Table 1 Transnational comparison of the standards for drinking water quality.
Classic water quality index | Maximum allowable value | |||
|---|---|---|---|---|
China | The United States | European Union | Japan | |
Turbidity | 1.0 NTU | 1.0 NTU | Acceptable for Users and No Abnormality | 2.0 NTU |
Chemical gen Demand (CODMn) | 3.0 mg/L | - | 5.0 mg/L | - |
Total Number of Bacterial Colony | 100 CFU/ml | 500 CFU/ml | No Abnormal Change | 100 CFU/ml |
Total Dissolved Solids (TDS) | 1000 mg/L | 500 mg/L | 2500 μs/cm of conductivity (≈1250 mg/L) | 500 mg/L |
Sulfate (SO42-) | 250 mg/L | 250 mg/L | 250 mg/L | - |
Total Hardness (measured in CaCO3) | 450 mg/L | - | - | 300 mg/L |
