Md. Code, Env't § 9-261

(a) The following sanitary districts and persons shall keep any record that the Secretary requires: (1) Any sanitary district or person who supplies water, ice, sewerage, or refuse disposal service to the public; (2) Any person who owns an industrial establishment; and (3) Any person who owns a private water supply system or private sewerage system. (b) Any sanitary district or person who keeps a record under subsection (a) of this section shall make the record available to the Secretary on request. (c) (1) To determine compliance with any regulation, permit, or order of the Secretary, a representative of the Secretary may: (i) Enter any private property; (ii) Enter any building, structure, or land owned by a sanitary district or person who supplies water, ice, sewerage, or refuse disposal service to the public; and (iii) Collect samples, records, and information. (2) To determine compliance with pretreatment requirements of this title, a representative of the Secretary may: (i) Enter any building, structure, or land of an industrial establishment that is or may be subject to pretreatment requirements; and (ii) Collect samples, records, and information. (d) The Secretary may bring an action for an injunction to enforce this section without showing lack of an adequate remedy at law.