In proposing a $509.3 million budget for 1978, Montgomery County executive James P. Gleason last week again sounded the theme of fiscal restraint that has been his central concern during the past two years.

Noting the "heavy impact" of government spending on taxpayers, particularly the less affluent, Gleason said he cut $22.4 million from the budget requests of county agencies in order to avoid seeking an increase in general property tax.

The current average tax rate is $3.91 per $100 of assessed value. Property is assessed annually at 50 per cent of market value.

(County council members, who have the final say on the budget, pointedly did not rule out a tax increase, however.)

Gleason also abolished 175 of 200 vacant county positions (although he added 120 new positions for the county's expanded local bus service). And he criticized the school board for presenting a budget request for $10 million higher than the $250 million range he and the County Council had all but ordered it to adhere to.

"The primary objective of the county budget is to avoid a tax increase . . . " Gleason said in a letter to the Council. "The current revenue picture is such . . . that we cannot absorb substantial increases in one agency without making corresponding cuts in another."

Even in an era of general economic caution, Gleason's great concern for the fiscal health of one of the nation's most affluent counties, viewed superficially, might seem misplaced.

Last year, only one other of the nation's 30 major affluent counties topped Montgomery County's average household income of $29,446. The county's median income of $23,100 - about three times the national average - placed it first among those affluent counties of 50,000 or more residents.

If these statistics lack substance, the large, expensive homes in such subdivisions as Bethesda, Chevy Chase, Potomac, and Kenwood provide ample evidence of the concentration of affluent individuals and families.

Further, the county government holds the select triple A bond rating (only 27 others of the nation's more than 4,000 counties do), which allows it to pay relatively low interest rates when borrowing money.

County finance director Albert F. Gault said the difference in interest saved over the life of a $40 million loan between a double A and a triple A rating can be as much as $1.5 million.

Thus, Montgomery County appears to be on solid fiscal ground.

Gleason and Council members agree, but are quick to point out that the affluence of individuals doesn't translate automatically into full county coffers. Indeed, they note, the fiscal health of the county is largely dependent on continued economic growth - which has been stymied in recent years by the lack of sewer capacity.

They note that county expenditures again are projected to outstrip county revenues, this time by about $3.5 million; that earlier population growth projections have proved too optimistic - partly because the high price of housing effectively excludes many moderate-income home buyers; and that development, as indicated by the amount of new construction, has declined in recent years.

All these occurrences have significant negative implications for the county's fiscal future.

Gleason said that while government revenues will increase by $6.3 per cent, expenditures will increase by 7.3 per cent.

According to county officials' projections (which are based on the current fiscal picture), the gap between county revenues and expenditures - between the money it gets from all taxes and fees and the money it must spend - will grow from $3.5 million in 1978 to just over $100 million by fiscal 1983.

Put simply, what those figures mean is that county revenues aren't keeping pace with the rising costs of doing business.

Hence, Gleason's anger at the school board, which he felt selfishly ignored the county's straitened fiscal circustances.

The two proposals to radically alter how the school board operates that Gleason submitted to the Maryland General Assembly last week are widely seen as a means of empasizing his ire rather then serious attempts at change. Their chances of passing are dim.

School board president Herbert Bennington, in a detailed 9-page letter to Gleason and the Council, defended the board's budget request of $262 million.

Bennington asserted that despite reductions in staffing positions and school programs, the 6 per cent salary increase given teachers, inflation for fixed costs and necessary program improvements made meeting Gleason's request impossible.

Bennington also said that "any substantial" budget cut by the Council could result in increased class size, fewer school programs, a reduction of up to 1,400 positions and a decline in educational quality.

The only significant increase in the budget is the $3 million proposed for funding the county's expanded "ride-on" minibus service in the lower portions of the county, particularly the Silver Spring area where a Metro station will open in November.

Gleason also proposed a 4 per cent cost of living increase for all county employees, including school teachers, that would cost $11 million to fund. The increase undercuts the 6 per cent board and teachers' union and is also less than the 6 per cent rise in the consumer price index.