Fairfax city residents will consider major changes in their government at a hearing July 26, including longer, staggered terms for council members and the elimination of the elected posts of treasurer and commissioner of revenue.

After 20 months of study, the city charter review commission has recommended doubling the terms of council members from two to four years and staggering them to provide greater continuity from year to year.

Other charter changes--all of which must be approved by the Virginia General Assembly--would have the new councils take office June 1 instead of July 1.

But apparently the most controversial proposals are the ones the commission recommended unanimously: eliminating the state-created posts of commissioner of revenue, who is responsible for collecting city and state taxes, and treasurer, who is the city's official bookkeeper.

The elected officers would be replaced by an appointed director of finance, ending a "costly and inefficient and needlessly politicized anachronism," wrote commission member John Peterson in an accompanying letter. A similar recommendation was urged by some citizens but rejected in the city's 1963 and 1973 charter changes.

Putting city financial affairs under a professional rather than political post was agreed to even before Frances Cox was convicted last fall of embezzling city funds as city treasurer.

"But that has certainly colored our recommendation," commission chairman Will H. Carroll said. "Still, the changes are controversial because any time you remove officers from the electorate, you're going to get some expression of concern."