COVID-19 Community Levels Map Update, Dec. 2, 2022: The Centers for Disease Control and Prevention has listed Fairfield, Hartford, Litchfield, Middlesex, New Haven, Tolland, and Windham Counties in the Medium/Yellow category as part of its COVID-19 Community Levels Map. New London County is currently listed in the Low/Green category. Visit the CDC COVID-19 Community Levels Map for updates.

The Drinking Water Section of the Connecticut Department of Public Health is working with our partners, including the Connecticut Section of the American Water Works Association, US Environmental Protection Agency, water utilities, and other states to develop a strategy for assessing, mitigating, and effectively treating for Harmful Algal Blooms in drinking water. Please check this page frequently as new information and publications will be available in the coming months.


CT Department of Public Health Fact Sheet - Harmful Algal Blooms and Drinking Water: For Connecticut Consumers
American Water Works Association and Water Research Foundation - A Water Utility Manager’s Guide to Cyanotoxins
Environmental Protection Agency - CyanoHABs Cyanobacterial Harmful Algal Blooms
World Health Organization - Management of Cyanobacteria in Drinking-Water Supplies:  Information for regulators and water suppliers

Water Utility Sampling Plan          
Circular Letter 2015-11 - No-cost Cyanotoxin Testing Available to Public Water Systems that Utilize Active Surface Water Reservoirs
Cyanotoxin Testing Information and Procedures:
Sampling Bottle Information:
-125 ml glass amber bottles will be supplied to all interested surface water reservoir utilities by the state lab in accordance with all conditions cited in the distributed Circular Letter dated August 31, 2015: 
-Utilities may contact the state lab at: or at 860-920-6674/6675 to have the bottles mailed to them, or;
-Utilities may pick up the sampling bottles at the state lab located at: 395 West Street, Rocky Hill, CT 06067, between the hours of 8:00 AM until 4:00 PM.
-Samples need to be cooled to between 4° C +/- 2° C and maintained at that temperature until delivery to the state lab during receiving hours (8:00 AM until 4:00 PM).