Coronavirus traces found in Mass. wastewater reach highest levels yet of the fall surge

The MWRA's Deer Island Sewage Treatment Plant is seen from Spectacle Island in Boston Harbor.Lane Turner/Globe Staff

In a troubling sign, the amount of coronavirus found in wastewater at the Massachusetts Water Resources Authority’s Deer Island treatment plant has reached the highest level yet of the fall surge.

New recent highs in COVID-19 RNA copies per milliliter of wastewater were reached for the southern section and the northern section, which includes Boston, according to the latest tests, which were conducted up until Tuesday.

Similar to other metrics in Massachusetts, the wastewater tests show a peak in the spring, with the virus levels appearing to dip and flatten off over the summer, and a current acceleration that appears to have begun in October.

The coronavirus is surging in Massachusetts and across the country. On Thursday, coronavirus cases in the state reached an all-time high of nearly 6,500, breaking a record set just the day before. In the United States, new cases have begun topping 200,000 per day, and the number of people hospitalized with the virus surpassed 100,000 on Thursday.

In Massachusetts, officials said on Thursday more than 49,000 people were estimated to have active cases of the virus.

Governor Charlie Baker said Thursday the state would be opening a new field hospital for coronavirus patients in Lowell in upcoming weeks, in addition to one set to open Sunday in Worcester.

On Wednesday, the director of the Centers for Disease Control and Prevention said the next couple of months could be “the most difficult time in the public health history of this nation,” because of the stress on the country’s health care system.

Dr. Robert Redfield warned total deaths in the US could approach 450,000 if people don’t follow public health recommendations to mitigate the virus’s spread.

Travis Anderson of the Globe staff and Globe correspondent Jeremy C. Fox contributed to this report. Material from the Associated Press was also used.