The bells might not be ringing at Richmond's Kennedy High School any time soon.
Classes were due to start in two weeks on the campus, part of which is under construction.
But on Monday, the school district announced it was prohibiting students and staff from entering the property after the chemical known as PCE was found underground.
It's been a problem across Richmond for years.
And one Vice Mayor Doria Robinson says stems from an old cleaning company that closed down 10 years ago.
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"Chemicals that were spilled over the course of a period of time got into the groundwater and have been moving on underground creek beds through the community," said Robinson.
The district says it's working with the state to test PCE levels by the school.
So far, none of those tests have detected hazardous levels, but officials say their move is precautionary.
"Getting those kids out of there is really great and a really good, cautious move," said Gina Solomon.
Solomon is the chair of occupational and environmental medicine at UCSF.
She says while it's possible to decontaminate areas from PCE, it can take time.
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"Unfortunately, once they're in the groundwater and in the soil, they hang out there for a long time. Slowly sort of oozing and evaporating upward into the air," said Solomon.
Medical experts say immediate health risks from PCE exposure are generally low.
Instead, it's the long term issues that they worry about.
"They include effects on the liver, effects on the kidney, effects on the reproductive system," said Dr. Peter Chin-Hong.
As of now, there is no timeline of when Kennedy High School might reopen.
Because in a city that's been plagued by environmental issues for years, safety is the top priority.
"Right now, what I feel and what I've seen is they're trying to be as careful and as cautious as possible to not put anybody in harm's way," said Robinson.
After ABC7's initial report, the mayor's office released the following statement:
"The Mayor's Office is aware of the preliminary testing results affecting Kennedy High School and the West Contra Costa Unified School District's decision to restrict access to the campus while additional testing is conducted."