In an investigation released Thursday, the Bureau of State Audits sharply criticized the California Department of Transportation for numerous lapses in managing a unit that tests foundations of bridges and other freeway structures to verify their soundness and safety.

Among the key findings of the four-year probe:

• Employees falsified test data in a total of 11 cases – 10 involving a technician and one involving an engineer. Caltrans eventually analyzed the suspect structures and deemed them safe.

• Caltrans allowed the technician who falsified data to access digital test archives for eight months after his fraud became known – leaving records open to deletion or manipulation. Thousands of data files necessary to understand the unit's testing history were lost or destroyed, either intentionally or by accident, making a comprehensive review of possible falsifications impossible.

• The test unit manager secretly misappropriated state property for personal use with the help of two technicians. The manager also approved improper payments of $13,788 to those technicians.

The audit report recommended efforts to recover misspent funds and improve data handling in the testing unit.

"These findings are very much in keeping with the hundreds of pages of reports Caltrans delivered to the Legislature in February," Caltrans spokesman Will Shuck said in a written statement. The agency has adopted most of the solutions recommended by the state auditor, he said.

The Bee previously reported those findings, among many others, in a series of articles over the past 16 months.

While the state auditor's report did not name any of the individuals involved in wrongdoing, The Bee has identified technician Duane Wiles as responsible for or linked to much of the falsified data. He admitted to falsifying data in at least one case.

Caltrans fired Wiles after a November 2011 Bee article detailed his transgressions – but rescinded that action and allowed Wiles to retire with full benefits. The state auditor noted that as part of the separation agreement, Wiles may not seek state employment – but cited "substantial risk" that the provision would be hard to enforce, because all references to Wiles' misconduct were removed from his personnel records.

Caltrans also fired Wiles' supervisor, Brian Liebich, for misappropriating building materials and approving improper payments. He denied the charges and appealed his firing, now under review by the State Personnel Board.

The auditor's report noted that one engineer was involved in data falsification. Earlier this month The Bee cited findings of a team of Caltrans experts, which indicated that four state engineers signed test reports that misrepresented or ignored data or other "consequential" information on freeway structures, including the Benicia-Martinez bridge.

Two of the engineers, Toua Vang and Tejinderjit Singh, work for Caltrans. The others, Michael K. Harris and Constantin I. Mercea, have since left the agency.

The auditor's report was one of several examinations of the Caltrans testing unit by state or federal authorities in recent months. A separate review by the Caltrans internal Division of Audits and Investigations has never been made public.

State Sen. Mark DeSaulnier, D-Concord, chairman of the Transportation and Housing Committee, told The Bee earlier this month that Caltrans' normal oversight process could be more effective if removed from the agency to ensure impartiality.

In February he introduced Senate Bill 486, which would shift the Caltrans Division of Audits and Investigations – which reports to agency managers – into the California Transportation Commission. The bill also would require oversight reporting to the governor and legislators, and public disclosure of its findings.

Call The Bee's Charles Piller, (916) 321-1113. Follow him on Twitter @cpiller.

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