{"abstract":"Under the requirements of the Clean Air Act (Act), the New Source Review (NSR) program includes Prevention of Significant Deterioration (PSD) measures, which protect air quality in areas that currently have clean air. For some pollutants, the PSD program protects clean air through a system of \"increments.\" These increments specify the maximum extent to which the ambient concentration of these pollutants may be allowed to increase above the legally defined baseline concentration in an area with clean air. In this rulemaking, we propose to refine several aspects of the method that may be used to calculate an increase in concentration for increment purposes. These refinements are intended to clarify how States and regulated sources may calculate increases in concentrations for the purposes of determining compliance with the PSD increments.","action":"Proposed rule.","agencies":[{"raw_name":"ENVIRONMENTAL PROTECTION AGENCY","name":"Environmental Protection Agency","id":145,"url":"https://www.federalregister.gov/agencies/environmental-protection-agency","json_url":"https://www.federalregister.gov/api/v1/agencies/145","parent_id":null,"slug":"environmental-protection-agency"}],"body_html_url":"https://www.federalregister.gov/documents/full_text/html/2007/06/06/E7-10459.html","cfr_references":[{"chapter":null,"citation_url":null,"part":51,"title":40},{"chapter":null,"citation_url":null,"part":52,"title":40}],"citation":"72 FR 31372","comment_url":null,"comments_close_on":"2007-08-06","correction_of":null,"corrections":[],"dates":"Comments. Written comments must be received on or before August 6, 2007.","disposition_notes":null,"docket_ids":["EPA-HQ-OAR-2006-0888","FRL-8320-7"],"dockets":[],"document_number":"E7-10459","effective_on":null,"end_page":31399,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2007/06/06/E7-10459.xml","html_url":"https://www.federalregister.gov/documents/2007/06/06/E7-10459/prevention-of-significant-deterioration-new-source-review-refinement-of-increment-modeling","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/E7-10459?publication_date=2007-06-06","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2007-06-06/E7-10459/mods.xml","not_received_for_publication":null,"page_length":28,"page_views":{"count":639,"last_updated":"2026-09-21 00:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2007-06-06/pdf/E7-10459.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":null,"publication_date":"2007-06-06","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2007/06/06/E7-10459.txt","regulation_id_number_info":{"2060-AO02":{"issue":"200810","html_url":"https://www.federalregister.gov/regulations/2060-AO02/prevention-of-significant-deterioration-refinement-to-increment-modeling-procedures","title":"Prevention of Significant Deterioration:  Refinement to Increment Modeling Procedures","xml_url":"http://www.reginfo.gov/public/do/eAgendaViewRule?pubId=200810&RIN=2060-AO02&operation=OPERATION_EXPORT_XML","priority_category":"Other Significant"}},"regulation_id_numbers":["2060-AO02"],"regulations_dot_gov_info":{"checked_regulationsdotgov_at":"2011-11-12T21:57:33Z"},"regulations_dot_gov_url":null,"significant":true,"signing_date":null,"start_page":31372,"subtype":null,"title":"Prevention of Significant Deterioration New Source Review: Refinement of Increment Modeling Procedures","toc_doc":"Increment modeling procedures refinement; prevention of significant deterioration new source review","toc_subject":"Air quality implementation plans:","topics":["Administrative practice and procedure","Air pollution control","Environmental protection","Intergovernmental relations"],"type":"Proposed Rule","volume":72}