New Particulate Matter Standards
On September 21, 2006, EPA announced some changes to the federal standards for particulate matter emissions. The standard for 24-hour PM2.5 emissions will become stricter, decreasing from 65 to 35 micrograms per cubic meter. The annual PM2.5 standard, which the Baltimore region is currently not reaching, will remain at 15 micrograms per cubic meter. States will be asked to make designation recommendations to EPA by December 2007. These recommendations will be based on monitoring data from 2004-2006. EPA designations will be based on data from 2007-2009, and will most likely become effective in April 2010. States will need to meet the 2006 standards by 2015.