A TTC vehicle operator failed a random drug test for the first time this week, the transportation agency said Thursday.

TTC spokesperson Brad Ross said the operator was tested on June 17 and the results came back positive on Wednesday.

He declined to provide where in the city the operator works or what substance was detected.

“We take impairment on the job very seriously,” Ross said, adding the employee was suspended with pay pending a disciplinary hearing.

A total of eight TTC employees have failed random substance tests since they were implemented last month.

None of the seven previous failures involved employees that operate vehicles.

Ross stressed that “the vast of our employees would never even dream of showing up for work anything but fit for duty,” but said the fact that employees continue to fail shows that the agency needs to continue screening.

The operator faces possible punishment up to and possibly including dismissal.

All employees in “safety sensitive” positions at the TTC are now subject random drug and alcohol screening.

TTC CEO Andy Byford was selected for screening two weeks ago and passed, Ross said.