Chapter 27. Waste Handling

All coal mine waste shall be placed in designated disposal areas within a permit area, which are approved by the Bureau for this purpose. Coal mine waste shall be placed in a controlled manner to:

Coal mine waste materials from activities located outside a permit area, such as those activities at other mines or abandoned mine waste piles, may be disposed of in the permit area only if approved by the Bureau. Approval shall be based on a showing by the permittee, using hydrologic, geotechnical, physical, and chemical analysis, that the disposal will be in accordance with the standards of this chapter.

The disposal facility shall be designed using current, prudent engineering practices to attain a minimum long-term static safety factor of 1.5 and to meet any design criteria established by the Bureau. A qualified registered professional engineer, experienced in the design of similar earth and waste structures, shall certify the design of the disposal facility.

The foundation and abutments must be stable under all conditions of construction. Sufficient foundation investigations, as well as any necessary laboratory testing of foundation material, shall be performed in order to determine the design requirements for foundation stability. The analyses of the foundation conditions shall take into consideration the effect of underground mine workings, if any, upon the stability of the disposal facility.

A qualified registered professional engineer, or other qualified professional specialist under the direction of the professional engineer, shall inspect the coal mine waste disposal facility during construction. The professional engineer or specialist shall be experienced in the construction of similar earth and waste structures.

Inspections shall be made at least quarterly throughout construction and during critical construction periods. Critical construction periods shall include at a minimum:

Regular inspections by the engineer or specialist shall be conducted during placement and compaction of coal mine waste materials. More frequent inspections shall be conducted if a danger of harm exists to the public health and safety or the environment. Inspections shall continue until the waste disposal facility has been finally graded and revegetated or until a later time as required by the Bureau.

The qualified registered professional engineer shall provide a certified report to the Bureau within 10 days after each inspection stating that the waste disposal facility has been constructed and maintained as designed and in accordance with the approved plan and this subtitle. The report shall include appearances of instability, structural weakness, and other hazardous conditions.

The certified report on the drainage system and protective filters shall include color photographs taken during and after construction, but before underdrains are covered with coal mine waste. If the underdrain system is constructed in phases, each phase shall be certified separately. The photographs accompanying each certified report shall be taken in adequate size and number with enough terrain or other physical features of the site shown to provide a relative scale to the photographs and to specifically and clearly identify the site.

A copy of each inspection report shall be retained at or near the mine site.

If any inspection discloses that a potential hazard exists, the Bureau shall be informed immediately of the findings and of emergency procedures considered necessary for public protection and remedial action. If adequate procedures cannot be immediately implemented, the Bureau shall notify appropriate emergency agencies of the need for measures to protect the public.

If the disposal area contains springs, natural or man-made water courses, or wet weather seeps, the design shall include diversions and underdrains as necessary to control erosion, prevent water infiltration into the disposal facility, and ensure stability. If a subdrainage system is used, it shall:

Rock underdrains shall be constructed of durable, nonacid, non-toxic-forming rock, for example, natural sand and gravel, sandstone, limestone, or other durable rock that does not slake in water or degrade to soil material, and which is free of coal, clay, or other nondurable material. Perforated pipe underdrains shall be corrosion resistant and shall have characteristics consistent with the long-term life of the fill.

Uncontrolled surface drainage may not be diverted over the outslope of refuse piles. All surface drainage runoff from the area above refuse piles and runoff from the surface of refuse piles shall be diverted into stabilized diversion channels designed to safely pass the runoff from a 100-year, 6-hour precipitation event.

Slope protection shall be provided to minimize surface erosion at the site. All disturbed areas, including diversion ditches that are not riprapped, shall be vegetated upon completion of construction.

All water discharged from a refuse pile shall comply with the effluent limitations of the Regulatory Program.

Refuse piles shall be constructed in compliance with the requirements of COMAR 26.20.26, except to the extent that the requirements of that chapter are varied in this regulation.

Refuse piles shall have a minimum static safety factor of 1.5.

Compaction requirements during construction or modification of all coal mine waste disposal facilities are as follows:

Following final grading of the coal mine waste disposal facility, the site shall be covered with a minimum of 4 feet of the best available nontoxic and noncombustible material in a manner that does not impede flow from subdrainage systems and shall be revegetated. The Bureau may allow less than 4 feet of cover material based on physical and chemical analyses which show that the revegetation requirements will be satisfied.

Permanent impoundments may not be allowed on completed refuse piles.

The final configuration of refuse piles shall be suitable for the approved postmining land use. Terraces may be constructed on the outslope if required for stability, control of erosion, conservation of soil moisture, or facilitation of the approved postmining land use. The grade of the outslope between terrace benches may not be steeper than 2h:1v (50 percent).

Non-coal wastes including, but not limited to, grease, lubricants, paints, flammable liquids, garbage, abandoned mining machinery, lumber, and other combustibles generated during surface mining activities shall be placed and stored in a controlled manner in a designated portion of the permit area. Placement and storage shall ensure that leachate and surface runoff do not degrade surface or ground water, fires are prevented, and that the area remains stable and suitable for reclamation and revegetation compatible with the natural surroundings.

Final disposal of non-coal wastes shall be in a designated disposal site in the permit area or a State-approved solid waste disposal area. Disposal sites shall be designed and constructed with appropriate water barriers on the bottom and sides of the site. Wastes shall be routinely compacted and covered to prevent combustion and wind-borne waste. When the disposal is completed, a minimum of 2 feet of soil cover shall be placed over the site, slopes stabilized, and revegetation accomplished. Operation of the disposal site shall be conducted in accordance with all local, State, and federal requirements.

Non-coal waste may not be deposited in a refuse pile or impounding structure. An excavation for a non-coal mine waste disposal site may not be located within 8 feet of any coal outcrop or coal storage area.

Any non-coal mine waste defined as “hazardous” under §3001 of the Resource Conservation and Recovery Act (PL 94-580) shall be handled in accordance with the requirements of Subtitle C of RCRA and any implementing regulations.

Coal mine waste may not be used in the construction of impounding structures unless it has been demonstrated that the stability of the structure will be ensured, and that the use of coal mine waste will not have a detrimental effect on downstream water quality or the environment due to acid seepage through the impounding structure. All demonstrations shall be submitted to and approval obtained from the Bureau before construction.

Impounding structures constructed of coal mine waste or impounding coal mine waste may not be retained permanently as part of the approved postmining land use.

All vegetative and organic materials shall be removed from the site and disposed of in an approved manner and location. All topsoil shall be removed and handled in accordance with COMAR 26.20.25.02.

Surface drainage that may cause instability or erosion to the embankment area, or the embankment features, whether during construction or after completion, shall be diverted away from the embankment by diversion ditches. Diversions that are designed to divert drainage from the upstream area or from the surface of the facility shall be designed to carry the peak runoff from a 100-year, 6-hour precipitation event. The diversion shall be maintained to prevent blockage, and sediment control measures shall be provided at the discharge of each diversion ditch before entry into natural watercourses.

The design of each dam and embankment constructed of coal mine waste, or intended to impound this waste, shall comply with the permanent and temporary impoundment requirements of the Regulatory Program, modified as follows:

Spillways and outlet works shall be designed to provide adequate protection against erosion and corrosion. Inlets shall be protected against blockage. The combination of principal and emergency spillways shall be able to safely pass the 100-year, 6-hour design precipitation event.

Dams or embankments constructed of or impounding waste materials shall be designed so that at least 90 percent of the water stored during the design precipitation event shall be removed within a 10-day period.