Some Long Beach swimming areas remained closed on Friday after 47,000 gallons of sewage seeped into the local bay during a storm that pummeled the city on Thursday.

City workers began posting signs around the recreational swimming areas of the Colorado Lagoon and Alamitos Bay on Thursday, according to the city’s Health Officer, Dr. Anissa Davis.

The sewage spill is due to “infrastructure challenges” faced by the Los Angeles County Sanitation District, the Health Department said.

While Thursday’s rain advisory urged residents to avoid swimming in those areas for three days, a sewage spill requires a mandatory closure, Davis said.

The Health Department’s Recreational Water Quality inspection team is will working to monitor the water until they comply with state quality standards.

The city has had to close its coastline for 63 days over the last five years due to upstream sewage spills. Since Long Beach is downstream from much of Los Angeles County, such spills remain a persistant problem.

Residents can check the status of the water quality by calling the water hotline at 562-570-4199 or by visiting Long Beach.gov/beachwaterquality.