What is the normal range for safe drinking water?

The normal range for safe drinking water, according to the World Health Organization (WHO), is as follows:

pH: 6.5-8.5

Turbidity: < 5 nephelometric turbidity units (NTU)

Total Dissolved Solids (TDS): < 500 mg/L

Chloride: < 250 mg/L

Sulfate: < 250 mg/L

Nitrate: < 50 mg/L

Nitrite: < 1 mg/L

Fluoride: 0.5-1.5 mg/L

Arsenic: < 0.01 mg/L

Cadmium: < 0.003 mg/L

Chromium: < 0.05 mg/L

Lead: < 0.01 mg/L

Mercury: < 0.001 mg/L

E. coli: 0 colony-forming units (CFU)/100 mL

These standards are based on health-based considerations and are intended to ensure that drinking water is safe for human consumption. However, it's important to note that these standards can vary depending on specific country regulations and local conditions, so it's always best to check with local authorities for the most up-to-date water quality guidelines in your area.