Ozone Nonattainment in Wisconsin

10 January 2018 Legal News: Environmental Publication
Authors: Mark A. Thimke Peter A. Tomasi

Just before the holiday break, U.S. EPA announced the potential return to “nonattainment ozone status” for a number of locations in the United States, including portions of eastern and southeastern Wisconsin. After achieving substantial reductions in VOC emissions that form ozone (volatile organic compounds (“VOC”) and nitrogen oxides (“NOx”)), southeastern Wisconsin achieved compliance with a prior ozone standard and avoided the restrictive nonattainment requirements for several years. However, in 2015, U.S. EPA lowered the Ozone National Ambient Air Quality Standards (“NAAQS”) from 75 ppb to 70 ppb. Due in significant part to the transport of ozone and its precursor from the Chicago area, U.S. EPA plans to designate southeastern Wisconsin as nonattainment with the new ozone standard.

Nonattainment status will affect the ability for major expansions and new facilities that emit significant amounts of VOC to proceed. In particular, future expansions in southeastern Wisconsin will be required to:

  • Obtain emission offsets – required on a 1.1 to 1 basis
  • Meet lowest achievable emission rate (“LAER”) for VOC and NOx

Because southeastern Wisconsin met the prior ozone standard, there are no “offsets” of VOC and NOx emissions that are immediately available. If and when offsets do become available, they are likely to be expensive given the limited availability.

U.S. EPA will be reviewing more recent ozone data from Wisconsin as well as accepting comments until February 5, 2018, on the nonattainment designation before making a final decision on nonattainment. Given the significant downside of being classified nonattainment, businesses in eastern and southeastern Wisconsin should consider commenting and/or, if necessary, challenging U.S. EPA’s action.

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