Honolulu is working to test sewage as an early warning system for COVID-19, but after facing challenges and setbacks is pivoting to a partnership with the University of Hawaii to speed up results.
“This is an emerging field and — no surprise — the most accurate and granular results take the longest,” said Josh Stanbro, Honolulu’s chief resilience officer.
The City and County of Honolulu first began its foray into testing wastewater for COVID-19 in May, using $25,000 in federal funds to pay BioBot Analytics, an East Coast company, to test wastewater from nine public treatment plants.
During the pilot project, only one test out of 36 identified COVID-19. Stanbro said this didn’t surprise him since very few Hawaii residents were testing positive in May.
“Both the nasal swab and the wastewater data reinforce the idea that Hawaii was the cleanest, safest place in the U.S. during that time,” he said. “Now looking forward with the recent activity it’s all the more important that we get this wastewater info turned around quickly.”
Testing wastewater can help provide a snapshot of how widespread the virus is in a given area, and is faster and cheaper than nasal swabbing a representative sample of the population.
The amount of RNA fragments from the virus identified in a sewage sample is an indicator of how many infected people are living in a community. The virus that causes COVID-19 can be detected in a person’s fecal matter within three days of infection, much earlier than the 14 days it can take to develop symptoms.
“When we see a spike in an area we want to get more resources in that area, like drive-thru testing, potentially before people are showing symptoms,” said Stanbro.
But when Honolulu started testing sewage in May, it took weeks for the city to receive results from BioBot Analytics, negating the point.
“BioBot went from testing 140 cities to over 400 in a matter of two weeks,” said Stanbro. “Hence the backlog.”
“This is the first time the city, state and university has worked together like this.” -Tao Yan, UH professor
BioBot Analytics also increased its rates from $120 per sample to $1200 per sample. Stanbro had planned to encourage local companies to get involved in the effort to test wastewater, but the BioBot pricing heightened his urgency.
Stanbro reached out to the University of Hawaii and connected with Tao Yan, a civil and environmental engineering professor. Yan first started testing wastewater for different pathogens in 2010, and the emergence of COVID-19 at the end of 2019 piqued his interest.
“We were working mostly on bacteria but it was natural for us to transition to the more pressing threat,” he said. He used a research grant from the National Science Foundation to convert his lab, and got it up and running the week of June 16.
But Yan’s lab was designed for research — not mass production — and bottlenecks have slowed effort’s to analyze Honolulu’s wastewater.
“COVID is a crisis and this is the first time the city, state and university have worked together like this so we’re charting these new paths,” said Yan.
Employees with the Honolulu Department of Environmental Services have continued to take nine samples a week, one from every public wastewater treatment plant on Oahu, since May 1.
The city’s backlog, combined with the testing Yan needs to fulfill his research grant, means he’s running his equipment around the clock.
“We asked Dr. Yan to build the plane while flying it and we appreciate UH working to figure out the correct methodology on this on the fly,” Stanbro said.
Because Honolulu has low COVID-19 saturation, analysis that worked in cities with high rates of COVID-19 isn’t appropriate.
UH is charging the city $300 to test and analyze each sample, which Yan said covers supplies and compensation for his team: two post-doctoral researchers and a graduate student. Once their methodology is set, Yan is confident he can turn around test results in 48 hours.
“I must email Yan every day, ‘Hey do you have our results?’” Stanbro said. “Because they’ll be so useful.”
The spike in COVID-19 cases on the mainland has cut Hawaii’s main private laboratory off from chemical reagents and led to longer wait times for results from nasal swabs.
“We need to have other lenses and other ways to see what COVID is doing,” Stanbro said.
Once the results of all 10 weeks of samples are finalized — which Yan and Stanbro hope will be sometime in the next two weeks — Stanbro plans to publish the data on the city’s COVID-19 website.
Oahu residents can find a map of the neighborhoods served by each public wastewater treatment plant on the Department of Environmental Services’ website. Residents connected to the private treatment plant in Hawaii Kai or the Schofield Army Barracks plant are not included in testing.
Yan is also fielding questions from concerned citizens on Kauai and the Big Island who want wastewater testing in their communities, and he’s disappointed that he can’t facilitate more testing.
“I want to help but would need higher capacity machines, which is why I’m asking for help,” he said.
Civil Beat is a small nonprofit newsroom that provides free content with no paywall. That means readership growth alone can’t sustain our journalism.
The truth is that less than 1% of our monthly readers are financial supporters. To remain a viable business model for local news, we need a higher percentage of readers-turned-donors.
Will you consider becoming a new donor today?