Government officials have not yet identified the source of the pungent odor that wafted over St. Croix last week, closing schools and sending dozens to the hospital complaining of dizziness and nausea, but said Tuesday that they are working together meticulously to pinpoint the source, assess the health risk and determine what needs to be done to prevent a repeat.

During a press briefing Tuesday, representatives of the agencies involved talked about the process they’re using in the investigation, which they’ve titled “Operation Breathe Easy.”

The agencies formed a "Unified Command" Friday when the scope of the problem became clear, but had been working together almost since the first telephone complaint about the smell a week ago, according to Alicia Barnes, commissioner of Planning and Natural Resources.

The Unified Command allows the various government agencies to work together without duplicating effort, she said, so that everyone is focused on one thing: safeguarding the public health.

"That’s our number-one goal," she said, "protecting public health and safety."

Members of the Unified Command appearing at Tuesday’s session included DPNR’s Barnes, VITEMA’s Gen. Elton Lewis, Dwayne Harrington of the EPA, Dr. Mark Jerome of the Department of Health and Maj. Kenneth Alleyne of the V.I. National Guard.

Barnes said in most such cases, the source of the odor quickly comes forward, identifying the material spilled and helping assess the danger and clean it up. In this case, that hasn’t happened. So one of the command’s first tasks is to figure out what has been spilled, by whom, and the danger level posed.

Air monitors have been posted, and Barnes said the first data was just being downloaded Tuesday. There are also portable units that can be sent out at the first report of trouble, she added.

Data from the monitors, along with weather patterns and the record of phone calls complaining of the odor will be brought together to help pinpoint where the trouble lies, she said. By tracking where the more than six-dozen calls came from and their times, and comparing that information with the weather patterns at the time, it helped show that the source was somewhere on St. Croix’s south shore.

Complicating the search is that callers have reported three distinctly different smells, she said, including a sharp, bitter sulfurous smell and a sweet, sickly odor. That leaves the group searching for signs of several different compounds, including sulfur dioxide, hydrogen sulfide and volatile organic compounds. The group is basing its search for a culprit in part on records of companies that employ processes that use or produce such compounds, she said.

“We are not eliminating anyone at this time,” Barnes said

She added that the process being employed is based on science, not hearsay, and declined to point a finger at possible suspects until the data is clear. In the meantime, members of the group have already monitored areas at the Cruzan Rum distillery, the Hovensa refinery, the Diageo distillery, Anguilla Landfill and the V.I. Waste Management Authority wastewater treatment plant. She said they hope to know the source as early as next week.

Along with briefing the media Tuesday, the Unified Command also held a separate briefing for Gov. John deJongh Jr. and Lt. Gov. Gregory Francis.

“Our main concern is for the health and safety of our citizens, and the fact that we are taking a scientific approach to determine the cause of the odors is significant,” deJongh said. “When we report to the community what our findings are and what corrective measures will be taken – possibly including fines and assessments – we will do so with sound data based on a scientific approach.”