What Is Vermont Doing To Prevent Blue-Green Algae Blooms?

Oct 4, 2017

Last week cyanobacteria, commonly known as blue-green algae, showed up in blooms that closed beaches on Lake Champlain and Lake Carmi, disappointing swimmers looking for relief from the late September swelter. But more than an inconvenience, it also posed health concerns for people and pets who might come into contact with the bacteria.

What is Vermont doing to prevent these blooms from happening? We asked Julie Moore, Vermont's Secretary of the Agency of Natural Resources.

On The Lake Carmi Watershed

"We've been actively working in the Lake Carmi watershed for several years now and actually formed an implementation team in 2015 focused on getting some more significant projects on the ground in the Lake Carmi watershed. There are two large agricultural practices that we expect to go on the ground this fall to address what we know are are some fairly significant sources of phosphorus pollution. We are also working at our own State Park facility to enhance the wastewater treatment provided at Lake Carmi State Park and are working on a partnership with a non-profit organization to look at doing some stream and wetland restoration," Moore said. "So those four projects are really significant and frankly compliment other work that's going on in the Lake Carmi watershed and throughout the Lake Champlain basin, working with the municipalities to address road-related runoff ,working with the Lake Carmi Campers Association to address runoff issues from some of their private roads, providing what we are calling "septic socials" getting people together to talk and think about their septic systems. And then also the Ag Agency, in partnership with the U.S. Department of Agriculture, has been very active in that watershed meeting on the ground with farmers to look at different options for applying conservation practices."

What causes algae blooms?

"It's excess nutrients and the nutrient of primary concern when we're talking about freshwater bodies Lake Champlain and Lake Carmi, is phosphorous," Moore says. "We know that phosphorus has a number of different sources in the environment. Agriculture is certainly a significant source particularly in Franklin County but we also look at foods from septic systems. There's actually phosphorous that's contained in runoff from roads, runoff from lawns. So it requires an all-in approach where we're looking at each different sector. The level of phosphorous pollution they contribute and then working to apply best management practices and conservation measures to control runoff from these areas."

Vermont's New Required Agricultural Practices

"I think the new practices are having the intended effect but we also have to recognize that there's time needed for the practices to have full benefits. There is a legacy effect, or a time lag in the system. When phosphorous pollution occurs it may move from the farm field and into the stream channels but not necessarily all the way to Lake Carmi at once. And even phosphorous that reaches Lake Carmi has the ability to continue to feed algae blooms for years to come. And that's a little bit of the scenario we believe is taking place in Lake Carmi. As you indicated the dynamics of an algae bloom are very complex. And while we know what factors increase the likelihood one will occur in every given year we cannot pinpoint with accuracy exactly what is driving a particular bloom," Moore said.

"The lake stratified, the water at the bottom becomes depleted of oxygen and that allows phosphorous to be released from the sediments ultimately the lake turns over and those phosphorous rich waters end up near the surface and then are available for algae to eat. And boy did they ever." - Julie Moore, ANR Secretary

"But we believe in Carmi this year it was a combination of a significant amount of rain this spring combined with relatively cool early summer temperatures. So the lake stratified, the water at the bottom becomes depleted of oxygen and that allows phosphorous to be released from the sediments and ultimately the lake turns over and those phosphorous rich waters end up near the surface and then are available for algae to eat. And boy did they ever," she said.  "And that's really what triggered the bloom. And unfortunately particularly in Lake Carmi, the timing of the lake turn-over with such that has happened just prior to that that extended period of warmth and sun that we enjoyed during September. And both warmth and sun are conditions that just promote algae growth."

On Water Quality Spending

"The state's portion of what's being spent on water quality right now is is on the order of $56 million a year. This money is also able to match and leverage additional federal funds so our total investment in water quality is upwards of $100 million a year. And we're, you know, there's a challenge in putting frankly that much money on the ground responsibly, efficiently and effectively. I think we're doing it. I know there are people that would like to see us go faster, but the faster we go I think the greater the risk that we make a misstep and right now our resources are extremely well matched to our capacity to do the work," Moore said.  

Click listen to hear the entire interview.