Maryland Environment Section 9-331

      By rule, regulation, order, permit, or otherwise, the Department may require the owner or operator of any source of a discharge of pollutants or of any source that is an industrial user of a publicly owned treatment works:

            (1)      To keep records;

            (2)      To make reports;

            (3)      To install, calibrate, use, and maintain monitoring equipment or methods, including, where appropriate, biological monitoring methods;

            (4)      To sample discharges in accordance with the methods, at the locations, at the intervals, and in the manner the Department requires; and

            (5)      To provide to the Department any information that the Department reasonably requires about:

                  (i)      Discharge of pollutants into the waters of this State; or

                  (ii)      Introduction of pollutants into publicly owned treatment works.