Louisiana Administrative Code
Title 43 - NATURAL RESOURCES
Part XV - Office of Conservation-Surface Mining
Subpart 5 - Permanent Program Performance Standards
Chapter 53 - Permanent Program Performance Standards: Surface Mining Activities
Section XV-5333 - Hydrologic Balance: Impoundments

1. Impoundments meeting the Class B or C criteria for dams in the U.S. Department of Agriculture, Soil Conservation Service Technical Release Number 60 (210-VI-TR60, Oct. 1985), Earth Dams and Reservoirs, 1985 shall comply with "Minimum Emergency Spillway Hydrologic Criteria" table in TR-60 and the requirements of this section. The technical release is hereby incorporated by reference. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from the National Technical Information Service (NTIS), 5285 Port Royal Road, Springfield, Virginia 22161, order Number PB 87-157509/AS. Copies can be inspected at the OSM Headquarters Office, Office of Surface Mining Reclamation and Enforcement, Administrative Record, Room 660, 800 North Capitol Street, Washington, D.C., or at the Office of the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, D.C.

2. Impoundments meeting the criteria of 30 CFR 77.216(a) shall comply with the requirements of 30 CFR 77.216 and § 5333.

3. Design Certification. The design of impoundments shall be certified in accordance with §2725. A as designed to meet the requirements of Chapter 53 using current prudent engineering practices and any design criteria established by the office. The qualified registered professional engineer shall be experienced in the design and construction of impoundments.

4. Stability

5. Freeboard. Impoundments shall have adequate freeboard to resist overtopping by waves and by sudden increases in storage volume. Impoundments meeting the Class B or C criteria for dams in TR-60 shall comply with the freeboard hydrograph criteria in the "Minimum Emergency Spillway Hydrologic Criteria" table in TR-60.

6. Foundation

7. Slope protection shall be provided to protect against surface erosion at the site and to protect against sudden drawdown.

8. Faces of embankments and surrounding areas shall be vegetated, except that faces where water is impounded may be riprapped or otherwise stabilized in accordance with accepted design practices.

9. Spillways. An impoundment shall include either a combination of principal and emergency spillways or a single spillway configured as specified in §5333. A.9 a, designed and constructed to safely pass the applicable design precipitation event specified in §5333. A.9 b, except as set forth in §5333. C 2

10. The vertical portion of any remaining highwall shall be located far enough below the low-water line along the full extent of the highwall to provide adequate safety and access for the proposed water users.

11. Inspections. A qualified registered professional engineer or other qualified professional specialist, under the direction of the professional engineer, shall inspect the impoundment. The professional engineer or specialist shall be experienced in the construction of impoundments.

12. Impoundments meeting the SCS Class B or C criteria for dams in TR-60, or the size or other criteria of 30 CFR 77.216 must be examined in accordance with 30 CFR 77.216-3. Impoundments not meeting the SCS Class B or C criteria for dams in TR-60, or subject to 30 CFR 77.216, shall be examined at least quarterly. A qualified person designated by the operator shall examine impoundments for the appearance of structural weakness and other hazardous conditions.

13. Emergency Procedures. If any examination or inspection discloses that a potential hazard exists, the person who examined the impoundment shall promptly inform the office of the finding and of the emergency procedures formulated for public protection and remedial action. If adequate procedures cannot be formulated or implemented, the office shall be notified immediately. The office shall then notify the appropriate agencies that other emergency procedures are required to protect the public.

1. the size and configuration of such impoundment will be adequate for its intended purposes;

2. the quality of impounded water will be suitable on a permanent basis for its intended use and, after reclamation, will meet applicable state and federal water quality standards, and discharges from the impoundment will meet applicable effluent limitations and will not degrade the quality of receiving water below applicable state and federal water quality standards;

3. the water level will be sufficiently stable and be capable of supporting the intended use;

4. final grading will provide for adequate safety and access for proposed water users;

5. the impoundment will not result in the diminution of the quality and quantity of water utilized by adjacent or surrounding landowners for agricultural, industrial, recreational or domestic uses;

6. the impoundment will be suitable for the approved post-mining land use;

7. the design precipitation event for the spillways for a permanent impoundment meeting the size or other criteria of 30 CFR 77.216(a) is a 100-year, 6-hour event, or greater event as specified by the office;

8. the design precipitation event for the spillways for a permanent impoundment not meeting the size or other criteria of 30 CFR 77.216(a) is a 25-year, 6-hour event, or greater event as specified by the office.

1. The office may authorize the construction of temporary impoundments as part of a surface coal mining operation.

2. In lieu of meeting the requirements in §5333. A.9 a, the office may approve an impoundment that relies primarily on storage to control the runoff from the design precipitation event when it is demonstrated by the operator and certified by a qualified registered professional engineer that the impoundment will safely control the design precipitation event, the water from which shall be safely removed in accordance with current, prudent, engineering practices. Such an impoundment shall be located where failure would not be expected to cause loss of life or serious property damage, except where: