Fire units were called to the Harford County Emergency Operations Center north of Bel Air on Thursday night after an "odor of burning" was reported in the building that houses the county's 911 call center and police, fire and emergency medical dispatching.

No fire was found, however, according to a spokesman for the Harford County Department of Emergency Services who said the odor was actually closer to that of raw sewage and appears to be the result of a ventilation problem inside the building, located in the 220 block of Ady Road, that is due to be replaced.

What was termed a possible "electrical fire" was called in about 7:45 p.m., according to monitored Harford County emergency radio broadcasts. Units from Bel Air, Darlington and Whiteford fire companies were called.

Robert Thomas, spokesman for emergency services which operates the building, said Friday, the staff working in the building smelled the odor in a conference room within 20-30 feet of where some electrical equipment caught fire last month.

"Because of that earlier incident and this particular odor last night, staff had fire equipment dispatched to check," Thomas explained. "They also called the Hazmat Team come and check for potential issues of concern." He said Hazmat Chief Clarence Ross personally responded.

"The odor actually turned out to be something similar to that of raw sewage," Thomas continued. "They believe the odor came from a vent or duct from where the older part of the building runs into newer additions that were built."

Thomas said it has not yet been determined what caused the odor itself but an investigation is under way.

"The bottom line is we are addressing the odor issue in the never ending saga of problems at emergency services facility," he added. The 38,000 square foot facility, which county officials say is obsolete, opened in the early 1960s and has two additions.

Early on the morning of July 21, a fire occurred in EOC's electrical equipment related to the heating and air conditioning system for the computer room in the building. There was no damage to the structure or the computer servers and other hardware; however, the air conditioning was knocked out in the entire building.

The county brought in large fans to keep the computer servers cool and emergency dispatchers and other staff remained on the job, as daytime temperatures soared into the 90s the next day. The repair was completed and the air conditioning put back into service on the afternoon of July 23.

Last Sunday, 100 county officials and representatives of local fire companies, police agencies and other emergency services providers gathered on the EOC property to officially break ground for a replacement emergency operations facility being built in two phases at a cost of $45 million. At 116,000 square feet, the new facility will be about three times larger than the current one. Completion is expected in December 2015.