Ozone, Particulate Matter, and EPA's "Good Neighbor" Plan"

15 mars 2023

The Wisconsin Department of Natural Resources held a meeting to update residents on Sheboygan County's air quality. The meeting, organized by the Sheboygan Ozone Reduction Alliance, focused on issues such as ozone, particulate matter, recent data, and the DNR's upcoming plans. Here are some key takeaways from the meeting:

1. Ground-level ozone is a common air pollutant that can harm human and environmental health. It is formed from chemical reactions involving volatile organic compounds and nitrogen oxide, heat, and sunlight in the air. Children, older adults, and individuals with asthma or engaging in outdoor activities are at the highest risk. Ozone can also limit plant growth.

2. Sheboygan County's ozone monitoring was split into two regions, with one monitoring site consistently recording high levels in the state. The addition of a second testing site inland was challenged by the environmental nonprofit Clean Wisconsin, but the site remained. The EPA expanded the nonattainment area in response.

3. Data from 2021 show that the lakeshore region, including Sheboygan, still exceeds federal standards for ozone. While there have been small decreases in ozone levels across the state, five out of 13 lakeshore monitors still exceeded the standard. Mobile sources like cars and trucks are the largest contributor to ozone.

4. Emissions from power plants and other industries in neighboring states also contribute to Wisconsin's ozone levels. The EPA proposed an updated "Good Neighbor" plan that would require 26 states, including Wisconsin, to reduce emissions at power plants and other industry sources to mitigate transported emissions across states. The rule is expected to be finalized on March 15.

5. The EPA did not specifically consider sources that impact Sheboygan, such as power plants, steel manufacturing, or paper mills south of Wisconsin, when proposing the Good Neighbor plan. The DNR commented heavily on the issue to the EPA and pointed out the county's consistently high ozone levels. The EPA also designated heavy-duty truck tampering as a compliance priority issue.