Evoqua – Duo-Deck Floating Steel Digester Covers provide distinct advantages over other floating covers. The completely all welded structure provides a sealed air space within which oxidation of the metal surfaces is virtually eliminated. Prevents scum blanket buildup. Floatable materials – oil, grease, hair, cellulose are kept constantly submerged and in contact with active digesting material. The material stays moist, aiding degradation. The safest design for maintenance personnel after several years of traffic under the cover.