Under the deal, Katherine O'Connor, 19, of Pittsburgh and another student, Robb Godshaw, 22, of Wilmette, Ill., will have to put in the service hours before an Oct. 21 court appearance, when a magistrate will dismiss the charges against them, the ACLU said.
Both students marched in the April parade sponsored by CMU's College of Fine Arts. O'Connor tossed condoms to spectators; Godshaw was dressed as an astronaut walking on a moon-like wheel before he took off his clothes, prompting the indecent exposure charge against him.
The ACLU said Monday it was important that the criminal charges be dismissed against the students because they could have been listed as sex offenders in some states had they been convicted.
University police charged the two last month after Bishop David Zubik of the Roman Catholic Diocese of Pittsburgh complained privately to school officials about O'Connor's performance, then publicly expressed concerns that her behavior was intolerant of Catholicism. Zubik was particularly upset because O'Connor had shaved her pubic hair in the shape of a cross.
The Rev. Ronald Lengwin, the diocesan spokesman, said that the bishop did not want the woman's future to be impaired by the criminal charge.
"Our concern from the very beginning as articulated by the bishop was a lack of respect for the religious beliefs of others," Lengwin said. "He hoped this would be a learning experience for this young woman. Now that community service is a way in which she can expunge her record, the bishop hopes that, too, would be a learning experience.
Mike Manko, a spokesman for the Allegheny County District Attorney's Office, said it wasn't "uncommon to dispose of misdemeanors in this way. In this case, all the parties involved including school officials and school police officials were in agreement on handling this matter this way."
University president Jared Cohon had previously apologized, saying the school encouraged artistic expression while acknowledging that public nudity is illegal.
The parade, known as the "Annual Anti-Gravity Downhill Derby," lampoons another event in which students push homemade vehicles and encourages performance art.
The ACLU said in a news release that O'Connor isn't commenting until the charges are formally withdrawn, though her attorney called the pending agreement to dismiss the charges "a great result." Godshaw's attorney didn't immediately return a call for comment.