Interim public works supervisor Roger Belknap said the problem was discovered late Tuesday afternoon.
Public works crews working late Tuesday night determined there was no problem in the street. Instead they believe there is a clog or collapsed lateral line to the building, Belknap said.
There are two lines serving the Village Hall, so some of the facilities are available and the building is open today, Belknap said.
He hopes to have a camera to scope the line yet this morning.
If they find a clog, they will clean it out, he said. If they determine the line is collapsed, they will have to dig a trench to replace what they believe is a 4-inch PVC pipe.
The Village Hall would still remain open to the public, with access from Savidge Street only, he said.
The backup was in a utility closet off a main floor conference room.
It was discovered by the Heritage Festival Committee members who were planning to have a potluck in the room, Belknap said. They moved their meeting to an upstairs conference room.