Citing the uncertain impact of federal and state budget cuts, Montgomery County Executive Charles W. Gilchirst yesterday vetoed $700,000 in additional spending the council had tacked on to the county's 1982 operating budget.

The vetoes, if sustained by the council, would lower the county budget to $729.7 million.

"A modest cut is what this is," said Gilchrist, "The County Council has a responsibility, too, and we didn't set out to undo everything they did."

Gilchrist vetoed 18 positions and other expenditures by the Maryland-National Capital Park and Planning Commission, the Health Department, the Department of Environmental Protection and several other county agencies.

Gilchrist said the reductions were not necessary to keep the property tax rate at its current level of $2.34 per $100 of assessed value, but the savings could be used to lower the rate by three-fourths of 1 cent, or to raise the budget surplus to $6.8 million. That will be decided by the council.

The county executive noted that the council has never sustained an operating budget veto, but said, "I hope the County Council will view this [as] fine tuning rather than as a conflict between the two branches of government."

An agmendment to the county charter last year changed the number of council votes necessary to override an executive veto on the budget from four to five, making it less likely that the council will succeed in overriding allof the vetoes. The amendment also gave the executive the right to veto items on the Montgomery County portion of the planning commission budget, subject to a four-vote override. The council has 30 days to take final budget action. t

In addition to the vetoes, Gilchrist cut $300,000 of a general fund contribution to the Recreation Department. Gilchrist said the recreation tax will have to cover the reduction.

Gilchrist vetoed $193,900 of spending for the park and planning commission, half of it for planning staff and $65,000 to replace park equipment.

His other vetoes included $176,000 that would pay for four nurses, one therapeutic counselor and a part-time doctor in the Health Department, and $52,800 for community use of schools. He asked that the county's elevator inspection program be phased out and assumed by the state with an initial cut of $100,000, and that half the funds for the waste-water analysis laboratory amounting to $55,500 be cut in favor of contractual services.