Many metal product manufacturing processes involve electroplating, which uses chemicals containing chromium trioxide. Inadequate treatment of such wastewater can result in heavy metal contamination of soil. Recently, the EPA listed a metal product manufacturing factory as soil and groundwater remediation site in Chiayi City.
Based on the Soil and Groundwater Pollution Control Act (土壤及地下水污染整治法), the EPA on 5 July announced Minfong Co. Limited as a polluter, and its 331m2 factory site at Property No. 0193-0000 in Yuandong Section, Chiayi City, as a pollution remediation site.
Set up on 9 April 1983, the factory manufactures molded and forged metal products and engages in electroplating. The process goes from shaping materials, polishing, electroplating (in which chemicals like chromium trioxide are used), cleansing, to polishing again before the final products are turned out. Wastewater in the factory mainly comes from manufacturing and washing empty barrels and goes through surface ditches before converging in wastewater storage tanks east of the manufacturing area. It is then transferred to a treatment plant for commissioned disposal.
The EPA provided details on the excessive levels of heavy metal concentrations in soil at the remediation site. The highest concentrations found were: chromium at 13,500 mg/kg (54 times the concentration required for control); copper at 1,780 mg/kg (4.45 times the concentration required for control), and; lead at 11,400 mg/kg (5.7 times the concentration required for control). Also, the chromium concentration in groundwater was found to be 36.7 mg/L, 73.4 times the level required for control in the second category of the groundwater control standard.
The site’s TOL score, a sum of points used to calculate a remediation site’s potential impacts, reached 1,366.99 after the preliminary evaluation. TOL scores over 1,200 require remediation based on the Regulations Concerning Preliminary Evaluation and Determination of Treatment Category for Soil and Groundwater Pollution Sites (土壤及地下水污場址初步評估暨處理等級評定辦法) Article 8, paragraph 1, subparagraph 1.
Excerpt from Major Environmental Policies, August 2022
- Ministry of Environment