Frequent Questions

Has EPA promulgated a maximum contaminant level (MCL) and maximum contaminant level goal (MCLG) for nickel?

EPA promulgated an MCL and MCLG of 0.1 mg/L for nickel on July 17, 1992 (57 FR 31776).  However, in September 1992, the Nickel Development Institute challenged the methodology used to establish the MCL and MCLG in a petition to the U.S. Court of Appeals. Subsequently, EPA agreed with the challenge and filed a joint motion along with the nickel industry petitioners to voluntarily remand the MCL and MCLG on February 9, 1995. The court granted the motion and the remand became effective on the same date. All other rules pertaining to nickel, including monitoring requirements and best available treatment technology development, remain in effect. Details of the remand can be found in the June 29, 1995, Federal Register (60 FR 33929). A list of contaminants and their MCLs is available at
Have more questions? Submit a request