Last week EPA issued its first new primary National Ambient Air Quality Standard for SO2 in 40 years. The new standard revokes the current 24-hour and annual SO2 standards and sets a new one-hour SO2 standard at 75 parts per billion (ppb), a level designed to protect against short-term exposures ranging from five minutes to 24 hours.

EPA is also changing the monitoring requirements for SO2. The new requirements assure that monitors will be placed where SO2 emissions impact populated areas. Any new monitors required by this rule must begin operating no later than Jan. 1, 2013.

EPA estimates that the health benefits associated with this rule range between $13 billion and $33 billion annually. These benefits include preventing 2,300 to 5,900 premature deaths and 54,000 asthma attacks a year. The estimated cost in 2020 to fully implement this standard is approximately $1.5 billion.

The final rule addresses only the SO2 primary standards, which are designed to protect public health. EPA will address the secondary standard – designed to protect the public welfare, including the environment – as part of a separate review to be completed in 2012.

 For more information, please contact Steve O’Day or Phillip Hoover, or visit EPA’s website here.