§ 421.230 Applicability: Description of the primary nickel and cobalt subcategory
§ 421.231 Specialized definitions
§ 421.232 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available
§ 421.233 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable
§ 421.234 Standards of performance for new sources
§ 421.236 Pretreatment standards for new sources