WASHINGTON — The moment the last of Fred Vautour’s five children walked across the stage as a Boston College graduate was priceless.

Not only did Mr. Vautour have the rare distinction of handing each of his children their diplomas, but he was also able to pay for their nearly 18 years of schooling by collecting trash, scrubbing toilets and mopping floors while the campus slept.

“As much as I struggled, it was incredible to be able to do that for them,” said Mr. Vautour, 64, who has worked the graveyard shift as a custodian at Boston College for 17 years. “I took this job for benefits, but never imagined this would be one of them.”

It may not be one for long — or at least could be severely curtailed. The sprawling House tax bill, set for a vote on Thursday, would tax the value of college tuition benefits conferred on thousands of university employees like Mr. Vautour, one of several provisions that would hit colleges, universities and their students, hard.