[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: 40CFR451.20] [Page 464] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 451_CONCENTRATED AQUATIC ANIMAL PRODUCTION POINT SOURCE CATEGORY--Table of Contents Subpart B_Net Pen Subcategory Sec. 451.20 Applicability. This subpart applies to the discharge of pollutants from a concentrated aquatic animal production facility that produces 100,000 pounds or more per year of aquatic animals in net pen or submerged cage systems, except for net pen facilities rearing native species released after a growing period of no longer than 4 months to supplement commercial and sport fisheries.