Environmental Protection Agency
EPA's Guideline on Air Quality Models ("Guideline") addresses the regulatory application of air quality models for assessing criteria pollutants under the Clean Air Act. In today's action we promulgate several additions and changes to the Guideline. We recommend a new dispersion model--AERMOD--for adoption in appendix A of the Guideline. AERMOD replaces the Industrial Source Complex (ISC3) model, applies to complex terrain, and incorporates a new downwash algorithm--PRIME. We remove an existing model--the Emissions Dispersion Modeling System (EDMS)--from appendix A. We also make various editorial changes to update and reorganize information.
Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Environmental Protection Agency 40 CFR Part 51 [AH-FRL-7990-9] RIN 2060-AK60 AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA's Guideline on Air Quality Models (“ Guideline ”) addresses the regulatory application of air quality models for assessing criteria pollutants under the Clean Air Act. In today's action we promulgate several additions and changes to the Guideline. We recommend a new dispersion model—AERMOD—for adoption in appendix A of the Guideline. AERMOD replaces the Industrial Source Complex (ISC3) model, applies to complex terrain, and incorporates a new downwash algorithm—PRIME. We remove an existing model—the Emissions Dispersion Modeling System (EDMS)—from appendix A. We also make various editorial changes to update and reorganize information. DATES: This rule is effective December 9, 2005. As proposed, beginning November 9, 2006, the new model—AERMOD— should be used for appropriate application as replacement for ISC3. During the one-year period following this promulgation, protocols for modeling analyses based on ISC3 which are submitted in a timely manner may be approved at the discretion of the appropriate Reviewing Authority. Applicants are therefore encouraged to consult with the Reviewing Authority as soon as possible to assure acceptance during this period. ADDRESSES: All documents relevant to this rule have been placed in Docket No. A-99-05 at the following address: Air…
Citation: 70 FR 68218
