The Virginia Department of Corrections, under mounting criticism over crowding in local jails, today announced an emergency plan to transfer 500 inmates to state prisons at a cost of $3.8 million.

The plan calls for 50 inmates a week to be taken to state institutions, according to Corrections Director Allyn R. Sielaff. He said most of the transfers will come from jails in the state's three major urban areas, Northern Virginia, Richmond and Hampton Roads.

A spokesman for the state's sheriffs, who run the local jails, praised the action.

John W. Jones, executive director of the Virginia State Sheriffs' Association, called the transfer plan "a step in the right direction," but he said that the administration of Gov. Charles Robb "should have moved earlier" on what Jones called "a long-term problem."

"We are seeing a population that no one anticipated," Sielaff responded. He said a state legislative study in April had predicted a leveling off in jail population.

Sielaff said that in June, "jail populations usually go down -- or at least not go up -- but that didn't happen this June."

He attributed the continuing rise in prisoners to "more people coming in the front end and fewer going out the back -- more are being sentenced and fewer are being paroled."

Sielaff said he learned at a corrections conference in Louisiana recently that "it is not just a Virginia problem, it's nationwide."

Because of crowding at the Alexandria City Jail, Sheriff Michael E. Norris told his deputies last week not to serve arrest warrants on suspects who are not considered to be dangerous, and Fairfax County Sheriff M. Wayne Huggins called crowding at his jail deplorable. The state "is asking for trouble if we continue," he had said.

Sielaff said today's announcement was the third step in a plan, begun in February, to deal with crowding. It was not in direct response to the complaints by several sheriffs during the weekend, he said.

Andrew B. Fogarty, secretary of transportation and public safety, is expected to meet Tuesday with a number of sheriffs in Charlottesville to work out details on which prisoners will be among the first moved.

The $3.8 million cost of the plan, which calls for hiring 114 employes, most of them corrections officers, will come from a contingency fund and from the Corrections Department budget.

As the state officials were announcing their plans, the two candidates for governor debated in Arlington on who is to blame for the jail crowding.

Republican Wyatt B. Durrette told the Virginia Association of Chiefs of Police that during the Democratic Robb administration, the prison "crisis has become a problem of unprecedented dimensions -- look at the problems in local jails."

It was the latest in a series of attacks Durrette has made against the popular governor, who cannot succeed himself.

"The relationships between the Corrections Department and local law enforcement officials have deteriorated," Durrette told the gathering of about 120 police officials. "That has to be restored."

Durrette arrived at the conference late and he appeared unaware that the Robb administration had announced that it was moving on some of the issue he raised. Democratic gubernatorial nominee Gerald L. Baliles had announced the Robb actions in his speech to the group.

The candidates used their sixth joint appearance to hammer at what they consider to be inconsistencies in each other's positions on law enforcement.

"I've gotten tired of listening to him misrepresent my position," Baliles, a former state attorney general, charged at one point in the frequently heated exchange.

"He's done it again today," countered Durrette, charging that Baliles was misstating a position he took on criminal justice issues during his six years as a state legislator from Fairfax County.

To accommodate the extra prisoners, Sielaff said, some inmates will be double-bunked and double-celled.

In addition, an old gymnasium will be converted to a dormitory at one prison in southern Virginia, and prisoners will be held in a basement at the Mecklenburg prison, also near the North Carolina border.

The transfers will mean that the three newest medium-security facilities, at Nottoway, Brunswick and Buckingham, designed for 500 inmates, will have to hold 725. "We will be at 145 percent of rated capacity," Sielaff said.

Sielaff said the first step in the state's plans to accept more prisoners from local jails included a decision in February to keep open a 300-bed building at the State Penitentiary in Richmond. The second was taking 300 additional prisoners from local jails to the state prisons on June 7, he said.

Completion of today's plan will raise to 10,800 the number of persons in state prisons, which have a capacity of 9,800, Sielaff said.

Sielaff jabbed back at the sheriffs today, noting that the transfer plan includes $375,000 for expanding a program that places nonviolent offenders in the community under supervision of state corrections officials.

That was "an idea the sheriffs shot down a couple years ago," he said.