40 CFR § 415.470
Applicability; description of the nickel salts production subcategory
June 9, 2020
The provisions of this subpart are applicable to discharges and to the introduction of pollutants into treatment works which are publicly owned resulting from the production of nickel salts, including (a) nickel sulfate, nickel chloride, nickel nitrate, and nickel fluoborate, and (b) nickel carbonate.