NEW SHOREHAM – Wastewater on Block Island has tested positive for COVID-19, indicating the island has seen a greater presence of the virus than was previously known.
Block Island’s Medical Center has reported two cases of the deadly virus to date, while a regular wastewater test conducted by the town’s Sewer Commission on July 5 revealed data signifying that an estimated 10 cases were found from sampling on the island. July 5 is the same day that an island restaurant worker tested positive for COVID-19.
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According to the R.I. Department of Environmental Management, Block Island is the only town in the state that is testing wastewater streams for the presence of COVID-19. DEM noted that while the method of testing wastewater is a “work in progress,” the agency is considering its use for the state’s response to the pandemic.
Jim Kern, New Shoreham’s interim town manager, said a wastewater “sample was taken on July 5. The report showed that the positive [result] was produced on July 9. We began testing the wastewater for COVID-19 on May 12. We are currently testing biweekly, utilizing a 24-hour composite sampling procedure, taken at one-hour intervals.”
“We will continue testing at the same interval for now and use the information to contribute to our understanding of trends or magnitude,” said Kern. “The data received from the report lines up with the dates for our positive individual. We see the wastewater testing as source of scale and direction information as opposed to specific cases.”
Kern said New Shoreham’s Sewer Commission began testing on its own, without “any direction from the state or federal government.”
Sewer Commission Supt. Dylan Chase said he “began testing the wastewater to help establish public and municipal awareness of COVID-19 infection rates. I thought that testing might provide a means for trending analysis, provide more comprehensive accountability as to the number of cases on Block Island, create more visibility to asymptomatic cases, and aid in municipal decision making on the island.”
“The 10 cases are an estimate based on the variability of viral shedding in stool,” said Chase. “We are evaluating results as the difference between precision and accuracy. We cannot precisely claim the number of cases with precision due to the variability of viral shedding; however, we can accurately state that cases are here. The results are a ‘canary in a coal mine,’ and are used as a metric for public awareness and municipal decision making. Moreover, the results reaffirm the protocols already set in place; wash your hands, wear your mask, practice social distancing.”
Chase said that Biobot Analytics, based in Cambridge, Mass., the lab that conducted the test, “found a concentration of 7,519 genetic copies of SARS-CoV-2 per liter of sewage or 7.5 copies per ml of the 150 ml sample collected. From July 4th to the 5th, the New Shoreham Wastewater Treatment facility treated 230,000 gallons during sampling, equating to roughly 870,600 Liters. These results would estimate a concentration of roughly 6.5 billion genetic copies.”
“The sample sent to Biobot was a 150 ml sample composite from all samples combined,” said Chase. “From the concentration found in that sample they determined 7,519 viral copies per one liter of sewage. Total flow that day was 230,000 gallons or 870,644 liters.”
Jay Hauck, a spokesman for Biobot Analytics, which claims it is the first company in the world to commercialize data from sewage, said “wastewater offers the opportunity to provide near real-time trend data to evaluate the impact of policy-making, early warning for second waves, and the opportunity to mass-test the U.S. population on a regular basis at a fraction of the cost of clinical testing.”
Biobot noted in a study that “SARS-CoV-2 titers (measurement of the amount of a substance in a solution) in wastewater are higher than expected from clinically confirmed cases,” although “estimates of viral load in stool from positive patients are still a matter of uncertainty. The data demonstrates the feasibility of measuring SARS-CoV-2 in wastewater. The implications of this research are that wastewater-based epidemiology can be leveraged to detect population level prevalence of SARS-CoV-2 in cities across the world. In a setting where in-person testing may not be available, longitudinal analysis of wastewater can provide population-level estimates of the burden of SARS-CoV-2.”
Chase said he learned about Biobot’s wastewater testing while reading a news article. “On April 11, I came across a CBS News article. The headline read: Sewage analysis suggests exponentially higher infection rate in a New England area. The article described how a Massachusetts based lab launched a partnership with Harvard University, Massachusetts Institute of Technology and Brigham and Woman’s Hospital. The lab had originally used its technology to map opioid use around the country, but now looked at repurposing its technology to map COVID-19.”
“As a wastewater superintendent, I was intrigued,” he said. “I looked up Biobot Analytics and found out that they were providing pro-bono testing through May. I contacted them and was provided my first test, and we have been testing consistently, every two weeks, since May 12.”
“Biobot was founded by an MIT biologist and an architect,” said Chase. “Their mission is to utilize the tool of wastewater epidemiology and turn wastewater treatment facilities into public health observatories. Biobot uses RT-qPCR, a well-known CDC protocol, the same testing that is standard for analyzing the nasal swabs in Rhode Island, and all over the country. A simple and widely used method of genetic testing, in use since the late 70s, the methodology is used to amplify and detect genetic sequences of viral RNA. A positive test is identified through the increase of florescent molecules that attach to the magnified genomes present in the sample.”
Chase said the funding for testing on Block Island “came from the Sewer Commission’s budget, as a special contingency. The cost of testing is expensive at around $1,200 per test, hence why I am currently only testing biweekly. I initiated the trial and conducted significant research before I committed to spending the ratepayer’s dollars on this.”
As for if other municipalities are testing their wastewater in the Ocean State, Joseph Wendelken, spokesman for the R.I. Department of Health, said, “I don’t know of any other cities or towns that are” testing. “In terms of us not testing, we are investing in efforts that will have the greatest impact on reducing the spread of disease.”
DEM spokesman Mike Healey said that the agency “is actively tracking the approach of investigating the presence of COVID-19 by analyzing wastewater. We have fielded many questions from Rhode Island wastewater treatment facility operators and have had preliminary discussions with the R.I. Department of Health about possibly including this as part of the state’s comprehensive response to the pandemic. To date, we have left it up to the individual wastewater treatment systems to evaluate the various vendors offering this service and to enter their own agreements with vendors to collect information. To our knowledge, New Shoreham is the only system that has gone forward, and they have shared their data with DEM and RIDOH.”
“Although surveilling community and state transmission trends by testing wastewater is very useful in theory, this methodology is clearly a work in progress and the sampling and analysis techniques are still being validated,” noted Healey. “The science is evolving quickly, and DEM will continue to coordinate with RIDOH, other state environmental agencies, and the EPA and CDC as it develops further. Although some states – Colorado, New York, and Ohio – have taken steps toward implementing wastewater surveillance efforts, the United States lacks a national COVID-19 program for it.”
Cassius Shuman is a PBN staff writer and researcher. He can be reached at shuman@pbn.com.
