An estimated 3,470 gallons of raw sewage flowed into Pearl Harbor's West Loch yesterday, the city said.

Crews from the city Department of Environmental Services responded to a 9:33 a.m. call of a wastewater overflow fronting 91-1147 Hamana Street in the West Loch Fairways subdivision.

City personnel arrived on the scene at 9:56 a.m. and secured the site at 11:31 a.m.

Tree roots clogged an 8-inch vitrified clay pipe causing a manhole on Hamana to overflow, sending untreated wastewater into a storm drain headed for West Loch.

The city Environmental Quality Division notified the state Department of Health. Signs have been posted and water sampling will begin Tuesday.