An Alexandria blue-ribbon committee has selected a site in the unpopulated Cameron Valley section of the city for the proposed jail/police department headquarters, the panel's chairman said this week.

The committee will make its written recommendation to the City Council on Saturday.

Jerry C. Wilkerson, chairman of the Police/Jail Advisory Committee, said the seven-member panel wants the new complex to be built on a 20-acre site east of Cameron Valley. To accommodate traffic in and out of the complex. Wheeler and Eisenhower avenues, both located between Duke Street and the Beltway, would have to be lengthened and joined, Wilkerson said.

When the committee makes it report on Saturday, the panel will also request that it be permitted to continue its existence to monitor the progress of the complex, Wilkerson said.

The choice of the site -- one of 22 the panel considered -- ends a two-month study prompted by deteriorating conditions at the city's existing police headquarters and jail.

The panel's recommendation will open the way for city discussion and public hearings on the new headquarters.

The panel used a series of site recommendations and plans prepared for the city by the VVKR architectural and engineering firm, and Phillips Swager Associates. The proposed cost of building an entirely new jail and police headquarters was estimated to be about $17 million, with construction taking place over a three-year period.

The consultant's reports used by the panel also called for constructing the buildings on a six-acre site, leaving space for future additions.

According to the consultants, the site chosen by the panel is now owned by investor William Banks. The upcoming Metrorail line, which will pass the site, is expected to be completed in 1982. Land currently sells in the area for $2.50 a square foot. In the past, several city officials said, the area has been flooded during the rainy season.

"Amazingly, this is the same site that was chosen by (City Manager Douglas) Harman," Wilkerson said. "I can't believe we actually agreed with the city on something."

Several weeks ago, Harman told the panel the site was his "preferred" location, although he did not flatly recommend it.

The largely unpopulated location of the site is expected to dilute criticism from citizens group who had been prepared to protest if a jail was located near their homes.

Currently, there is little development in the area, and proposed construction of condominums and officies is several years away, according to city planners.

Because the complex would require only six acres, there could be plenty of empty "buffer" space if the 20-acre site is accepted by the council, planners said.

The city jail is now in such poor condition that last year the federal Law Enforcement Assistance Administration refused to turn over $250,000 in funds until the city would guarantee that it would use the money in ways "other than . . . to enhance the life expectancy of the substandard jail," according to a report by Sheriff Michael A. Norris.

Police officiers are so cramped at their headquarters in Old Town that officiers on desk duty bump knees with each other. Chief Charles T. Strobel says that officier efficiency is reduced by the crowded conditions.

If the council chooses to buy the land, it might sell the existing 1.9-acre that includes the current jail and police headquarters to help raise money for the new compltx. The site is bounded by Princess, N. Pitt, Oronoco and N. St. Asaph streets.