On October 1, 2015, the United States Environmental Protection Agency (EPA) lowered the existing ozone National Ambient Air Quality Standard (NAAQS) to 70 parts per billion (ppb) from its current level of 75 ppb. The rule can be found here. This revision, if upheld by the courts, will result in more Wisconsin counties being classified as nonattainment which will, in turn, result in higher regulatory burdens for expanding economic activity within those areas. EPA estimates the cost of the rule at $1.4 billion with concurrent public health benefits between $2.9 billion and $5.9 billion, however industry critics disagree with these values.

By way of background, the Clean Air Act required EPA to set NAAQS for ozone and five other pollutants. NAAQS are set at levels which are deemed protective of human health and the environment with an adequate margin of safety. The Clean Air Act requires EPA to review these standards every five years and update the standards if necessary.

The last ozone NAAQS review process was completed in 2008 and resulted in EPA setting the ozone standard at 75 ppb. On January 19, 2010, EPA proposed lowering the ozone NAAQS to a level between 60 and 70 ppb, with former EPA Administrator Jackson recommending 65 ppb. However on September 2, 2011, President Obama directed EPA to withdraw the proposal. This prompted a lawsuit wherein a federal court judge ordered EPA to finalize its review of the ozone NAAQS by October 1, 2015.

In November 2014, EPA proposed revising the ozone standard within a range of 65 to 70 ppb, but sought comment on lowering the standard to 60 ppb. This proposal was quite controversial since the lower end of the range approaches natural background ozone levels in portions of the western United States.

On October 1, 2015, EPA finalized the new standard at 70 ppb. EPA justified departing from Administrator Jackson’s 2010 recommendation of 65 ppb by asserting that EPA now has more data that was unavailable in the past.

Now that EPA has lowered the standard, States must begin the implementation process. EPA issued a memorandum dated October 1, 2015 which provides states and EPA Regional offices with guidance on how to implement the new standard. Within the memo, Acting EPA Air Chief Janet McCabe asserts that EPA will work with states “to carry out the duties of ozone air quality management in a manner that maximizes common sense, flexibility and cost-effectiveness while achieving improved public health expeditiously and abiding by the legal requirements [of the Clean Air Act].”

This memorandum commits EPA to issue new designation guidance in early 2016. Nonetheless, nonattainment designations will likely be due within two years (Fall 2017) and therefore will be based on ozone data collected in calendar years 2014 through 2016. Infrastructure state implementation plans (SIPs) will be due within three years (Fall 2018) and attainment plans within 5 years (Fall 2020). Attainment will be required by 2020 and 2023 for marginal and moderate nonattainment areas, respectively.

Effects on Wisconsin

The new ozone NAAQS will impact many Wisconsin counties. Preliminary analyses using current ozone monitoring data (2012-2014) suggest the following counties may be challenged with avoiding a nonattainment designation under the 70 ppb standard:  Brown, Calumet, Dodge, Door, Fond du Lac, Jefferson, Kenosha, Kewaunee, Manitowoc, Milwaukee, Oconto, Outagamie, Ozaukee, Racine, Rock, Sheboygan, Walworth, Washington, Waukesha and Winnebago. This list is not official and will likely change as the 2015 and 2016 ozone data is compiled.

Stationary sources located in counties classified as nonattainment face increased regulatory burdens when seeking to construct new or expanded capacity. These regulatory burdens can include increased stringency of emission controls for VOCs and NO_X emissions, a requirement to offset increases in VOC and NO_X emissions and increased regulatory analyses as part of the permitting process. Existing stationary sources in these counties can be required to install new NOx and VOC emission controls.