[Code of Federal Regulations] [Title 40, Volume 29] [Revised as of July 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR436.140] [Page 353] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 436_MINERAL MINING AND PROCESSING POINT SOURCE CATEGORY --Table of Contents Subpart N_Potash Subcategory Sec. 436.140 Applicability; description of the potash subcategory. Authority: Sec. 306, Federal Water Pollution Control Act, as amended. The provisions of this subpart are applicable to the processing of potash. Potash obtained from brine lakes is regulated in the saline from brine lakes subcategory (subpart L of this part).