of these regulations applies to all composting facilities as described

of these regulations applies to all composting facilities as described therein, unless otherwise specified or excluded in paragraph B. of this rule. (9) Solid waste management facilities failing to satisfy these criteria are considered to be open dumps for purposes of State waste management planning and are prohibited under Section 4005 of RCRA and the Mississippi Solid Waste Disposal Law, where there are criteria applicable to the facilities. (10) MSWLF units containing sewage sludge and failing to satisfy these criteria violate sections 309 and 405(e) of the Clean Water Act. (11) Solid waste management facilities which manage or dispose of sewage sludge must comply with 40 CFR 503 – Standards for the Use or Disposal of Sewage Sludge, which are incorporated herein and adopted by reference. B. Exclusions. Notwithstanding anything in these regulations to the contrary, the management of solid waste is subject to these regulations except as described herein: (1) Hazardous wastes, which are subject to regulation under Subtitle C of the Federal Resource Conservation and Recovery Act (RCRA), as amended. (2) Domestic sewage or industrial wastewater that passes through a sewer system or wastewater treatment works and which is subject to regulation under any other state or federal environmental regulatory program. (Unless paragraph B.5. of this rule is applicable, this exclusion does not apply to sludges and other materials once they are removed from the wastewater treatment works and disposed.) (3) Solid wastes generated by the growing or harvesting of agricultural crops or the raising of animals (including animal manure), where such wastes are uniformly and promptly returned to the soil as fertilizers or soil conditioners. (4) Rubbish that is legitimately used, reused, recycled or reclaimed, except for rubbish wastes which is composted or which, due to its chemical or physical constituency, would result in an endangerment to the environment or the public health, safety, or welfare. (5) Beneficial uses of solid wastes that have been determined by the Department to have physical and chemical qualities that make the wastes suitable for use as a replacement material for other raw materials or products. The Commission may adopt additional guidance or standards to evaluate such wastes for beneficial use. (6) Beneficial fill projects involving an area occupying less than one acre in size and for a duration of less than 120 days. Beneficial fill projects involving an area larger than one acre or for a duration of more than 120 days may be excluded upon the review and approval of the Permit Board or the Permit Board’s designee. (7) Solid wastes generated in silviculture activities (e.g., timber harvesting slash and land clearing debris) whenever such wastes are left onsite. (8) Solid wastes processed on the same property on which wastes are generated in a processing facility owned and operated by the generator. (9) Solid wastes which do not constitute an endangerment to the environment or the public health, safety or welfare and which are disposed of on the same property on which wastes are generated, upon the concurrence of the Permit Board or the Permit Board’s designee. In determining whether a solid waste constitutes an endangerment to the environment or the public health, safety or welfare, the Permit Board or the Permit Board’s designee shall consider both the quantity and quality of the solid waste, the method of disposal, the location of the disposal property and any other factors which would warrant special concern. Garbage and rubbish containing garbage have been determined by the Commission and by the Department to have characteristics that constitutes an endangerment to the environment, public health, safety, and welfare of the general public within the meaning of Section 17-17-13, Mississippi Code Annotated, and accordingly, are not included in this exemption. All garbage and rubbish containing garbage regardless of where it is disposed or who the generator is, shall be managed in accordance with these regulations and other laws, rules, and regulations pertaining to the management of garbage and rubbish containing garbage. (10) Solid wastes contained within mining overburden that is returned to the mine site. (11) Wastes subject to regulation under Part C of the Federal Safe Drinking Water Act (Underground injection wells). (12) Wastes associated with the exploration or production of crude oil or natural gas, except where those wastes are disposed or processed in a commercial oil field exploration and production waste disposal facility. C. Definitions. Unless otherwise noted, all terms contained in this regulation are defined by their plain meaning. This section contains definitions for terms that appear throughout this regulation. Additional definitions appear in the specific sections to which they apply. (1) "Active life" means the period of operation beginning with the initial receipt of solid waste and ending at completion of closure activities in accordance with these regulations. (2) "Active portion" means that part of a facility or unit that has received or is receiving wastes and that has not been closed in accordance with these regulations. (3) "Airport" means a public-use airport open to the public without prior permission and without restrictions within the physical capacities of available facilities. (4) "Aquifer" means a geological formation, group of formations, or portion of a formation capable of yielding significant quantities of groundwater to wells or springs. (5) "Areas susceptible to mass movement" means those areas of influence (i.e., areas characterized as having an active or substantial possibility of mass movement) where the movement of earth material at, beneath, or adjacent to the landfill, because of natural or man-induced events, results in the downslope transport of soil and rock material by means of gravitational influence. Areas of mass movement include, but are not limited to, landslides, avalanches, debris slides and flows, soil fluction, block sliding, and rock fall. (6) "Backyard composting or vermicomposting" means the composting of organic solid waste, such as yard waste and household garbage, generated by a homeowner or tenant of a single or multi-family residential unit, where such composting occurs at the site of the residence. (7) “Beneficial Fill” means the use of uncontaminated, non-water soluble, non- decomposable class II rubbish wastes to level an area or bring the area to a grade for beneficial purposes, where an earthen cover is applied upon completion of the fill. Such beneficial purposes must not be conducted for monetary compensation and may include landscaping, erosion control or repair, land stabilization, construction base preparations or other land improvements. (8) “Beneficial Use” means the legitimate use of a solid waste in the manufacture of a product or as a product for construction, soil amendment, or other purposes, where the solid waste replaces a natural or other resource material by its utilization. (9) "Bird hazard" means an increase in the likelihood of bird/aircraft collisions that may cause damage to the aircraft or injury to its occupants. (10) "Cation Exchange Capacity" means the sum of exchangeable cations a soil can absorb expressed in milliequivalents per 100 grams of soil as determined by sampling the soil to the depth of cultivation or solid waste placement, whichever is greater, and analyzing by the summation method for distinctly acid soils or the sodium acetate method for neutral, calcareous or saline soils. (11) "Certificate of Coverage" means a written grant of coverage under an existing general permit. (12) "Church" means a permanent structure with a permanent foundation and constructed roof, floors, and walls, the primary use of which is for a group of persons to meet at least weekly for religious services. (13) "Class I Rubbish Site" means a rubbish site, which receives the types of rubbish described in Rule 6.B of these regulations. (14) "Class II Rubbish Site" means a rubbish site, which receives only the type of rubbish described in Rule 6.C of these regulations. (15) "Coastal wetlands" means such areas as defined by and subject to the Coastal Wetlands Protection Act. (16) "Commercial nonhazardous solid waste management facility" means any facility engaged in the storage, treatment, processing or disposal of nonhazardous solid waste for compensation or which accepts nonhazardous solid waste from more than one (1) generator not owned by the facility owner. (17) "Commercial oil field exploration and production waste disposal" means storage, treatment, recovery, processing, disposal or acceptance of oil field exploration and production waste from more than one (1) generator or for a fee. (18) "Commercial solid waste" means all types of solid waste generated by stores, offices, restaurants, warehouses, and other nonmanufacturing activities, excluding residential and industrial wastes. (19) "Commercial waste incinerator" means an incinerator which burns solid waste received from more than one generator or for compensation, but excluding those which burn only wood or paper waste. (20) "Commission" means the Mississippi Commission on Environmental Quality. (21) "Composite liner" means a system consisting of two components; the upper component must consist of a minimum 30-mil flexible membrane liner (FML), and the lower component must consist of at least a two-foot layer of compacted soil with a hydraulic conductivity of no more than 1 x 10-7 cm/sec. FML components consisting of High Density Polyethylene (HDPE) shall be at least 60-mil thick. The FML component must be installed in direct and uniform contact with the compacted soil component. (22) "Compost" means the resulting product from a composting facility after having undergone biological decomposition, less residuals or recyclables, and which has been stabilized to a degree that it is potentially beneficial to plant growth and which is used or sold for use as a soil amendment, artificial topsoil, growing medium amendment, or other similar uses. (23) "Composting facility" means a facility which produces compost, excluding backyard composting or vermicomposting, or normal farming operations. (24) "Composting or compost plant" means an officially controlled method or operation whereby putrescible solid wastes are broken down through microbic action to a material offering no hazard or nuisance factors to public health or well- being. (25) “Cumulative pollutant loading rate” means the maximum amount of an inorganic pollutant that can be applied to an area of land. (26) "Curing" means the final stage of the composting process beginning in the later part of the mesophilic stage. During the curing process oxygen demand is reduced as the pile is recolonized by soil-dwelling micro-organisms. Once cured, the compost will not generate odors. (27) "Department" means the Mississippi Department of Environmental Quality. (28) "Disposal" means the discharge, deposit, injection, dumping, spilling, leaking, or placing of any solid waste into or on any land or water so that such solid waste or any constituent thereof may enter the environment or be emitted into the air or discharged into any water, including groundwater. (29) "Disease vectors" means any rodents, birds, flies, mosquitoes, or other animals, including insects, capable of transmitting disease to humans. (30) "Displacement" means the relative movement of any two sides of a fault measured in any direction. (31) "Dumpster" means a specially constructed, removable waste container of any size designed to be mechanically picked up, dumped, and/or transported by a specially constructed vehicle designed for that purpose. (Commonly referred to as roll-off containers, green boxes, or commercial containers.) (32) "Endangered or threatened species" means any species listed as such pursuant to the Federal Endangered Species Act of 1973, as amended, or as defined by Section 49-5-105, Mississippi Code Annotated. (33) "Executive Director" means the Executive Director of the Mississippi Department of Environmental Quality. (34) "Existing facility" means a facility that has obtained a valid permit or other authorization from the Department before the effective date of the rules applicable to the facility, excluding those which have closed and are no longer authorized to receive solid waste. (35) "Existing MSWLF unit" means any municipal solid waste landfill unit that is receiving solid waste as of the effective date of these regulations. Waste placement in existing units must be consistent with past operating practices or modified practices to ensure good management. (36) "Facility" means all contiguous land and structures, other appurtenances, and improvements on the land used for the management of solid waste. (37) "Fault" means a fracture or a zone of fractures in any material along which strata on one side have been displaced with respect to that on the other side. (38) "Floodplain" means the lowland and relatively flat areas adjoining inland and coastal waters, including flood-prone areas of offshore islands that are inundated by the 100-year flood. (39) "Garbage" means putrescible animal and vegetable wastes resulting from the handling, preparation, cooking and consumption of food, including wastes from markets, storage facilities, handling and sale of produce and other food products, and excepting such materials that may be serviced by garbage grinders and handled as household sewage. (40) "Gas condensate" means the liquid generated as a result of gas recovery process(es) at an MSWLF unit. (41) "General Permit" means a permit, which applies to a specified category of similar facilities or activities that involve similar solid wastes or have similar operating and/or monitoring requirements and restrictions. (42) "Groundwater" means water below the land surface in a zone of saturation. (43) "Hazardous wastes" means any waste or combination of waste of a solid, liquid, contained gaseous, or semisolid form which because of its quantity, concentration or physical, chemical or infectious characteristics, may (a) cause, or significantly contribute to an increase in mortality or an increase in serious irreversible or incapacitating reversible illness; or (b) pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of, or otherwise managed which are listed by the Environmental Protection Agency as hazardous wastes which exceed the threshold limits set forth in the Environmental Protection Agency regulations for classifying hazardous waste. Such wastes include, but are not limited to, those wastes which are toxic, corrosive, flammable, irritants, strong sensitizers, or which generate pressure through decomposition, heat or other means. Such wastes do not include those radioactive materials regulated pursuant to the Mississippi Radiation Protection Law of 1976, appearing in Section 45-14-1 et seq.. (44) "Holocene" means the most recent epoch of the Quaternary period, extending from the end of the Pleistocene Epoch to the present. (45) "Household waste" means any solid waste (including garbage, trash, and sanitary waste in septic tanks) derived from households (including single and multiple residences, hotels and motels, bunkhouses, ranger stations, crew quarters, campgrounds, picnic grounds, and day-use recreation areas). (46) "Incinerator" means a combustion device specifically designed for the destruction by high temperature burning of solid, semi-solid, liquid, or gaseous combustible waste and from which the solid residues contain little or no combustibles. (47) "Individual Permit" means a permit, which applies only to a specific facility or location. (48) "Industrial solid waste" means solid waste generated by manufacturing or industrial processes that is not a hazardous waste regulated under Subtitle C of RCRA. Such waste may include, but is not limited to, waste resulting from the following manufacturing processes: Electric power generation; fertilizer/agricultural chemicals; food and related products/by-products; inorganic chemicals; iron and steel manufacturing; leather and leather products; nonferrous metals manufacturing/foundries; organic chemicals; plastics and resins manufacturing; pulp and paper industry; rubber and miscellaneous plastic products; stone, glass, clay, and concrete products; textile manufacturing; transportation equipment; and water treatment. This term does not include mining waste or oil and gas waste. (49) "Karst terrains" means areas where karst topography, with its characteristic surface and subterranean features, is developed as the result of dissolution of limestone, dolomite, or other soluble rock. Characteristic physiographic features present in karst terrains include, but are not limited to, sinkholes, sinking streams, caves, large springs, and blind valleys. (50) "Lake or reservoir" means a body of water, not owned by the applicant or facility owner, having greater than ten acres of surface area at such time as the spillway overflows, with a primary purpose other than wastewater storage or treatment. (51) “Land Application” means the incorporation of waste into the soil, the injection of waste below the land surface or other application of waste to the land for soil amendment or conditioning purposes or for biodegradation of the waste. (52) "Land application site" means a site upon which land application activities are conducted. (53) "Landfill" means a controlled area of land upon which solid wastes are deposited, compacted, and covered with no on-site burning of wastes, and which is so located, contoured, drained and operated so that it will not cause an adverse effect on public health or the environment. This term includes MSWLF units and other landfills, but not sites which receive only rubbish. (54) "Lateral expansion" means a horizontal expansion of the waste boundaries of an existing solid waste management facility. In the context of an MSWLF unit, this term includes previously permitted areas where such areas have not received wastes. In the context of other facilities, this term does not include previously permitted areas where such areas have not received waste. (55) "Leachate" means a liquid that has passed through or emerged from solid waste and contains soluble, suspended, or miscible materials removed from such waste. (56) "Liquid waste" means any waste material that is determined to contain "free liquids" as defined by Method 9095 (Paint Filter Liquids Test), as described in "Test Methods for Evaluating Solid Wastes, Physical/Chemical Methods" (EPA Pub. No. SW-846). (57) "Lithified earth material" means all rock, including all naturally occurring and naturally formed aggregates or masses of minerals or small particles of older rock that formed by crystallization of magma or by induration of loose sediments. This term does not include man-made materials, such as fill, concrete, and asphalt, or unconsolidated earth materials, soil, or regolith lying at or near the earth's surface. (58) "Lower explosive limit" means the lowest percent by volume of a mixture of explosive gases in air that will propagate a flame at 25oC and atmospheric pressure. (59) "Maximum horizontal acceleration in lithified earth material" means the maximum expected horizontal acceleration depicted on a seismic hazard map, with a 90 percent or greater probability that the acceleration will not be exceeded in 250 years, or the maximum expected horizontal acceleration based on a site-specific seismic risk assessment. (60) "Mesophilic stage" means the biological stage in the composting process characterized by active bacteria which favor a moderate temperature range of 20 to 45C (68 to 113F). It occurs later in the composting process after the thermophilic stage and is associated with a moderate rate of decomposition. (61) “Mining Overburden” means all earth and other natural materials which are removed to gain access to the desired minerals in the process of surface mining and shall mean such material before or after its removal by surface mining. (62) "Municipal solid waste" means any nonhazardous solid waste resulting from the operation of residential, commercial, governmental, industrial or institutional establishments except oil field exploration and production wastes and sewage sludge. (63) "Municipal solid waste management facility" means any land, building, plant, system, motor vehicles, equipment or other property, whether real, personal or mixed, or any combination of either thereof, used or useful or capable of future use in the collection, storage, treatment, utilization recycling, processing, transporting or disposal of municipal solid waste, including transfer stations, incinerators, sanitary landfill facilities or other facilities necessary or desirable. (64) "Municipal solid waste landfill unit (MSWLF unit)" means a discrete area of land or an excavation that receives household waste (including ash from a municipal solid waste combustion facility) and that is not a land application unit, surface impoundment, injection well, or waste pile, as those terms are defined under 40 CFR Part 257.2. A MSWLF unit may also receive other types of RCRA subtitle D wastes, such as commercial solid waste, nonhazardous sludge, small quantity generator waste and industrial solid waste. Such a landfill may be publicly or privately owned. A MSWLF unit may be a new MSWLF unit, an existing MSWLF unit or a lateral expansion. (65) "New facility" means a facility that has not received waste and which has not applied for or received a valid permit or other authorization from the Department to receive waste prior to the effective date of the rule applicable to the facility, including any land area of an existing facility that has not been previously permitted. (66) "New landfill" means a landfill that has not received waste and which has not applied for or received a valid permit or other authorization from the Department to receive waste prior to the effective date of the rule applicable to the landfill, including any land area of an existing landfill that has not been previously permitted. (67) "New MSWLF unit" means any municipal solid waste landfill unit that has not received waste prior to the effective date of the rule applicable to the unit. (68) "Normal Farming Operations" means the customary and generally accepted activities, practices, and procedures that farmers adopt or utilize on their own property for their own use during the production and preparation for market of poultry, livestock and associated farm products, and in the production and harvesting of crops, including agronomic, horticultural and silvicultural crops. (69) "Open burning" means the combustion of solid waste without the following: (a) control of combustion air to maintain adequate temperature for efficient combustion, (b) containment of the combustion reaction in an enclosed device to provide sufficient residence time and mixing for complete combustion, and (c) control of the emission of the combustion products. (70) "100-year flood" means a flood that has a 1-percent or greater chance of recurring in any given year or a flood of a magnitude equalled or exceeded once in 100 years on the average over a significantly long period. (71) "Outdoor facility" means a facility in which any solid waste management activity, including storage, is not adequately enclosed within a walled and roofed structure. (72) "Owner" means the person(s) who owns a facility or part of a facility and is responsible for the overall operation. (73) “Pathogens” means disease-causing organisms, including but not limited to certain bacteria, protozoa, viruses and viable helminth ova. (74) "Permit" means the formal written approval issued by the Mississippi Environmental Quality Permit Board to operate a solid waste management facility. A permit may be an individual permit, issued to a person, or a general permit, issued for a specified category of similar facilities or activities that involve similar solid wastes or have similar operating and/or monitoring requirements and restrictions. (75) "Permit Board" means the Mississippi Environmental Quality Permit Board, as established under Section 49-17-28, Mississippi Code Annotated. (76) "Permit Board's designee" means the Executive Director or a member of the Department staff. (77) "Person" means any individual, trust, firm, joint-stock company, public or private corporation (including a government corporation), partnership, association, state, or any agency or institution thereof, municipality, Commission, political subdivision of a state or any interstate body, and includes any officer or governing or managing body of any municipality, political subdivision, or the United States or any officer or employee thereof. (78) "Plant Available Nitrogen" means the amount of nitrogen available for plant uptake. It consists of all of the nitrate and ammonia present in the soil and a fraction of the organic nitrogen present which can be expected to be converted to an inorganic form during a given year. (79) "Polychlorinated biphenyls (PCBs)" means any chemical substance that is limited to the biphenyl molecule that has been chlorinated to varying degrees or any combination of substances, which contains such substances. (80) "Polychlorinated biphenyl (PCB) waste(s)" means those PCBs and PCB items that are subject to the disposal requirements of Subpart D of 40 CFR Part 761. (81) "Poor foundation conditions" means those areas where features exist which indicate that a natural or man-induced event may result in inadequate foundation support for the structural components of a landfill. (82) "Processing facility" means a facility, other than a composting facility or transfer station used to sort, shred, grind, bale, treat or otherwise process solid waste. The term does not include facilities which receive and manage only recyclable components of solid wastes that are removed at least annually. (83) "Public water supply well" means a water supply well, which is regulated by the Safe Drinking Water Act of 1974, the Mississippi Drinking Water Law of 1976, or regulations promulgated thereunder. (84) "Putrescible wastes" means solid wastes which are capable of being decomposed by micro-organisms with sufficient rapidity to cause nuisances from odors or gases. (85) "Qualified groundwater scientist" means a scientist, geologist or engineer, who has received a baccalaureate or post-graduate degree in the natural sciences, geology or engineering and has sufficient training and experience in groundwater hydrology and related fields as may be demonstrated by State registration, professional Certifications, or completion of accredited university programs that enable that individual to make sound professional judgments regarding groundwater monitoring, contaminant fate and transport, and corrective-action. (86) "Recyclables" means materials which are intended to be sold or delivered to the open market for recycling or processing into a marketable product. (87) "Regulated hazardous waste" means a solid waste that is a hazardous waste, as defined in 40 CFR Part 261.3, that is not excluded from regulation as a hazardous waste under 40 CFR Part 261.4(b) or was not generated by a conditionally exempt small quantity generator as defined in 40 CFR Part 261.5. (88) "Residuals" means material removed from a processing or composting facility which cannot be processed or composted. (89) "Rubbish" means nonputrescible solid wastes (excluding ashes) consisting of both combustible and noncombustible wastes. Combustible rubbish includes paper, rags, cartons, wood, furniture, rubber, plastics, yard trimmings, leaves and similar material. Noncombustible rubbish includes glass, crockery, metal cans, metal furniture and like material which will not burn at ordinary incinerator temperatures (not less than 1600 degrees F.). (90) "Rubbish site" means a site, which receives rubbish for the purpose of disposal. (91) "Run-off" means any rainwater, leachate, or other liquid that drains over land from any part of a facility. (92) "Run-on" means any rainwater, leachate, or other liquid that drains over land onto any part of a facility. (93) "Saturated zone" means that part of the earth's crust in which all voids are filled with water. (94) "Scavenging" means the uncontrolled and unauthorized removal of materials at any point in the solid waste management system. (95) "Seismic impact zone" means an area with a ten percent or greater probability that the maximum horizontal acceleration in lithified earth material, expressed as a fraction of the earth's gravitational pull (g), will exceed 0.10g in 250 years. (96) "7Q10 flow" means the average streamflow rate over seven (7) consecutive days that may be expected to be reached as an annual minimum no more frequently than one (1) year in ten (10). (97) "Sewage Sludge" means the solid, semi-solid or liquid residue generated during treatment of municipal wastewater in a treatment works. Sewage sludge includes, but is not limited to, domestic septage; scum or solids removed in primary, secondary, or advanced wastewater treatment processes; and a material derived from sewage sludge. Sewage sludge does not include ash generated during the firing of sewage sludge in a sewage sludge incinerator or grit and screenings generated during preliminary treatment of domestic sewage in a treatment works. (98) "Single family dwelling unit" means either (a) a conventional single family detached dwelling or mobile home, or (b) a unit within a multi-family residential complex (townhouses, condominiums, or apartments). (99) "Sludge" means any solid, semi-solid, or liquid waste generated from a municipal, commercial, or industrial wastewater treatment plant, water supply treatment plant, or air pollution control facility exclusive of the treated effluent from a wastewater treatment plant. (100) "Solid waste" means any garbage, or refuse, sludge from a wastewater treatment plant, water supply treatment plant, or air pollution control facility and other discarded material, including solid, liquid, semi-solid, or contained gaseous material resulting from industrial, commercial, mining, and agricultural operations, and from community activities, but does not include solid or dissolved materials in domestic sewage, or solid or dissolved materials in irrigation return flows or industrial discharges that are point sources subject to permit under 33 U.S.C. 1342, or source, special nuclear, or by-product material as defined by the Atomic Energy Act of 1954, as amended (68 Stat. 923). (101) "Solid waste management facility" means any facility which manages nonhazardous solid waste, including landfills, rubbish sites, land application sites, processing facilities, composting facilities, transfer stations, and waste incinerators, but excluding ordinary storage vessels such as trash cans, dumpsters, etc. (102) "Storage" means the containment of wastes, either on a temporary basis or for a period of years, in such a manner as not to constitute disposal of such wastes. (103) "Stream or river" means a flowing body of water with a 7Q10 flow greater than zero. (104) "Structural components" means liners, leachate collection systems, final covers, run-on/run-off systems, and any other component used in the construction and operation of the MSWLF that is necessary for protection of human health and the environment. (105) "Thermophilic stage" means the biological stage in the composting process characterized by active bacteria which favor a high temperature range of 45 to 75C (113 to 167F). It occurs early in the composting process before the mesophilic stage and is associated with a high rate of decomposition. (106) "Transport" means the movement of wastes from the point of generation to any intermediate points, and finally to the point of ultimate storage or disposal. (107) "Transfer station" means a fixed facility used for the primary purpose of transferring solid waste from one solid waste transportation vehicle to another. Dumpsters or other comparable solid waste containers loaded and unloaded onto a transportation vehicle are not included in this definition. (108) "Unstable area" means a location that is susceptible to natural or human-induced events or forces capable of impairing the integrity of some or all of the landfill structural components responsible for preventing releases from a landfill. Unstable areas can include poor foundation conditions, areas susceptible to mass movements, and Karst terrains. (109) "Uppermost aquifer" means the geologic formation nearest the natural ground surface that is an aquifer, as well as, lower aquifers that are hydraulically interconnected with this aquifer within the facility's property boundary. (110) "Vermicomposting" means a composting process that utilizes worms in the biological decomposition of waste. (111) "Washout" means the carrying away of solid waste by waters of the base flood. (112) "Waste management unit boundary" means a vertical surface located at the hydraulically downgradient limit of the unit. This vertical surface extends down into the uppermost aquifer. (113) "Wetlands" means those areas that are defined in 40 CFR 232.2. Wetlands include, but are not limited to, swamps, marshes, bogs, and similar areas. (114) "Yard Waste" means the leaves, grass cuttings, weeds, garden waste, tree limbs, and other vegetative wastes generated at residential, commercial, institutional, governmental, or industrial properties. D. Effective Date The effective date of these regulations is October 1, 1993, except where Part 258 of Title 40 of the Code of Federal Regulations allows for a later date for MSWLF units and except where amendments to these regulations are effective at a later date. The effective date of the amendments adopted by the Commission on February 22, 1996, is April 3, 1996. The effective date of the amendments adopted by the Commission on April 28, 2005 is June 17, 2005. E. Severability If any provision, section, subsection, sentence, clause or phrase of any of these regulations, or the application of same to any person or set of circumstances is for any reason challenged or held to be invalid or void, the validity of the remaining regulations and/or portions thereof or their application to other persons or sets of circumstances shall not be affected thereby.