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Denver's air quality violates federal ozone standard

Release Date: 11/20/2007
Contact Information: Callie Videtich, [email protected], 303-312-6434 Cindy Cody, [email protected], 303-312-6228 Kerri Fiedler, [email protected], 303-312-6493

Area does not meet health-based standard for ground-level ozone

(Denver, Colo. -- Nov. 20, 2007) EPA's Region 8 office today announced it will not grant another extension date for Denver to meet EPA's 8-hour ozone standard. The result is a federal nonattainment designation for the Denver area.

According to state-validated air quality data from 2005, 2006 and the first three quarters of 2007, the Denver area violated the 8-hour federal health-based standard for ozone. Based on this data, EPA has allowed a nonattainment designation to take effect, thus the area has forfeited its participation in the Early Action Compact program. The Denver Early Action Compact agreement was signed in December 2002 by the Regional Air Quality Council, Colorado Department of Public Health and Environment, Colorado Department of Transportation, the Air Quality Control Commission, the Denver Regional Council of Governments and EPA. The nonattainment designation will require local and state officials to submit a new plan to reduce ground-level ozone pollution.

In April 2004, EPA designated the Denver area (Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson and parts of Larimer and Weld counties) as nonattainment for the 8-hour ozone standard, but deferred the effective date of the designation based on a commitment from the State of Colorado, the Regional Air Quality Council and others to implement ozone control measures sooner than required by the Clean Air Act. This commitment was contained in the Denver Early Action Compact. In return for this early action and for meeting certain milestones, EPA agreed to defer the effective date of the nonattainment designation under the 8-hour ozone standard.

The latest deferral date was November 20. Because the state's monitoring data shows a violation of the 8-hour ozone standard, EPA has not granted another extension, and the 8-hour ozone nonattainment designation for the Denver EAC area is effective today.

Ground-level ozone, a primary ingredient in smog, is formed when volatile organic compounds and nitrogen oxides react chemically in the presence of sunlight. Cars, trucks, power plants and industrial facilities are the primary sources of these emissions. Ozone pollution is a concern during the summer months when weather conditions needed to form ground-level ozone - stagnant air, lots of sun and hot temperatures - normally occur. Ozone is unhealthy to breathe, especially for people with respiratory diseases and for children and adults who are active outdoors.

CDPHE, the RAQC and others are working on a revised state implementation plan to address the Denver area's 8-hour ozone nonattainment issues. The revised plan is expected to contain additional control measures that will ensure the area meets the 8-hour ozone standard in the shortest time possible.