Acceptable: Pond is deemed safe for recreational activities such as swimming, wading, fishing and boating.

Use Advisory: Avoid contact with the water, do not swallow water, keep pets out and avoid activities such as swimming, fishing, or wading.

What are Cyanobacteria? 

Cyanobacteria have been often referred to as blue-green algae; however, they are a group of microorganisms that share similar characteristics of algae, such as the ability to perform photosynthesis like green plants using the chlorophyll in their cells. Cyanobacteria may occur as single cells, thread-like filaments, or as colonies of various sizes and shapes composed of groups of many filaments or cells. They are naturally occurring in all waterbodies with some species growing in waterbody sediments, while other cyanobacteria can move within the water column. Some cyanobacteria have the ability to produce toxins, called cyanotoxins.

Brewster Ponds Monitoring

In an effort to keep our residents and visitors informed of the current public health advisories for Brewster ponds, the BPC Citizen Science Program is testing 19 Brewster ponds for cyanobacteria bi-weekly from May through October. We will report results by pond to the Brewster Health Department, and make these results available here on our website. You can also find the same information posted on the Town of Brewster website by clicking here.  

When are public health advisories issued? 

A public health advisory for Harmful Algae Blooms at recreational freshwater locations is issued when at least one of the following criteria is met:

1. A visible cyanobacteria scum or mat is evident; (Most common)
2. Total cell count of cyanobacteria exceeds 70,000 cells/mL;
3. Exceedance of one of the following cyanotoxin guideline values:

• Microcystins - 8 µg/L
• Cylindrospermopsin - 15 µg/L
• Anatoxin-a* – 60 µg/L

A public health advisory for Harmful Algae Blooms is rescinded when there is no visible scum or mat present and the Massachusetts Department of Public Health has completed two successive samples, collected a week apart, demonstrating cell counts and toxin levels below the quantitative guidelines values. 

Public health advisories can only be issued by the Brewster Health Department for Brewster's ponds. 

What should I do if I see a potential CyanoHAB?

The first step an individual should take if they observe a potential CyanoHAB is to AVOID CONTACT with the affected water. While most algae are harmless, cyanobacteria can be skin irritants and some are capable of producing and releasing cyanotoxins, which can make people and animals sick. Contact the Brewster Health Department (508-896-3701), and alert them to what you have observed, along with the name and location of the waterbody. 

Additional Cyanobacteria Information:

• MA Department of Public Health Cyanobacteria Information
• Identifying Cyanobacteria Blooms
• MA Department of Public Health Active Advisories
• Barnstable County Cyanobacteria Information
• Brewster Cyanobacteria Poster
• CDC Protect Yourself and Pets
• CDC Cyanobacteria Blooms FAQs

Previous Brewster Cyanobacteria Monitoring Updates: 

• ​​Week of July 6, 2026
• Week of July 20, 2026
• Week of July 27, 2026
• Week of August 3, 2026
• Week of August 10, 2026
• Week of August 17, 2026
• Week of August 31, 2026
• Week of September 14, 2026

John Keith, BPC President, began the meeting with highlights of the organization’s activities since August 2025. Most importantly, he noted the Town of Brewster’s recently completed Integrated Water Resources Management Plan (IWRMP) and draft Pond Management Plan (PMP), both that the BPC took an active role in supporting, contributing research, and providing comments and suggestions. Together, these plans are critically important to ensuring the protection of our ponds and resources.  

​Key highlights of the Septic System Phosphorus Travel Study, Citizen Science, Pond Education, Scholarship, and Pond Outreach programs were provided. In addition, John shared key details about Adult Education initiatives and the BPC’s participation in several annual town-wide events. He also presented the long-term strategic goals and priorities for the 2026-2027 business year. The yearly finances were summarized, giving attendees an overview of income, expenses, and how donations are allocated among the various segments of the organization. 

You can view John’s slide presentation here for more details. 
​
The Splash Award​

At each Annual Meeting, the BPC presents its
​“Splash Award,” recognizing a volunteer who has made a splash through his or her contributions to improve the water quality, beauty, or natural habitats of Brewster’s ponds. This year, Ron Essig (Board member and Citizen Science Team leader) presented the award to Roy Bellush.

Pictured here is Roy accepting his award from Ron. 

Ron explained that Roy has been sampling for cyanobacteria from the inception of the Citizen Science  program 10 years ago in Upper Mill Pond. Back then, he worked with Bryan Horsley of the Association to Preserve Cape Cod (APCC) to help develop the sampling techniques. Roy uses his own boat to sample along with other team members at the deepest point of Upper Mill and Walkers ponds. These are the only two ponds on the Cape sampled for cyanobacteria by boat. Roy has also pitched in and delivered samples to APCC when needed. He is very willing to sample off-cycle and to share photos from other Upper Mill Pond residents with the BPC and the Town when there are cyanobacteria scums. In addition, Roy takes Marty Burke out to obtain Secchi disc measurements in Upper Mill Pond 10-12 times a year to ground truth satellite imagery. This is the fifth year that he has participated in this research project done in cooperation with the Cape Cod Commission and NOAA. 

The Guest Speakers

The first guest speaker was Mark Nelson, principal hydrogeologist with the Horsley Witten Group. Mark has worked with the Town of Brewster since 2011 as an environmental consultant and developed the IWRMP. He presented the updated plan, explaining how it incorporates all water connections such as rain, groundwater, estuaries, and ponds. The main components of the broad plan are coastal estuaries, freshwater ponds, and drinking water. 

Mark explained how the IWRMP analyzed the number of homes in Brewster with septic systems within 300 feet of ponds. BPC volunteers were integral in this analysis by reviewing the Town land records and identifying 523 locations. When the ponds are identified and categorized in the PMP in regards to impairment level, Mark advised that subsequent wastewater management will then be determined. He further noted that there are no requirements to reduce nitrogen loads to Cape Cod Bay and no sewering in this watershed is anticipated in the foreseeable future. Lastly, he advised that Brewster’s drinking water quality is excellent. This was determined by the IWRMP mapping capture areas to the Town’s wells under average pumping conditions. No threats are expected from current development related to emerging contaminants. 

The audience then heard from Dr. Kim Crocker-Pearson, a physician specializing in occupational and environmental toxicology and a consultant in environmental science and policy. Kim is currently Chair of the Natural Resources Advisory Commission (NRAC) and member of the Brewster Board of Health. The NRAC has been responsible for drafting the PMP. Kim explained how the draft PMP has developed four quadrants that categorize the impairment or threat plan of Brewster’s ponds: 1) protect; 2) prevent; 3) remediate; and 4) rehabilitate. She noted that the draft plan suggests pilot studies in each of the four quadrants, as follows:

• Quadrant 1 (Protect): Sheep Pond - develop educational strategies regarding pond shore buffers to preserve pond quality
• Quadrant 2 (Prevent): Elbow Pond - determine what effect the adjacent cranberry bog has had in the past and potentially will have in the future so that impairment can be prevented
• Quadrant 3 (Remediate): Upper Mill Pond - has suffered significant impairment from cyanobacteria per the MA DEP criteria, also affected by the nutrients every year from the herring run
• Quadrant 4 (Rehabilitate): Blueberry Pond - the most complex situation due to real impairment combined with intense, ongoing watershed loading

You can download and view each of the guest speakers' presentations via these links:

• Mark Nelson's IWRMP presentation
• Dr. Kim Crocker-Pearson's draft PMP presentation

​John closed the Annual Meeting by thanking the attendees for their support and volunteer activities, and the Cape Cod Bible Alliance Church for the use of its facilities, audiovisual capabilities, and the support of its staff.