MWRA is tracking COVID-19 in wastewater

The coronavirus pandemic has presented many challenges. It has been difficult, for example, to accurately track the presence of COVID-19 as well as to predict and prevent outbreaks in communities.

Given current clinical screening processes, it is costly and impractical to conduct large-scale testing of individuals on a regular basis. Compounding the problem, many people who contract the virus are asymptomatic and therefore remain undetected if they have not been tested. They are nevertheless capable of infecting others and causing outbreaks.

If only there was some relatively simple, cost-effective way to identify rising infection levels in an area before the virus has a chance to spread. It turns out there is: by analyzing wastewater.

Researchers have discovered that before they show symptoms, infected people shed the virus in their stool. Scientists in the Netherlands first reported that they were able to detect the genetic signal of the virus in wastewater samples. Cambridge-based Biobot Analytics was the first in the United States to trace COVID-19 by using wastewater samples from the Deer Island Treatment Plant in Boston.

Subsequently, the Massachusetts Water Resources Authority (MWRA) awarded a $200,000 contract to Biobot in June to conduct a pilot study of wastewater at Deer Island. The study’s data, which is collected three times a week, serves as an early warning system for Eastern Massachusetts. It can predict infection upticks, transmission rates, and other trends one to two weeks ahead of more traditional clinical diagnoses. The MWRA makes the study’s data available on its website:

Wastewater from Boston and 42 other communities flows through Deer Island where it is treated and then discharged through a 9.5-mile, 24-foot-diameter outfall tunnel under the harbor and into Massachusetts Bay. The plant’s 130-foot-tall, egg-shaped anaerobic digesters, which treat sludge and scum that is extracted from sewage, are a distinctive and prominent sight in Boston Harbor.

The MWRA was formed in 1985 in response to federal environmental regulations and a court order to address the wastewater that was polluting Boston Harbor. To comply, the agency rebuilt the Deer Island facility, and GBPCA contractors and Local 12 plumbers played an important role in constructing the massive project. It is one of the largest wastewater plants in the world.

According to Mike Perrotta, estimator and project manager at GBPCA contractor Harding and Smith, the Biobot study is not able to trace virus rates at a city or town level. But it is able to track the virus coming from a cluster of communities in Boston and north of the city and another cluster of communities south of the city. That’s because influent arrives at the plant from two regional pumping stations: Nut Island in Quincy to the south and the Chelsea Creek Headworks in Chelsea to the north.

“I find it amazing that it’s possible to pinpoint levels of COVID based on wastewater,” Perrotta says.

Harding and Smith, which specializes in providing process piping for the waste and water treatment industry, has worked extensively at the Deer Island plant and is currently working on a project at the Chelsea Creek Headworks.

Biobot is now partnering with 43 states and provinces in North America and 182 local agencies to test wastewater for COVID-19 using samples from 360 wastewater facilities. The company told the Boston Globe that “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.”

The MWRA’s pilot program with Biobot extends through the end of 2020. The agency says that at the conclusion of the period, it will likely develop a long-term testing program that will continue into 2021 and beyond if the pandemic has not abated.