Industry Insights · Regulation and environment · Sep 22, 2026

Emission Facility Regulations for Surface Treatment Sites — Wastewater Discharge Facilities under the Water Environment Conservation Act, Air Emission Facilities under the Clean Air Conservation Act, and the Scope of Integrated Environmental Management

Anodizing sites can be subject to installation permits or reports for wastewater discharge facilities and air pollutant emission facilities. This article summarizes the applicable criteria confirmed in the annexes to the Enforcement Rules of the Water Environment Conservation Act and the Clean Air Conservation Act, and the scope of the integrated environmental management system.

Surface treatment processes generate wastewater from acid and alkaline process tanks and rinse tanks, and acid and alkaline mist above the process tanks. Sites are therefore subject to the emission facility provisions of both the Water Environment Conservation Act and the Clean Air Conservation Act. This article summarizes the provisions confirmed in the annexes to the Enforcement Rules of both Acts and the scope of the integrated environmental management system.

Water Environment Conservation Act: Wastewater Discharge Facilities

Annex 4 of the Enforcement Rule of the Water Environment Conservation Act (amended 2019-12-31) sets the criteria and classification for wastewater discharge facilities.

Criteria: A facility that discharges wastewater containing specified water pollutants is a wastewater discharge facility if its maximum daily wastewater volume is 0.01 m³ or more; for wastewater without such pollutants, the threshold is 0.1 m³ or more. The maximum daily wastewater volume is the sum of wastewater from all facilities at the site on the day of highest generation in the year, including volumes sent for outsourced treatment, volumes reused and volumes treated by prevention facilities.
Exclusions: Certain cases are excluded, such as discharging 20 m³ or less per day of wastewater containing no mineral oil into a public sewage treatment facility.
Classification: Common facility item 80) "plating facilities" refers to facilities whose main process is plating, excluding those that fall under item 25 (metal product manufacturing facilities) as part of another process. Item 63) metal product manufacturing facilities is defined to "include cases that are part of the main process and are not included in the plating facilities of the common facilities." Specialist anodizing and chemical conversion coating sites are usually classified as plating facilities or metal product manufacturing facilities, so the classification should be confirmed with the competent authority.

Whether specified water pollutants apply is determined by whether substances contained in raw and auxiliary materials are present in the wastewater at or above the criteria in Annex 13-2. Note that if any process uses specified water pollutants such as hexavalent chromium, fluorine or nickel, the threshold drops to 0.01 m³/day.

Clean Air Conservation Act: Air Pollutant Emission Facilities

Annex 3 of the Enforcement Rule of the Clean Air Conservation Act (amended 2021-12-30) lists emission facilities by industry. The categories for primary iron, steel and nonferrous metal manufacturing; metal product, machinery and transport equipment manufacturing; and automotive parts manufacturing all include the following "surface treatment facilities."

Plating, degreasing, acid and alkaline treatment, and chemical conversion treatment facilities with a volume of 1 m³ or more
Drying facilities for metal surface treatment with fuel consumption of 30 kg or more per hour or a volume of 3 m³ or more (excluding post-rinse drying facilities)

Anodizing, etching, desmutting and chemical conversion coating tanks with a volume of 1 m³ or more are therefore air emission facilities, which entails an installation permit or report, installation and operation of prevention facilities (scrubbers, etc.) and self-monitoring obligations. Because the annex is based on facility volume, change report requirements should also be reviewed when tank sizes are changed or capacity is added.

Scope of the Integrated Environmental Management System

According to the Ministry of Environment, the integrated environmental management system under the Act on the Integrated Control of Pollutant-Discharging Facilities applies to Class 1 and Class 2 air or water sites (air pollutant generation of 20 tons or more per year, or wastewater discharge of 700 m³ or more per day) in the 19 industries listed in Annex 1 of the Enforcement Decree, and has been phased in by industry since 2017. Industries covered from 2021-01-01 include automotive parts manufacturing (303). Most small and medium-sized surface treatment sites are therefore not subject to integrated permits and remain under the existing media-specific (water and air) permit and reporting system, but their industry classification and site class should still be confirmed.

Related Obligations

Sites with emission facility permits or reports are also linked to the industry determination for the chemical emission survey under Article 11 of the Chemicals Control Act.
Prevention facility operation records, self-monitoring records and wastewater treatment outsourcing contracts are most efficiently managed together with environmental management system (ISO 14001) records.

EF Technology manages the permit and reporting scope of its wastewater and air emission facilities and the operation records of its prevention facilities within its ISO 14001 system.

References

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