ON WEDNESDAY, a letter to the editor from Edmund L. Castillo of Washington had a few less than laudatory things to say about the Capitol Hill groundskeeping performance by the office of the Architect of the Capitol, George White. Mr. Castillo reported that the portion of the Capitol grounds north of D Street NE, and particularly the area north of Massachusetts Avenue, was suffering from almost total lack of maintenance--even though Mr. White's work force--"judging from the size and apparent nonchalance of the occasional crew I see in the area--is hardly insufficient or underfunded. . . ."

The issue, in a word, was litter--six to eight weeks' worth before any cleanup--usually spread out and soaked by puddles from broken underground sprinkler pipes.

But since Wednesday's letter, Mr. Castillo has filed an additional report: On Thursday, out of the blue (or out of the Capitol) came a large and hustling crew of Mr. White's troops who in short order apparently did quite a cosmetic job on the area in question. "The area was crawling with work crews," Mr. Castillo said, noting that they removed litter, replaced some unsightly yellow barrels with new markers on pedestals, raked and spiffed up the allegedly temporary parking lot still used by Hill staff.

Though the neighbors are delighted by this sudden face lift, no one is quite sure how intensive the groundskeeping will continue to be. Mr. Castillo, while impressed by the coincidence of events, is reported to have stationery and stamped envelope at the ready.