An Arlington woman and her 13-year-old baby sitter said yesterday they are planning to sue a Lively, Va., recreation center for refusing to admit the girl to its swimming pool because she is black.

Jan Anderson and her baby sitter, identified only as Beverly, said at a news conference that they plan to sue the center because of an Aug. 15 incident when they visited friends in Lively, a small community on Virginia's Northern Neck, and attempted to swim at the Upper Lancaster Ruritan Recreation Center. "We walked up to the window and the young man in charge looked up, saw Beverly, and said, 'We don't allow blacks in our pool,' " Anderson said.

The pool's manager, Carl Oliver, could not be reached. A pool employe, who would not give his name, said the center is a private club whose membership is determined by a board of directors. He said no blacks are members of the center.

Victor Glasberg, an Alexandria attorney who said he is representing Anderson and Beverly, said he is researching the center's status. "If it's private, they can exclude whomever they want," said Glasberg, who represented three black women who sued a Marshall restaurant for failing to serve them. Glasbery said the swim center appears to have been organized by a social service group.