“Pollutant” shall mean dredged spoil, solid waste, incinerator residue, filter backwash wastewater, garbage, wastewater sludge, munitions, chemical wastes, biological materials, radioactive materials (except those regulated under the Atomic Energy Act of 1954, as amended [42 U.S.C. 2011 et seq.]), heat, wrecked or discarded equipment, rock, sand, cellar dirt or industrial, municipal and agricultural waste discharged into water or other entity, other than, or in addition to, domestic strength wastewater.