N.D. Admin. Code 69-05.2-21-04

Current through Supplement No. 393, July, 2024

Section 69-05.2-21-04 - Performance standards - Backfilling and grading - Thin overburden

The provisions of this section apply only to mining activities where the final thickness of all available spoil and waste materials over the permit area is less than 0.8 of the initial thickness of the overburden and the coal or commercial leonardite prior to coal or commercial leonardite removal. The final thickness is the product of the overburden thickness prior to coal or commercial leonardite removal times the overburden swell factor. When the demonstration is made that thin overburden exists over the permit area, in addition to meeting subdivision b of subsection 3 of North Dakota Century Code section 38-14.1-24, the operator shall:

1. Transport, backfill, and grade, using all available spoil and suitable waste materials from the entire permit area, to attain the lowest practicable stable grade, to achieve a static safety

factor of 1.3 to provide adequate drainage and long-term stability of the regraded areas, and to cover all toxic-forming materials.

2. Eliminate highwalls by grading or backfilling to stable slopes not exceeding thirty-five percent, or lesser slopes as the commission may specify to reduce erosion, maintain the hydrologic balance, or achieve the approved postmining land use.

3. Transport, backfill, grade, and revegetate to achieve an ecologically sound land use compatible with the prevailing use in unmined areas surrounding the permit area.

4. Transport, backfill, and grade to ensure that impoundments are constructed only where:

a. It has been demonstrated to the commission that all requirements of chapter 69-05.2-16 have been met; and

b. The impoundments have been approved by the commission as suitable for the approved postmining land use and meet the requirements of this article and all other applicable state laws and regulations.

N.D. Admin Code 69-05.2-21-04

Effective August 1, 1980; amended effective June 1, 1983; May 1,1990.

Amended by Administrative Rules Supplement 2016-362, October 2016, effective 10/1/2016.

General Authority: NDCC 38-14.1-03

Law Implemented: NDCC 38-14.1-24