scums or accumulations near shorelines or in down-wind coves. Do not inadvertently drink the water in these areas, and do not let small children, pets, or livestock play in these areas or drink from the lake. Shower after swimming, and do not use lake water for household uses like cooking or drinking. 

      Out of an abundance of caution: When in Doubt -Stay Out!

      What you can do RIGHT NOW to help:

       

        • Donate to 30 Mile to support our water quality monitoring program and our work to address this problem: https://30mileriver.org/ways-to-give/
        • Become a member of the Androscoggin Lake Improvement Corporation (ALIC) https://androscogginlake.org/alic/how-to-help/donate/   
        • Be an advocate for lake protection at the town level. Local select boards, planning boards, and code enforcement officers all make decisions that can impact the lake. 
        • Share this information with your friends, family and neighbors. Be an ambassador for the lake!
        • Address erosion on your property. Exposed soil delivers phosphorus to the lake each time it rains. Phosphorus feeds algae in the lake!
        • If you are a landowner with an erosion site identified during the 2022 watershed survey, contact 30 Mile to see what cost-sharing opportunities are available to help implement your project!
        • Establish or improve the vegetation on your shoreline. The bigger (wider) your shoreline buffer, the better it is for Androscoggin Lake.
        • Do you live on a camp road? Gravel roads can be a huge polluter of the lake when sediment and pollutants from the road flow into streams and lakes during rain events. Be sure that your road isn’t part of the problem. Contact 30 Mile for technical assistance and learn more about how to maintain your road and protect the lake: https://www.maine.gov/dep/land/watershed/camp/road/gravel_road_manual.pdf  
        • Become LakeSmart! Contact ALIC’s LakeSmart team to receive a FREE property visit to learn more about how you can improve your property for the benefit of Androscoggin Lake. Visit https://www.lakes.me/lakesmart to learn more about this fantastic statewide program!
        • Stop using fertilizers on your lakefront properties
        • Maintain a healthy septic system, and pump your septic tank regularly. Visit https://30mileriver.org/septic-system-vulnerability-study/ to learn more about proper septic maintenance and go through our questionnaire to learn what else you can do to properly maintain your system. 
        • Volunteer. Help support water quality monitoring and LakeSmart. Sign up here: https://30mileriver.org/volunteer/ 

        Learn more about how you can reduce your impact by visiting Maine DEP’s website for Shorefront Property Owners: https://www.maine.gov/dep/land/watershed/camp/index.html or Maine Lake’s Lake Library: https://www.lakes.me/library.

      Where can I learn more information?

      Algal Blooms in Maine Lakes (Maine DEP): https://www.maine.gov/dep/water/lakes/algalbloom.html 

      Cyanobacteria and Toxins (Maine DEP): https://www.maine.gov/dep/water/lakes/cyanobacteria.html   

      Most recent water quality data and reports (30 Mile): https://30mileriver.org/androscoggin-lake/ 

      Most recent information about blooms in Androscoggin Lake, and what 30 Mile and ALIC are doing in response: https://30mileriver.org/androscoggin-bloom/ 

      Near-Live Water Quality Data & Annual Monitoring Reports

      30 Mile continues to monitor Androscoggin Lake into October to document improved conditions in the lake. Over the winter months, we will analyze the data and compile our findings into an annual water quality monitoring report, which will be available via our website once complete. 

      In the meantime, be sure to check out the Secchi disk and dissolved oxygen data collected throughout this year’s monitoring season by visiting 30 Mile’s water quality webpage for Androscoggin Lake: https://30mileriver.org/androscoggin-lake/.

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