Students in two residence halls at Colorado State University will have to quarantine after a “significantly high level of COVID-19” was found in wastewater, school officials said Friday.

A letter was distributed Thursday night to student in Braiden and Summit halls.

Residents were placed into a mandatory quarantine. They are prohibited from leaving for any reason, according to the letter.

“The quarantine will be in place until all positive cases and close contacts in the residence halls have been identified and the wastewater results return to normal,” the letter reads.

“You should not leave your residence hall room, except for limited circumstances, such as to pick up a meal as outlined below or get tested at the tent outside of your residence hall.”

Student should not go home or stay elsewhere during the quarantine. The quarantine will last for a “period of time.”

Anyone who tests positive for the novel coronavirus will be placed into isolation.

In a letter to the university at large, President Joyce McConnell said she was not certain what the quarantines mean for the school community.

“The benefits of our wastewater early detection and rapidly-deployable onsite testing are that we can — and hope to — identify a relatively small COVID-19 outbreak, address it with medical care, and contain it through self-isolation and contact tracing of positive cases,” she wrote.

“So, while this new development is concerning, we remain hopeful that our community’s commitment to following public health precautions will help us stay open on campus. We are not interested in blaming anyone or pointing fingers; we just want to address our situation and get everyone healthy.”

CSU has had 304 positive COVID-19 cases since classes began in August.

Cases have surged at college campuses in Colorado, notably at the University of Colorado in Boulder.

On Thursday, Boulder County barred the gathering of 18- to 22-year-olds for two weeks after a massive spike in positive cases.