A Farmington firefighter climbs down a ladder on Monday after investigating a gas-leak at Hermosa Middle School in Farmington.
A Farmington firefighter climbs down a ladder on Monday after investigating a gas-leak at Hermosa Middle School in Farmington. (Jon Austria — The Daily Times)

FARMINGTON — Hermosa Middle School in Farmington was briefly evacuated Monday morning after numerous residents in the area reported smelling a gas-like odor.

Farmington Fire Department Battalion Chief Nick Mrzlak said his department began to receive complaints of the smell at 10:45 a.m.

The school, at 312 E. Apache St., was evacuated shortly before 11 a.m., but students began filing back into class about 30 minutes later after inspectors determined there was no explosive gas present in the building.

Mrzlak said he suspects that the smell was actually caused by a mercaptan leak, not a natural gas leak. Mercaptan is the odorant that provides natural gas it's distinctive smell and is added to the odorless gas by companies after extraction.

Mrzlak said a mercaptan injector site is located by Ricketts Park and he suspects the smell originated there.

"The smell disappeared before we could locate the source," he said.