Chapter 28. Backfilling
Regulation .01 Contemporaneous Reclamation.LinkCopy Citation
A.
Reclamation efforts, including, but not limited to, backfilling, grading, topsoil replacement and revegetation, of all land that is disturbed by surface mining activities, shall occur as contemporaneously as practicable with mining operations.
B.
Unless otherwise approved by the Bureau, upon a demonstration by the permittee, through a detailed written analysis, in the permit application, that a variation is necessary:
(1)
In contour mining operations, rough backfilling and grading shall follow coal removal by not more than 1500 linear feet;
(2)
In area surface mining operations, rough backfilling and grading may not be more than three spoil ridges behind the pit being worked, the spoil from the active pit being considered the first ridge;
(3)
In addition to, and notwithstanding the requirements of, §B(1) and (2) of this regulation, rough backfilling and grading shall begin within a time not to exceed 60 days of completion of all coal removal within a pit, designated area, or phase, and shall be continuous until completion;
(4)
Within 5 days of completion of all coal removal on the permit area, rough backfilling and grading shall begin on the unreclaimed areas, and shall be continuous until completion, not to exceed 1 year after all coal removal.
C.
The number of open acres may not exceed the open acre limit.
D.
In order to minimize the amount of area that has not been backfilled and seeded by the close of a planting season, the Bureau may require backfilling, grading, topsoil redistribution, and seeding of open acres at times, rates, and locations that do not impinge upon the areas required for overburden removal, spoil placement, coal removal, approved haul roads, sediment control structures, and processing and shipping areas.
Regulation .02 Method for Backfilling and Grading.LinkCopy Citation
A.
Except as specifically exempted in this chapter, all disturbed areas shall be returned to their approximate original contour. All spoil shall be transported, backfilled, compacted (where advisable to ensure stability or to prevent leaching) and graded to eliminate all highwalls, spoil piles, and depressions.
B.
Backfilled material shall be placed to minimize erosion and water pollution both on and off the site, to minimize adverse effects on ground water, and to support the approved postmining land use.
C.
The postmining graded slopes need not be of uniform slope.
D.
Cut-and-fill terraces may be used only in those situations expressly identified in Regulation .03 of this chapter.
Regulation .03 General Requirements.LinkCopy Citation
A.
Postmining final graded slopes need not be uniform but shall approximate the general nature of the pre-mining topography. These requirements may be modified by the Bureau where the surface mining activities are reaffecting previously mined lands that have not been restored to these standards, and sufficient spoil is not available to otherwise comply with this chapter. The permittee shall, at a minimum:
(1)
Retain all overburden and spoil on the solid portion of existing or new benches; and
(2)
Backfill and grade to the most moderate slope possible to eliminate the highwall which does not exceed either the angle of repose or such lesser slope as is necessary to achieve a minimum long-term static safety factor of 1.5. In all cases the highwall shall be eliminated.
B.
On approval by the Bureau in order to conserve soil moisture, ensure stability, and control erosion on final graded slopes, cut and fill terraces may be allowed. The terraces shall be compatible with the approved postmining land use, and can be appropriate substitutes for construction of lower grades on the reclaimed lands. The terraces shall meet all of the following requirements:
(1)
The width of the individual terrace bench may not exceed 20 feet, unless specifically approved by the Bureau as necessary for stability, erosion control, or roads included in the approved postmining land use plan.
(2)
The vertical distance between terraces shall be as specified by the Bureau to prevent excessive erosion and to provide long-term stability.
(3)
The slope of the terrace outslope may not exceed 2:1. Outslopes which exceed 2:1 may be approved, if they have a minimum static safety factor of 1.5, provide adequate control over erosion, and closely resemble the surface configuration of the land before mining. Highwalls may not be left as part of terraces.
C.
Small depressions may be constructed, if they:
(1)
Are approved by the Bureau to minimize erosion, conserve soil moisture, create and enhance wildlife habitat, or promote vegetation;
(2)
Do not restrict normal access; and
(3)
Are approved, in writing, by the landowner.
D.
Preparation of final graded surfaces shall be conducted in a manner which minimizes erosion and provides a surface for replacement of topsoil which will minimize slippage.
E.
Spoil may be placed on the permit outside the mined-out area in non-steep slope areas to restore the approximate original contour by blending the spoil into the surrounding terrain if the following requirements are met:
(1)
All vegetative and organic material shall be removed from the area;
(2)
The topsoil on the area shall be removed, segregated, stored, and redistributed in accordance with COMAR 26.20.25.02;
(3)
The spoil shall be backfilled and graded on the area in accordance with the requirements of this chapter.
Regulation .04 Covering Coal and Acid-Forming and Toxic-Forming Materials.LinkCopy Citation
A.
Cover.
(1)
The permittee shall either cover, with a minimum of 4 feet of the best available nontoxic and noncombustible material, or treat all exposed coal seams remaining after mining, and all acid-forming materials, toxic-forming materials, combustible materials, or any other materials identified by the Bureau as exposed, used, or produced during mining.
(2)
Cover or treatment shall be provided so as to neutralize toxicity, acidity, and combustibility in order to prevent water pollution and sustained combustion, and to minimize adverse effects on plant growth and land uses.
(3)
Where necessary to protect against upward migration of salts, exposure by erosion, formation of acid or toxic seeps, to provide an adequate depth for plant growth, or otherwise to meet local conditions, the Bureau shall specify thicker amounts of cover using nontoxic materials, or special compaction and isolation from ground water contact.
(4)
Acid-forming or toxic-forming material may not be buried or stored in proximity to a drainage course so as to cause or pose a threat of water pollution.
B.
Drainage from acid-forming and toxic-forming spoil into ground and surface water shall be avoided by:
(1)
Identifying, burying, and treating, where necessary, spoil which in the judgement of the Bureau may be detrimental to vegetation or may adversely affect water quality if not treated or buried;
(2)
Preventing water from coming into contact with acid-forming and toxic-forming spoil and other measures as required by the Bureau; and
(3)
Burying or otherwise treating all acid-forming or toxic-forming spoil within 30 days after it is first exposed on the mine site, or within a lesser period required by the Bureau. Temporary storage of the spoil may be approved by the Bureau upon a finding that burial or treatment within 30 days is not feasible, and that storage will not result in any material risk of water pollution or other environmental damage. Storage approval shall expire as soon as burial or treatment first becomes feasible. Acid-forming or toxic-forming spoil to be stored shall be placed on impermeable material and protected from erosion and contact with surface water.
C.
Stabilization. Backfilled materials shall be selectively hauled or conveyed, and compacted, wherever necessary to prevent leaching of acid-forming and toxic-forming materials into surface or ground waters and wherever necessary to insure stability of the backfilled materials. The method and design specifications of compacting materials shall be approved by the Bureau before acid-forming and toxic-forming materials are covered.
Regulation .05 Overburden.LinkCopy Citation
Surface mining activities shall be conducted to meet, at a minimum, the following standards:
A.
All spoil and wastes not required to achieve the approximate original contour of the mine plan area shall be hauled or conveyed, backfilled, or graded to the lowest practicable grade, to achieve a static factor of safety of 1.3 and cover all acid-forming and other toxic-forming materials;
B.
Haul or convey, backfill, and grade excess spoil and wastes only within the permit area and dispose of the materials in accordance with COMAR 26.20.26.
C.
Haul or convey, backfill, and grade excess spoil and wastes to maintain the hydrologic balance and to provide long term stability by preventing slides, erosion, and water pollution;
D.
Haul or convey, backfill, grade, and revegetate wastes and excess spoil to achieve an ecologically sound land use approved by the Bureau as compatible with the prevailing land uses in unmined areas surrounding the mine plan area;
E.
Eliminate all highwalls and depressions by backfilling with spoil and suitable waste materials; and
F.
Meet the revegetation requirements for all disturbed areas.
Regulation .06 Regrading or Stabilizing Rills and Gullies.LinkCopy Citation
When rills or gullies deeper than 9 inches form in areas that have been regraded and top-soiled, the rills and gullies shall be filled, graded, or otherwise stabilized and the area area reseeded or replanted in accordance with the revegetation requirements. The Bureau shall specify that rills or gullies of lesser size be stabilized and the area reseeded or replanted if the rills or gullies are disruptive to the approved postmining land use or may result in additional erosion and sedimentation.
Chapter annotations
Authority: Environment Article, §15-503, Annotated Code of Maryland
History: Effective date:
History: Regulations .01—.06 were previously codified as COMAR 08.13.09.34A—F, respectively. Recodification occurred in April, 1993. For a history of these regulations before April, 1993, see "Administrative History of COMAR 08.13.09 before April, 1993" which follows COMAR 26.20.01.
History: Chapter recodified from COMAR 08.20.28 to COMAR 26.20.28, June 1996