A plumber in the Shuswap region of B.C. is upset his daughter's school was not closed for the day after sewer gas forced some children to leave the building Tuesday.

Chris Snow said his 17-year-old daughter complained to him about the terrible smell after she came home from Salmon Arm Secondary School.

That concerned him because as a plumber he said he knows about the dangers of sewer gas.

"It's toxic. It's a toxic bacterial sludge of urine and feces and other kinds of waste water that is off gassing horrible chemicals that the children at this school were breathing," said Snow.

Several children left school because of the odour, but officials kept the remaining kids in the building. Snow thinks students should have been sent home for the day.

"You know if students are gagging, it's not okay. That's basic plumbing 101."

Evacuation not necessary, says district

But school district superintendent Glen Borthistle said despite the smell, operational staff determined children were safe.

"If there was any sign, we would have implemented a process to evacuate the school, but that's not what was deemed necessary in this case," said Borthistle.

The source of the sewer gas has been located and the problem fixed, said the superintendent.

Salmon Arm Secondary School

Salmon Arm Secondary School was not evacuated after noxious odours from the sewers were detected on Tuesday. School officials say students were not at risk and the problem has been fixed. (Google Maps)

Sewer gases are created from the decomposition of organic waste and can include hydrogen sulphide, ammonia, methane, esters, carbon monoxide, sulfur dioxide and nitrogen oxides.