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Visibility and Haze

Technical Support Document for EPA’S Updated 2028 Regional Haze Modeling

September 19, 2019 -- EPA released a Technical Support Document (TSD) that details updated 2028 regional haze modeling data and results, including domestic and international source contributions to National Parks, wildlife refuges, and wilderness areas (“Class I areas”). The goal of this modeling effort was to project 2028 visibility conditions and source sector contribution information, including international anthropogenic visibility impacts, for each mandatory Class I federal area. EPA conducted this visibility modeling to inform the regional haze state implementation plan (SIP) development process for the second implementation period under EPA’s Regional Haze Rule.

On October 15, 2019, EPA hosted a webinar giving an overview of the updated 2028 regional haze modeling results. The slides from the webinar are available below.

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