Eco-loggers You may have heard in the news that EPA is proposing to strengthen standards for ozone. See here for the press release: http://yosemite.epa.gov/opa/admpress.nsf/d9d1f718ae373653852572a000655936/27000f081fd42325852573010045ce51!OpenDocument
You might not be aware that, besides "primary" health standards, EPA also sets ozone "secondary" standards to protect welfare (i.e. vegetation, ecosystems, soils etc.). In 1997, the "primary" health and "secondary" welfare ozone standards were set equal (3-yr average of the annual 4th highest daily maximum 8-hr average = 0.084ppm). For the current proposal released this week, EPA is taking comment on various options on the ozone secondary standard to protect vegetation and ecosystems: -One option is a new cumulative, seasonal standard expressed as an index of the annual sum of weighted hourly ozone concentrations (using the W126 form), set at a level in the range of 7 to 21 ppm-hours. The index would be cumulated over the 12-hour daylight period (8:00 a.m. to 8:00 p.m.) during the consecutive 3-month period within the O3 season with the maximum index value. -Another option is to revise the current secondary standard by making it identical to the proposed 8-hour primary standard, which is proposed to be within the range of 0.070 to 0.075 ppm. For this option, EPA also solicits comment on a wider range of 8-hour standard levels, including levels down to 0.060 ppm and up to the current standard (i.e., effectively 0.084 ppm with the current rounding convention). -EPA is also soliciting comment on an alternative approach for a setting cumulative, seasonal standard(s) that would afford differing degrees of protection for O3-related impacts on different types of vegetation with different intended uses. All the information on the current ozone proposal can be found here: http://epa.gov/groundlevelozone/actions.html The specific pages in the proposal that discuss the secondary ozone standard are 255-387 in the document linked below: http://epa.gov/groundlevelozone/pdfs/20070620_o3npr.pdf You can also further read about the secondary standard review and analyses in Chapters 7 & 8 of the Ozone Staff Paper: http://epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_sp.html EPA will accept public comments for 90 days after the proposed revisions to the ozone standards are published in the Federal Register. It has not been published yet, but will be soon. If you wish to make public comments, instructions are here: http://epa.gov/groundlevelozone/fs20070620.html#howtocomment In March of 2008, EPA will finalize any revisions of the ozone primary and secondary standards. Jeff
