The state Department of Health’s Clean Water Branch is warning the public to stay out of waters near the Fort Kamehameha wastewater treatment plant outfall after a sewage spill Sunday night.

About 70,000 gallons of partially treated sewage was accidentally discharged in Mamala Bay near the entrance of Pearl Harbor near the reef runway, the department said.

A tripped circuit breaker at 9:45 p.m. at the Fort Kamehameha wastewater plant led to the discharge of the effluent from an outfall pipe 1.5 miles from shore.

The Health Department said the effluent had undergone secondary treatment and disinfection, but did not go through sand filtration.