Cyanobacteria found in White Pond July 2026

The Town of Concord reports on July 17, 2026::

We have received a few bloom reports and can confirm that we have a small bloom within Thoreau’s cove.  From samples taken at Thoreau’s cove this week, we observed Microcystis and confirmed the presence of toxin within the collected material.  Yesterday we tested the cove for Microcystis and found low to moderate toxin.  We then tested at the Town beach and the sample showed less than 2.5ppb - not detectable with our test.  We continue to remove cyanobacteria from the A-Pod trap and will continue to closely monitor over the summer.

Please use caution with pets and avoid contact with the water if there are visible signs of “pollen”. At this point, in mid-late July, we are most likely looking at cyanobacteria rather than pollen.

Please report suspected cyanobacteria blooms to the Town of Concord at  https://concordma.gov/FormCenter/Land-Use-Conservation-Building-Divisions-6/Report-a-Bloom-101

Here's what a bloom looks like: