What is the allowable lead quantity in water?

What is the allowable lead quantity in water?

• A. 5 ppb/L, or 5 mg/L
• B. 1 ppb/L, or 1 mg/L
• C. 15 ppb/L, or 15 mg/L
• D. 50 ppb/L, or 50 mg/L

Answer: (C)

Lead in drinking water is limited to 15 parts per billion. This means the allowable amount is 15 ppb, which is the same as 15 micrograms per liter (15 µg/L) or 0.015 milligrams per liter (0.015 mg/L). So the correct sense is 15 ppb (0.015 mg/L). Saying 15 mg/L would be far above the limit (that’s 1,000 times higher). Units are usually given as ppb or µg/L for drinking water; mg/L would imply a much larger concentration.

Lead in drinking water is limited to 15 parts per billion. This means the allowable amount is 15 ppb, which is the same as 15 micrograms per liter (15 µg/L) or 0.015 milligrams per liter (0.015 mg/L). So the correct sense is 15 ppb (0.015 mg/L). Saying 15 mg/L would be far above the limit (that’s 1,000 times higher). Units are usually given as ppb or µg/L for drinking water; mg/L would imply a much larger concentration.