Required mining waste site inspections, record keeping, reporting, and responses
Wis. Stat. § 295.635
in effect(1) Definitions. In this section:
(a) “Active dam” means a dam and associated settling area into which tailings or wastewater are being introduced or that has not been reclaimed in a manner approved by the department.
(b) “Inactive dam” means a dam and associated settling area that is no longer being used for disposal of tailings or wastewater and that has been reclaimed in a manner approved by the department.
(2) General. The operator shall, at least monthly, visually inspect all of the following and record observations in a mining waste site operating log:
(a) The active portions of the mining waste site for possible damage or structural weakening.
(b) Mining waste handling and monitoring equipment and readings, to ensure normal operation and measurements.
(c) Fences or barriers around the mining waste site, for possible damage.
(d) The buffer area around the mining waste site, for possible environmental damage related to its operation.
(3) Active dams. The operator shall, at least monthly, inspect active dams and record the findings in the mining waste site operating log. The operator shall record at least all of the following findings:
(a) Condition of vegetation on the dam and within 50 feet from the outside base.
(b) Piezometric levels within the mass of the dam.
(c) Condition of soil surfaces on the top and slopes of the dam and within 50 feet from the outside base.
(d) Condition of drainage ditches near the base of the dam.
(e) Liquid surface level and amount of freeboard.
(f) Condition of spillways, conduits, and water level control structures.
(4) Inactive dams. The operator shall inspect inactive dams quarterly and record the findings in the mining waste site operating log. The operator shall record at least all of the following findings:
(a) Condition of soil surfaces on the top and slopes of the dam and within 50 feet from the outside base.
(b) Piezometric levels within the mass of the dam if that instrumentation has been determined to be necessary or is required in the long-term care provisions of the mining waste site feasibility study and plan of operation.
(c) Condition of spillways, conduits, and water level control structures.
(5) Defective conditions of dams posing risk of adverse impact. When a defective condition that poses a significant risk of adverse impact to the environment is found during an inspection of a dam, the operator shall ensure that it is recorded and corrected at the earliest practicable time. At the earliest practicable time, the operator shall make a written report to the department of the condition and the actions proposed and taken for its correction. Within 5 business days of receipt of a written report, the department may confirm the correction of the condition and specify any necessary additional corrective action. An operator shall consider any of the following items as indicating a condition that requires prompt investigation and that may require corrective action:
(a) Seepage on the outer face of the dam accompanied by boils, sand cones, or deltas.
(b) Silt accumulations, boils, deltas, or cones in the drainage ditches at the base of the dam.
(c) Cracking of soil surface on the top or either face of the dam.
(d) Bulging of the outside face of the dam.
(e) Seepage, damp areas, or boils in the vicinity of, or erosion around, a conduit through the dam.
(f) Any shrinkage of the top or faces of the dam.
(6) Potential defects of dams. All of the following conditions indicate potential defects and the operator shall closely check them on subsequent inspections for an active dam and conduct an intermediate inspection if they exist for an inactive dam:
(a) Patches of overgrown vegetation on the outside face or close to the base of the dam.
(b) Surface erosion, gullying, or wave erosion on the inside of the dam.
(c) Surface erosion, gullying, or damp areas on the outside of the dam, including the berm and the area within 50 feet from the outside base.
(d) Erosion below any conduit.
(e) Wet areas or soggy soil on the outside of, or in natural soil below, the dam.
(7) Record keeping related to dams.
(a) The operator shall retain all records relating to dam monitoring, analytical, and verification activities and data, including all original strip chart recordings and instrumentation, calibration, and maintenance records, until termination of operator responsibility, except to the extent that copies of those records have previously been provided to the department.
(b) The operator shall maintain in a permanent file all of the following construction records pertaining to any dam in case they are needed for future reference:
1. Aerial photos of the construction site before construction.
2. Construction drawings and modifications of the drawings.
3. Construction specifications and modifications of the specifications.
4. Results of all soil tests on foundations and fill materials.
5. Logs of borings and engineering geology reports.
6. Copies of construction progress inspections pertinent to core trench, toe drain, internal drains, and other significant phases of the structure including, at the option of the operator, photographs of various structural items.
7. Aerial photos of the entire dam taken within 90 days after all construction is completed.
8. A description of and justification for all deviations or variances from the construction plans and specifications.
(8) Responses to unplanned events. If a mining waste site has an accidental or emergency discharge, a fire, an explosion, or other unplanned or unpredicted event that is likely to damage human health or the environment, the operator shall follow the procedures set forth in the contingency plan under s. 295.51 (6) (f) and shall report the incident to the department and to county, town, and tribal governmental agencies immediately after the operator has discovered the event.
(9) Annual report. The operator shall submit to the department an annual summary report concerning the mining waste site containing all of the following:
(a) Statistical summaries of annual and cumulative data.
(b) A comparison of the summaries under par. (a) to mining waste characterization, leachate characterizations, effluent predictions, and baseline water quality and background water quality data as contained in the approved mining waste site feasibility study and plan of operation.
(c) The results of verification procedures and a presentation of the error associated with each parameter reported.
(d) Information from monitoring wells that have not been affected, including a discussion of whether the baseline values should be modified due to natural variability and what the new values should be.
(10) Applicability. This section does not apply to a surface mine that is backfilled with mining waste.
Source: WI Statutes (Official Site)URL: https://docs.legis.wisconsin.gov/document/statutes/295.635Fetched: 10/7/2026