EL PASO, Texas -- You would think a middle school student would be at school on a Monday afternoon. Brandon had to skip class, but he wasn’t playing hooky. He said he got a whiff of a smell so funky that it forced him from his classroom at Brown Middle School.

"It smelled like sewage and like urine," Brandon told KFOX.

Parents said their children have been complaining about this for months, others said two years.

"It smells like feces, poop, farting, heavy duty," is how Ann Livingston said the children at the school described it to her. Livingston has a child who attends the school.

Brandon said he tried to concentrate on his work, but he just couldn't take it.

"My head started hurting. I got a little dizzy, my stomach started to feel queasy," said Brandon.

And so with the funk in mind, parents said at least 20 of them decided to pull their kids out of Brown Middle School early on Monday.

"We drove with the windows down so he could get some fresh air,” said Michael Bock, who picked up his son early. “Gave him a little Sprite and gave him some Tylenol for the headache."

KFOX passed by the school at around 2 p.m. and saw students who appeared to be having class outside. Livingston said classes had to be moved outside because of the odor.

“I think the school, when it's this bad, should be evacuated,” Livingston said. “There's no way these students should be sitting in class all day long smelling that."

The El Paso Independent School district issued a written statement to KFOX stating that the smell that students were sniffing was hydrogen sulfide, a colorless gas that smells like rotten eggs.

School district officials said El Paso Water Utilities removed a water seal at the district’s request, but they did not inform the district of when they were performing the job.

They said removing the water seal contributed to the strong odor.

To rectify the ongoing problem, EPISD officials said they have done tests on the sewage system and made repairs. They said they have installed air scrubbers and exhaust fans.

The district said it has done air sampling and results that were completed by Dec. 2, 2008 showed that hydrogen sulfide concentrations were below the analytical detection limit.

The district’s testing showed that hydrogen sulfide levels are detectable, but they believe concentration levels are not harmful.

The Texas Department of State Health Services Regional Industrial Hygenist and the senior toxicologist from Austin have investigated causes and risk of hydrogen sulfide at Brown Middle School, but the report has not been published.