Md. Code, Nat. Res. § 3-916
The exercise of the powers granted by this subtitle is and will be in all respects for the benefit of the people of the State of Maryland and the participating counties, for the increase of their commerce, welfare and prosperity, and for the improvement of their health and living conditions, and since the activities of the Authority and the operation and maintenance of its projects will constitute the performance of essential governmental functions, the Authority shall be exempt from any payment of or liability for any and all taxes, whether federal, State, or local, now or hereafter levied or imposed, and any assessments or other governmental charges. The bonds of the Authority, their transfer, the interest payable thereon, and any income derived therefrom, including any profit realized in the sale or exchange thereof, shall at all times be exempt from taxation of every kind and nature whatsoever by the State of Maryland or by any of its political subdivisions, municipal corporations, or public agencies of any kind.
Md. Code, NR § 3-916