Section 784.20. Subsidence control plan

(a) Presubsidence survey. Each application must include:

(1) A map of the permit and adjacent areas at a scale of 1:12,000, or larger if determined necessary by the division, showing the location and type of structures and renewable resource lands that subsidence may materially damage or for which the value or reasonably foreseeable use may be diminished by subsidence, and showing the location and type of drinking, domestic, and residential water supplies that could be contaminated, diminished, or interrupted by subsidence.

(2) A narrative indicating whether subsidence, if it occurred, could cause material damage to or diminish the value or reasonably foreseeable use of such structures or renewable resource lands or could contaminate, diminish, or interrupt drinking, domestic, or residential water supplies.

(3) A survey of the quantity and quality of all drinking, domestic and residential water supplies within the permit area and adjacent area that could be contaminated, diminished or interrupted by subsidence. If the applicant cannot make this survey because the owner will not allow access to the site, the applicant will notify the owner in writing of the effect that denial of access will have pursuant to § 45.1-258 D of the Code of Virginia, as amended. The applicant must pay for any technical assessment or engineering evaluation used to determine the quantity and quality of drinking, domestic, or residential water supplies. The applicant must provide copies of the survey and any technical assessment or engineering evaluation to the property owner and the division.

(b) Subsidence control plan. If the survey conducted under subsection (a) of this section shows that no structures, or drinking, domestic, or residential water supplies, or renewable resource lands exist, or that no material damage or diminution in value or reasonably foreseeable use of such structures or lands, and no contamination, diminution or interruption of such water supplies would occur as a result of mine subsidence, and if the division agrees with this conclusion, no further information need be provided under this section. If the survey shows that structures, renewable resource lands, or water supplies exist and that subsidence could cause material damage or diminution in value or reasonably foreseeable use, or contamination, diminution or interruption of protected water supplies, or if the division determines that damage, diminution, in value or foreseeable use, or contamination, diminution, or interruption could occur, the application must include a subsidence control plan that contains the following information:

(1) A description of the method of coal removal, such as longwall mining, room-and-pillar removal or hydraulic mining including the size, sequence and timing of the development of underground workings;

(2) A map of the underground workings that describes the location and extent of the areas in which planned subsidence mining methods will be used and that identifies all areas where the measures described in subdivisions (b) (4), (b) (5), and (b) (7) of this section will be taken to prevent or minimize subsidence and subsidence related damage; and, when applicable, to correct subsidence related material damage;

(3) A description of the physical conditions, such as depth of cover, seam thickness and lithology of overlaying strata, that affects the likelihood or extent of subsidence and subsidence related damage;

(4) A description of the monitoring, if any, needed to determine the commencement and degree of subsidence so that, when appropriate, other measures can be taken to prevent, reduce, or correct material damage in accordance with 4VAC25-130-817.121 (c).

(5) Except for those areas where planned subsidence is projected to be used, a detailed description of the subsidence control measures that will be taken to prevent or minimize subsidence and subsidence related damage, such as, but not limited to:

(i) Backstowing or backfilling of voids;

(ii) Leaving support pillars of coal;

(iii) Leaving areas in which no coal is removed, including a description of the overlying area to be protected by leaving coal in place; and

(iv) Taking measures on the surface to prevent or minimize material damage or diminution in value of the surface.

(6) A description of the anticipated effects of planned subsidence, if any.

(7) For those areas where planned subsidence is projected to be used, a description of methods to be employed to minimize damage from planned subsidence to noncommercial buildings and occupied residential dwellings and structures related thereto; or the written consent of the owner of the structure or facility that minimization measures not be taken; or, unless the anticipated damage would constitute a threat to health or safety, a demonstration that the costs of minimizing damage exceed the anticipated costs or repair.

(8) A description of the measures to be taken in accordance with 4VAC25-130-817.41 (j) and 4VAC25-130-817.121 (c) to replace adversely affected protected water supplies or to mitigate or remedy any subsidence related material damage to the land and protected structures.

(9) Other information specified by the division as necessary to demonstrate that the operation will be conducted in accordance with 4VAC25-130-817.121.

Historical Notes

Derived from VR480-03-19 § 784.20, eff. December 15, 1981; amended, eff. June 28, 1982; October 28, 1982; December 14, 1982; October 11, 1983; December 27, 1983; May 8, 1984; June 22, 1984; August 2, 1984; October 16, 1985; January 7, 1987; July 22, 1987; November 25, 1987; October 12, 1988; December 26, 1990; July 1, 1991; July 17, 1991; November 20, 1991; July 7, 1992; May 5, 1993; October 19, 1994; Volume 14, Issue 05, eff. December 24, 1997; Errata, 14:10 VA.R. 1751 February 2, 1998; amended, Virginia Register Volume 23, Issue 13, eff. April 4, 2007.

Statutory Authority

§§ 45.1-161.3 and 45.1-230 of the Code of Virginia.