Oregon Administrative Rules
Chapter 340 - DEPARTMENT OF ENVIRONMENTAL QUALITY
Division 239 - LANDFILL GAS EMISSIONS
Section 340-239-0015 - Definitions

(1) "Active landfill" means a landfill in which solid waste is being placed or a landfill that is planned to accept waste in the future.

(2) "Bioreactor" means a landfill or portion of a landfill where any liquid other than leachate (leachate includes landfill gas condensate) is added in a controlled fashion into the waste mass (often in combination with recirculating leachate) to reach a minimum average moisture content of at least 40 percent by weight to accelerate or enhance the anaerobic (without oxygen) biodegradation of the waste.

(3) "Component" means any equipment that is part of the gas collection and control system and that contains landfill gas including, but not limited to, wells, pipes, flanges, fittings, valves, flame arrestors, knock-out drums, sampling ports, blowers, compressors, or connectors.

(4) "Component leak" means the concentration of methane measured one half of an inch or less from a component source that exceeds 500 parts per million by volume (ppmv), other than nonrepeatable, momentary readings. Measurements from any vault must be taken within three inches above the surface of the vault exposed to the atmosphere.

(5) "Closed landfill" means that a landfill is no longer accepting solid waste for disposal and has documentation that the closure was conducted in accordance with the applicable statutes, regulations, and local ordinances in effect at the time of closure.

(6) "Continuous operation" means that the gas collection and control system is operated continuously, the existing gas collection wells are operating under vacuum while maintaining landfill gas flow, and the collected landfill gas is processed by a gas control system 24 hours per day.

(7) "Controlled landfill" means any landfill at which collection and control systems are required under this division. The landfill is considered controlled at the time a Collection and Control System Design Plan is required to comply with OAR 340-239-100(6) or OAR 340-239-100(7).

(8) "Corrective action analysis" means a description of all reasonable interim and long-term measures, if any, that are available, and an explanation of why the selected corrective action(s) is/are the best alternative(s), including, but not limited to, considerations of cost effectiveness, technical feasibility, safety, and secondary impacts.

(9) "Decomposable solid waste" means any solid waste that is not nondecomposable solid waste.

(10) "Destruction efficiency" means a measure of the ability of a gas control device to combust, transform, or otherwise prevent emissions of methane from entering the atmosphere.

(11) "Enclosed combustor" means an enclosed flare, steam generating boiler, internal combustion engine, or gas turbine.

(12) "Energy recovery device" means any combustion device that uses landfill gas to recover energy in the form of steam or electricity, including, but not limited to, gas turbines, internal combustion engines, boilers, and boiler-to-steam turbine systems.

(13) "Gas control device" means any device used to dispose of or treat collected landfill gas, including, but not limited to, enclosed flares, internal combustion engines, boilers and boiler-to-steam turbine systems, fuel cells, and gas turbines.

(14) "Gas collection system" means any system that employs various gas collection wells and connected piping, gas mover equipment, or any system that is a passive collection system.

(15) "Gas control system" means any system that disposes of or treats collected landfill gas by one or more of the following means: combustion, gas treatment for subsequent sale, or sale for processing offsite, including for transportation fuel and injection into the natural gas pipeline.

(16) "Gas mover equipment" means the equipment (i.e., fan, blower, compressor) used to transport landfill gas through the header system.

(17) "Gas mover system" includes all of the gas mover equipment,

(18) "Gas collection and control system" means any system consisting of a Gas Collection System and a Gas Control System.

(19) "Inactive area" means a separate area of a landfill in which solid waste is no longer being placed. The area must be separated from other areas of the landfill to ensure that the landfill gas does not migrate between active and inactive areas.

(20) "Inactive landfill" means a landfill that is no longer accepting solid waste for disposal, or can document that the landfill is no longer receiving solid waste.

(21) "Landfill" means an area of land or an excavation in which wastes are placed for permanent disposal, and that is not a land application unit, surface impoundment, injection well, or waste pile as those terms are defined under 40 C.F.R. § 257.2.

(22) "Landfill gas" means any untreated, raw gas derived through a natural process from the decomposition of organic waste deposited in a landfill, from the evolution of volatile species in the waste, or from chemical reactions of substances in the waste.

(23) "Landfill surface" means the area of the landfill under which decomposable solid waste has been placed, excluding the working face.

(24) "Leachate recirculation" means the practice of taking the leachate collected from the landfill and reapplying it to the landfill by any of one of a variety of methods, including pre-wetting of the waste, direct discharge into the working face, spraying, infiltration ponds, vertical injection wells, horizontal gravity distribution systems, and pressure distribution systems.

(25) "Nondecomposable solid waste" means solid waste that is biologically and chemically inactive and does not form landfill gas. Examples include, but are not limited to, earth, rock, concrete asphalt paving fragments, uncontaminated concrete (including fiberglass or steel reinforcing rods embedded in the concrete), brick, glass, ceramics, clay products, inert slag, asbestos-containing waste, waste tire chips, and demolition materials containing minor amounts (less than 10 percent by volume) of wood and metals.

(26) "Nonrepeatable, Momentary Readings" means indications of the presence of methane, which persist for less than five seconds and do not recur when the sampling probe of a portable gas detector is placed in the same location.

(27) "Open Flare" means an open combustor without enclosure or shroud.

(28) "Operator" means any person that:

(29) "Owner" means any person that:

(30) "Passive collection system" means a gas collection system that solely uses positive pressure within the landfill to move the gas rather than using gas mover equipment.

(31) "Ppmv" means parts per million by volume

(32) "Professional engineer" means an individual who is registered in Oregon and holds a valid certificate to practice engineering in Oregon as provided under ORS 672.002 to 672.325.

(33) "Remedial Action" means the definition provided under ORS 465.200.

(34) "Root cause analysis" means an assessment conducted through a process of investigation to determine the primary cause, and any other contributing causes, of positive pressure at a wellhead.

(35) "Scfm" means standard cubic feet per minute

(36) "SEM" means Surface Emission Monitoring

(37) "Solid waste" means all decomposable and nondecomposable solid, semisolid, and liquid wastes, including garbage, trash, refuse, paper, rubbish, ashes, industrial waste, manure, vegetable or animal solid and semisolid wastes, sludge, and other discarded solid and semisolid wastes. Solid waste also includes any material meeting the definition of solid waste in 40 C.F.R. § 60.751.

(38) "Treatment system" means a system that filters, de-waters, and compresses landfill gas.

(39) "Waste-in-Place" means the total amount of solid waste placed in the landfill in tons. The solid waste density is assumed to be 1,300 pounds per cubic yard and the decomposable fraction is assumed to be 70 percent by weight unless DEQ approves alternative values.

(40) "Well raising" means a landfill activity where an existing gas collection well is temporarily disconnected from a vacuum source, and the nonperforated pipe attached to the well is extended vertically to allow the addition of a new layer of solid waste or the final cover; or is extended horizontally to allow the horizontal extension of an existing layer of solid waste or cover material. The extended pipe (well extension) is then reconnected in order to continue collecting gas from that well.

(41) "Working face" means the open area where solid waste is deposited daily and compacted by landfill equipment.