River Water
Korean river water quality standards are classified into seven grades (Grades I to VI) based on living environment criteria, with standards established for five main categories.
The human health standards are set at 17 items including cadmium and arsenic.
Cadmium (Cd): ≤ 0.005 mg/L, Arsenic (As): ≤ 0.05 mg/L
Cyanide (CN): Must not be detected (detection limit: 0.01 mg/L)
Mercury (Hg): Must not be detected (detection limit: 0.001 mg/L)
Organophosphorus compounds: Must not be detected (detection limit: 0.0005 mg/L)
Polychlorinated Biphenyls (PCB): Must not be detected (detection limit: 0.0005 mg/L)
Lead (Pb): ≤ 0.05 mg/L, Hexavalent Chromium (Cr6+): ≤ 0.05 mg/L, Anionic Surfactants (ABS): ≤ 0.5 mg/L, Carbon Tetrachloride: ≤ 0.004 mg/L
1,2-Dichloroethane: ≤ 0.03 mg/L, Tetrachloroethylene (PCE): ≤ 0.04 mg/L, Dichloromethane: ≤ 0.02 mg/L, Benzene: ≤ 0.01 mg/L
Living Environment Standards (River Water)
| Grade | Biochemical Oxygen Demand (BOD) (mg/L) | Standard | ||||||
|---|---|---|---|---|---|---|---|---|
| Hydrogen Ion Concentration (pH) | Suspended Solids (SS) (mg/L) | Total Nitrogen (T-N) (mg/L) | Total Phosphorus (T-P) (mg/L) | Total Coliforms (colonies/mL) | Ecotoxicity (TU) | |||
| Very Good | Ⅰ a | 6.5~8.5 | ≤ 1 | ≤ 25 | ≥ 7.5 | ≤ 50 | ≤ 10 | |
| Good | Ⅰ b | 6.5~8.5 | ≤ 2 | ≤ 25 | ≥ 5.0 | ≤ 500 | ≤ 100 | |
| Slightly Good | Ⅱ | 6.5~8.5 | ≤ 3 | ≤ 25 | ≥ 5.0 | ≤ 1,000 | ≤ 200 | |
| Moderate | Ⅲ | 6.5~8.5 | ≤ 5 | ≤ 25 | ≥ 5.0 | ≤ 5,000 | ≤ 1,000 | |
| Slightly Poor | Ⅳ | 6.0~8.5 | ≤ 8 | ≤ 100 | ≥ 2.0 | |||
| Poor | Ⅴ | 6.0~8.5 | ≤ 10 | Should not have floating debris | ≥ 2.0 | |||
| Very Poor | Ⅵ | > 10 | < 2.0 | |||||
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 | ||||||||