The smell of Mercaptan, the chemical added to natural gas to give it that raw eggs odor, could be detected on Lexington and White streets. On Ripley Road, a backhoe and repair trucks from National Grid were tearing up the street outside 22 Ripley to find and repair a serious leak in a gas line entering the house.
As workers took out the pavement on the closed street, Belmont Fire Department crews were finishing taking air measurements after receiving a call around noon that gas was leaking into the basement of 22 Ripley.
An investigation found a major gas leak on the street, requiring the gas utility to also dig out a portion of nearby Beech Street to stem the gas flow.
National Grid crews said the leak should be repaired by 4 p.m. if not earlier.
While fire crews were at the site, Belmont received mutual aid from Waltham and Cambridge.