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Visibility and Haze

Technical Guidance on Tracking Visibility Progress for the Second Implementation Period of the Regional Haze Program

December 20, 2018 - EPA prepared this final guidance document to support states with some of the technical aspects of developing regional haze state implementation plans (SIPs) for the second implementation period of the program. Specifically, this guidance document describes EPA’s recommended methods on two technical aspects of regional haze SIP development: 1) the visibility tracking metrics and 2) estimating international anthropogenic impacts and optional adjustment to the URP glidepath. This document provides final EPA guidance on topics addressed in section 5 of the 2016 draft guidance.

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