About 5,800 Contra Costa employees, dissatisfied with the county's latest contract offer, walked off the job Tuesday.

The one-day strike left government offices countywide vacant, or manned by skeleton crews of administrators.

"They gave us an incomplete offer," said Roland Katz, business manager for Public Employees Union Local No. 1.

The current proposal would see wages remain flat for the two years. The third and fourth years would bring a 2 percent increase annually. In addition, those with 10 or more years invested in the county would receive a longevity increase of 21/2 percent. The deal includes an immediate $1,000 payment when the contract is ratified.

"It was an offer they should have made a couple of months ago," said Michael Weinberg, representative of Service Employees International Union Local 535. "To put that on the table a couple of hours before the strike was insulting."

Tuesday morning, clerks, criminalists, eligibility workers, public defenders, social workers and public health nurses descended upon the Board of Supervisors chamber in a noisy protest over the failed talks.

Later, hundreds more trekked across a Highway 4 overpass en route to the health services complex, stopping traffic at noon.

"It's being felt throughout the county," Cullen said. "I want to apologize to the people of Contra Costa County for not being able to deliver the high level of service they are accustomed to. Things will get back to normal soon."

Contracts ran out a year ago. Talks have run aground since. A state mediator was brought in to help break the impasse.

"There are employees at the county who earn at, above and below market wages," said Supervisor John Gioia of Richmond, the board chairman. "The county has said it wants to address those who may be paid below market in areas where we have a recruitment problem."

For instance, if environmental health inspectors did not receive a raise, the county would continue hemorrhaging qualified inspectors to counties that pay more.

Negotiations between the bargaining groups and the county will resume Thursday. Both sides predicted the other will now dig into negotiations with a new vigor.

"We're hopeful," Weinberg said. "We think the Board of Supervisors finally understand."

A festive atmosphere dominated at the courts, hospital, social services center and other government buildings as strikers blew whistles, pounded drums and toted picket signs, and motorists honked their support.

The entire criminal laboratory staff cleared out for the day, said investigator Warren Cohn. If not striking, he would be testifying in court or analyzing evidence.

On the courthouse steps, a lawyer wearing a Jerry Garcia tie pounded an empty water jug.

All 120 employees from the public defender's office walked out, said lead attorney Roberto Najera.

"I've seen this county grow astronomically, but our numbers haven't grown," Najera said. "Our caseloads get bigger and bigger -- homicide clients, multiple three-strike clients. This county is losing quality people to private practice, or counties that pay better."

At the county hospital, nurses, who were enjoined from striking by court order, stopped by on lunch breaks, many dressed in black.

"These are people I work with every day," said nurse Mary Knodt. "I want to support them as they would want to support me."

Rebecca Rosen Lum covers county government. Reach her at 925-977-8506 or rrosenlum@cctimes.com.

One-day strike at a glance

Bargaining: Members of six union locals have been working without a contract since September 2005. The next bargaining session is slated for June 29. Although the unions have not ruled out another short-term strike, none is planned.

The number of affected county workers: 5,800.

Striking unions:

• American Federation of State, County and Municipal Employees, Nos. 512 and 2700

• Service Employees International Union Local No. 535

• Public Employees Union Local No. 1

• Western Council of Engineers

• Physicians and Dentists of Contra Costa County

What they are seeking: A 6.5 percent wage increase over three years. Reductions in case loads in some jobs. Seniority preference in job transfers.