Surface mining activities shall be planned and conducted to minimize changes to the prevailing hydrologic balance in both the mine plan and adjacent areas, in order to prevent long-term adverse changes in that balance that could result from those activities. Changes in the depth to ground water, in water quality and quantity, and in the location of surface water drainage channels shall be minimized so that the approved postmining land use of the permit area is not adversely affected. Federal and State water quality statutes, regulations, standards, or effluent limitations may not be violated. Operations shall be conducted to minimize water pollution, and treatment methods shall be used to control water pollution where necessary. Mining activities shall emphasize mining and reclamation practices that prevent or minimize water pollution. The Bureau may require that water accumulated in a pit be removed and the pit maintained in a dewatered condition whenever water quality or spoil stability is affected or before the approval of temporary cessation of mining activities. In this chapter, the following document is incorporated by reference. Document Incorporated. U.S. Department of Agriculture, Soil Conservation Service Technical Release No. 60 (210-VI-TR60, October, 1985), “Earth Dams and Reservoirs”, (TR-60). If drainage from the disturbed areas is mixing with drainage from other areas not disturbed by current surface coal mining and reclamation operations, the permittee shall achieve the effluent limitation set forth below for all the mixed drainage when it leaves the permit area. Discharges of water from areas disturbed by surface mining shall be made in compliance with applicable State laws and regulations, the federal Clean Water Act, and with effluent limitations for coal mining promulgated by the U.S. Environmental Protection Agency set forth in 40 CFR 434. Adequate facilities shall be installed, operated, and maintained to treat any water discharged from the disturbed area so that it complies with all federal and States laws and regulations and the limitations of this regulation. If the pH of water to be discharged from the disturbed area is less than 6.0, an automatic lime feeder or other automatic neutralization process approved by the Bureau shall be installed, operated, and maintained. The Bureau may authorize the use of a manual system if it finds that: Flow is infrequent and presents small and infrequent treatment requirements to meet applicable standards which do not require use of an automatic neutralization process; and Timely and consistent treatment is ensured. Overland flow, including flow through litter, and shallow ground water flow from undisturbed areas, and flow in ephemeral streams, may be diverted away from disturbed areas by means of temporary or permanent diversions, if required or approved by the Bureau as necessary to minimize erosion, to reduce the volume of water to be treated, and to prevent or remove water from contact with acid-forming or toxic-forming materials. The following requirements shall be met for all diversions and for all collection drains that are used to transport water into water treatment facilities and for all diversions of overland and shallow ground water flow and ephemeral streams: Temporary diversions shall be constructed to pass safely the peak runoff from a 2-year, 24-hour precipitation event with sufficient freeboard to pass a 10-year, 24-hour precipitation event or a larger event as specified by the Bureau. To protect fills and property and to avoid danger to public health and safety, permanent diversion shall be constructed to pass safely the peak runoff from a 10-year, 24-hour precipitation event, or a larger event as specified by the Bureau. Permanent diversions shall be constructed with gently sloping banks that are stabilized by vegetation. Asphalt, concrete, or other similar linings shall be used only when approved by the Bureau to prevent seepage or to provide stability. Diversions shall be designed, constructed, and maintained in a manner which prevents additional contributions of suspended solids to streamflow and to runoff outside the permit area, to the extent possible using the best technology currently available. Appropriate sediment control measures for the diversions may include, but not be limited to, maintenance of appropriate gradients, channel lining, revegetation, roughness structures, and detention basins. A diversion may not be located so as to increase the potential for landslides. A diversion may not be constructed on existing landslides, unless approved by the Bureau. When no longer needed, each temporary diversion shall be removed and the affected land regraded, topsoiled, and revegetated. Diversions shall be designed to minimize adverse impacts to the hydrologic balance within the permit and adjacent areas, to prevent material damage outside the permit area, and to assure the safety of the public. Diversion design shall incorporate the following: Channel lining shall be designed using standard engineering practices to pass safely the design velocities. Freeboard shall be not less than 1 foot. Protection shall be provided for transition of flows and for critical areas such as swales and curves. Where the area protected is a critical area as determined by the Bureau, the design freeboard may be increased. Energy dissipators shall be installed when necessary at discharge points, where diversions intersect with natural streams and exit velocity of the diversion ditch flow is greater than that of the receiving stream. Excess excavated material not necessary for diversion channel geometry or regarding of the channel shall be disposed of. Topsoil shall be handled in accordance with the Regulatory Program. Diversions may not be constructed or operated to divert water into underground mines without the approval of the Bureau. Flow from perennial and intermittent streams within the permit area may be diverted, if the diversions: Are approved by the Bureau after making a finding that the diversion will not adversely affect the water quantity and quality and related environmental resources of the stream; Comply with other requirements of this regulation; and Comply with local, State, and federal statutes and regulations. When streamflow is allowed to be diverted, the stream channel diversion shall be designed, constructed, and removed, in accordance with the following: The longitudinal profile of the stream, the channel, and the floodplain shall be designed and constructed to remain stable and, to the extent possible using the best currently available technology, to prevent additional contributions of suspended solids to streamflow or to runoff outside the permit area. These contributions may not be in excess of requirements of State or federal law. Erosion control structures such as channel lining structures, retention basins, and artificial channel roughness structures shall be used in diversions only when approved by the Bureau as being necessary to control erosion. These structures shall be approved for permanent diversions only where they are stable and will require infrequent maintenance. The combination of channel, bank, and floodplain configurations shall be adequate to pass safely the peak runoff of a 10-year, 24-hour precipitation event for temporary diversions, a 100-year, 24-hour precipitation event for permanent diversions, or larger events specified by the Bureau. However, the capacity of the channel itself should be at least equal to the capacity of the unmodified stream channel immediately upstream and downstream of the diversion. The design and construction shall be certified by a qualified professional engineer as meeting the design criteria of the Regulatory Program. When no longer needed to achieve the purpose for which they were authorized, all temporary stream channel diversions shall be removed and the affected land regraded and revegetated. At the time diversions are removed, downstream water treatment facilities previously protected by the diversion shall be modified or removed to prevent overtopping or failure of the facilities. This requirement does not relieve the permittee from maintenance of a water treatment facility otherwise required under this chapter or the permit. When permanent diversions are constructed or stream channels restored, after temporary diversions, the operator shall: Restore, enhance where practicable, or maintain natural riparian vegetation on the banks of the stream; Establish or restore the stream to its natural meandering shape or an environmentally acceptable gradient, as determined by the Bureau; and Establish or restore the stream to a longitudinal profile and cross section, including aquatic habitats that approximate pre-mining stream channel characteristics. Appropriate sediment control measures shall be designed, constructed, and maintained using the best technology currently available to: Prevent, to the extent possible, additional contributions of sediment to streamflow or to runoff outside the permit area; Meet the more stringent of applicable State or federal effluent limitations; and Minimize erosion to the extent possible. Sediment control measures include practices carried out within and adjacent to the disturbed area. Sediment control methods include but are not limited to: Disturbing the smallest practicable area at any one time during the mining operation through progressive backfilling, grading, and prompt revegetation; Diverting runoff away from disturbed areas; Diverting runoff using protected channels or pipes through disturbed areas so as not to cause additional erosion; Using straw dikes, riprap, check dams, mulches, vegetative sediment filters, and other measures that reduce overland flow velocity, reduce runoff volume, or trap sediment; Treating with chemicals. Exemptions. Exemptions to the requirements of this regulation may be granted if the: Disturbed drainage area within the total disturbed area is small; and Operator demonstrates that siltation structures and alternate sediment control measures are not necessary to meet the effluent limitations in this chapter and the applicable State and federal water quality standards for receiving waters. In this regulation, the following terms have the meanings indicated. Terms Defined. Disturbed Area. “Disturbed area” means an area from which vegetation, topsoil, or overburden is removed or land occupied by topsoil stockpiles, spoil piles, the open pit, access or haul roads, haulageways, storage areas, shop areas, processing and shipping areas, drainage or sediment control structures, coal processing wastes, underground development waste, or non-coal waste. “Disturbed area” does not include those areas where the: Only surface mining activities include diversion ditches, siltation structures, or roads that are designed, constructed, and maintained in accordance with COMAR 26.20.19; and Upstream area is not otherwise disturbed by the operator. “Other treatment facilities” means any chemical treatments, such as flocculation, or mechanical structures, such as clarifiers, that have a point source discharge and that are utilized to prevent additional contribution of suspended solids to streamflow or runoff outside the permit area. “Siltation structure” means a sedimentation pond, a series of sedimentation ponds, or other treatment facility. General Requirements for Siltation Structures. All siltation structures: Shall prevent additional contributions of suspended solids sediment to streamflow or runoff outside the permit area to the extent possible using the best technology currently available; Shall collect all surface drainage from the disturbed area before leaving the permit area, except as provided in §A of this regulation; Shall be constructed before beginning a surface mining activity in an area and, upon construction, be certified by a qualified professional engineer as being constructed in accordance with the approved design; Shall be designed, constructed, and maintained in accordance with Regulation .08 of this chapter if the structure impounds water; Shall be maintained until: Removal is authorized by the Department; The disturbed area has been stabilized and revegetated; The quality of the untreated drainage from the disturbed area meets applicable State and federal water quality standards for the receiving stream; and May not be removed if augmented seeding has occurred within the last 2 years. When a siltation structure is removed, the land on which the structure was located shall be regraded and revegetated in accordance with the approved reclamation plan. The design, construction, and maintenance of a siltation structure does not relieve the person from compliance with applicable effluent limitations. Sedimentation Ponds. Sedimentation ponds shall be used individually or in series and shall be: Designed, constructed, and maintained in accordance with Regulation .08 of this chapter; Located as near as possible to the disturbed area and out of perennial streams, unless approved by the Bureau; and Designed, constructed, and maintained to: Provide a minimum sediment storage volume of 67 cubic yards per acre of drainage area to the pond; Provide adequate detention time to allow the effluent from the ponds to meet State and federal effluent limitations; Contain or treat the 10-year, 24-hour precipitation event so there is no outflow through the emergency spillway unless a lesser design event is approved by the Bureau based on terrain, climate, other site conditions, and on a demonstration by the operator that the effluent limits of Regulation .02 of this chapter will be met; Provide a nonclogging dewatering device adequate to maintain the detention time; Minimize, to the extent possible, short circuiting; and Provide for the removal of sediment when the volume of sediment accumulates to 60 percent of the sediment storage volume. The dewatering device required by §G(3)(d) of this regulation may not be located at an elevation lower than the maximum elevation of the sediment storage volume, unless approval is obtained from the Bureau. Other Treatment Facilities. Other treatment facilities shall be designed: In accordance with the applicable requirements of this section; and To contain or treat the 10-year, 24-hour precipitation event unless a lesser design event is approved by the Bureau in accordance with §G(3)(c) of this regulation. Discharge from sedimentation ponds, permanent and temporary impoundments, coal processing waste dams and embankments, and diversions shall be controlled, by energy dissipators, riprap channels, and other devices, where necessary, to reduce erosion, to prevent deepening or enlargement of stream channels, and to minimize disturbance of the hydrologic balance. Discharge structures shall be designed according to standard engineering-design procedures. General Requirements. The requirements of this section apply to both temporary and permanent impoundments. Impoundments shall be designed and constructed to ensure: Compliance with USDA, Natural Resources Conservation Service, Maryland Conservation Practice, Standard Pond Code 378 (January 2000), as incorporated by reference in COMAR 26.17.02.01-1B(2); Compliance with requirements of COMAR 26.17.04.05 if the embankment is more than 15 feet in height as measured from the upstream toe of the embankment to the crest of the emergency spillway; Impoundments meeting the Class (b) or (c) criteria for dams in “Earth Dams and Reservoirs”, TR-60 shall comply with “Minimum Emergency Spillway Hydrologic Criteria” table in TR-60 and the requirements of this regulation; The minimum elevation at the top of the settled embankment shall be 1 foot above the water surface in the pond with the emergency spillway flowing at design depth; The height of the embankment is a minimum of 5 percent over the design height to allow for settlement, unless it has been demonstrated to the Bureau that the material used and the design will ensure against all settlement; The top width of the embankment is not less than the quotient of (H+35)/5, when H is the height, in feet, of the embankment, as measured from the upstream toe of the embankment; Perimeter slopes are stable, are not steeper than 2:1, and are protected against erosion where water enters the impoundment; The combined upstream and downstream side slopes of the settled embankment are not less than 5:1 with neither slope steeper than 2:1; The crest of the emergency spillway is a minimum of 1 foot above the crest of the principal spillway; A cut-off trench is installed before initiating the placement of fill material for the embankment with side slopes not steeper than 1:1; The embankment foundation area is cleared of all organic material and the entire area scarified; The embankment begins by placing and spreading fill material at the lowest point of the foundation, is brought up in horizontal layers not to exceed 8 inches as required to facilitate compaction, and is compacted as specified in the design approved by the Bureau; Fill material used in the construction of the embankment is free of sod, large roots and other vegetative matter, frozen soil, and coal processing waste; The embankment slope is protected against surface erosion and against damage caused by sudden drawdown; The embankment faces and surrounding areas are vegetated, except that the faces where water is impounded may be riprapped or otherwise stabilized in accordance with accepted design practices; and Newly constructed areas and those areas disturbed by the construction are vegetated immediately upon completion of the construction. Stability. Impoundments meeting the Class (b) or (c) criteria for dams contained in “Earth Dams and Reservoirs”, TR-60 or the size or other criteria of 30 CFR §77.216(a) shall have a minimum static safety factor of 1.5 for a normal pool with steady state seepage saturation conditions and a seismic safety factor of at least 1.2. Impounds not included in §B(1) of this regulation, except for coal mine waste impounding structures, shall be constructed to achieve a minimum static safety factor of 1.3 for a normal pool with steady state seepage saturation conditions. Unless otherwise determined by the Department based on site specific conditions, impoundments meeting the criteria of §§A(1) and B(2) of this regulation shall be considered to meet a minimum static safety factor of 1.3 for a normal pool with steady state seepage condition, if the: Embankment is not constructed of organic soil or clay of high plasticity; Embankment is constructed of fill material that contains sufficient moisture content to achieve proper compaction; and Existing slope of the foundation area is not steeper than the slope provided for the soil type to be used to construct the embankment in the chart at §B(4) of this regulation. Soil Classification Chart. An indication of sufficient moisture content in the fill material referenced in §B(3)(b) of this regulation is that the soil should form a ball which does not readily separate when kneaded by hand. The engineer may also specify other methods of testing moisture content. Freeboard. Impoundments shall have adequate freeboard to resist overtopping by waves and by sudden increases in storage volume. Impoundments meeting the Class (b) or (c) criteria for dams in “Earth Dams and Reservoirs”, TR-60 shall comply with the freeboard hydrograph criteria in “Minimum Emergency Spillway Hydrologic Criteria” table in TR-60. Foundation. Foundations and abutments for an impounding structure shall be stable during all phases of construction and operation and shall be designed based on adequate and accurate information on the foundation conditions. For an impoundment meeting the Class (b) or (c) criteria for dams contained in “Earth Dams and Reservoirs”, TR-60 or the size or other criteria of 30 CFR §77.216(a), foundation investigation, as well as any necessary laboratory testing of foundation material, shall be performed to determine the design requirements for foundation stability. For impoundments not meeting the size or other criteria of 30 CFR §77.216(a), foundation investigation, as well as any necessary laboratory testing of foundation material, may be required to establish the stability of the foundation. Spillways. An impoundment shall include either a combination of principal and emergency spillways or a single spillway configured as specified in §D(2) of this regulation, designed and constructed to safely pass the applicable design precipitation event specified in §D(3) of this regulation. The Department may approve a single open-channel spillway that is: Of nonerodible construction and designed to carry sustained flows; or Rock or grass-lined and designed to carry short-term, infrequent flows at nonerosive velocities when sustained flows are not expected. The required design precipitation event for impoundments meeting the spillway requirements of this section are: For an impoundment meeting the size or other criteria of 30 CFR §77.216(a), a 100-year, 24-hour event, or larger event specified by the Department; For impoundments not meeting the size or other criteria of 30 CFR §77.216(a), a 25-year, 24-hour event, or larger event specified by the Department; or For impoundments meeting the Class (b) or (c) criteria for dams in “Earth Dams and Reservoirs”, TR-60, in accordance with the emergency spillway hydrograph criteria in the “Minimum Emergency Spillway Hydrologic Criteria” table in TR-60, or larger event specified by the Department. Impoundments meeting the size or other qualifying criteria of 30 CFR §77.216(a) shall comply with 30 CFR §77.216 and this regulation. The plan required to be submitted to the district manager of the Mine Safety and Health Administration (MSHA) under 30 CFR §77.216 shall also be submitted to the Department as part of the permit application. All temporary and permanent impoundments shall be designed by, or under the supervision of, a professional engineer, using current, prudent, engineering practices and design criteria, and the design certified by a professional engineer. Impoundments shall be routinely maintained during the mining operations in the following areas: Vegetative growth shall be cut where necessary to facilitate inspection and repair; Ditches and spillways shall be cleaned; Combustible material present on the surface, other than material like mulch or dry vegetation used for surface stability, shall be removed; and Other appropriate maintenance procedures shall be followed. Plans for an enlargement, reduction in size, reconstruction, or other modification of dams or impoundments shall be submitted to the Department and shall comply with the requirements of this regulation. Except when a modification is required to eliminate an emergency condition constituting a hazard to public health, safety, or the environment, the Department shall approve the plans before modification begins. Construction Inspections. A qualified professional engineer or other qualified specialist, under the direction of the professional engineer, shall inspect the impoundment. The professional engineer or specialist shall be experienced in the construction of impoundments. These inspections shall be made: At appropriate times during construction, including: Site preparation, Construction of the cut-off trench, Placement of the principal spillway pipe, including anti-seep collars and riser base, Placement and compaction of fill material around the principal spillway, Placement and compaction of fill in the impounding structure; and Upon completion of construction. After each inspection required by §A(1) of this regulation, the professional engineer shall submit to the Department a certified report that the impoundment is being constructed in accordance with the approved plan and Regulation .08 of this chapter. A copy of each report shall be retained at or near the mine site. Certification of Construction. Upon completion of construction, a certification statement and as-built drawing shall be submitted for each impoundment and impounding structure. The as-built drawing shall show the approved design and any modification or minor changes. The certification statement shall be signed and sealed by a professional engineer, and shall certify that: The impoundment and impounding structure has been constructed in accordance with the plans and specifications in the approved permit; Observations and measurements were made at appropriate times during and following construction by a professional engineer or a qualified person experienced in the design and construction of impoundments and impounding structures acting as a representative and reporting directly to the professional engineer; The completed impoundment and impounding structure meet the safety requirements of safe engineering practices, the regulatory program, and the design approved in the permit application; and Modifications made during construction meet the requirements of the regulatory program. The Department may require color photographs to be taken at the appropriate times specified in §A(1) of this regulation and submitted with the certification statement. Annual Inspection. An impoundment shall be inspected at least annually by a professional engineer or other qualified specialist under the direction of the professional engineer until removal of the impoundment or release of the performance bond. The professional engineer or specialist shall be experienced in the construction of impoundments. After each annual inspection, the professional engineer shall submit to the Department a certified report that the impoundment has been maintained in accordance with the approved plan and this chapter. The report shall include discussion of: Appearances of instability; Structural weakness or other hazardous conditions; Depth and elevation of any impounded waters; Existing storage capacity; Existing or required monitoring procedures and instrumentation; and Other aspects of the structure affecting stability. A copy of the report shall be retained at or near the mine site. Examinations. Impoundments meeting the Class (b) or (c) criteria for dams in “Earth Dams and Reservoirs”, TR-60 or the size or other criteria of 30 CFR §77.216 shall be examined in accordance with 30 CFR §77.216-3. Other impoundments not meeting the Class (b) or (c) criteria for dams in “Earth Dams and Reservoirs”, TR-60 or subject to 30 CFR §77.216 shall be examined at least quarterly by a qualified person for appearance of structural weakness and other hazardous conditions. If an examination or inspection discloses that a potential hazard exists, the permittee shall immediately notify the Department of the hazard and of the emergency procedures formulated for public protection and remedial action. If adequate emergency procedures cannot be formulated or implemented, the Department shall be notified immediately. The Department shall then immediately notify the appropriate agencies that other emergency procedures are required to protect the public. Permanent Impoundments. A permanent impoundment of water may be created, if authorized by the Department in the approved permit, based upon a demonstration that the: Size and configuration of the impoundment will be adequate for its intended purposes; Quality of the impounded water will be suitable on a permanent basis for its intended use and after reclamation will meet applicable State and federal water quality standards; Discharges from the impoundment will meet applicable effluent limitations and will not degrade the quality of receiving water below applicable State and federal water quality standards; Water level will be sufficiently stable and capable of supporting the intended use; Final grading will provide for adequate safety and access for proposed water users; Impoundment will not result in diminution of the quality and quantity of water utilized by adjacent or surrounding landowners for agricultural, industrial, recreational, or domestic uses; Impoundment will be suitable for the approved postmining land use; and Vertical portion of any remaining highwall shall be located far enough below the low-water line along the full extent of the highwall to provide adequate safety and access for the proposed water users. Temporary Impoundments. The Department may authorize the construction of temporary impoundments as part of a surface coal mining operation. Before final bond release of the permit area, the permittee shall renovate all permanent sedimentation ponds, diversions, impoundments, and treatment facilities to meet criteria specified in the detailed design plan of the permanent structures and impoundments. Environment Article, §15-503, Annotated Code of Maryland Effective date: Regulations .01—.09 were previously codified as COMAR 08.13.09.24A—I, 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. Regulation .02 amended effective October 11, 1993 (20:20 Md. R. 1569) Chapter revised effective October 23, 1995 (22:21 Md. R. 1614) Chapter recodified from COMAR 08.20.21 to COMAR 26.20.21, June 1996 Regulation .01-1 adopted effective March 14, 2005 (32:5 Md. R. 582) Regulation .08 amended effective March 14, 2005 (32:5 Md. R. 582) Regulation .09D amended effective March 14, 2005 (32:5 Md. R. 582)