NEW BERLIN, Wis. (CBS 58) -- A cleanup effort is underway after a gas spill in New Berlin Wednesday, March 8. 

Police say it happened at a gas station near Calhoun and Greenfield during the transfer from a delivery semi to an underground storage tank. It's estimated that up to 70 gallons of gasoline was spilled in the incident. 

The spill occurred around 6:30 p.m. Wednesday but was not reported until around 5 a.m. Thursday by nearby residents. 

Authorities say a hazardous materials cleanup company was contacted after officials determined that gasoline entered the stormwater system into a nearby creek. 

Police say there is currently no known risk to residents. 

Specialists with equipment will be working along the creek Thursday.