The truth-in-menu movement, which arose in Los Angeles a year ago and has caught the fancy of consumer protectors, health inspectors snd attorneys general from coast to coast, has now slipped quietly into the District of Columbia. And Washington restauranteurs are peeved.

Chopped sirloin, they acknowledge, almost invaluably "ground-up sirloin is dry like straw," says one restaurant owner - and Idaho potatoes can come from just about anywhere.

"But the basic fact is that people know what they're eating," says Art Anderson, manager of the Golden Ox at 1615 L Street NW. In any case, "the industry in town is not that booming," says Anderson. "We don't need this."

The Golden Ox is one of about so restaurants that have been visited over the last two weeks by the District's Office of Environmental Health Education and Program Evaluation.

"We're just conducting a survey," explains Robert M. Beck, the office's director. "We're not out at this point to try to find fraud or anything." On the need for additional legislation, "we're open-minded," says Beck.

While results of the survey won't be revealed until its completion several weeks from now, Beck has informed the Restaurant Association of Metropolitan Washington of the first day's findings. Of five restaurants surveyed, four, according in Beck's office, were guilty of some form of menu misreprsentation. Typical errors included:

A "20-ounce Maine Lobster" weighed only 16 ounces.

"prime roast beef" was choice grade.

"Fresh calves liver" and "fresh rockfish" were frozen.

"Roquefort cheese," "Vermont turkey," "Danish ham," "Alleghany mountain trout," "Icelandic baby lobster tails," and "Canadian baby back pork ribs" all hailed from locations other than those advertised.

"Atlantic Bay shrimp salad" was not only canned but came from the Norh Pacific.

Although Beck says his office is only researching the issue at this stage, several Washington restaurant owners already have gone through their menus with red ink. The owner of one large downtown restaurant says he was advised by a health department inspector, who had toured the premises, to amend or delete such statements as "We bake our own bread, rolls and cake" (the inspector found an outside loaf of pumpernickel), "fresh juices" (the tomato was canned), "our own marinated herring" (canned, again) and "spring lamb" (in October).

Restaurantt managers and D.C. official agree that some phrases - for instance, "prime ribs" used regardless of government grade - are so wide-spread and longstanding that they "just become the name," as Beck puts it.

Beck also disavows any interest in monitoring claims as tos tyles or nationalities of cooking, although some restaurant people seem to have gotten a different impression and are busily renaming their "Spanish omelettes" and "Hungarian goulash."

At the Golden Ox, according to manager Anderson, he was put on notice about the phrase "aged beef" - some of his beef is aged on the premises, says Anderson, and some undergoers a simulated aging process called "cry vac" during transport.

He also was warned about "freshly baked rum pie." Anderson says. "Mine is baked tow blocks away and it comes here two hours later. I don't have the facilities to make something like that."

Anderson says he was not cautioned about the phrase "Kansas City sirloin - the steak that was born in our stock yards." His steaks don't come exclusively from Kansas City. Anderson concedes, but they do come from the West (the Golden Ox is owned by the "Kansas City Stock Yards Co. of Maine.")

"To make a menu right," says Anderson. "you have to make it so that the words sound appetizing . . . The health department is going about this thing like they think we're a bunch of crooks."