(of HAPs) -- Any stationary source or group of stationary sources located within a contiguous area and under common control that emits or has the potential to emit considering control that emits or has the potential to emit considering control, in the aggregate, 10 tons per year or more of any hazardous air pollutant or 25 tons per year or more of any combination of hazardous air pollutants. The Administrator of the U.S. EPA may establish a lesser quantity, or in the case of radionuclides a different criteria, for a major source than that specified in the previous sentence, on the basis of the potency of the air pollutant, persistence, potential for bioaccumulation, other characteristics of the air pollutant, or other relevant factors. Fed
a source that emits or has the potential to emit more than 100 tons of any pollutant regulated under the federal Clean Air Act, more than 10 tons of any hazardous air pollutants or 25 tons of all hazardous air pollutants
a facility that is capable of emitting more than certain amounts of air contaminants
This is any stationary source that has emissions exceeding the threshold level for a particular pollutant. The specific emissions level that defines a major source depends upon the pollutant and the degree of pollution in the nonattainment area.
A stationary facility that emits a regulated pollutant in an amount exceeding the threshold level depending on the location of the facility and attainment with regard to air quality status.
Under the PSD regulations it is a facility, belonging to one or more of 28 source categories, having the potential to emit 100 tons per year of a pollutant regulated under the federal Clean Air Act (CAA). For categories other than the 28 sources, the potential emission level can not exceed 250 tons per year. A major source for the purpose of Title V in the CAA is a stationary source that has the potential to emit 100 tons per year a pollutant regulated under the CAA and/or a source that has the potential to emit 10 tons per year for a single hazardous air pollutant or 25 tons per year of a combination of all hazardous air pollutants.
(also "Major Stationary Source") The definition varies depending upon the level of attainment for a particular pollutant in the area in which the plant is located. For example, in severe ozone nonattainment areas, a major source will be one that emits more than twenty-five tons of ozone precursors. For hazardous pollutants, a major source is an industrial facility which emits 10 tons per year of any single air toxic on 25 tons per year of any combination of air toxics.
As defined by The Clean Air Act Amendment of 1990: "any stationary source or group of stationary sources located within a contiguous area and under common control that emits or has the potential to emit considering controls, in the aggregate, 10 tons per year or more of any hazardous air pollutant or 25 tons per year or more of any combination of hazardous air pollutants."
Any source defined as major under the Prevention of Significant Deterioration program; in a nonattainment area; or all other sources not meeting the definition of PSD or nonattainment area who emit 100 tons per year of a regulated pollutant. For sources subject to federal MACT rules, a major source is one that emits 10 tons per year of a single hazardous air pollutant or 25 tons per year of any combination of hazardous air pollutants. Maximum Achievable Control Technology (MACT) -- The maximum degree of reduction in air pollution for new and existing sources, taking into consideration cost, non-air quality health and environmental impacts and energy requirements.
In an attainment area, a major source is defined as any facility or stationary source which emits or is able to emit 100 tpy or more of any criteria air pollutant, or which emits or is able to emit 10 tpy or more of any individual federal hazardous air pollutant, or which emits or is able to emit 25 tpy or more of combined federal hazardous air pollutants. In a non-attainment area, a major source is defined using lower tons per year cut-off levels.
A stationary source which emits or has the potential to emit any pollutant regulated under the Clean Air Act at a significant emission rate.
Federal regulations require states to initially classify a combustion facility as Major if its physical capacity (i.e., heat input design rating) and operational capacity (i.e., continuous operation-24 hrs/day, 365 days/yr), also known as potential to emit (PTE), equal or exceed the Major thresholds. Limiting factors such as seasonal operation or fuel usage may give a more realistic actual annual emission level. However, these limiting factors must be recorded in a DEC air permit to be considered valid.
A stationary source that emits a large amount of pollution. In nonattainment areas, under Title I of the CAAA, a major source is one which emits more than 100, 50, 25 or 10 tons per year, depending on whether the area is classified as Marginal or Moderate, Serious, Severe or Extreme, respectively. For hazardous air pollutants, under Title III of the CAAA, a major source is one which can emit more than 10 TPY of any one HAP or 25 TPY of total HAPs.