Interview #2

Declan McCabe, Biology Department Chair and Associate Professor

10/27/14 in Cheray Science Hall

CC: Could you explain the work you’ve done involving the water quality of Lake Champlain?

DM: Absolutely. So, we’re interested in how our use of the landscape affects the quality of the water that’s going into the streams. So for example, North Campus has a whole lot of paved surfaces. And because of those paved surfaces, it impacts the amount of phosphorus going in, and other contaminants. So St. Mike’s together with the state built a retention pond up there to catch many of those contaminants. And we can see the affects there. So my main work is to look at, in general, the affects of land use on water quality, and how that affects the insects in the lake and then the streams.

CC: Is it students that you’re working with over the summer?

DM: Yeah, we hire student interns. And they get paid $5000 for the summer. So that’s not too shabby! So, they work in the lab downstairs, they do a lot of work in field sites around the place. So we have auto-samplers that are set up around the lakes, well, some on the lake, but mostly in the rivers. What happens is as soon as there’s a storm and water starts to rise in the river, it triggers the auto-sampler. And the auto-sampler will take samples at regular intervals over the course of the storm. So the floodwater in the stream will usually rise steeply, and then peak, and then tail off gradually as all the rainwater finds its way into the streams and eventually to the lake. And that’s when most of the contaminants move downstream. So that’s what we’re interested in capturing. The primary thing we’re interested in looking at is phosphorus. Because it’s phosphorus that impacts the lake directly. It causes the harmful algal blooms that produce toxins, and produce fish kills, and has even killed a couple of dogs on occasion. That’s when the newspapers finally pay attention. But the problem is much bigger and much older than that.

CC: Would they have to drink a lot to die?

DM: No, the toxins that they get from a blue green algal bloom- it doesn’t take a whole lot. So it happens on occasion.

CC: And it’s not producing toxins all the time, just some of the time?

DM: No. There’s specific blue green algae that occur during the big algal blooms that produce the toxins. That’s why they call it a harmful bloom as distinct from an algal bloom.

CC: How do you see people being affected personally by this issue?

DM: Some of the issues are, you know, in terms of the economy of Vermont, the lake is one of our biggest assets. And when people notice that the lake is bright green or bluish green, that’s not an attractive sight. And if more pictures like that circulate, as they will if the blooms continue, then you know it will have an impact on tourism. So that’s one impact. The other impact is just on people who like to use the like locally. Forget about the tourists, just consider the locals who want to stick in their sea kayak and go for a nice paddle. They don’t want to go through green soup.

CC: What do you see as some realistic goals for solving this problem?

DM: If we can continue to build our infrastructure in terms of retention pons, and reducing the amount of runoff- for example, St. Mike’s has done a really great job in capturing runoff and preventing it from going into streams. So, if you see a new paving surface going in on campus, you’ll see one of two things. It either will sheath of to the side, to the grass, or it will actually be a pervious surface made out of bricks so that the water can actually go through. So the college is trying to reduce the amount of pervious surfaces to reduce the runoff. There used to be a volleyball court over at the townhouses, one reason that that was a sand volleyball court is that we can dig it up periodically without damaging the landscaping. And underneath there’s a tank that captures all the runoff from the roofs and from the roads of the townhouses and the roads associated with the townhouses. Anytime you channel water to any body of water, it increases the erosion in that body of water. So you’re going to erode the banks, the riverbed, you’re going to move phosphorus downstream towards the lake, so any particle that is eroded off the landscape will typically contain phosphorus. And phosphorus is sticky and binds to particles, and it gets transported to the lake. So the big thing I would say is to reduce impervious surfaces, make rain gardens, rain barrels, anything to keep the roof water and the driveway water out of the street. Get it onto your garden instead. Let is soak into the landscape and reduce that erosive potential.

CC: How long before we start seeing results? Is this going to be a really long-term thing?

DM: It’s going to be really long term. And the problem is, if you could stop all phosphorus today, there’s a deep thick legacy of phosphorus in the lake that is on the bottom. And it recirculates. And it doesn’t tend to leave the system very easily. So when the temperatures get high enough, and the water is stagnant for long enough, you’ll actually tend to get phosphorus at least from the sediment into the water column. And it’s going to take a lot of years for that cycling to gradually get the phosphorus out of the system. But it’s a very slow process. The other problem is, every gain we make in terms of reducing phosphorus input, under the current conditions of climate change, the big affect in the Northeast is that we have additional rainfall, and bigger, more erosive storms. So you can just look at the numbers, it doesn’t take a rocket scientist by any means. The numbers of seriously out of the ordinary storms have increased over the last couple of decades. And every one of those storms brings more phosphorus to the lake because of erosion. Hurricane Irene is a great example.  So there you go, it’s a long-term problem. A lot of phosphorus moved in a very short period of time. At some point you have to stop putting the phosphorus in. If you don’t do that, then it’s a permanent problem. So you’re choosing between a permanent problem and a long-term problem. So I think you should choose the long-term problem.

CC: How do you think farms will be affected these solutions?

DM: A farmer doesn’t ever want to put too much phosphorus on the land. Farmer education has been huge; farmers have paid a big part in reducing phosphorus spread onto the land. The bigger problem, though, is large dairy operations that have nowhere to put the excess manure, and that ends up being spread on the land. And that’s when a farmer will actually put too much phosphorus on the land. Because you’ve got to put that manure somewhere. And that’s an expensive problem to deal with in any other way. So the cheapest solution is to spread it on the land, and the more expensive solution, in big farming operations farther south, is they make them install a sewage plant. The sewage plants in Vermont have done a remarkable job in terms of producing phosphorus. When you flush at St. Mike’s, it goes through a pipe that goes over to South Burlington sewage plant, which was upgraded two years ago, that plant is excellent. The one in Essex Junction is even better. They really have done a good job of capturing the phosphorus and not releasing it from the sewage plants.