Skip to content

Ozone Standard: SC Boundary Designations

2008 Ozone Boundaries

May 21, 2012

EPA published the implementation rule (77 FR 30160) for the 2008 ozone standard, which included the area classifications approach, attainment deadlines and revocation of the 1997 ozone standard for transportation conformity purposes. The effective date of this rule is July 20, 2012.

April 30, 2012

EPA has designated all of South Carolina as unclassifiable/attainment for the 2008 ozone standard, except for a portion of York County. Although the monitor in York County is meeting this standard, EPA included the eastern, urbanized area of York County in the Charlotte-Rock Hill, NC-SC nonattainment area because of its proximity to Charlotte.

This is the same portion of York County that EPA designated as nonattainment for the 1997 ozone standard, with the exception of the Catawba Indian Nation Reservation. EPA included the Catawba Indian Nation Reservation in the 1997 nonattainment area, but the EPA designated it as unclassifiable/attainment for the 2008 ozone standard. Learn more about the EPA's attainment/nonattainment designations for South Carolina.

February 29, 2012

DHEC responded to EPA's December 8, 2011, proposed boundary for the 2008 ozone standard.

February 7, 2012

EPA proposed the implementation rule for the 2008 ozone standard.

December 20, 2011

EPA announced a public comment period for its responses to states' and tribes' boundary recommendations for the 2008 ozone standard. On January 12, 2012, EPA extended the comment period deadline from January 19, 2012, to February 3, 2012.

December 9, 2011

DHEC certified the ozone monitoring data for the 2011 Ozone Season, further substantiating the attainment recommendation for each county of the entire State of South Carolina for the 2008 ozone standard.

December 8, 2011

EPA responded to DHEC's October 11, 2011, boundary recommendation for the 2008 ozone standard. EPA intends to modify DHEC's recommendation so that a portion of York County would be a part of the Charlotte-Gastonia-Salisbury, NC-SC nonattainment area. This is the same portion of York County that EPA designated nonattainment for the 1997 ozone standard. For more information, see EPA's website.

October 11, 2011

DHEC submitted an amendment to the 2008 boundary recommendations to EPA recommending all counties of the entire state be designated attainment.

September 22, 2011

EPA announced that it will implement the 2008 ozone standard. In this announcement, EPA discussed the designation process for the 2008 standard.

January 19, 2010

EPA announced it was extending by one year the deadline that it was extending by one year the deadline for promulgating designations for the 2008 ozone standard that were promulgated in March 2008. The new deadline was set for March 2011.

September 16, 2009

EPA announced it would reconsider the 2008 ozone standard.

July 12, 2009

DHEC submitted an errata to the 2008 boundary recommendations to EPA.

March 12, 2009

Upon delegation of Governor Mark Sanford's authority, DHEC submitted South Carolina's boundary recommendations for the 2008 ozone standard to EPA.

Previous Ozone Standards - History

1997 8-Hour Ozone Standard

In 1997, EPA promulgated an 8-hour ozone standard to replace the 1-hour standard. EPA revised the standards to establish the more stringent 8-hour standard at a level of 0.08 ppm. This was done to reflect the latest understanding of the effects of ozone exposure and to provide public health protection with an adequate margin of safety.

1997 8-hour Ozone Early Action Compact (EAC) process

On July 14, 2000, in accordance with the requirements of Section 107 of the Clean Air Act, DHEC submitted initial boundary recommendations for the 1997 8-hour ozone standard. These were based upon 1997 through 1999 monitored ozone data. DHEC recommended that the boundaries of seven Metropolitan Planning Organizations (MPOs) be designated nonattainment areas. EPA then proposed changes, recommending that whole counties be designated nonattainment, and requested more information and further documentation to adequately support the state's partial county recommendations.

On July 14, 2003, the state submitted a revised proposal to EPA for nonattainment area designations. In April 2004, EPA designated three areas in South Carolina as nonattainment but deferred the effective date for two of these areas because of their participation in the Early Action Compact process.

In April 2008, EPA redesignated these areas to attainment.

Additional Resources

Sign up to receive ozone forecast information using Enviroflash, Twitter, or to hear the forecast call 1-866-238-4973 after 4 p.m. daily.