At approximately 645 p.m. yesterday, Katonah Fire Department was dispatched to New Street on a report of both a smell of oil as well as what appeared to be oil in the creek under the road. Upon arrival of KFD units, members spread out in an attempt to locate and mitigate the source of the leak. Car 2211, Car 2212, Engine 116, Rescue 17, Engine 115 and Utility 8 responded. Notification was made to DEC, DEP, and the Westchester County Hazmat team was requested to respond. After a thorough search of the surrounding neighborhood, the source was traced to a leaking fuel tank in the basement of a nearby residence with oil company techs already working to fix the leak. An environmental cleanup agency was contracted via the oil company to continue the clean up efforts started by fire department personnel. After placing absorbent booms and checking for additional leaks, the scene was turned over to NYSDEP. Units were operating on scene for approximately two- and a half-hours.