The Deeper Dig: When waste hits waterways

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[T]hroughout the summer, heavy rains have caused sewer overflows in most of Vermont’s largest cities.

In late July, 9.7 million gallons of stormwater and wastewater spilled from Rutland’s sewers into the East and Otter creeks.

Beaches on Lake Champlain were closed after Burlington’s system malfunctioned in May and June. In July, a computer glitch there let out three million gallons of untreated water.

Similar events, which pose public health hazards and contribute to water pollution, have hit Montpelier, St. Albans, St. Johnsbury and beyond.

Jeff Wennberg, Rutland’s commissioner of public works, oversees the state’s largest wastewater treatment plant. He says the city’s sewer system has always bypassed the plant when it’s inundated with rainwater.

“It’s functioning exactly as designed when we have an overflow,” he says.

Since 2016, those overflows have been increasingly visible thanks to legally mandated public notifications sent by the Agency of Natural Resources.

In Rutland, Wennberg is hoping that the heightened awareness will help convince the public to support major infrastructure investments.

“There’s enormous progress that’s been made, and the reality is the combined sewer overflows are like that last five percent of the problem,” he says. “That last little bit is very hard, and very expensive.”

Wennberg says it’s difficult to face the negative feedback that comes with constant reminders that the region’s waterways are being polluted. But in the long run, educated citizens are more likely to vote for bond proposals that would let the city invest in solutions.

On this week’s podcast, Jeff Wennberg and VTDigger’s Elizabeth Gribkoff talk about how wastewater releases might be resolved.

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Throughout the summer, we’ve been hearing more about sewer overflows in Vermont’s largest cities. And while public officials aren’t happy about these events, they’re hoping that increased awareness will get communities more involved in working on solutions.

So you’re on the site?

Elizabeth Gribkoff: Mmhmm. I am on the public alert notification site for sewer overflows from wastewater treatment facilities around the state.

Our environmental reporter Elizabeth Gribkoff reports on water issues.

It’s this big blue and white table with all this data. Just reading through it: on August 17 at the Pine Street CSO, which is located in Burlington, an estimated 10,000 to 25,000 gallons came out.

Scrolling down, on August 18 in Rutland City, there’s about 1, 2, 3, 4—6 different overflows that happened. And those are ranging from 37,505 gallons up to 476,078 gallons.

And we’ve got some Montpelier up at the top. We can basically see some of these from this room, more or less.

Elizabeth Gribkoff: Yeah, and one on Northfield going into the Dog River. That was on July 6th, 100,000 gallons.

What does all this data actually tell us?

Elizabeth Gribkoff: Starting in 2016, wastewater treatment plant operators or heads of town and city public works departments had to report when they have a combined sewer overflow. Combined sewer overflows usually happen when you have a big storm, and wastewater treatment plants basically can’t handle all that inundation of water that’s running off of roads and buildings, and going into their plants.

Combined sewer overflows are estimated to be about 95% stormwater, and then about 5% of wastewater. And wastewater is a combination of industrial wastewater coming from restaurants, maybe breweries, and also sewage. So there is raw, untreated sewage that’s coming out of this, and that’s why it’s really a public health concern. Because you can have E. coli and other pathogens present in these water bodies for up to — if they’re in rivers, for up to 48 hours.

So starting in 2016 the public is notified.

And this is just a list of all the public notifications?

Elizabeth Gribkoff: Yes.

Got it. On the one hand it sounds kind of scary, these huge numbers of gallons of wastewater being released into our waterways. On the other hand, looking at this list it seems kind of routine.

Elizabeth Gribkoff: Yeah, it is routine. There’s 17 towns and cities around Vermont that have these combined sewer systems. And basically the systems are designed to have these overflows because if they didn’t happen, the treatment plants wouldn’t be able to handle all the incoming storm water. And so it starts to back up into people’s homes and onto the streets.

So these are routine. What’s maybe newer is people actually being informed of these overflows when they happen.

Scrolling through this list, there’s this name that comes up over and over again, Jeff Wennberg. Tell me about Jeff.

Elizabeth Gribkoff: Jeff is commissioner of the City of Rutland Department of Public Works. He had previously served as mayor of Rutland. He was also Commissioner of the Department of Environmental Conservation for five years.

Jeff Wennberg: That got me going. And I was involved with the National League of Cities when I was mayor for a bunch of years. I chaired their Energy Environment Natural Resources Policy Committee for a year and was on it for, I don’t know, six years or something like that. And so just kind of developed a real interest in it.

So you weren’t like, as a kid, into the sewers.

Jeff Wennberg: No, no, that was not it. I was into the stars. Cosmology was my interest — about as far away from the sewers as you can get.

Elizabeth Gribkoff: He’s not the wastewater treatment plant operator, but he’s in charge of that department. I’d interviewed Jeff in July because Rutland had definitely a higher than normal combined sewer overflow. And part of that is because Rutland actually has, I think it’s six outfalls, so you kind of tally all those different points. And on that one day, I think it was July 23, they had around 9.7 million gallons of a combined sewer overflow — that’s higher than normal.

What did he tell you about why these overflows are happening?

Elizabeth Gribkoff: Well, he said that this is kind of the system functioning as it’s supposed to.

Jeff Wennberg: One of the misunderstandings on combined sewer overflows that a lot of people have is they think that somebody at a treatment plant somewhere is throwing a great big valve and releasing all of this stuff to the streams. And that doesn’t happen. That’s not it at all. What it is, is they’re actually permanent structures that are built in the collection system that meter, if you will, the water that the collection system and the treatment plant can handle. And if the water coming in is in excess of what the plumbing and the treatment plant can handle, it passes over a dam. It’s an underground structure. So but it’s a weir. It’s a low dam. And if the level gets up past a certain amount, it flows over the dam. Or that which doesn’t go down the pipe flows over the dam and that’s what goes straight out to the stream.

So it’s the way the system is designed. It’s designed exactly to do this. It’s functioning exactly as designed when we have an overflow.

It’s essentially totally automatic.

Jeff Wennberg: It’s totally automatic. Yeah, absolutely.

Elizabeth Gribkoff: The wastewater treatment plant in Rutland — which is actually, he said, the biggest in the state — they have increased capacity over the years to handle over 22 million gallons of stormwater and wastewater. Which is a lot. But it’s still not enough when they have these storm events.

Jeff Wennberg: The good news is when it isn’t that high, which is the majority of the time, vast majority of the time, when the rainfall isn’t so much that it has to overflow, it’s all going to the treatment plant. And we treat about a half a billion gallons of stormwater a year through this plant. I mean, 500 million gallons is a small lake. So that’s an enormous benefit to water quality.

So the challenge is, how do we retain that benefit. We don’t want to throw that away and at the same time, kind of minimize and control these overflows.

So anything that comes out in a combined sewer overflow is completely untreated.

Elizabeth Gribkoff: Yeah, it is untreated.

When we’re talking about treated versus untreated wastewater, what’s the real difference?

Elizabeth Gribkoff: So, treated wastewater and stormwater, which in these combined sewer systems is all one, it all eventually drains into the same pipes, which go to these treatment plants.

Jeff Wennberg: It all comes in here. There’s a screen in this building here. It takes out big stuff, you know, grit, rags, all kinds of things like that.

Elizabeth Gribkoff: So wastewater that goes through the treatment plant, it moves through a variety of biological processes that basically cause solids to settle out.

Jeff Wennberg: These tanks go down 27 feet, so this a lot of volume in here. That’s so the water has a lot of residence time. It gives the bugs, the microscopic organisms, time to break everything down. It’s very similar to what happens in the gut of a human being only it’s a little more advanced and a lot bigger. And so this is all about delivering oxygen to feed the bugs. The billions and billions trillions that are in here are actually the ones that are doing the treatment. They do all the work.

Elizabeth Gribkoff: At the end of the treatment system it’s disinfected with chlorine.

Jeff Wennberg: This is the — it’s like a labyrinth. Like a little flume ride, I’ve never thought of that before.

So this is where we inject the chlorine. And it needs a certain amount of time in order to effectively kill anything that might still be alive in there, so that’s why it goes through this kind of labyrinth, to give it more and more residence time, contact time. And then the chlorine is neutralized just before it goes out.

Elizabeth Gribkoff: And then it heads out into the rivers, looking, as we saw, pretty clean.

Jeff Wennberg: It cascades down here, right out into the Otter Creek.

So it comes in kind of brown and murky, and then you see it go out, and it’s just like regular clear water, like it would come out of the tap.

Elizabeth Gribkoff: Yeah.

When these thousands or millions of gallons of untreated water drain into waterways, what are the actual consequences of that?

Elizabeth Gribkoff: I think the the biggest concern from these is a concern for public health from anyone who might be swimming or paddling or fishing or just otherwise hanging out near these outfalls.

Jeff Wennberg: Well, obviously, if some of this, even if it’s a small amount, is bypassing the treatment plant, it’s also bypassing disinfection. So it’s going out to the stream alive. And some of those are going to be pathogens that — I mean, it’s human waste, so they can be injurious to people.

So you want to be really really careful. It’s why they close the beaches up on Lake Champlain, is
because treatment plants on the lake, if they have a release where the disinfection hasn’t been effective, that could make contact — recreation, swimming — somewhat of a risky activity. So to be safe, they close the beach.

In the case of a river, it’s a 48 hour period. They die off over 48 hours. And of course, the stream moves over 48 hours. So the stream will clean itself. But for that first 48 hours, fishing and doing all kinds of other activities that might cause them to come in contact with water — we need to do the best job we can of notifying them that you might want to wait a couple of days.

Elizabeth Gribkoff: So that concern is basically, there’s all kinds of stuff in untreated wastewater that you don’t want to be coming into contact with. It can make people become nauseous. You can also develop more serious long term illnesses from this. A lot of people have heard about E. coli, but there’s also other pathogens present. There’s some pretty serious public health concerns.

So when people hear about these overflows, that’s part of why they’re taking it really seriously.

Elizabeth Gribkoff: Yeah.

We’ve been hearing about these a lot more over the past two summers. What are the trends that we’re seeing in how often these are happening and how these municipalities are responding to them?

Elizabeth Gribkoff: That’s a little bit hard to know, exactly. Because starting in 2016 was the first year that treatment plant managers had to actually report all of these overflows. So I think it’s a little bit challenging to know whether or not these have increased over the years. But it does, from speaking with Jeff and others about this, it doesn’t seem like the amount of overflows has necessarily increased. It’s more that people’s awareness of them and the actual tracking of them has become better.

Jeff Wennberg: It wasn’t until about 1963 that we treated anything. I mean, 100% of all of the wastewater and the stormwater was collected in the same pipes just went straight to wherever the river was. And in this case it’s Otter Creek.

So starting in the 1960s, we started to build treatment plants, which didn’t do a particularly good job, but radically better than doing nothing, which was what was done before that.

Elizabeth Gribkoff: In the case of Rutland, they have been over the years upgrading their treatment plant to to handle more stormwater. But that’s complicated by the fact that due to climate change, these high intensity storm events, which really are what cause problems at treatment plants and lead to combined sewer overflows, those have also been increasing.

Jeff Wennberg: The number of intense rain events in the northeastern United States has increased by 71% in like the last 10 years, and we’ve seen it here. So it’s almost like moving the goalposts. You know, you make progress, and we’ve increased the ability of the system to prevent an overflow. And then Mother Nature is getting — you know, we have a five year storm twice a year, 25 year storm once every two years. The definition of the storm is, that’s the long term historical average. That’s how often you see that much rain in that limited period of time. But that’s over a 30 year span.

We’re seeing, over the last 10 years, a significant, dramatic increase in the number and intensity of rain events, especially in the summertime, and that drives all of these events. It’s not wastewater, it’s not the plumbing that comes from your house that’s driving these events. It’s what comes from the heavens that really causes this to happen.

Elizabeth Gribkoff: So it’s sort of like, okay, you keep developing this to handle more water and you’re trying to reduce the number overflows, but then you’re you’re competing with storms that are getting worse. And treatment plants, there comes a point where you just can’t really build them big enough to be able to handle storms of that size.

Jeff Wennberg: So there’s enormous progress that’s been made, and the reality is the CSOs are like that last 5% of the problem. And you know, when you do the first 95% of the problem, you try to squeeze the last 5% out: If it was easy, it would have been done a long time ago. And if it was cheap, it would have been done a long time ago.

So that last little bit — and it’s a little bit compared to where we’ve come from — that last little bit is very hard and it’s very expensive.

Jeff is really interesting in that he actually sounds really excited for people to know more about the overflows and to understand why they’re happening.

Elizabeth Gribkoff: Yeah, I think part of it is you know, a public health concern, wanting to make sure. They post these on their Facebook page. They want to make sure people who might be swimming or fishing in the Otter Creek are aware of this. But also, he was saying that to really to minimize the amount of combined sewer overflows that happen in Rutland, it’s going to cost millions of dollars. And he’s gonna have to come to taxpayers with votes for bonds to actually pay for that, and he wants — in order to get those votes, he wants people to be aware of this.

Jeff Wennberg: The state has a website. Everybody with a CSO is required to issue an alert within an hour of discovering it. We take the extra step of putting it up on social media. And needless to say, on Facebook in particular, we get comments. They are not always praising the work of the department or the folks who operate these things.

And we leave them up there and then try to respond to them when it’s an opportunity to educate. So that people understand that, you know, it is better than it has been, but we still have a ways to go, and it’s going to cost a lot of money. It’s going to take a lot of time, and you need to be aware, and we’re going to need your support.

It can be a little painful to deal with the public comments, but every one of those is an opportunity for people to better understand. In the long run, that’s going to be good for all of us.

Elizabeth Gribkoff: You were talking about when you were first slogging through Facebook comments, seeing some misunderstandings out there. I was wondering, what are the main common misunderstandings about CSOs?

Jeff Wennberg: The main one is, people get upset and they just write, “Just fix it.” I mean it’s just, “Just fix it.” And it’s like, golly, I wish we could just fix it. But every time you see one of those, it’s an opportunity. I keep saying, it’s an opportunity to say, well here’s why we can’t just fix it.

Elizabeth Gribkoff: He sees all these opportunities for education and tries not to take it personally.

How does Rutland’s system compare to some of the other cities that we’re seeing on this list?

Elizabeth Gribkoff: Well, Rutland has the biggest wastewater treatment plant in the state, and they’re treating wastewater and stormwater not just from Rutland, but from some of the other surrounding towns as well.

The Burlington events that have actually garnered the most attention are not combined sewer overflows. The Burlington wastewater releases that people have seen in the news, including on our site, and that have led to beach closures, they have pretty much all been cases of wastewater going through the treatment plants but not being properly disinfected for various reasons. So it’s a little bit different because you’re having a lot of those solids and pathogens actually removed in the treatment process.

It’s like that last step of the process you were talking about where the water gets chlorinated, and then de-chlorinated, and then goes into the water way, it kind of skips that part of the process.

Elizabeth Gribkoff: Yeah, and one of those was caused by a computer failure that didn’t activate those valves that should have been disinfecting. I think a lot of the issues around Burlington are more, the treatment plant is aging and needs needs some upgrades. That’s what’s causing issues there this year.

Gotcha. How big of a role do these actually play in this broader conversation about improving water quality around the state?

Elizabeth Gribkoff: They’re certainly an area of concern. Treatment plants have had to make some upgrades in order to remove more phosphorus from waste and stormwater that’s moving through those plants. From what I’ve been able to gather, the combined sewer flows are more concerning for their kind of immediate public health impact, and maybe not quite as much for the longer term water quality impact as people might think.

Jeff Wennberg: That’s the main concern is the human health concern. The water quality concern is more of a storm water issue than it is actually a wastewater issue because a component of the overflow that’s wastewater is very, very small. It’s like 5% or less of the volume. So the vast majority of the volume is stormwater, which we wouldn’t even have to report or notify anybody every time it rains, because it would just go to the stream. But we much prefer to treat it through the plant and disinfect it so we know that that’s safe, because there are pathogens in there as well, even coming out of the National Forest. The main thing is the inability to disinfect and the need to alert the public for the concern that the pathogens could still be in there.

Elizabeth Gribkoff: Looking back through some articles I’ve written, I’ve actually seen a lot of comments about people concerned about these causing algae blooms. And I don’t know that you can necessarily draw that correlation. There’s other sectors, like agricultural runoff from developed lands going right into the lake that’s probably contributing more directly to algae blooms.

The wastewater, there’s some amount of phosphorus involved here. Just not as much in proportion to those other things.

Elizabeth Gribkoff: Yeah. The CSOs are, in some ways, more of a short term water quality impact. Like, for those 48 hours after the city of Rutland has a combined sewer overflow into the Otter Creek, you know, you wouldn’t want to be swimming or otherwise in that area for that time. But in terms of this bigger water quality issue in Lake Champlain and some other water bodies around the state, that really stems from phosphorus pollution that’s leading to algae blooms.

Wastewater treatment plants and CSOs do contribute some phosphorus, so they are a part of that problem. But they’re not, according to the EPA and other state officials, they’re not necessarily the biggest player in that.

The number one biggest contributor, with about 40% of the phosphorus pollution into Lake Champlain is runoff from agricultural lands, runoff from developed lands that’s not treated — in some cities like Burlington, not all of the stormwater necessarily goes through the wastewater treatment plant — so it’s really multiple sectors around the state that are contributing to that kind of longer term water quality problem.

Thanks, Elizabeth.

Elizabeth Gribkoff: Thanks.

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