SOME SAY it started with aid to federally impacted areas. Others insist it really got its big lift from the National Environmental Policy Act. Whatever the case, the impact-statement business is booming. Once environmentalists had shown how the technique could be employed to spotlight, pinpoint and catalogue practically anything, and in the process keep some things from happening . . . well, then people concerned about everything else that might be bruised by government just had to demand an impact statement, too.

President Ford called for inflation-impact statements. (Their impact on inflation hasn't been immense.) Congressional committee added paperwork-impact statements, which added to paperwork, and budget-impact statements, which gave the Congressional Budget Office more to do. Some civil libertarians want privacy-impact statements. Social-welfare groups think family-impact statements would be grand. The Justice Department has recommended enforcement-impact statements. The chief justice would like statements of everything's impact on the courts.

Now the Carter administration is earnestly working up another category: urban-impact analyses. According to National Journal, agencies will have to describe the impact of their "major initiatives" on cities, suburbs and non-metropolitan areas, rich and poor. The UIAs (better get used to that) will cover just a few small topics: employment, population, income and local fiscal conditions in each type of town. The analyses are also supposed to be, thank heavens, short and easy to prepare.

Or so they say. What we say is: Enough! An impact used to produce a sharp, emphatic sound - as when a bulldozer hits a tree. But what, pray tell, is the sound of a tax policy "impacting" on a suburb, or regulations "impacting" on a family's privacy - or yet another impact-statement controversy impacting on the courts? It is, we suspect, the dry rustling sound of paper shuffling its way across desk tops, accompanied by the happy hum of guaranteed employment for the people who are doing the shuffling.