The Radionuclides Rule added for the first time an MCL, for uranium of ______

The Radionuclides Rule added for the first time an MCL, for uranium of ______

• A. 5 micrograms/L
• B. 10 micrograms/L
• C. 25 micrograms/L
• D. 30 micrograms/L

Answer: (D)

The important idea is that the Radionuclides Rule established an enforceable drinking water limit for uranium. The first MCL for uranium is 30 micrograms per liter. This value was chosen based on health considerations for consuming water—uranium can affect kidney function—and was set at a level that water systems could realistically treat to meet it using common treatment technologies. The unit micrograms per liter (µg/L) is the same as parts per billion, a typical way to express trace contaminants in water. The other numerical options do not represent the uranium MCL set by the rule.

The important idea is that the Radionuclides Rule established an enforceable drinking water limit for uranium. The first MCL for uranium is 30 micrograms per liter. This value was chosen based on health considerations for consuming water—uranium can affect kidney function—and was set at a level that water systems could realistically treat to meet it using common treatment technologies. The unit micrograms per liter (µg/L) is the same as parts per billion, a typical way to express trace contaminants in water. The other numerical options do not represent the uranium MCL set by the rule.