BRISTOL, R.I. (AP) – Crews continued cleaning up Wednesday after millions of gallons of raw sewage spilled into streets and homes here.

The overflow occurred Tuesday after pumps that serve the town’s sewage treatment plant failed, causing pipes to back up.

Workers were using three pumps to reroute the wastewater back to the treatment plant, said Matthew Calderiso, Bristol’s superintendent of water pollution control.

Meanwhile, the state Health Department said the public drinking water supply is safe, but spokesman Robert Marshall recommended that people using private wells flooded by sewage test their water before using it.

Calderiso said cleanup crews have been called to a handful of homes where sewage overflowed and that several thousand gallons of sewage still need to be pumped out.

The state Department of Environmental Management closed waters in Bristol Harbor and surrounding Hog Island to shellfish harvesting on Wednesday. Water samples will be taken on Friday and Monday to determine when the areas can be reopened, department spokeswoman Gail Mastrati said.

Mastrati had estimated the overflow at between 2 to 4 million gallons. The Health Department estimated the overflow to be between 1 to 2 million gallons.