The following sanitary districts and persons shall keep any record that the Secretary requires: Any sanitary district or person who supplies water, ice, sewerage, or refuse disposal service to the public; Any person who owns an industrial establishment; and Any person who owns a private water supply system or private sewerage system. 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. To determine compliance with any regulation, permit, or order of the Secretary, a representative of the Secretary may: Enter any private property; 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 Collect samples, records, and information. To determine compliance with pretreatment requirements of this title, a representative of the Secretary may: Enter any building, structure, or land of an industrial establishment that is or may be subject to pretreatment requirements; and Collect samples, records, and information. The Secretary may bring an action for an injunction to enforce this section without showing lack of an adequate remedy at law.