County Affected:

Parts of Yuma County | View on a Map >

Nonattainment Area Designation Date:

Nov. 6, 1991

Learn more about the designation of the area in the Federal Register (FR) (56 FR 56694, Page 32) | View >

Classification Level: 

Moderate

Pollutant of Concern:

PM₁₀ (particulate matter 10 microns or less in diameter; 1987 standards)

Summary: 

The concentration of PM₁₀ in the air in Yuma is frequently above the federal limit established in the federal National Ambient Air Quality Standards (NAAQS). ADEQ is developing a nonattainment State Implementation Plan (SIP) to improve the area's air quality. The Clean Air Act requires that ADEQ include an updated emissions inventory, a modeled attainment demonstration and a strategy for possible exceptional events demonstrations and rules for PM₁₀ controls. ADEQ will be working with permitted facilities, local government, and community stakeholders in a collaborative effort to develop the SIP. 

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Regulatory Background:

In 2006, EPA determined that the Yuma PM₁₀ Nonattainment Area had met the 1987 PM₁₀ NAAQS and issued a clean data determination (CDD). This suspended the need for Clean Air Act requirements related to nonattainment planning for as long as the Yuma area continued to meet the PM₁₀ NAAQS. The CDD did not, however, remove the nonattainment status for the Yuma PM₁₀ Nonattainment Area.

On May 17, 2022, EPA took final action to recall the CDD based on recent air quality monitoring data that showed the area violated the PM₁₀ standard. In that same action, EPA also determined that the SIP was substantially inadequate to meet the PM₁₀ standard in the Yuma Nonattainment Area and requested ADEQ to submit a SIP revision meeting the applicable nonattainment plan requirements.  Failure to submit would cause the Yuma Nonattainment Area to become subject to sanctions including the suspension of federal highway funds, the requirement of 2-for-1 offsets, and the imposition of a Federal Implementation Plan.

ADEQ must work with Yuma stakeholders to develop new rules to reduce PM₁₀ emissions and bring the Yuma Nonattainment Area into compliance with NAAQS. The area is currently classified as "Moderate" and is at risk of being reclassified as “Serious,” if the area doesn’t attain the PM₁₀ NAAQS by the applicable attainment date set in EPA’s action.

Rulemaking:

Learn more about the state level rulemaking to incorporate additional controls for the Yuma PM₁₀ Nonattainment Area | View >

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