Medical waste that washed up on Jersey Shore beaches last month came from storm sewers that overflowed, according to state Department of Environmental Protection sources.

Debris, including 20 syringes, was found on an 8-mile stretch of Long Beach Island from Surf City to Barnegat Light on June 28. Health officials say they're confident all the medical waste is cleaned up from the incident.

A state DEP official says waste washing up on the beaches is rare, but is known to happen after heavy rain.