Allowable lead quantity in water?

Allowable lead quantity in water?

• A. 5 ppb/L
• B. 30 ppb/L
• C. 50 ppb/L
• D. 15 ppb/L, or 15 mg/L

Answer: (D)

Lead in drinking water is regulated by an action level of 15 parts per billion. That threshold is the point at which a water system must take steps to reduce corrosion and protect public health. In metric terms, 15 ppb is 0.015 milligrams per liter, so the allowable concentration is very small. The option that lists 15 mg/L would imply a concentration 1,000 times higher than the actual limit, which isn’t correct. So the correct understanding is 15 ppb (0.015 mg/L), recognizing that the wording about mg/L in the choice may be a misprint, but the essential standard is the 15 ppb action level.

Lead in drinking water is regulated by an action level of 15 parts per billion. That threshold is the point at which a water system must take steps to reduce corrosion and protect public health. In metric terms, 15 ppb is 0.015 milligrams per liter, so the allowable concentration is very small. The option that lists 15 mg/L would imply a concentration 1,000 times higher than the actual limit, which isn’t correct. So the correct understanding is 15 ppb (0.015 mg/L), recognizing that the wording about mg/L in the choice may be a misprint, but the essential standard is the 15 ppb action level.