Colorado Moves Toward Statewide Wastewater Monitoring Coverage
Once you’ve taken care of your business and pushed the handle of your toilet, it’s out of sight, out of mind, right?
But when the pandemic started, some people, like Pieter Van Ry, realized there was actually gold in this stuff.
“How it started was I actually woke up one Sunday morning and read an article from Popular Mechanics,” he said. It was early March 2020 when the first wave of COVID-19 infections hit. “At the end of this article it was written: ‘If you have a wastewater treatment facility and are interested in participating in this study, please contact us. “”
In fact, it happened to have a sewage treatment facility.
Van Ry leads South Platte Renew. Its Englewood wastewater treatment plant serves 300,000 people southwest of Denver. This article read by Van Ry had a catchy title: How Poop Offers Hints About The Spread of Coronavirus.
To see how, I visited the South Platte facility. On a snowy February afternoon, a trap door was opened to a dark creek where effluent flows into the plant.
“So that’s basically where it comes in,” Van Ry said, pointing to where the big pipes come together more than a dozen feet down.
Let’s just say the smell didn’t carry the delicious scent of a dozen roses.
Van Ry’s colleague, lead operator Brandon Hinkhouse, demonstrated how a machine siphoned fluid through piping into a white plastic container.
“He takes a sample and then purges it again. Then he’ll take a sample and that’s what we’ll collect,” he said.
The South Platte team sends these wastewater samples to a company in Massachusetts called Biobot Analytics. Its mission: “the analysis of the health of the population fed by wastewater”.
How the test works
Early on, lab results from the samples showed exactly what the virus was doing, Van Ry said. The South Platte Renew team had stumbled upon a powerful new public health tool: testing sewage to monitor, wave by wave, the spread of a virus.
“It was spreading quickly in the community,” Van Ry said.
In a conference room, he showed a slide of data from samples. All the pushes were clear: alpha, delta and then a dramatic spike driven by a new variant in early 2022.
The technique spread throughout Colorado and the country. The Colorado Mesa University program, in conjunction with the Broad Institute of MIT and Harvard, generated national coverage via an article in The New York Times.
Now, the federal Centers for Disease Control and Prevention aims to expand wastewater testing with the National Wastewater Surveillance System.
And Colorado is doing the same.
At the Denver State Laboratory, technicians wearing masks and white coats collect fluid with pipettes.
“The samples come in here and they start their initial processing,” said lab director Emily Travanty. “They are concentrated and filtered, then they move on to detection and sequencing.”
People infected with SARS-CoV-2, the virus that causes COVID-19, release viral RNA, the genetic material of the virus, in their stool. In sewage tests, scientists use this RNA to tell what is in it.
Travanty said the Colorado Department of Public Health and Environment (CDPHE) started doing this five years ago with routine testing for foodborne illnesses, such as salmonella.
“So we were able to pivot that expertise to COVID-19 when the pandemic emerged and build on that expertise within the lab,” she said.
The effort could extend
The agency currently works with 47 sanitation utilities that currently serve approximately 60% of Colorado’s population. Its goal is to cover the entire state.
The state compiles data from various sites on a public dashboard. It also shares its numbers with the CDC. Approximately $9.4 million in federal funds are funding the state wastewater testing project from January 2021 through at least July 2023. The total includes personnel, supplies, equipment and contracts.
Travanty’s colleague, epidemiologist Rachel Jervis, noted that with clinical testing for coronavirus, someone has to see a doctor, get tested and then get results.
“Whereas with COVID sewage, we have found that up to 50% of people will excrete the COVID virus in their stool whether or not they have symptoms,” she said. “So we’re kind of removing the human behavioral component of seeking medical care.”
Along with normal testing, it gives an early warning sign of where the spread of COVID is highest.
“Essentially, we’re looking at trends. We rarely use a single sample to infer much about our COVID sewage data,” Jervis said. “We are looking at trends across multiple samples.”
“It’s a blunt instrument in a way, isn’t it? You can say, ‘Yeah, there seems to be a lot of virus in there right now,'” said Jude Bayham, an assistant professor at Colorado State University. and at the Colorado School of Public Health, which is also a member of the state’s COVID-19 modeling team.
Bayham said that as overall COVID-19 trends improve and Colorado moves into the next phase — and perhaps scaled back further testing — the ever-changing sewage analysis promises to grow. ‘intensify.
“Wastewater monitoring is a relatively cheap alternative that can provide a lot of information,” he said.
This type of information can guide the response to the coronavirus.
Action at the University of Denver
At the University of Denver, outside a red brick dormitory, members of the school’s response team recently opened a heavy steel manhole cover.
Below, a steady stream of sewage flowed.
“It’s the sewage right now. Well, that’s it right now,” said Keith Miller, associate professor of chemistry and biochemistry at DU. “It’s heavy, isn’t it? They’re taking showers right now. So there aren’t a lot of solids.”
In the fall of 2020, the first few weeks of the in-person school year, the DU team began collecting pipe samples like this.
Mechanical engineer Corinne Lengsfeld oversees the campus saliva testing lab. She said a sewage sample taken on a Friday early this semester was off the charts. “It was a million viral units per litre,” she said. “Saint Toledo!
This information convinced school officials to have everyone in the dorm take rapid nasal tests. “That’s what the sewage test is – it’s the one that will give you the biggest picture first,” Miller said.
Using sewage data, along with tracking rapid tests, allowed them to quickly identify 10 infectious students and move them to an isolation dorm. Lengsfeld said that without it, maybe 100 more students in the dorm of 300 could have caught it.
“It works. I mean, it’s definitely a case study, I think, of exactly how to control the spread,” she said.
How testing sewage will help in the future
Back in Platte Valley, Pieter Van Ry is also proud of his team’s work. Processing plants like this have generally gone unrecognized, doing key work no one wants to think about, and are often the butt of jokes.
“Yeah, your number two is our number one,” he said. “There are a lot of good ones out there.”
But now there is a new high priority: to be a sentinel of the contagion to come. And not just for COVID-19. Eventually, it could also be used to detect other diseases.
“It might be one of those things that is kind of a game-changer in terms of understanding community health,” Van Ry said.
“We’re really excited about this new tool,” said state epidemiologist Dr. Rachel Herlihy. “It will help us understand regional differences. It has also been extremely helpful for us in understanding the emergence of new variants.”
“We’re still figuring out how best to use it,” Herlihy added.
A senior CDC official also sees it that way, telling reporters on a recent conference call that the agency plans to use the system for infectious diseases and other things.
“One of the strengths of wastewater monitoring is that it’s very flexible,” said CDC microbiologist Dr. Amy Kirby, team leader of the National Wastewater Surveillance System. “So once we’ve built that infrastructure to collect the samples, get them to a lab, get the data to the CDC, we can add tests for new pathogens pretty quickly.”
If a new pathogen of interest emerges, she said, they could ramp up that system within weeks to start collecting community-level data on it.
The agency expects to be able to use the system to target other pathogens, such as antibiotic resistance, foodborne infections and an emerging fungal organism called Candida auris.
There’s also interest down the road in using it for non-infectious diseases, such as substance abuse tracking, Kirby said.
Although the approach is revolutionary in the United States, it has been used for years elsewhere.
“Sewage surveillance has been used for many decades to track polio in communities, not in the United States, but certainly abroad as part of polio eradication efforts,” Kirby said. “And they use it basically the same way we do – to find communities where polio is circulating, and then use it as a trigger for additional clinical surveillance in those communities.”
TSR: John Daley / Wastewater Monitoring in National Covid Plan: Federal Centers for Disease Control and Prevention aims to expand wastewater testing with the National Wastewater Monitoring System. And it’s all part of the Biden plan to track and contain covid going forward. Colorado does this to such an extent that much of its population is “covered” – but nationally only a quarter of the population is covered. John Daley, CPR.