Maryland Code, Natural Resources § 8-101

(e)(1) “Pollution” means every contamination or other alteration of the physical, chemical, or biological properties, of any waters of the State.

(2) “Pollution” includes change in temperature, taste, color, turbidity, or odor of the waters of the State or the discharge or deposit of any organic matter, harmful organism, or liquid, gaseous, solid, radioactive, or other substance into any waters of the State as will render the waters of the State harmful, detrimental, or injurious to public health, safety, or welfare, domestic, commercial, industrial, agricultural, recreational, other legitimate beneficial uses, or livestock, wild animals, birds, fish, or other aquatic life.

(1) Both surface and underground waters within the boundaries of the State subject to its jurisdiction;

(2) That portion of the Atlantic Ocean within the boundaries of the State;

(3) The Chesapeake Bay and its tributaries;

(4) All ponds, lakes, rivers, streams, public ditches, tax ditches, and public drainage systems within the State, other than those designed and used to collect, convey, or dispose of sanitary sewage; and

(5) The floodplain of free-flowing waters determined by the Department of the Environment on the basis of the 100-year flood frequency.