Air quality has long been an important consideration for the MPO transportation planning and project development process in the Greensboro MPO area. Guilford County was first designated by the Environmental Protection Agency (EPA) as "non-attainment" for one-hour ozone on January 6, 1992. Non-attainment designation was a result of local air quality monitors exceeding the federal standards for ozone pollutants. On November 8, 1993, the County was re-designated to "maintenance" for one-hour ozone. Under this designation, the area was required to complete conformity analysis and conformity determination reports. Conformity analysis is required to demonstrate that identified pollutants are not expected to exceed the standards set by the Environmental Protection Agency (EPA) and the NC Division of Environmental Quality.
The EPA decided to strengthen the air quality standards by requiring analysis for eight-hour ozone rather than eight-hour ozone. In April 2004, the EPA officially designated Guilford as "non-attainment" for eight-hour ozone. However, the MPO had entered into an agreement in 2002 with EPA, known as the Early Action Compact. The Compact pledged the County would meet the standard earlier than required by meeting certain criteria and milestones. As a result the County’s non-attainment status was deferred until December 31, 2007, the date which all milestones were to be met. On April 15, 2008, Guilford, along with other Triad Counties, was designated as "attainment" for the eight-hour ozone for successfully meeting all requirements. Also on April 15, 2008 EPA revoked the one-hour ozone standard for Guilford County. Effective April 15, 2009, the Triad Area no longer had to demonstrate conformity for the standard.
The conformity analysis requirement came around again though, as Guilford County was designated "non-attainment" for fine particulate matter, "PM2.5" on April 5, 2005. The area was re-designated as "maintenance" for the PM 2.5 standard on December 19, 2011. On October 24, 2016 the EPA determined the Triad Area no longer had to demonstrate conformity for the PM 2.5 standard.
Guilford County is currently classified as attainment, but air quality remains an important concern for the MPO planning process.
Links to Historical Triad Area Conformity Documents
- Triad Air Quality Conformity Determination Report (2040 MTP & 2016-2025 MTIP)
- Final Conformity Analysis and Determination Report for the Triad PM 2.5 Non-Attainment Area Amendment #1
- Final 2035 LRTP Update & 2012-2018 MTIP Air Quality Conformity Determination
- Final Triad PM 2.5 Air Quality Conformity Determination Report