Ambient Air Definition/Interpretations
| Date | Title | EPA Office | Author | Issues Addressed |
|---|---|---|---|---|
| 12/02/2019 | Revised Policy on Exclusions from "Ambient Air" (pdf) | Administrator | Wheeler, Andrew | Addresses what atmosphere may be eligible for exclusion from the scope of “ambient air.” |
| 05/23/1977 | Applicability of PSD Increments Over Company Property (pdf) | OAQPS | Barber, Walter | Whether PSD increments apply over property owned by a new source if the general public is effectively precluded from access to that property. |
| 12/19/1980 | Dec. 19, 1980 Ambient Air Letter (pdf) | Administrator | Costle, Douglas | Letter explaining when the exemption from the definition “ambient air” is applicable. |
| 09/11/2007 | Region 10 | Helm, Nancy | Determination of ambient air boundary for leased property for 3 scenarios. | |
| 03/01/1985 | Applicability Determinations for Columbian Chemical Company (pdf) | CPDD | Tyler, Darryl | Whether reductions in H2S can be considered in calculating SO2 concentrations given that H2S converts to SO2 in the ambient air surrounding the facility and whether replacement of the existing boiler with a new larger boiler will be subject to PSD. This memorandum also addresses the definition of ambient air when the facility intends to restrict general public access to this land. |
| 10/17/1989 | Ambient Air (pdf) | OAQPS | Bauman, Robert | Discusses proposal that PSD modeling for Mitsubishi discount the contribution of a background source to the predicted concerning in a number of ways. |
| 06/22/2007 | Interpretation of "Ambient Air" in Situations Involving Leased Land Under the Regulations for Prevention of Significant Deterioration (PSD) (pdf) | OAQPS | Page, Stephen | Responds to various inquiries about the interpretation of the definition of “ambient” air as it pertains to situations involving leased land under the PSD regulations. |
| 04/13/1992 | Request For Further Clarification on EPA's Definition of "Ambient Air" (pdf) | OAQPS | Seitz, John | Provides further clarifications regarding the definition of ambient air as it relates to air intakes of mechanically ventilated buildings. |
| 08/01/2000 | Interpretation of Ambient Air (pdf) | Region 7 | Toensing, Don | Interprets ambient air for a source that has purchased adjacent agricultural land with a three-strand barb-wire fence enclosing the land and where the source will post “no trespassing” signs around the perimeter and at all entrances, will gate and lock all entrances, and will enter into a “License Agreement” with a farmer. |
| 01/09/2007 | Ambient Air for Offshore Liquified Natural Gas Broadwater Project (pdf) | Region 2 | Riva, Stephen | Whether emissions from a docked liquefied natural gas (LNG) carrier be assessed inside the ambient air boundary since the boundary only pertains to Broadwater itself and whether it is appropriate to use the Coast Guard’s proposed safety and security zone as a surrogate for defining an ambient boundary around the proposed LNG facility. |
| 07/27/1987 | Ambient Air Issue from New Jersey Department of Environmental Protection (pdf) | OAQPS | Helms, G. Tom | Determination of ambient air applicability in the vicinity of a proposed cogeneration unit which will build and operate the plant on property leased through a long-term lease. |
| 09/21/1987 | Project Notification (pdf) | OAQPS | Helms, G. Tom | Regards need for clarification of EPA policy on PSD increment consumption on rooftops. |
Related Topics: Prevention of Significant Deterioration (PSD) Increments | Significant Impact Levels (SILs) & Cumulative Analyses | Air Quality Monitoring
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