Maryland Code, Public Utilities § 12-123

(a)(1) An owner shall be a member of a one-call system.

(2) Except as provided in paragraph (3) of this subsection, an owner becomes a member of a one-call system by registering with the one-call system.

(3) The Department of Transportation, its administrations, and the Maryland Transportation Authority shall become members of the one-call system through a separate agreement and using the information collected under § 12-124(b)(2) of this subtitle.

(b)(1) An owner-member of a one-call system shall submit to the one-call system, in writing, the telephone number of the person to which calls concerning proposed excavations or demolitions shall be directed.

(2) An owner-member shall ensure that all contact information provided to the one-call system remains current.