Salt Lake Tribune
July 31, 2003

Chemical depot worker convicted

By Pamela Manson and Derek P. Jensen
The Salt Lake Tribune

A federal jury on Wednesday night convicted a Deseret Chemical Depot supervisor of falsifying the results of tests conducted to show whether air monitoring machines were operating correctly at the Tooele facility, where chemical weapons are destroyed.

After four hours of deliberation, jurors at U.S. District Court in Salt Lake City found David James Yarbrough guilty on seven counts of making false statements to a government agency.

"I'm disappointed," Yarbrough said as he exited the courtroom with family members. "It's difficult to go against someone big and powerful like the government."

Yarbrough was accused of omitting data or misreporting test numbers, so monitoring units that determine if any toxic gases are being released into the air falsely appeared to be working. Prosecutors with the U.S. Attorney's Office said that figures produced by Yarbrough were different from the results given by the machines.

The charges carry a maximum term of 5 years each. Sentencing was scheduled for Oct. 10 at 2:30 p.m.

During the trial, Yarbrough adamantly denied altering data or concealing test results. He created his own worksheets to collect as much information as possible on how the machines were working and recorded figures correctly, he said.

"I did not change any number on an operator's log sheet and I did not pull a number out of the air," Yarbrough testified.

"I just think it's a sad thing," he said after hearing the verdict Wednesday. "Managers should know how to conduct safe monitoring."

Yarbrough, 52, a worker at the Oquirrh Mountain Facility Plant at the depot, has been a civilian employee there for more than 20 years. The charges against the Stockton man concerned baseline tests that are performed to ensure the air monitoring machines were functioning correctly.

The depot suspended operations in August 2002 at Oquirrh because of inconsistencies found in the results of baseline tests supervised by Yarbrough. Operations resumed a few months later after a new baseline monitoring system was completed.

Yarbrough was assigned other duties after being indicted last fall.

Workers from the depot who testified during the three-day trial before Judge Tena Campbell said that there were inconsistencies between the test figures produced by the machines and the figures recorded in some of Yarbrough's reports.

The witnesses also testified about the importance of accurate readings to ensure everyone's safety and said incorrect numbers that allow a faulty monitoring machine to operate would be dangerous. The machine's units set off an alarm to warn employees of any unexpected release of toxic air.

"My life might be on the line," said Dallen Cox, chief of the analytical division at the depot.

The depot is about 40 miles southwest of Salt Lake City and covers 19,000 acres. Under an international treaty, workers are destroying the nation's stockpile of chemical weapons.