This Circular promulgates the list of production and processing sectors that generate wastewater containing heavy metals: 1. Leather tanning and reprocessing; 2. Coal mining; metal mineral mining and processing; 3. Fabric and fiber dyeing; 4. Chemical production; 5. Mechanical engineering, metallurgy, meta working, machine and spare part manufacture; 6. Manufacture of electric and electronic components and equipment; 7. Metal recycling; recycling of metallurgical scraps and other industrial wast