MILL VALLEY (CBS SF) — A chemical spill related to an outdoor pool at Tamalpais High School in Mill Valley Tuesday morning has been stabilized, a city spokeswoman said.

The spill occurred inside a maintenance and storage room near the pool and the cleanup should be finished by around noon, Mill Valley spokeswoman Linn Walsh said.

A shelter in place order was issued within a half-mile radius from the pool. Mill Valley police wrote on Twitter about the spill around 8:45 a.m.

WATCH: CBSN Bay Area – 24/7 Digital News Channel from KPIX 5

Roads in the area are open, but motorists should drive with their windows closed, Walsh said.

“We’re advising residents to stay inside their home with ventilation off or make sure it is not bringing in outside air” Walsh said. “It’s not a full lockdown.”

The Southern Marin Fire Protection District and Marin County hazardous materials team also responded to the spill.

The school at 700 Miller Ave. in Mill Valley is closed this week for Thanksgiving recess, but Walsh did not know if it was open Tuesday for any recreational uses.