The Chittenden Reservoir is on high-alert after large amounts of blue-green algae were observed by monitors during a recent visit. According to the post on the state's blue-green algae tracker "dense scums or highly colored waters were present." The notification was posted Wednesday. The algae, also known as cyanobacteria, can make people and animals sick. As part of the post, a notice was included that said the water was not safe for recreational use in this area which encompassed the entire reservoir. Those who use the water for swimming should contact the state's Department of Health information for about beach closings and hazardous areas. A toxin test was not conducted.