CFR > Title 40 > Chapter I > Subchapter N > Part 436 > Subpart E CFR > Title 40 > Chapter I > Subchapter N > Part 436 > Subpart E – Gypsum Subcategory Current as of: 2024 | Check for updates | Other versions § 436.50 Applicability; description of the gypsum subcategory § 436.51 Specialized definitions § 436.52 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available