Current through Register Vol. XLI, No. 50, December 13, 2024
Section 38-2B-4 - SUBMITTAL REQUIREMENTS4.1Submittals - Submittals for construction, operation, enlargement, modification, removal of materials, and abandonment of all coal refuse disposal areas shall be in accordance with these regulations. The submittal shall be prepared by or under the direct supervision of, and certified by, an engineer experienced in the design and construction of similar facilities. The coal refuse disposal portion of the submittal shall contain the following information in order:
a. Narrative and Discussionb. Emergency Procedures if required by Section D.05c of these regulations.c. Hydrology and Hydraulics 1. Design data in graphical or tabular form2. Hydrologic analysis shall include all supporting calculations, charts, graphics, tables.3. Hydraulic analysis shall include all supporting calculations, cross sections, profiles, and results.4. If computer analysis is used include input data and results used specifically in the design only.d. Stability 1. Design data in graphical or tabular form.2. Stability analysis shall include supporting calculations, charts, cross-sections and results.3. If computer analysis is used include input data and results used specifically in the design only.e. Haulageways and sediment control.f. If applicable, plans and calculations concerning abandoned mine openings, combustion control, underground coal refuse disposal, and disposal of coal refuse or sludge from outside the permit area.i. Maps and Drawings (reduced size if necessary for engineering drawings)j. Separate from the other copies of the submittal, two sets of maps and plans on standard 24" by 36" size plan sheets shall be submitted.4.2Narrative and Discussion - A general narrative and discussion of the project shall be submitted to include as a minimum a discussion of existing site conditions, the design life of the facility, quantity and type of coal refuse to be placed, subsidence potential, design methodology backed up with design computations a data, method of operation to include clearing and grubbing, topsoil stockpiling, construction of surface and subsurface drainage facilities, phases of construction, method and location of coal refuse placement or removal, coal refuse placement during inclement weather, routine inspection and maintenance, possible abandonment prior to the planned design life, and a sequence for construction of drainage facilities, critical construction phases, reclamation and final abandonment procedures. In addition, a description of the duties, responsibilities and lines of communication of those persons responsible for the design and construction of the coal refuse disposal area shall be included.4.3Mapsa. Maps and plans shall be provided showing the site in relation to major highways, county seats, and major drainage. County highway maps may be used for this purpose.b. A map showing the limits of the watershed with respect to the site shall be provided. The minimum mapping requirement shall be a 7 1/2 minute U.S.G.S. map with the site plotted on it.c. A plan view of the site shall be provided showing detailed contours, limits of the coal refuse disposal area, all drainage facilities, location of springs, seeps, mine drainage and/or openings, location of the subdrain system, project stationing, location of cross sections, location of borings, test pits and instrumentation and other pertinent data required for project control.d. Cross-sections of the coal refuse disposal area transversely and longitudinally shall be provided showing original ground, subdrain location, elevations, benches, spillways, and other pertinent features of the site. A cross-section shall be provided for stability computations showing the site at critical areas with materials profile plotted.e. Cross-sections and profiles of major drainage facilities shall be provided. Cross-sections shall be taken in all critical areas.f. Construction drawings shall be provided for subdrains, spillways, antiseep mechanisms, and other pertinent structures at the site.4.4Specifications - Specifications for site development shall be provided to include as a minimum: c. excess material disposalg. details of the coal refuse disposal area and drainage facilitiesh. spreading and compaction requirements during placementi. material and/or gradation requirements for subdrainage structuresj. water quality control from acid-forming or toxic-forming materialso. installation and reading of monitoring devicesp. inspection and maintenanceq. topsoil redistribution4.5Pre-development Analysisa. Hydrologic Balance 1. Structures meeting the requirements of 3.1.b.1. and 3.1.b.2. shall be prohibited unless the following can be demonstrated:(a) The quality of the impounded water shall be suitable on a permanent basis for its intended use, and discharge of water from the impoundment must comply with the requirements of Section 6B.4 and 7B.4 of the surface mining regulations.(b) The level of the water shall be sufficiently stable to support the intended use.(c) Adequate safety and access to the impounded water shall be provided for proposed water users.(d) Water impoundments shall not result in the diminution of the quality or quantity of water used by adjacent or surrounding landowners for agricultural, industrial, recreational, or domestic use.(e) The design, construction and maintenance of dams and impoundments shall achieve the minimum design requirements applicable to structures constructed and maintained under the provisions of Sections 4 and 5 of these regulations. All other impoundments (as specified in 3.1.b.3.) must meet the minimum design requirements of the Handbook for Surface Mining.(f) The size of the impoundment is adequate for its intended purposes.(g) The impoundment will be suitable for the approved post-mining land use.2. Sediment Control - Slope protection and vegetation shall be provided to minimize surface erosion at the site and sediment control measures shall be required where necessary to reduce the sediment leaving the site.3. Excavations for special purpose ponds (3.1.b.3.) that will impound water during or after the mining operation shall have perimeter slopes that are stable and shall not be steeper than 2H:1V or shall meet the requirements of the Handbook for Surface Mining (Excavated Pond Section). Where surface runoff enters the impoundment area, the side slopes shall be protected against erosion.b. Hazard Classification 1. Impoundments - The hazard potential of structures meeting the requirements of Sections 3.1.b.1. and 3.1.b.2. shall be determined by the applicant based on the potential loss that would result due to a failure and the classification determined as listed below: (a) Class A--Impoundments located in rural or agricultural areas where failure may damage farm buildings, agricultural land, or secondary highways. Failure of the structure would cause only loss of the structure and loss of property use such as related roads, but with little additional damage to adjacent property. Any impoundment exceeding 25 feet in height measured at the downstream toe or 200 acre-feet storage volume or having a watershed exceeding 500 acres shall not be a Class A structure.(b) Class B--Impoundments located in predominantly rural agricultural areas where failure may damage isolated homes, primary highways or minor railroads or cause interruption of relatively important public utilities. Failure of the structure may cause great damage to property and project operations.(c) Class C--Impoundments located where failure may cause loss of life, serious damage to homes, industrial and commercial buildings, important public utilities, primary highways, or main railroads. This classification must be used if failure would cause possible loss of human life.c. Emergency Procedures - For a Class C Structure or if a dangerous condition exists, notification and action procedures shall be formulated by the operator or owner, for public protection and remedial action in the event of an emergency. All emergency procedures must be submitted and become part of the approved plan. If adequate emergency procedures cannot, for whatever reason, be formulated by the owner or operator, then he must so notify the director in writing. The director may then notify the Office of Emergency Services and request that emergency procedures be developed for the coal refuse disposal area.d. Hydrology and Hydraulics 1. Design Data Required - All data (precipitation, watershed characteristics, etc.), graphs, curves, etc. required for hydrologic and hydraulic design of coal refuse embankments and impoundments shall be presented.2. Design Requirements(a) Impoundments and Dams (1) Design storm - All impoundments related to the surface effects of coal mining shall be designed to meet the following criteria based upon hazard classification. Precipitation values may be obtained from Technical Paper 40, U.S. National Weather Service. (i) Class A Impoundments shall be designed for a minimum of P100+0.12 (PMP-P100) inches of rainfall in six hours plus three feet of freeboard. If the storage times effective height is less than 3,000 (acre-feet) (feet) then Soil Conservation Service Pond Standard 378 may be substituted.(ii) Class B impoundments shall be designed for a minimum of P100+0.40 (PMP-P100) inches of rainfall in six hours plus three feet of freeboard.(iii) Class C impoundments shall be designed for the probable maximum precipitation of the appropriate duration.(2) Impoundment Requirements - All impoundments must be capable of passing that portion of the design storm that cannot be safely stored in the impoundment. (i) Class A impoundments must be provided with an open channel spillway unless otherwise approved by the director. Ninety percent of the stored portion of the design storm must be discharged or removed within ten days after the storm event.(ii) Class B impoundments shall be designed with either an open channel spillway only, or with an emergency spillway and a principal spillway together. Ninety percent of the stored portion of the design storm shall be discharged or removed within ten days after the storm event.(iii) Class C dams may be designed in one of three ways:1 An impoundment designed without discharge structures shall be capable of storing a minimum of two 36 hour duration probable maximum storms. Water shall be removed from the impoundment to its lowest practical level by pumping or by other means if storm water reduces the storage capacity to one probable maximum storm or less.2 An impoundment designed with a decant or principal spillway only shall be capable of storing at least one 36 hour duration probable maximum storm. Ninety percent of the stored portion of the storm shall be discharged or removed within ten days after the storm event.3 An impoundment designed with either an open channel spillway only, or with an emergency spillway and principal spillway together shall be capable of discharging that portion of the six hour duration probable maximum storm that cannot be safely stored in the impoundment. Ninety percent of the stored portion of the storm shall be discharged or removed within ten days after the storm event.(3) Spillways and Outlet Works(i) Spillways - One or more spillways must be provided to pass that portion of the design storm that cannot be safely stored using standard engineering flood routing techniques and to draw down the stored portion of the design storm within the specified time. The outlets of all spillways must be carried safely beyond the toe of the dam to a natural drainway.1-- Open Channel Spillways - All channels must comply with this Section, Section 4.5 d.2.(c) and the following additional requirements:a-- Any open channel spillway designed for less than 100% probable maximum precipitation shall be provided with freeboard above the maximum water surface as determined by the equation 1+.025vd 1/3.b-- Excess excavated material not needed to construct and maintain the spillway channel must be properly disposed of in the permit area unless otherwise approved by the director.c-- Topsoil removed from channel excavation shall be handled in accordance with Section 5.22-- Pipe Spillways - All pipe spillways must comply with the requirements of this Section and the following additional requirements. a-- The pipe spillway inlet must be protected by a designed trash rack.b-- All riser type spillways must be designed to prevent vortexing.c-- A skimming device is required where floating pollutants exist or are anticipated.d-- An adequate foundation and bedding shall be designed for all pipes and risers.e-- all pipe spillways shall be designed to provide seepage control along the conduit.f-- The pipe spillway shall be of sufficient strength to withstand the maximum load of the fill above it.g-- All pipe spillways shall be constructed of suitable material to resist deterioration for the design life of the facility.h-- The outlet of all pipes, where blockage by animals can occur, must be protected by an animal guard.(ii) Drainpipes - All freshwater impoundments meeting the size requirements of Sections 3.1.b.1. and 3.1.b.2. constructed after the effective date of the Act must be designed with a gated drainpipe or principal spillway gate for draining the impoundment. All drain pipes must meet the requirements for pipe spillways.(iii) Concrete Structures - Concrete structures shall be designed in accordance with standard engineering practice. Special design considerations should be provided where deterioration of the environment may be expected.(b) Diversion Channels - The entire coal refuse embankment shall be protected from surface water runoff by diversion systems unless otherwise approved by the director. (1) Design storm - All diversion ditches and stream channel diversions shall be designed to carry the peak runoff from a 100-year frequency, six hour duration rainfall.(2) Freeboard - A freeboard equal to or greater than the formula 1+.025vd 1/3 shall be added to the design flow depth of the diversion ditch to obtain the total depth of the diversion ditch.(3) Additional Requirements - All ditches must comply with this Section, 4.5 d.2.(c) and the following additional requirements:(i) Each diversion ditch must be designed to carry the peak flow with freeboard from the contributing watershed area.(ii) 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 fullest extent possible.(iii) Excess excavated material not required for construction or maintenance of the diversion ditch must be properly disposed of in the permit area unless otherwise approved by the director.(iv) Topsoil removed from the channel excavation shall be handled in accordance with Section 5.2.(v) All diversion systems shall exit safely beyond the toe of the embankment in a natural drainway capable of carrying the design flow without excessive erosion.(vi) All stream channel diversions must be designed to carry the design flow around the disturbed area. The diversions must outlet into the original channel or a natural channel of equal cross section without excessive erosion.(vii) Diversions in refuse must be lined with soil or a suitable substitute unless sediment protection is provided.(viii) Permanent diversion systems designed to convey water under a coal refuse embankment by means of a pipe or conduit are unacceptable. However, diversion by means of a pipe or conduit may be permitted during active operation provided that height or storage limits for impoundments as defined by Section 3.1.b.2 are not exceeded, the pipe or conduit is used in conjunction with surface ditches to meet applicable design storm requirements (Section 4.5 d.2.(b.)(1)), and the design of the pipe or conduit accounts for durability and design life, load limits, joint sealing, trash rack protection, and maintenance requirements throughout the operational life of the structure.(c) Hydraulics All hydraulic structures shall be designed to safely control the flow using energy dissipators and/or channel protection based upon design flow velocity to prevent excessive erosion. Seepage control devices shall be used to prevent undercutting of nonflexible linings. The potential for landslides or slope failures shall be considered in the location of all hydraulic structures. Channels shall not be located on or near an existing landslide unless approved by the director. No surface runoff or slurry may be diverted into underground mines unless diverted in accordance with Section 4.5.i.3. Hydrological and Hydraulic Analyses. All hydrological and hydraulic design must be done using accepted engineering methods and meet the minimum requirements of this Section. The application shall include all design data and calculation results. If a computer analysis is used, only the input data and results used specifically in the design shall be submitted. If graphical flood routing techniques are used, all charts and graphs shall be included. Adequate cross sections and profiles shall be given for all hydraulic structures.e. Subsurface Drainage - All springs, seepage, and groundwater flow observed or anticipated during wet conditions must be identified. If site conditions dictate necessity, a properly designed subdrainage system for the purpose of structural integrity and preservation of water quality shall be provided to: 1. Intercept all anticipated or observed groundwater sources and/or seepage;2. Be constructed of durable rock consisting of non-degradable, non-acid or toxic forming rock such as natural sand or gravel, sandstone, or other durable rock that will not slake in water and will be free of coal, clay or shale. Limestone may not be utilized in any location where acid water conditions are observed or anticipated unless otherwise approved by the director. Subdrainage systems shall be protected by a properly designed filter zone or filter cloth where required;3. Be designed and sized based upon measured or anticipated flows using standard engineering design techniques with field data and computations for design provided in the submittal.4. The upstream end of the subdrain shall be covered by a filter medium during all phases so as to protect against contamination.f. Stability - All coal refuse impoundments must be analyzed and/or designed in accordance with this Section. Non-impounding coal refuse embankments must be designed in accordance with this Section unless any proposed modifications to the design standards of this Section are justified through appropriate stability analysis. Where obvious site conditions indicate that failure will not occur, the director may waive the requirement for a stability analysis on non-impounding structures so long as all other design requirements of Section 4.5.f.2 are met.1. Design Data Required - All data required for the structural analysis and/or design of coal refuse embankments and impoundments shall be presented in the submittal in graphical or tabular form.(a) Subsurface Investigation - A subsurface investigation shall be performed unless obvious site conditions preclude the necessity of this requirement. The number, location, and depth of borings, test pits, and/or trenches shall be reasonable for the size, purpose, soils present, and foundation type of the structure. The investigation shall consider depth of soil to bedrock, field classification of soils, character of bedrock, in-situ testing, soil sampling, determination of groundwater location, and a soil profile for critical locations in the structure, hydraulic structures and other pertinent locations which may affect the safety of the structure. A geologic study shall also be conducted for impounding structures to evaluate landslides into the impoundment, bedrock discontinuities such as soft seams, joints, joint systems, bedding planes, and fault zones which may adversely affect the structure's performance. Past and future mining to include height of seam, depth and cover rock of the seam, and previous subsidence problems shall be considered where subsidence may affect the safety of the structure.(b) Laboratory investigation - Laboratory tests shall be conducted on all foundation and embankment materials to include soil classification through hydrometer analysis, density, water content, compaction tests, shear strength, consolidation, and permeability unless the scope, characteristics, or design concept of the site make one or more of these requirements unnecessary.2. Design Requirements(a) Foundation stability - Potential subsidence and settlement and their consequences must be considered using standard engineering techniques. The foundation must have or must be treated to have adequate bearing capacity to support the embankment and any appurtenant works.(b) Slope stability - Coal refuse embankments and impoundments must achieve a minimum static factor of safety of 1.5 and a seismic factor of safety of 1.2 for construction and longterm conditions under normal and proposed hydrostatic conditions using standard geotechnical engineering techniques. Any final graded slope shall be no steeper than 2H:1V between benches with a 20-foot wide bench for each 50 feet of change in elevation.(c) Compaction - Compaction shall be specified for construction or modification of all coal refuse disposal areas to insure that future stability and prevention of combustion is attained. Minimum spreading and compaction requirements shall be a maximum of two foot horizontal lifts to achieve 90 percent Standard Proctor Density (AASHTO Specification T 99-74). Special compaction requirements shall be considered for approval for such cases as fine refuse (-28 mesh), combined refuse, coarse refuse where 30 percent of the material will not pass the 3/4 sieve, impervious zones, refuse placement over previously burning refuse, initial lifts over fine refuse, etc.(d) Liquefaction - The potential for liquefaction must be considered. Safeguards against the development of this condition shall be provided where required.(e) Instrumentation - Considerations for installation of instrumentation such as piezometers, settlement markers, slope indicators, and similar monitoring devices shall be included in the plan to monitor present hazardous conditions, construction conditions, and to verify design assumptions. A plan for monitoring these devices shall also be provided.3. Stability Analyses - All stability analyses shall be done using standard engineering techniques. The submittal shall include cross-sections at critical locations in the embankment showing the materials profile, location of critical potential failure surfaces and their factors of safety, estimated or measured phreatic surfaces for construction and/or long term seepage conditions, and a tabulated listing of strength parameters used. If a computer analysis is used, only the input data and results used specifically in the design shall be submitted.g. Abandoned Openings - Plans for sealing abandoned openings and covering the seal with four feet of an impermeable non-toxic material before placement of refuse over them shall be submitted to the director. Such plans shall consider prevention of water buildup behind the seals, toxicity of the refuse and mine strata, gradient of the opening, hydrologic balance and passage of any acid water to a treatment facility. If a mine seal is in the impoundment area of an impounding coal refuse disposal area, the seal shall be designed to safely withstand full hydrostatic head with a factor of safety of at least 1.5 against blowout. Higher factors of safety may be required where dictated by the consequences of failure. Calculations and cross-sections used in the analyses shall be submitted.h. Combustion Control - Coal refuse fires shall be extinguished. Plans for the extinguishment of burning areas shall be submitted to the regulatory authority and shall contain, at a minimum, method of extinguishment, safety measures for equipment operators and persons working or living in the vicinity of the site, and a provision that only those persons authorized by the operator, and who have an understanding of the procedure to be used, shall be involved in the extinguishing operation.i. Underground Refuse Disposal - Plans for underground refuse disposal shall be submitted to and approved by the director and the Mine Safety and Health Adminstration. All plans must include:1. Method of disposal including a description of the source of the transport medium;2. Maps of mines where coal refuse materials are to be disposed with a description of the percent of mine void to be filled;3. Considerations to location of active workings including plans, specifications and methods of constructing underground retaining walls;4. Potential areas of breakout in active mine workings and on the surface of the ground;5. Effects of subsidence on the plan;6. The effects on groundwater including a permanent monitoring well or station to be located in the lowest practical elevation of the backfill area;7. Gradient of the mine from the backfill area;8. Description of stratum underlying the mined coal, source and potential acid or toxic-forming quality of the waste, and the treatment of water if released to surface streams; and9. A contingency plan formulated to alleviate or correct any hazardous conditions which may result from a blowout.j. Any coal refuse materials or acid mine treatment sludge not previously approved for disposal at the site by the director may be disposed of in the permit area only if approved by the director. Approval shall be based on a showing by the person conducting surface or underground mining activities in the permit area using hydrologic, geologic, geotechnical, physical, and chemical analyses, that disposal of these materials does not:1. Adversely affect water quality, water flows or vegetation;2. Create public hazards;3. Cause instability in the disposal areas.4.6Reprocessing or Removal of Abandoned Coal Refuse Disposal Piles A special permit may be obtained for reprocessing or removal of an abandoned coal refuse disposal area. This permit must accomplish a more desirable land use or have the effect of protecting the public and the environment. A bond of $1,000 per disturbed acre, $10,000 minimum, in the permit area shall be provided. a. Application Requirements - An application for a special permit for removal of an abandoned refuse disposal area shall be submitted to the director for review. Plans and specifications for removal and reclamation shall be prepared by or under the direct supervision of an engineer. The application shall include two sets of maps and plans on standard 24" by 36" size plan sheets with seven copies of a submittal containing a project narrative, reclamation plan, specifications, supporting data, reduced maps and plans.1. The project narrative shall include as a minimum a discussion of existing site conditions, how the operation will protect the public or environment or accomplish a more desirable land use, the design life of the operation, quantity and type of material to be removed, method of operation to include phases of removal, sequence of critical construction phases, and a description of the duties, responsibilities, and lines of communication between engineers and those persons responsible for construction of the operation.2. The reclamation plan shall include as a minimum the location and capacity of sediment control facilities, and reclamation procedures and specifications for the revegetation and grading of the site.3. Supporting data shall include as a minimum the assumptions and parameters used in the design of the operation, the calculations used in the operation design, and the results of any necessary design calculations for sediment control facilities, removal of materials, diversion ditches, spillways, stability analysis, fire control and revegetation.4. Maps and plans shall be provided to show the following information with the scale designated on the drawing:(a) A location map showing the site in relation to major highways, nearest post office and major drainage. County highway maps may be used for this purpose.(b) A map showing the limits of the watershed with respect to the site. The minimum requirement shall be a U.S.G.S. 7 1/2 minute map with the site plotted on it.(c) A plan view of the site showing contours, limits and acreage of the permit area, location of drainage facilities, location of cross-sections, and other pertinent data for project control.(d) Cross-sections and profiles of drainage facilities, sediment control devices, and any stability analysis cross-sections.(e) A plot of inflow hydrographs and stage-storage curves as necessary for refuse impoundment and 100-year frequency, six hour duration diversion design only.b. Design Requirements1. General Requirements - All reprocessing or removal operations must be designed to: (a) Provide sediment control facilities in accordance with the Handbook for Surface Mining requirements. Variances may be granted where the operator can show that insufficient space exists to meet the Handbook for Surface Mining requirements and that existing or proposed sediment structures will meet effluent standards.(b) Provide diversion or discharge facilities in accordance with the requirements of this section.(c) Provide for removal of refuse in successive horizontal lifts with a maximum elevation difference between working benches of twelve feet or removal down to a maximum 2H:1V slope from the top to the toe. No refuse may be removed from the toe of the original embankment until the final removal process.(d) Provide a plan for fire control in present or unforeseen burning areas in accordance with Section 4.5.h.(e) Provide wherever possible a final graded refuse slope no steeper than 2H:1V and a twenty foot wide bench for every 50 feet of change in elevation at completion of the operation. Natural slopes shall be stabilized as necessary.(f) Provide adequate revegetation of refuse and natural ground slopes in accordance with Section 4F of the Surface Mining regulations. All refuse materials disturbed by the operation shall be provided with a minimum cover of non-toxic and non-combustible material sufficient to establish adequate vegetation.2. Specific Requirements (a) Non-impounding Refuse Areas (1) Working surface ditches shall be designed where necessary based on the one year, 24 hour duration storm event as a minimum during the operation.(2) Removal operations shall not create any impoundment of water through the life of the project.(3) For partial removal within the permit area, a 100-year, 6-hour duration diversion ditch shall be provided for that part of the pile where refuse will remain. A stability analysis shall be performed as deemed necessary by the director to demonstrate an adequate factor of safety in critical areas where refuse will remain.(b) Impounding Refuse Areas(1) Sufficient storage and spillway capacity for the design storm shall be provided through the removal operation. The design storm shall be in accordance with Sections 4.5.b and 4.5.d.2.(2) A maximum five foot elevation difference is permitted between the elevation of slurry and the breach invert elevation unless otherwise approved by the director.(3) Pumps, or pumps with ditches, must be provided to maintain the lowest possible water level in the impoundment.(4) For partial removal within the permit area, the site shall be converted to a non-impounding fill at completion of the operation. A stability analysis shall be performed if deemed necessary by the director to demonstrate an adequate factor of safety in critical areas for the remaining refuse embankment. A 100-year, 6-hour duration diversion ditch shall be provided in accordance with Section 4.5 d.2.(b).3. Disposal of Reprocessing Coal Refuse Materials - If reprocessing coal refuse materials are to be disposed of in the special permit area, the refuse disposal area must, in addition to applicable general requirements, be designed to: (a) Provide compaction of refuse in accordance with Section 4.5.2(c).(b) Disposal of reprocessing coal refuse materials from outside the special permit area shall be in accordance with Section 4.5.4.7Abandonment Requirements - The abandonment plan shall address the following requirements and include a schedule for their implementation: a. No impoundment exceeding 10,000 cubic-feet of water shall remain upon constructed fills upon abandonment. Impoundments remaining upon abandonment must meet the requirements of Section of the Surface Mining regulations.b. No refuse embankment or impoundment may be abandoned until it meets the requirements of Sections 4.2, 4.3, 4.5, Section 4F of the Surface Mining regulations, and has final bond release.c. A timetable in working days and plans to remove each structure meeting the size requirements of 3.1.b.3 shall be provided where appropriate.d. The final top elevation of the refuse embankment must be higher than, and sloped into, the diversion ditch. Maximum slope of the top of the embankment to the diversion ditch shall be 5 percent unless otherwise approved by the director.e. All pipes under refuse areas left as non-impounding fills shall be sealed with concrete at the upstream end prior to abandonment.f. At abandonment all fine refuse disposal areas shall be covered with a minimum three foot layer of coarse refuse prior to final covering in accordance with Section 4.5g of the Surface Mining regulations unless otherwise approved by the director.g. At abandonment all coal refuse shall be covered with a minimum of 4 feet of the best available non-toxic and non-combustible material in a manner that does not impede flow from sub-drainage systems. The director may allow less than 4 feet of cover material where it can be demonstrated that the requirements of Section 4F of the Surface Mining regulations shall be met.h. A certificate of approval for completion of construction shall be issued upon completion of the above requirements. A certificate may be issued for fresh water impoundments after completion of construction has been certified.