BOSTON - If you live in Boston or any of more than three dozen other eastern Massachusetts communities, you could be sending vital data to public health officials with each flush of your toilet.

Through the end of the year, the sewage arriving at the Deer Island Treatment Plant will be tested three times a week for signs of the coronavirus, meant to serve as an early warning system for spikes in COVID-19 activity in communities that account for more than 40 percent of the state’s cases.

The Massachusetts Water Resources Authority board last week approved a six-month, $200,000 contract with Biobot Analytics, a startup founded by MIT graduates and faculty, to collect and test samples of wastewater arriving at two different intakes at Deer Island and to conduct rapid analysis for signs of the virus that causes COVID-19.