The state's top environmental enforcement official said more needs to be done to protect Lake Champlain's drinking water supplies from toxic algae blooms.
For years, state officials warned recreational users to stay away from the toxic green scum that floats on the surface of the water during mid- to late-summer months.
Algae toxins could enter drinking water supplies from Lake Champlain, says David Mears, commissioner of the Vermont Department of Environmental Conservation. The state is working to improve its testing protocols, he said.
The water is frequently monitored and tested, he said. When an algae bloom is spotted near a drinking water intake pipe, he said, the facility is notified.
So far no water supplies have been contaminated, he says.
But algae toxins can move across the water and within the water column, making it difficult to track in real time. State officials say many towns and drinking water facilities along the lake need more guidance on to how to deal with algae alerts more quickly.
The algae break down to form cyanobacterial toxins that can cause symptoms ranging from short-term illness and allergic reactions to liver damage, according to the health department. Approximately 200,000 people drink water from Lake Champlain.
Algae blooms come from agriculture and human phosphorus runoff.
Ellen Parr Doering, deputy director of the DEC's Drinking Water and Groundwater Protection Division, said DEC has not issued any public notices of a drinking water threats to date.
But Mark Simon, co-owner of Simon Operation Services Inc., which oversees water and wastewater facilities, says that almost every year there is a bloom above the Grand Isle intake pipe.
Simon said when there is an algae bloom near the intake pipe, the operator contacts the health department and it tests the raw drinking water. To date, he said no toxins have been detected in the water.