Sewer Supt.: Wastewater testing can prevent outbreaks of Covid-19

Thu, 08/27/2020 - 8:00pm

As continued testing of raw influent at the Block Island Wastewater Treatment Plant shows a pattern of fewer and fewer possible cases of Covid-19 on the island, Supt. Dylan Chase also believes that testing can be used as a predictor to prevent possible outbreaks, particularly at schools.

The latest test, performed on Aug. 17, 2020, showed a possible 10 cases.

Samples taken on Aug. 9, 2020, according to the testing formula done by BioBot Analytics, showed that there were a possible 20 cases of Covid-19 on the island.

The first test done in late July showed a possible 25 cases on the island.

Chase has been careful to frame these as a possible number of cases, in part because the presence of the virus can still be found in individuals after they have recovered, but he was pleased by the results.

“Good news,” said Chase in an email. “Concentrations are going down.”

Chase has also written to Gov. Gina Raimondo recommending that testing of raw influent from all schools might help prevent an outbreak before students head back to school.

“As you may know, I am engaged in collecting wastewater samples for testing of Sars-Cov-2. I would like to recommend to you the real potential value of wastewater epidemiology as a metric to help protect our community and hopefully save lives,” Chase wrote to Raimondo.

“If the peer-reviewed analysis is correct… viral shedding occurs 5 to 6 days before symptom onset. If waste or fecal analysis show a predictive result, wastewater epidemiology may be the source to better protect against community spreading; specifically, the use of [testing] to analyze the wastewater from schools,” Chase wrote. “As you and your administration continue to try to aim for opening and reintegration to some sense of normalcy, testing wastewater from schools may be one of the best courses of action to protect, not only from community spread but also provide a distinct sense of awareness and calm to the public, which may also assure uneasy parents that they may allow their children to go back to school and parents themselves, to go back to work.”

Chase said he had not heard back from the governor’s office as of Wednesday, Aug. 26. As for testing the school’s wastewater for the presence of Covid-19, Chase said:

“The testing question remains under thoughtful deliberation as we assess the value to the Block Island community and its decision-makers.”

Chase also said the “Centers for Disease Control has begun a wastewater surveillance program, validating the usefulness of the methodology and data as a possible predictor mechanism against Covid-19 outbreaks.”

For more information on that program, visit: