The reunion episode will feature cast members Gloria Reuben (Jeanie Boulet), George Clooney (Doug Ross), Noah Wyle (John Carter), Laura Innes (Kerry Weaver), Anthony Edwards (Mark Greene), Julianna Margulies (Carol Hathaway), Goran Visnjic (Luka Kovac), Paul McCrane (Robert Romano), Ming-Na Wen (Jing-Mei Chen), Laura Cerón (Chuny Marquez), Yvette Freeman (Haleh Adams), Conni Marie Brazelton (Connie Oligario), Ellen Crawford (Lydia Wright) and CCH Pounder (Angela Hicks). This special episode of Stars in the House will be held in benefit of the Waterkeeper Alliance — the fastest growing global nonprofit focused solely on clean water.