EL PASO, Texas -- Hydrogen sulfide, a dangerous gas, has been found at Brown Middle School. The problem, however started over a year ago, and parents are angry they were not notified sooner.

Susanna Moran’s son is a seventh-grader at Brown Middle School, and often comes home not feeling well.

“He was complaining about headaches," Moran said.

After a meeting called by the disctrict, Moran may now know where her son's headaches are coming from.

Since its opening a year and a half ago, Brown Middle School has dealt with a disgusting smell of sewage in its buildings.

"[My son] just said it was a very bad odor," Moran said.

Sewage carries with it hydrogen sulfide, which can cause upper respiratory problems and other illnesses.

"We would take care of the problem and then it would start again. The only time that it really peaked was in November," Principal Victoria York said.

In November, nearly a year after the first time the odor was smelled, the district began to take air quality measurements, and did find hydrogen sulfide in the school's air.

The measurements were low, but school officials admit they do not know the health risks of long term low exposure to the gas.

“It’s the children's health, they don't know if it’s risky to children’s health or not,” Moran said.

On top of fear for their children's health, parents are angry they were not notified of the threat earlier.

"Frankly I was busy with the district, for them getting all the equipment we needed out here and for them trying to find whatever the solution was to the problem, and there wasn't really a time," York said.

The school district has teamed with El Paso Water Utilities and are installing a water seal on a sewage line, that they think is the root of the problem.

However, until Moran can be sure her son is safe, it is not enough.

"I'm still the same as when I came in, without knowing anything,” Moran said.

The district has offered concerned parents the option of transferring their student to another middle school until the problem is resolved.