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Categorical User Information

This page contains information, documents, and links related to Federal Categorical Regulations. Categorical Regulations, also called Effluent Guidelines, are federal limits and requirements for specific industrial categories that apply nationwide. Industrial Users subject to Categorical Regulations with applicable Pretreatment Standards or requirements are called Categorical Industrial Users or CIUs. All CIUs are automatically considered Significant Industrial Users (SIUs). The categorical limits for each CIU are compared to their POTW's local limits (Allocation Table), and the more stringent limits are applied.

The most common Categories used in NC are:

  • 40 CFR 433 - Metal Finishing
  • 40 CFR 439 - Pharmaceuticals
  • 40 CFR 414 - Organic Chemicals, Plastics, and Synthetic Fibers (OCPSF)

General Information on Categorical Regulations