Phat Luong, who operates Phat's Barber Shop in central Halifax, said someone slipped into the alley next to his business and cut the oil-tank line.
The ensuing spill could cost hundreds of thousands of dollars to cleanup.
"It can cost me my whole life. Everything I worked for for 15 years," he said Monday.
Luong has won awards for his work and is popular with his clients, but vandals have broken his shop windows before.
The shop is covered by video cameras and on the weekend, they captured someone walking down the street late at night, using an open umbrella to cover his or her face.
The person slips down the alley and returns moments later. The umbrella continues to cover the person's face as he or she walks quickly away.
Hundreds of litres of oil poured into the ground and foundation before the cut was discovered. Crews were on site Monday starting the costly cleanup. Luong said that would likely be covered by insurance.
He opened Phat's Barber Shop as usual Monday.
"99.9 per cent of people are good. It's just one guy. Only one," he said.
Halifax Regional Police are investigating the incident.