Ambient Air Quality Standards for Ozone and Particulate Matter
Most Recent Action
A final rulemaking order was filed on July 30, 2009.
Background
Chapter NR 404, Wis. Adm. Code, contains ambient air standards which are intended to be the same as the federal NAAQS promulgated by EPA, as is required under Section 285.21(1)(a), Wis. Stats.
Chapter NR 484, Wis. Adm. Code, incorporates by reference the federal air pollution monitoring requirements related to the ambient air standards that are employed by the Department.
In 1987, the EPA promulgated NAAQS for particulate matter of less than 10 micrometers in diameter (PM10) because PM10 was found to be noticeably detrimental to the human respiratory system. In 1997, the EPA promulgated NAAQS for particles less than 2.5 micrometers in diameter (PM2.5) because PM2.5 was demonstrated to significantly impact the human respiratory system.
In 2006, the EPA lowered the 24 hour PM2.5 NAAQS to better reflect the scientific understanding of fine particle effects on humans, and revoked the annual PM10 NAAQS, citing a lack of evidence linking health problems to long-term exposure to PM10.
Authority
The Department is required under s. 285.21(1)(a), Stats., to promulgate by rule ambient air standards similar to, but not more restrictive than the national ambient air quality standards (NAAQS).
The Department is also authorized under s. 285.11(6), Stats., to promulgate rules in order to prepare and implement the State Implementation Plan for the prevention, abatement and control of air pollution in the state.
Standard
The DNR amended chs. NR 404 and 484, Wis. Adm. Code, to address the above-noted NAAQS changes to better reflect the current understanding of how particulate matter affect human health and to maintain consistency with the federal NAAQS.
This rule:
- Repealed the ambient air quality standard for annual PM10 from ch. NR 404;
- Repealed the monitoring requirements incorporated by reference in NR 484 corresponding to annual PM10 standard; and
- Adopted the PM2.5 NAAQS into NR 404 and incorporates by reference corresponding monitoring requirements in NR 484.
The rule originally included a repeal of the air quality standard for total suspended particulates (TSP) that would mirror federal standards. After the close of the public comment period in October, 2007, concerns were expressed by several citizens and the NRB regarding the proposed repeal. Consequently, the final rule did not include the repeal of the TSP air standard. The DNR assured the public the TSP standards would be addressed at a future time, but action has yet to be taken.
Related Documents
Natural Resource Board Agenda Item for Hearing (green sheet)
Natural Resources Board Agenda Item (Amended green sheet)