PORTLAND — The Portland Water District and Saint Joseph’s College are hoping their new partnership will help detect the presence of the coronavirus virus in certain areas days earlier than waiting for individual patients’ test results.

Over the next three months, the water district will be sampling wastewater from treatment plants on the East End and on Park Road in Westbrook and sending the samples for testing at the college in Standish.

Scott Firmin, director of wastewater services for the water district, said the tests can give a sense of how quickly, and where, the coronavirus virus is spreading. The tests can detect the presence of the virus six to seven days earlier than individual clinical tests can be added to official case counts.

“People who are infected with COVID-19 will shed the virus,” he said, often before they feel any symptoms. “Wastewater samples provide statistical estimates of infection rates in the city.”

Scientists, he added, can trend that data “to see if if it is steady, if it is going up or if it is going down.”

“Some people may be asymptomatic. Some people may be subclinical, meaning they have a cough for two or three days and think it is allergies or some may not have as severe of symptoms, and may not go to the doctor. Others may not be able to afford to go,” said Yolanda Brooks, assistant professor of biology at Saint Joseph’s College, who is analyzing the wastewater samples.

“With this testing you see the shedding of the virus over the entire community,” Brooks said.

She will test the wastewater samples for RNA fragments of the coronavirus. The testing method was created by Idexx Laboratories in Westbrook.

According to the Maine Center for Disease Control and Prevention on July 29, there have been 811 COVID-19 cases in Portland and 258 in Westbrook.

Firmin said by tracking which pump station wastewater came from, it may be possible to pinpoint infection rates coming from particular neighborhoods.

The partnership between the district and the college highlights the role microbiology can play in solving a public health crisis, Brooks said.

Similar programs have begun in other parts of the country, but Firmin said they are usually targeted at places where the infection rate in higher than it is in Maine, which is seeing 29 cases per 10,000 people. Elsewhere, the testing cost per sample can be as much as $1,500 per sample, but Saint  Joseph’s College is charging $120 per sample.

“We hope to develop a program that is a little more sensitive and appropriate for a rural state like Maine,” he said.

Results will be sent weekly to the Department of Environmental Protection and the Department of Health and Human Services. Firmin said he hopes the wastewater testing will be another data point to help officials understand just how prevalent the virus is in their communities.

“It is not helpful for just me, the wastewater director to have that information,” Firmin said. “It helps to have it available for the decision makers.”

Firmin said it is unlikely the wastewater discharge that is being sampled contains active elements of the virus and according to the federal Centers for Disease Control “while data (is) limited, there is no information to date that anyone has become sick with COVID-19 because of exposure to wastewater.”