What's Happening With the Potomac River Sewage Spill?
Aging infrastructure has caused one of the largest sewage spills in U.S. history.
A pipe collapse outside Washington, D.C., has spilled nearly 300 million tons of sewage into the Potomac River.
In its wake, researchers have discovered high levels of harmful pathogens like E. coli and antibiotic-resistant Staphylococcus aureus (MRSA). Recent frigid temperatures and long-term infrastructure challenges are making cleanup a formidable task as officials warn the public to avoid the river.
Natalie Exum, PhD ’16, MS, an assistant professor in the Department of Environmental Health and Engineering and an affiliate of the Johns Hopkins University Water Institute, joined Public Health On Call to discuss the spill, its health impacts, and whether it could have been prevented.
Topics discussed:
- The infrastructure problems behind the spill and how winter weather exacerbated them.
- The ecological and human health risks of a spill this size, and how these risks should be communicated to the public.
- The dangers of sewer water and the high levels of pathogens reported in the river in the weeks since the spill.
- How stakeholders are approaching clean up.
- Whether this type of event could have been prevented.
- What this spill illustrates about the state of water safety and ecological health in the United States.
Key Quotes From the Episode
On the concerning contaminants that would typically be processed in a water treatment plant:
“Industrial pollution is always of greatest concern because there’s a lot of chemicals in there that can be known to be hazardous and harmful.” (5:23)
“It's mostly human sewage ... household sewage. ... All that’s just going directly into the river now. ... Some of the sampling that’s been done by the University of Maryland has found that the E. coli levels are about 3,000 times higher than the recreational standard.” (5:37)
On how winter weather is complicating things further:
“It’s happening at such a cold period of time that this is also getting locked up in the ice. ... We always say in environmental health, the solution to pollution is dilution. Well, the river is very low right now. There is very little contribution from other flows.” (4:40)
“You just have basically sewage that’s locked in there, that’s sitting there. And we really haven’t studied this very well to understand, what is the slow release of pathogenic material going to do both to health and to the environment?” (5:03)
On effective communication:
“The key here is public trust. And how do you restore people’s trust in the quality of the river? Because it’s been completely taken away at this point.” (10:24)
“This is the drumbeat of my work, which is that the infrastructure that we cannot see is keeping us healthy and safe.” (13:12)
On whether spills can be prevented:
“Our aging infrastructure in the United States means we are always vulnerable to something like this happening. And it’s very hard to know which pipe under the ground is most susceptible to breaking at any point in time. ... In general, I think it’s very hard to prevent these.” (11:30)
On what local residents can do:
“For the people listening in the region who are concerned about the river, I think that active engagement on this is going to be needed into the spring and the summer, especially if you’re a paddler or you go and recreate on the river. I think people need to speak up, maybe be asking your councilmembers what’s going on with this. I think we need to show that the environmental and the public health parts of this just can’t be just washed away. We need to really keep this at the forefront of our minds.” (13:22)
On how such an incident can undo decades of progress:
“What this really reveals is how vulnerable we are to those clean rivers becoming cesspools again. ... We’re able to recreate and live near our water bodies in ways that I think today we take for granted. But it was a lot of work that got us to this point. And I think this sewage spill really shows that in the break of one pipe, that can all be gone and taken away.” (14:18)
Transcript
Note: The following transcript is automatically generated and may contain errors. Please cross-reference the audio before quoting.
Lindsay Smith Rogers
Natalie Exum, welcome back to Public Health On Call. How are you?
Natalie Exum
00:28
Great. Good to be with you, Lindsay.
Lindsay Smith Rogers
00:30
So, today we are talking about a sewage spill in the Potomac River. So, first of all, just so our audience remembers who you are, tell us a little bit about you and what you do.
Natalie Exum
00:41
Yeah, happy to share that. I am an assistant professor here in the Department of Environmental Health and Engineering, and I have both training in environmental engineering—and so hydrology and how water moves to the environment—but my focus really is on public health outcomes and waterborne infections and how pathogenic material in our environment can get into us and get us sick. And so, my real passion is combining those two areas.
Lindsay Smith Rogers
01:07
We are going to talk about all of that today. Could you first start out by telling us where this sewage spill was located and what happened?
Natalie Exum
01:16
Yeah, so this is the Potomac River. It borders between Maryland, Virginia, and D.C. So, this is basically three separate state and local governments. And it was right below, if you know the area, the 495 bridge. So, lots of traffic going through there. Very densely populated, mostly residential, very-little-industrial-sites area. And so, when we think about what was actually in that spill, we're talking a lot of human sewage.
Lindsay Smith Rogers
01:45
And so, tell us about the spill and when, who found it, what happened?
Natalie Exum
01:48
Yeah, so this was one of the largest sewage spills in U.S. history. It started before the big freeze. So, if everyone remembers, it got very, very cold right around mid-January, but this started before then. The story of it starting is really just collapsing, aging infrastructure. This was an interceptor, a major interceptor, which brought sewage over from Virginia, crossed under the Potomac, was collecting sewage also from Maryland. This was just a major site of collection, was known to be aging.
There had been about $200 million of an investment allocated to start fixing it, but the pipe just broke too soon. What ended up happening is it collapsed, it broke. Boulders got into it. And so, it is making both the stoppage of the sewage flowing very challenging because now they have to remove those boulders. But there's just been so much sewage that has gone into the Potomac, but they're trying to kind of pump it into this empty canal, the C&O Canal, that goes down that area to even just have a holding spot for it, that they're now pumping back into the wastewater system. So, a long explanation there, but this is very challenging work and also in frigid temperatures.
Lindsay Smith Rogers
02:59
How much sewage are we talking about here?
Natalie Exum
03:01
Yeah, we're talking probably 300 million gallons. This is enormous, and there's still kind of ongoing releases. Just over the Super Bowl Sunday weekend, we saw maybe up to another million gallons because of the cold temperatures where these pumps that are supposed to be pumping the water from the canal were locked up. They just froze up. So, this is not over, and these releases are still going on. And I just think that's important that everybody knows that this is still off limits to have any contact with this water.
Lindsay Smith Rogers
03:34
And so, what happens when you have a sewage spill of this size? It's going into a body of water that's in a very densely populated area. How do you even begin to address this kind of accident?
Natalie Exum
03:46
Yeah. Well, from the public health perspective, and one of the main things you should think about first is where are we getting our drinking water? And is this going to get millions of people sick if they're drinking the water? And, thankfully, this occurred right below where DC Water gets its intake for the public drinking water system for Washington, D.C. So, that was fortunate. The other piece of this is—you know, there's the ecological concerns—but more short-term are the public health concerns. And yes, absolutely, it smells. The challenge is it's happening at such a cold period of time that this is also getting locked up in the ice. And so, where we always say in environmental health: the solution to pollution is dilution. Well, the river is very low right now. There is very little contribution from other flows.
And so, basically, as the Potomac Riverkeeper coined it, this is a real gut punch to the river. So, you just have basically sewage that's locked in there, that's sitting there. And we really haven't studied this very well to understand what is the slow release of pathogenic material going to do both to health and to the environment.
Lindsay Smith Rogers
04:56
What's in sewage water? What are we concerned about?
Natalie Exum
04:59
We are concerned about a lot of things. You know, I mentioned that industrial pollution is always of greatest concern because there's a lot of chemicals in there that can be known to be hazardous and harmful potentially. Hopefully not because it's put into the sewer, but it can be more complicated. This area, what we're talking about, as I said, is very highly populated. It's mostly human sewage, right? Household sewage. So, any kind of cleaner, any kind of pharmaceutical or any drugs people are on, this stuff used to go down to the wastewater treatment plant and go through many, many different steps and processes to break down and take out of whatever we put back into the river down below the Blue Plains treatment plant. But all that's just going directly into the river now.
The immediate concern really is the infectious material that’s coming out of all of us. And so, the sampling that's been done by the University of Maryland has found that the E. coli levels are about, you know, 3,000 times higher the recreational standard is right now. They've also found methicillin-resistant staph aureus, which can be challenging infection. And then just also staph aureus as well. They found staph aureus at one third of these sites that they have taken, not just right where the spill happened, but further down the river. And then there's lots of antibiotic-resistant kind of other types of bacteria in there as well. Those are the ones that I, from a public health perspective, would be most concerned about.
And, you know, the thing about this is the river is kind of acting like a big refrigerator for the bacteria right now. And where if it were hot, these things would, you know, they'd be dying off. But they're kind of just in their hold state, and once it warms up, they're gonna be ready to inflict harm.
Lindsay Smith Rogers
06:46
And you mentioned that this is an ongoing situation. So, they stopped the initial outpouring of sewage, but then you've had these other problems popping up. How do you address these piecemeal?
Natalie Exum
06:52
Yeah, so, now people are on the scene and so, you know, there's a little bit more hands on to address these things as they come up. But the real concern was just the gigantic geyser of poop that was flowing for that long. So, the second best solution was putting it in the C&O Canal to make sure it wasn't getting out into the environment.
But you just—I think the real message here is ongoing vigilance because due to these boulders now that they've discovered, it's gonna take another four to six weeks to actually fix this interceptor, this large gigantic pipe bringing sewage down to the wastewater treatment plant. So, vigilance is required, and we really need everyone's hands on deck to make sure that the river is going to be okay.
Lindsay Smith Rogers
07:39
And that was going to be my next question. There's a lot of different parties that have to be involved with an accident like this. Like, people are looking at the problem from different angles and then someone's got to pay for it. Like who's at the table? Who is—who's like a first responder and then who's monitoring the problem?
Natalie Exum
07:51
Yeah. DC Water, and they are on the scene for this. And the people that foot the bill are the people, you know, on DC Water's bill, right? So, this is very much the nightmare of when you're trying to manage a utility, is just the huge costs that go into fixing the breaks that occur. And that takes up a big part of your budget, but that, you know, that is who is paying for this. And those are the crews that are on the scene there.
So, there's DC Water that's managing it. But because this is, you know, Maryland and Virginia and D.C., you know, the big part of this is also the monitoring to see what's in the water. And so, it's a very challenging coordination effort right now of who is in charge of taking those samples, of reporting them out, and making sure that this is a coordinated response. And so, the Potomac Riverkeepers have really been on the scene doing this. They were the ones collecting the samples as earliest as they could. They sent those over to a laboratory at the University of Maryland and are getting these samples done. DC Water is also doing that, but their main responsibility is to make sure the infrastructure is up and running, not to be taking on these other tasks that could be done by other agencies.
We have had recreational use advisories come in now from Montgomery County and from Prince George's County. And, you know, there's been some shellfish advisories as well because concerns from people eating shellfish downstream of this. But there's been no official language from real public health entities to say, “The water is dangerous. Don't go into it.” You know, it's also cold, so, maybe they're assuming no one's going into it. We have—public health really has this down for, say, summer recreational contamination of our bodies of water that people go into and they're regularly monitored, but this is kind of off-season. And so, we haven't really seen that foot forward from the public health agencies that we would have liked to.
Lindsay Smith Rogers
09:49
You mentioned that the cleanup of all of this is really complicated. What does that look like?
Natalie Exum
09:55
So, this is going to last longer than normally occurs because of the temperatures and this kind of, as I was saying, slow release of this pathogenic water once we thaw out here on the East Coast. And so, again, we're going to just hope that it gets diluted and it gets washed down the river and the river is able to recover.
But the key here is public trust. And how do you restore people's trust in the quality of the river? Because it's been completely taken away at this point, you know. Crew teams—think about all the crew teams around the area that are rowing on this river. I had kayakers reach out to me yesterday to say, “What's going on? Can we get out there? What can I do to help? Because I care and love about this river.” And so, there's a lot of recreational use. I mean, you—if we think back to even just, you know, over the summer, right, we had our HHS secretary swimming in one of the tributaries into this river. And there's a lot of spots on the Potomac River where people get in.
And now my greatest concern is that this is going to kind of go under the radar because it's happened in January and, now, here we are in May and it's hot and we want to, you know, take our kids down to the river, but we need monitoring. We need daily monitoring and a dashboard so people can go on there and see it, wherever these monitoring sites are, to have confidence. And we need public funds to be able to do that because that's a very expensive effort.
Lindsay Smith Rogers
11:27
Yeah. Could this have been prevented?
Natalie Exum
11:30
I hesitate to say that it could have been prevented because our aging infrastructure in the United States means we are always vulnerable to something like this happening. And it's very hard to know which pipe under the ground is most susceptible to breaking at any point in time. And so, you know, I think the details of this one case we'll learn about inmonths to come. But in general, I think it's very hard to prevent these.
Lindsay Smith Rogers
11:56
What do you see happening in the next few months? Are there efforts to kind of create that public communication that needs to happen? That like this spill—it needs time to dilute. Is there a sense of like when this might happen? Like maybe after a few heavy rainfalls in the spring as things melt? Like, what's the time frame here we're looking at?
Natalie Exum
12:15
It really matters what kind of rain we get and hopefully the spring is coming soon. And even still, I think we have not had this massive amount of sewage dumped into a river where it's been able to kind of sit and settle. And because there's not much precipitation coming into the river right now, there's been a lot of settling happening.
And so, this is going to get kind of locked up in sediments as well on the bottom of the river. And so, you could go in and dip your Nalgene bottle and cap it and send it off to a laboratory, and they could analyze it and find that the levels of E. coli are below what we deem are recreationally safe. But what does that mean when you step into the bottom of the river and you kick up those soils. Your two year old—we all know how easily this kind of water gets in their mouth when they're playing in it, right? Like that's where kind of public health concerns are coming from.
Lindsay Smith Rogers
13:16
Last thoughts on this. This is a big situation, it's an evolving situation for public health. What do our listeners need to know about this?
Natalie Exum
13:24
You know, this is the drumbeat of my work, which is that the infrastructure that we cannot see is keeping us healthy and safe in ways that we don't even really understand. For the people listening in the region who are concerned about the river, I think that active engagement on this is going to be needed into the spring and the summer, especially if you're a paddler or you, you know, go and recreate on the river. I think people need to speak up, maybe be asking your councilmembers what's going on with this so that if you do really—I think we need to show that the environmental and the public health parts of this just can’t be washed away, right? We need to really keep this at the forefront of our minds.
One of the last thoughts to leave your listeners with is that we in the United States through the Clean Water Act have done such a good job of cleaning up our water bodies and our rivers such that you can have a big river, the Potomac River, right next to a major city that is so clean that you can take your boat or you can take your fishing rod or you can take your kids and go into it and believe that you're not going to get sick.
I think what this really reveals is how vulnerable we are to those clean rivers becoming cesspools again because if this were 100 years ago, these areas would be cesspools, right? The Gowanus Canal is a great example. It was a complete cesspool. It's being cleaned up now, right? And so, we're able to recreate and live near our water bodies in ways that, I think, today we take for granted. But it was a lot of work that got us to this point. And I think this sewage spill really shows that in the break of one pipe, that can all be gone and taken away.
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