If the council of any city in the State having a population of more than one hundred thousand, according to the last federal census, shall, upon such investigation as it deems necessary, determine:
The commissioners shall present to the Secretary of State an application signed by them, which shall set forth (without any detail other than the mere recital):
When the application has been made, filed and recorded, as herein provided, the authority shall constitute a public body and a body corporate and politic under the name proposed in the application; the Secretary of State shall make and issue to the said commissioners a certificate of incorporation pursuant to this Part, under the seal of the State, and shall record the same with the application.
The boundaries of such authority shall include said city and the area within 10 miles from the territorial boundaries of said city, but in no event shall it include the whole or a part of any other city nor any area included within the boundaries of another authority. In case an area lies within 10 miles of the boundaries of more than one city, such area shall be deemed to be within the boundaries of the authority embracing such area which was first established, all priorities to be determined on the basis of the time of the issuance of the aforesaid certificates by the Secretary of State. After the creation of an authority, the subsequent existence within its territorial boundaries of more than one city shall in no way affect the territorial boundaries of such authority.
In any suit, action or proceeding involving the validity or enforcement of or relating to any contract of the authority, the authority shall be conclusively deemed to have been established in accordance with the provisions of this Part upon proof of the issuance of the aforesaid certificate by the Secretary of State. A copy of such certificate, duly certified by the Secretary of State, shall be admissible evidence in any such suit, action or proceeding, and shall be conclusive proof of the filing and contents thereof.
N.C. Gen. Stat. § 143B-1253