30 CFR §77.216-4

1. (a)Except as provided in paragraph (b) of this section, every twelfth month following the date of the initial plan approval, the person owning, operating, or controlling a water, sediment, or slurry impoundment and impounding structure that has not been abandoned in accordance with an approved plan shall submit to the District Manager a report containing the following information:
   1. (1)Changes in the geometry of the impounding structure for the reporting period.
   2. (2)Location and type of installed instruments and the maximum and minimum recorded readings of each instrument for the reporting period.
   3. (3)The minimum, maximum, and present depth and elevation of the impounded water, sediment, or slurry for the reporting period.
   4. (4)Storage capacity of the impounding structure.
   5. (5)The volume of the impounded water, sediment, or slurry at the end of the reporting period.
   6. (6)Any other change which may have affected the stability or operation of the impounding structure that has occurred during the reporting period.
   7. (7)A certification by a registered professional engineer that all construction, operation, and maintenance was in accordance with the approved plan.
2. (b)A report is not required under this section when the operator provides the District Manager with a certification by a registered professional engineer that there have been no changes under paragraphs (a)(1) through (a)(6) of this section to the impoundment or impounding structure. However, a report containing the information set out in paragraph (a) of this section shall be submitted to the District Manager at least every 5 years.