County public works officials yesterday discovered a 12-inch sewer main in Linthicum severed in two places, pouring up to 160,000 gallons of raw sewage a day into a tiny tributary of the Patapsco River.

The county Department of Health closed Stoney Run between the BWI Amtrak Station to the Patapsco River, warning the public to stay out of the isolated creek.

Ron Bowen, director of public works, said it was unclear how long the main has been broken. Officials speculated that it may have collapsed as recent heavy rains flooded the creek with stormwater runoff.

"First we must replace the sections ... that were impacted...