National categorical pretreatment standards:

The federal government has established discharge limits for specific industries, called categorical dischargers. These must obtain a full King County permit regardless of their wastewater discharge volume. Categorical industries include the following:

• Aluminum forming
• Battery manufacturing
• Centralized waste treatment
• Circuit-board manufacturing
• Coil coating
• Copper forming
• Electrical/electronic components
• Electroplating
• Inorganic chemical manufacturing
• Iron/steel manufacturing
• Leather tanning finishing
• Metal finishing
• Metal foundries
• Nonferrous metal manufacturing
• Pesticide manufacturing
• Petroleum refining
• Pharmaceutical manufacturing
• Porcelain enameling
• Pulp/paper mills
• Wood preserving

Authority: These are technology-based limitations on pollutant discharges to POTWs promulgated by EPA in accordance with Section 307 of the Clean Water Act that apply to specified process wastewater of particular industrial categories, see 40 CFR 403.6 and 40 CFR Parts 405- 471 (external link).