The Cincinnati-Hamilton moderate ozone nonattainment area (Cincinnati-Hamilton area) was redesignated to attainment on June 19, 2000. The Cincinnati-Hamilton area includes the Ohio Counties of Hamilton, Butler, Clermont, and Warren and the Kentucky Counties of Boone, Campbell, and Kenton. On September 11, 2001, the United States Court of Appeals for the 6th Circuit (Court) vacated EPA's redesignation of the Cincinnati-Hamilton area, after concluding that EPA erred in one respect that pertained solely to the Ohio portion of the area. Therefore, pursuant to the Court's decision, EPA is making a technical amendment to the listing of the Ohio portion of the Cincinnati-Hamilton area to reflect the designation of Hamilton, Butler, Clermont, and Warren Counties, Ohio as nonattainment for ozone, with a classification of moderate nonattainment, effective as of July 5, 2000, the effective date of EPA's June 19, 2000 rulemaking. The status of the Kentucky portion of the Cincinnati-Hamilton area has been addressed in a separate rulemaking action.