When the sagebrush in the Utah desert blooms each year, alarms at the Deseret Chemical Depot near Tooele go off. They also occasionally sound when someone walks into the facility with freshly polished shoes.
   
Or strong perfume.
   
Clearly, these are false alarms. Yet, every time an alarm rings at Tooele or one of seven other stockpile sites where chemical weapons are stored, workers must don gas masks and respond as if the monitors have actually detected nerve agents wafting through the corridors.
   
Some outside the plants worry that the large number of false alarms will eventually cause workers at the military installations to ignore them.
   
"It [false alarms] causes the public to have distrust of the system," said Robert Downing, a county commissioner from Anniston, Ala., where the Army is destroying 7 percent of the nation’s chemical weapons stockpile. "And it causes officials like myself to wonder how reliable these monitors are."
   
Because of concerns expressed by elected officials like Downing, residents living near stockpile sites and their congressional representatives, the U.S. Army is considering tweaking its monitoring system. Monitors play a crucial role in protecting communities in the event of an accidental release of nerve agents at stockpile sites.
   
The re-evaluation is being driven in part by a provision inserted into the Defense Authorization Act last year directing the Army to find better monitors for the eight stockpile sites around the country, including the Pine Bluff Arsenal.
   
Signed by U.S. Sen. Blanche Lincoln, D-Ark., and other representatives of areas with stockpile sites, the resolution cites National Research Council studies that raise concern about the false alarms and the 15-minute lag between when a reading is taken and when the results show up on a monitor.
   
While the Army acknowledges that the monitors — called Automatic Continuous Air Monitoring system — can’t measure in "real time," they say it’s the best technology on the market today.
   
Army officials also point to the fact that because the monitors are capable of measuring microscopic quantities of chemical agents, they also register other chemicals. Industrial cleaning products, drifting pesticides and even flatulence can trigger the system.
   
"The [false alarm] issue stems from the fact that we are dealing with very sensitive instruments of agent concentrations," said Tim Thomas, chief of operations for the Chemical Materials Agency, which oversees the national chemical weapons destruction program. "We’re talking about parts per million and parts per billion — that’s a very low level. And of course, we have set up the program to be responsive to that extremely low level of concentrations."
   
First deployed in the mid-1980s, the monitoring system samples air inside the chemical storage igloos and chemical destruction facilities, analyzes it and triggers an alarm if chemical agents are detected. About 250 monitoring units are placed throughout chemical incineration facilities and about 75 in neutralization plants.
   
The monitors can measure nerve agents down to levels in parts per trillion. To put that in perspective, one drop of dye in 18 million gallons of water is equal to one part per trillion.
   
The monitors work in conjunction with the Depot Area Air Monitoring System, which consists of small glass tubes designed to capture traces of chemical agents and confirm monitor readings.
   
The tubes are placed along the perimeter of most installations, sometimes on telephone poles. Workers pull the tubes at least once every 12 hours or when a continuous air monitor detects the presence of chemicals.
   
Craig Williams, director of the Chemical Weapons Working Group, a Kentucky-based organization opposed to the incineration of weapons, said he believes the automatic continuous air monitors do an adequate job of protecting workers inside the destruction facility. But, he says, supplemental "real-time" monitors are needed to scan for chemical agents outside the facility.
   
"In Kentucky, there are about 523 tons of weapons stored and a construction site about 400 yards away," Williams said. "And there’s nothing between those igloos and the construction site. That is absolutely unacceptable for the 600-800 people who are going to work there."
   
U.S. Sen. Jim Bunning, R-Kentucky, agrees.
   
In June, the Kentucky senator secured $2 million to install advanced monitoring at the Blue Grass Chemical Depot in his home state.
 
 The allocation sent ripples through other stockpile communities as residents wondered why their sites didn’t need advanced monitoring, too.
   
"We all should have the best protection through fast, accurate detection of these chemicals," said Evelyn Yates, a resident of Pine Bluff. "Not just at some chemical weapons sites, but at all weapons sites."
   
While Williams said members of his group aren’t wed to the technology, they see great promise in a laser-based perimeter detection device known as Fourier Transform Infrared Spectrometer.
   
The infrared technology and a dozen others were discussed in August during an Army-sponsored workshop in Washington, D.C. The workshop was held partly because of the congressional directive.
   
Army officials, however, remain convinced that the two monitoring systems are the only ones capable of meeting the newly revised airborne exposure limits for workers for GB or Sarin, VX and mustard gas, the nerve agents contained in munitions at stockpile sites.
   
In the meantime, the Army will continue to pump money into the Chemical Material’s Agency research and design division, which tests new technology, including monitors.
   
Officials at stockpile sites will also look for ways to reduce false alarms by getting a better grasp on what triggers them.
   
"Right now, from everything we have seen and everything we know, there is nothing better out there than what we’re already doing," said Kevin Flamm, program manager for the Elimination of Chemical Weapons.