NO FEDERAL OFFICIAL is likely to relish the thought of holding up construction of a factory in california or suspending federal highway aid to Michigan and New York. But those and similarly jolting step may well have to be taken in the next several months to keep the national clean-air efforts on track. The law says that by today -- July 1, 1979 -- every state must have come up with acceptable plans for meeting air-pollution standards by the end of 1982. The regions with severe smog problems, including Washington, may get extensions from 1982 to 1987 -- but only if, by now, they have agreed to set up programs for inspecting all motor vehicles and making owners maintain their pollution-control system properly.

Congress set hefty penalties for foot-dragging. From now on, until a state's plan has been approved, the Environmental Protection zAgency may not issue a permit for any new construction, such as a factory or power plant, that would add a major load of pollution to the air. If a state proves to be really recalcitrant -- for instance, by flatly refusing to move toward a car-inspection program -- federal aid for highways is to be withheld and funds for sewage treatment and other projects phased out.

In this area, where the primary pollution problem in smog the planning process is advancing rather well. The Maryland and Virginia legislatures have at least expressed their willingness to set up the required kind of vehicle-inspection programs. The District has agreed to expand its current efforts when the two states comply. President Carter's decision to raise the price of parking at federal offices was a big gain. And, at least in this regard, the gas crisis has turned out to be helpful by pushing so many commuters to mass transit and encouraging employers to adjust working hours to relieve the rush-hour jams.

In some other areas the picture is not as bright. Although the July 1 deadline was no secret, perhaps a dozen states -- including California -- are still far from submitting reasonable plans to EPA. The New York Legislature, for one, failed to adopt a vehicle-inspection plan this spring. EPA officials are not planning to be beastly to the laggard states. But the agency is in a difficult spot. If it is too patient, environmental groups are likely to sue for strict enforcement of the sanctions in the law. But if it does start holding up major industrial projects or suspending federal aid, the pressure on Congress to relax the deadlines could get very heavy.

The crucial signals will come from Congress -- and Congress ought to stand behind the deadlines it has set. Where states do have stubborn pollution problems, a little slippage in refining plans should not bring harsh sanctions into force. But Congress and EPA should insist on serious and timely commitments to clean up.