Public Sewage Treatment Facilities (As per Article 3, Paragraph 1, Subparagraph 1 of the Sewerage Act and Article 14 of the Act on the Promotion and Support of Water Reuse)
| Category | Biochemical Oxygen Demand (BOD) (mg/L) | Total Organic Carbon (TOC) (mg/L) | Suspended Solids (SS) (mg/L) | Total Nitrogen (T-N) (mg/L) | Total Phosphorus (T-P) (mg/L) | Total Coliforms (colonies/mL) | Ecotoxicity (TU) | |
|---|---|---|---|---|---|---|---|---|
| Sewage Treatment Capacity ≥ 500 m³/day | Ⅰ Zone | ≤ 5 | ≤ 15 | ≤ 10 | ≤ 20 | ≤ 0.2 | ≤ 1,000 | ≤ 1 |
| Ⅱ Zone | ≤ 5 | ≤ 15 | ≤ 10 | ≤ 20 | ≤ 0.3 | ≤ 3,000 | ||
| Ⅲ Zone | ≤ 10 | ≤ 25 | ≤ 10 | ≤ 20 | ≤ 0.5 | |||
| IV Zone | ≤ 10 | ≤ 25 | ≤ 10 | ≤ 20 | ≤ 0.2 | |||
| Sewage Treatment Capacity 50 ≤ x < 500 m³/day | ≤ 10 | ≤ 25 | ≤ 10 | ≤ 20 | ≤ 2 | |||
| Sewage Treatment Capacity < 50 m³/day | ≤ 10 | ≤ 25 | ≤ 10 | ≤ 40 | ≤ 4 | |||
Simple Public Sewage Treatment Facilities
| Category | Biochemical Oxygen Demand (BOD) (mg/L) | Total Coliforms (colonies/mL) | ||
|---|---|---|---|---|
| Ⅰ Area | From July 17, 2014 to December 31, 2018 | ≤ 60 mg/L | From July 17, 2014 to December 31, 2018 | |
| From January 1, 2019 to December 31, 2023 | ≤ 60 mg/L | After January 1, 2024 | ≤ 3,000 colonies/mL | |
| After January 1, 2024 | ≤ 40 mg/L | |||
| Ⅱ Area | From July 17, 2014 to December 31, 2019 | ≤ 60 mg/L | From July 17, 2014 to December 31, 2019 | |
| From January 1, 2020 to December 31, 2024 | ≤ 60 mg/L | After January 1, 2025 | ≤ 3,000 | |
| After January 1, 2025 | ≤ 40 mg/L | |||
| Ⅲ & Ⅳ Areas | ||||
Water Quality Standards by Use for Recycled Water from Sewage and Wastewater Treatment
| Category | Cleaning & Toilet Water | Washing & Sprinkling Water | Landscaping Water | Recreational Water | River & Stream Maintenance Water | Agricultural Water | Groundwater Recharge | Industrial Water | |
|---|---|---|---|---|---|---|---|---|---|
| Total Coliforms (colonies/100 mL) | Not detectable | ≤ 1,000 | ≤ 1,000 | Not detectable | ≤ 1,000 | Direct contact consumption | Not detectable | Must comply with the drinking water quality standards as specified in "Standards for Drinking Water Quality and Inspection," Annex 1. | Determined by agreement between the supplier and the user |
| Indirect contact consumption | ≤ 200 | ||||||||
| Combined Residual Chlorine (mg/L) | ≥ 0.2 | ≥ 0.1 | |||||||
| Turbidity (NTU) | ≤ 2 | ≤ 2 | ≤ 2 | ≤ 2 | Direct contact consumption | ≤ 2 | |||
| Indirect contact consumption | ≤ 5 | ||||||||
| Biochemical Oxygen Demand (BOD) (mg/L) | ≤ 5 | ≤ 5 | ≤ 5 | ≤ 3 | ≤ 5 | ≤ 8 | |||
| Odor | Should not be unpleasant | Should not be unpleasant | Should not be unpleasant | Should not be unpleasant | Should not be unpleasant | Should not be unpleasant | |||
| Color (Hazen units) | ≤ 20 | ≤ 10 | |||||||
| Total Nitrogen (T-N) (mg/L) | ≤ 10 | ||||||||
| Total Phosphorus (T-P) (mg/L) | ≤ 0.5 | ≤ 0.5 | |||||||
| Hydrogen Ion Concentration (pH) | 5.8~8.5 | 5.8~8.5 | 5.8~8.5 | 5.8~8.5 | 5.8~8.5 | 5.8~8.5 | |||
| Chloride (mg Cl/L) | ≤ 250 | ||||||||
| Electrical Conductivity (µS/cm) | Direct contact consumption | ≤ 700 | |||||||
| Indirect contact consumption | ≤ 2000 | ||||||||