This episode's headline: Ruckelshaus Nomination. The guests include Rep. ELLIOTT LEVITAS, Democrat, Georgia; Sen. ROBERT STAFFORD, Republican, Vermont; In Chicago: Dr. SAMUEL SPSTEIN, Environmental Expert. Byline: In New York: ROBERT MacNEIL, Executive Editor; In Washington: JIM LEHRER, Associate Editor; JOE QUINLAN, DAN WERNER, Producers; NANCY NICHOLS, Reporter