The following water quality updates have been issued for Wednesday, June 21, 2023:

  • A Public Health Advisory is removed at Mystic Lake due to two samplings for cyanobacteria being Acceptable.
  • Pet Advisory signage remains in place at Schoolhouse Pond due to high estimated Microcystin toxins being present.

Cyanobacteria Pet Advisory

Pet Advisory Level

Schoolhouse Pond, Hyannis







If you are interested in receiving more information about Cyanobacteria and locations monitored, you may view the 2023 Cyanobacteria Monitoring Map at

If you are interested in receiving email notifications when there is a potential toxic bloom identified by Association to Preserve Cape Cod (APCC), you may opt-in by clicking this link: where you will be asked to enter your email address in order to receive cyanobacteria alerts.

Thomas A. McKean, RS, CHO
Director of Public Health