Cyanobacteria, or blue green algae, are considered by MassDEP to be an emerging contaminant for several reasons: there is a growing awareness of the potential presence in drinking water supplies of toxins produced by cyanobacteria, leading to the potential for human exposures; toxins produced by cyanobacteria can adversely affect human health; no Massachusetts or federal drinking water standards or limits exist; and there is evolving information on health impacts due to human exposures.  

Cyanobacteria are the result of a symbiotic relationship that happened about two billion years ago between an algae ingested by a bacterium. The result is an organism which has characteristics of both bacteria and algae although it is more closely related to bacteria. The name cyanobacteria comes from the color of the bacteria (Greek: κυανός (kyanós) = blue). Cyanobacteria are one of the more widespread and successful groups of microorganisms on earth. Thousands of cyanobacteria species are known to exist.  They are genetically diverse and are present in a wide range of freshwater, marine and terrestrial ecosystems. Cyanobacteria can cause problems when they undergo explosive growth, most commonly in the summer months. Warm water, sunlight and nutrients in the water can lead to blooms. Certain species of cyanobacteria can produce toxins which pose a serious health risk to the exposed public. Key health concerns include effects on the liver and nervous system.  

MassDEP Workplan: 

Due to the increased awareness of the threat posed by cyanobacteria in drinking water, MassDEP is taking several steps to prevent harm to human health. Specifically, the agency will:

  • Prepare several guidance documents including, but not limited to, documents covering drinking water monitoring protocols, outreach and training for water suppliers, and health assessment and event management protocols for protecting public health from consuming drinking water with cyanotoxins. Upon completion, these documents will be posted on the MassDEP website.
  • Work with public water suppliers on testing and managing blooms, using information on the types and levels of cyanobacteria cells and toxins in drinking water samples.
  • Develop testing protocols for private testing laboratories to utilize.
  • Work on a case-by-case basis at affected water supplies until full implementation of the program in spring 2014.

It is important to note that the Massachusetts Department of Public Health (DPH) is the state agency responsible for cyanobacteria in recreational waters and for providing advice for people and pets who may be exposed. MassDEP is developing its Guidance for Drinking Water Supplies in coordination with DPH.