CFR›Title 40›Chapter I›Part 436›Subpart E ContainsSections 436.50–436.52CorpusDaily eCFRDisplayed edition2026-05-14Last updated2026-05-14 Subpart E—Gypsum Subcategory Sections 436.50 § 436.50 Applicability; description of the gypsum subcategory. 436.51 § 436.51 Specialized definitions. 436.52 § 436.52 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available. Previous D Subpart D—Industrial Sand Subcategory Next F Subpart F—Asphaltic Mineral Subcategory