The health department posted warning signs and are collecting water samples after 21,0000 gallons of untreated sewage was dumped in Waimano Stream Thursday after a 10-inch force main broke at the city’s Pacific Palisades wastewater pump station.

An operator noticed the break around noon at the pump station located at 1810 Komo Mai Dr.

Crews worked to install a bypass around the spill area, taking the wastewater downstream of the break.

The bypass was completed at 3:30 p.m.

People are encouraged to stay out of the affected waters until signs have been taken down.