Third, emission facilities are particularly strictly managed in heavily polluted regions. Even stricter permissible emission levels can be applied to industrial complexes and other areas of severe air pollution that have been designated as “air conservation special countermeasure areas.” Such strict permissible emission levels are currently applicable to the Ulsan-Onsan Industrial Complex and Yeosu Industrial Complex. Moreover, permissible emission levels may be tightened by a municipal ordinance in designated “air quality control areas” and other regions where it is difficult to meet national or regional air quality standards.