Chapter 13. Surface Effects of Deep Mines

Each mine entry which is temporarily inactive, but has a further projected useful service under the approved permit application, shall be protected by barricades or other covering devices, and fenced and posted with signs, to prevent access into the entry and to identify the hazardous nature of the opening. These devices shall be periodically inspected and maintained in good operating condition by the person who conducts the underground mining activities.

Each exploration hole, other drill hole, or borehole, shaft, well, and other exposed underground opening which has been identified in the approved permit application for use to return underground development waste, coal processing waste, or water to underground workings, or to be used to monitor ground water conditions, shall be temporarily sealed until actual use.

Unless excepted under §B of this regulation, each shaft, drift, adit tunnel, exploratory hole, entryway, or other opening to the surface from underground shall be capped, sealed, backfilled, or otherwise properly managed, as required by the Bureau. Permanent closure measures shall be designed to prevent access to the mine workings by people, livestock, fish and wildlife, and machinery, and to keep acid or other toxic drainage from entering ground or surface waters.

Permanent closure may not be required where an opening is needed for monitoring purposes, or is approved for transfer as a water well or some other use upon a showing of no adverse environmental or health and safety effects. Bureau approval shall be required for all these exceptions.

Mine opening seals shall be:

The surface disturbance for the face-up area may not exceed 400 lineal feet along the seam to be mined.

The face-up area shall be prepared in such a manner that drainage from the face-up area will result in minimum erosion and sedimentation. The face-up area may not be located in an area where the original contour of the land, measured from the cropline of the seam to be mined to the estimated toe of the fill bench, exceeds 20 degrees from the horizontal, unless no fill bench is created and the spoil from the face-up area is disposed in a suitable disposal area.

The amount of overburden and the amount of coal to be removed from the face-up area shall be set forth in the plan.

Surface openings and accesses to underground workings shall be located to prevent gravity discharge of water from the mine, unless it is demonstrated that the untreated discharge will comply with the performance standards of COMAR 26.20.21.02F.

In this regulation, an owner of interest in real property includes an owner, a renter, a tenant, or a lessee of real property.

Operations shall be conducted to minimize water pollution, and, where necessary, treatment methods shall be used to control water pollution.

Acceptable practices to control and minimize water pollution include but are not limited to:

The permittee shall promptly replace the water supply of an owner of interest in real property who obtains all or part of the owner's supply of water for domestic, agricultural, industrial, or other legitimate use from an underground or surface source that is contaminated, diminished, or interrupted proximately resulting from underground mining activities.

Upon agreement by the permittee and the water supply owner, the obligation to pay such operation and maintenance costs may be satisfied by a one time payment in an amount which covers the present worth of the increased annual operation and maintenance costs for a period agreed to by the permittee and the water supply owner.

If the affected water supply was not needed for the land use in existence at the time of loss, contamination, or diminution, and if the supply is not needed to achieve the postmining land use, replacement requirements may be satisfied by demonstrating that a suitable alternative water source is available and could feasibly be developed. If this approach is selected, written concurrence shall be obtained from the water supply owner.

All surface drainage from the disturbed area, including disturbed areas that have been graded, seeded, or planted, shall be passed through a sedimentation pond, a series of sedimentation ponds, or a treatment facility before leaving the permit area. Any discharge of water from underground workings to surface waters which does not meet the effluent limitations of the Regulatory Program shall also be passed through a sedimentation pond, a series of sedimentation ponds, or a treatment facility before leaving the permit area.

Sedimentation ponds and treatment facilities for surface drainage from the disturbed area shall be maintained until the disturbed area has been restored and the vegetation requirements are met and the quality of the untreated drainage from the disturbed area meets the applicable State and federal water quality standards requirements for the receiving stream. Sedimentation ponds and treatment facilities for discharges from underground workings shall be maintained until either the discharge continuously meets the effluent limitations of the Regulatory Program or until the discharge has permanently ceased.

The Bureau may grant exemptions from these requirements only in accordance with the following:

Sedimentation ponds shall be constructed in accordance with the Regulatory Program, in appropriate locations before beginning any underground mining activities in the affected drainage area.

If the sedimentation ponds or series of sedimentation ponds are used so as to result in the mixing of drainage from the disturbed areas with drainage from other areas not disturbed by current surface coal mining and reclamation operations, the permittee shall achieve the effluent limitations of the Regulatory Program for all of the mixed drainage when it leaves the permit area.

Underground mining activities shall be planned and conducted so as to prevent subsidence from causing material damage to the extent technologically and economically feasible, and so as to maintain the value and reasonably foreseeable use of surface lands. This may be accomplished by leaving adequate coal in place, backfilling, or other measures to support the surface, or by conducting underground mining in a manner that provides for planned and controlled subsidence.

Except as provided in §C of this regulation, underground mining activities that employ mining technology that provides for planned subsidence in a predictable and controller manner shall utilize necessary and prudent measures, consistent with the mining method employed, to minimize material damage to the extent technologically and economically feasible to all structures.

Measures required to minimize material damage to structures under §B of this regulation are not required if:

Nothing in this regulation prohibits the standard method of room-and-pillar mining.

The person engaged in underground mining activities shall comply with all provisions of the approved subsidence control plan prepared in accordance with COMAR 26.20.02.16.

Presubsidence Surveys of Water Supplies.

The mining schedule shall be distributed by mail to all owners of property and residents within the area above the underground workings and adjacent areas. Each of these persons shall be notified by mail at least 6 months before mining beneath his property or residence.

The notification shall contain, as a minimum:

Each person who conducts underground mining activities shall adopt all measures approved by the Bureau to reduce the likelihood of subsidence, to prevent subsidence that causes material damage or reduces the value of reasonably foreseeable use of surface lands, and to mitigate the effects of this damage or reduction of the value of reasonably foreseeable use of surface lands, and to mitigate the effects of this damage or reduction which may occur.

Each person who conducts underground mining which results in subsidence that causes material damage or reduces the value or reasonably foreseeable use of the surface lands shall, with respect to each surface area affected by subsidence:

Each person who conducts underground mining activities will:

In determining whether damage to protected structures was caused by subsidence from underground mining, the Bureau shall consider all relevant and reasonably available information.

Underground mining activities may not be conducted beneath or adjacent to any perennial stream, or impoundment having a storage volume of 20 acre-feet or more, unless the Bureau, on the basis of detailed subsurface information submitted by the applicant, determines that subsidence will not cause material damage to streams, water bodies and associated structures. If subsidence causes material damage, measures will be taken to correct the damage and to prevent additional subsidence from occurring.

Underground mining activities beneath any aquifer that serves as a significant source of water supply to any public water system shall be conducted so as to avoid disruption of the aquifer and consequent exchange of ground water between the aquifer and other strata. The Bureau may prohibit mining in the vicinity of the aquifer or may limit the percentage of coal extraction to protect the aquifer and water supply.

Underground mining activities may not be conducted beneath or adjacent to any public buildings or facilities, including but not limited to churches, schools, hospitals, courthouses, and government offices, unless the Bureau, on the basis of detailed subsurface information, determines that subsidence from those activities will not cause material damage to these structures and specifically authorizes the mining activities. If the Bureau determines that it is necessary in order to minimize the potential for material damage to the features or facilities described above or to any aquifer or body of water that serves as a significant water source for any public water supply system, it may limit the percentage of coal extracted under or adjacent to it.

Underground mining activities may not be conducted within the subjacent area where mining is predicted to result in subsidence of any public bridge.

If subsidence causes material damage to any of the features or facilities covered under this regulation, the Bureau may suspend mining under or adjacent to those features or facilities until the subsidence control plan is modified to ensure prevention of further material damage.

The Bureau shall suspend underground coal mining under urbanized areas, cities, towns, and communities, and adjacent to industrial or commercial buildings, major impoundments, or permanent streams, if imminent danger is found to inhabitants of the urbanized areas, cities, towns, or communities.

Within a schedule approved by the Bureau, the operator shall submit a detailed plan of the underground workings. The detailed plan shall include maps and descriptions, as appropriate, of significant features of the underground mine, including:

Except for the approved mine entries, a barrier of solid coal shall be provided around the perimeter of the underground mine area. The barriers shall be:

Barriers shall be a minimum of 50 feet in width or greater as determined by the formula W = 20 + 4T + 0.1D, when
W = width of the barrier, T=thickness of the extraction, and D=depth of overburden. Perimeter barriers shall have a minimum of 50 feet of overburden.

Barriers subject to a hydrostatic head shall be at least 1 foot wide for each foot to head.

When mining is proposed to be conducted beneath barriers in an existing underground mine, the barriers in the existing upper mine shall be provided subsidence protection sufficient to assure preservation of their design integrity.

Two copies of a projection map as required by Environment Article, §15-615(c), Annotated Code of Maryland, shall be submitted to the Bureau at least once every 6 months. The map shall be prepared by, or under the supervision of, and certified by a qualified registered professional engineer. Unless approved by the Bureau, the scale of the map shall be the same as the map submitted under COMAR 26.20.02.18A(4).

The map shall provide the following information: