Will White Pond's clean water quality prevail in 2025?

For the past three years, White Pond has successfully mitigated harmful algae blooms thanks to reduced fertilizer use, maintaining septic systems, controlling shoreline erosion, crowd control at Sachem’s Cove and—most notably—the deployment of the A-Pod system. But clean water at White Pond is not guaranteed. Here is the outlook for 2025.

Last summer, many Massachusetts lakes and ponds were closed for swimming due to water quality issues. In 2024 alone, nearby Walden Pond was closed on eighteen separate days because of elevated bacteria levels. Cyanobacteria blooms were reported across the state, affecting the Charles River and numerous other water bodies, including Lake Cochituate (Natick), Devol Pond (Westport), Long Pond (Barnstable), Billington Sea (Plymouth), Carbuncle Pond (Oxford), Waushakum Beach (Framingham), and Crystal Lake (Newton).

Cyanobacteria, also known as blue-green algae, are naturally occurring but can become highly concentrated under certain environmental conditions. These harmful algal blooms (HABs) may release toxins that affect the skin, liver, and nervous system. Exposure can occur through ingestion, skin contact, or inhalation of

contaminated water droplets.

What Is a Sentinel A-Pod?

We are pleased to announce that the successful strategy of the last few years continues into 2025 with an exciting upgrade: the introduction of the new Sentinel A-Pod.

The Sentinel A-Pod is designed for long-term, continuous use to manage nutrient loading—one of the major drivers of cyanobacteria growth. It captures and controls excess nutrients from sources like tree pollen and forest particulates, helping to manage the annual buildup of cyanobacteria and phytoplankton biomass. We learned in a 2024 presentation that tree pollen especially is a major culprit in cyanobacteria blooms that close the pond.

What’s Happening at White Pond This Year?

In late May 2025, two standard-size Sentinel A-Pods will be launched at White Pond. Jon Higgins of Higgins Engineering will oversee their operation through June 30, 2025. During this time, he will also train Concord town personnel in the deployment, use, and retrieval of the new pods, which will then be maintained by the town moving forward.

The A-Pod technology plus a little luck from high water levels in 2024 that discouraged visitors, has made a critical difference in restoring White Pond’s water quality from several years ago. While the environmental outlook for 2025 is unpredictable, the continued use of the Sentinel A-Pod gives White Pond its best chance for long-term health.