On January 12, 2009, U.S. EPA proposed a major revision to its rules implementing the 1997 8-hour ozone standard.

In yesterday’s post, I discussed the possibility of E-check expanding in Ohio as a result of U.S. EPA’s proposed revisions to implementation of the 1997 8-hour ozone standard (.08 ppm).  Today I want to discuss the larger ramifications of the proposed rule.  The proposal provides a crystal ball type glimpse into how U.S. EPA may implement the 2008 8-hour ozone standard (.075 ppm). 

Depending upon how EPA builds off this proposed rulemaking when developing an implementation rule for the new .075 ppm ozone standard, there could be good news for many areas in the Country, including areas in Ohio.  This is especially true for Cleveland which has been under the most stringent ozone requirements in the State. 

As discussed in yesterday’s post, the rigidness of U.S. EPA’s requirements is largely dependent upon how areas are classified under the Clean Air Act. The short version- Subpart I good…Subpart II bad.  The chart below captures how EPA requirements ratchet up the more severe your ozone problem.  With each higher classification Subpart II piles on more federal mandates.  Subpart I areas don’t carry these same mandates.  In addition, there is no classification system-all areas area considered "basic" non-attainment areas.

In recognition that Subpart II carries with it far more regulatory baggage, in 2004 U.S. EPA tried to expand the scope of Subpart I. In order to expand the scope of Subpart I, U.S. EPA drew a line in the sand at a 1-hour design values of .121 ppm.  Areas below .121 ppm were placed in Subpart I. Using this dividing line, there were 126 areas in country designated "non-attainment" for ozone, 84 were under Subpart I and 42 were under Subpart II.  Cleveland was the only Subpart II area in Ohio.

However, legal challenges resulted in the Court throwing out EPA’s dividing line of .121 ppm.  The D.C. Circuit Court said that the Supreme Court required .09 ppm on the 8-hour scale as the level for determining which areas would be subject to Subpart II.  In its latest proposal, EPA acknowledges it has discretion to place areas with an 8-hour design value of less than .09 ppm into Subpart I. EPA is proposing to forgo this option and place all areas under a Subpart II classification because it does not want to delay implementation of the 8-hour ozone standard any further. 

I would predict they will not forgo this option when it comes to implementation of the 2008 8-hour ozone standard of .075 ppm.  I believe they will put all areas with design values less than .09 ppm into Subpart I in order to provide maximum flexibility to the States designing their control plans to meet the standard (referred to as SIPs- State Implementation Plans). 

What is the ozone status in Ohio right now?  Based upon 2005-2008 Air Quality Data here are the current ozone design values for the highest ozone areas in the state.

CINCINNATI- .085 ppm

COLUMBUS- .08 ppm

CLEVELAND- .084 ppm

Based on current air quality Ohio should have no areas close to the .09 ppm cut off for placing areas into Subpart II of the Clean Air Act.  This would include Cleveland which is currently under Subpart II. This is good news for the States.  This approach would give Ohio EPA and other States the maximum flexibility in putting together their SIPs to attain the .075 ppm ozone standard.