221320 — Sewage Treatment Facilities
NAICS 221320 is 'Sewage Treatment Facilities', a 2022 U.S. national industry under Sector 22 (Utilities); the SBA small-business size standard is $35,000,000.
Description
This industry comprises establishments primarily engaged in operating sewer systems or sewage treatment facilities that collect, treat, and dispose of waste.
Exclusions & Cross-References
- Operating waste treatment or disposal facilities (except sewer systems or sewage treatment facilities)--are
- classified in Industry 56221, Waste Treatment and Disposal;
- Operating water treatment plants and/or operating water supply systems--are classified in Industry 221310,
- Water Supply and Irrigation Systems;
- Pumping (i.e., cleaning) cesspools, portable toilets, and septic tanks or renting portable toilets--are
- classified in U.S. Industry 562991, Septic Tank and Related Services; and
- Cleaning and rodding sewers and catch basins--are classified in U.S. Industry 562998, All Other
- Miscellaneous Waste Management Services.
Overview Facts
| NAICS Code | 221320 |
|---|---|
| Industry Title | Sewage Treatment Facilities |
| SBA Size Standard | $35,000,000 |
| IRS PBA Code | 221300 (rolled-up match) |
| Sectors Hierarchy | Sector 22 → 221 → 2213 |
| Source / Verified | US Census 2022 NAICS Manual / 2026-06-28 |
NAICS Structure: 221320
National Industry
Sector (2)
22
Utilities
Subsector (3)
221
Utilities
Industry Group (4)
2213
Water, Sewage and Other Systems
Industry (5)
22132
Sewage Treatment Facilities
National Industry (6)
221320
Sewage Treatment Facilities
Legacy SIC Concordance
Trace the historical mapping chain from the 1987 Standard Industrial Classification (SIC) to the modern 2022 NAICS code format.
- SIC 4952 - Sewerage Systems (via SIC1987:4952→NAICS1997:22132→2002:221320→2007:221320→2012:221320→2017:221320→2022:221320)
Related Resources & Compliance Guides
Further regulatory reference links for NAICS code 221320:
- Sector 22 Directory Hub — List of related industries in the Utilities sector.
- SIC ↔ NAICS Crosswalk Tool — Look up mappings between legacy SIC codes and modern classifications.
- SBA Size Standards Guide — Complete rules and averaging periods for small business classifications.
- Calculating Annual Receipts Guide — Detailed worked example of revenue calculation rules.
- IRS Principal Business Activity Guide — How NAICS codes map to corporate and entity tax filings.
Related Industries in 2213
Frequently Asked Questions (FAQ)
Is 221320 a valid 2022 NAICS code?
NAICS 221320 is 'Sewage Treatment Facilities', a 2022 U.S. national industry under Sector 22 (Utilities); the SBA small-business size standard is $35,000,000.
What is the SBA size standard for NAICS 221320?
The SBA small business size standard for NAICS 221320 is $35,000,000 (based on receipts).
What is the legacy SIC code mapping for 221320?
NAICS code 221320 maps to the legacy 1987 SIC codes: 4952 - Sewerage Systems.