221320 — Sewage Treatment Facilities
Description
This industry comprises establishments primarily engaged in operating sewer systems or sewage treatment facilities that collect, treat, and dispose of waste (as defined in the official U.S. Census Bureau 2022 NAICS Manual).
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
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)
Suggested Product Service Codes (Advisory)
The following Product Service Codes (PSCs) are advisory suggestions aligned with this NAICS code. Note: NAICS and PSC codes map to different dimensions of procurement (industry vs. product/service). There is no official binding 1:1 crosswalk.
- PSC M1ND — OPERATION OF SEWAGE AND WASTE FACILITIES
Source: DoD DPCAP PSC Selection Tool (Ingested: 2026-06-29)
Frequently Asked Questions (FAQ)
Is NAICS code 221320 valid in 2022? ▾
Yes, 221320 is a valid 6-digit 2022 NAICS national industry code representing 'Sewage Treatment Facilities' under Sector 22 in the official classification index.
What is the SBA size standard for NAICS code 221320? ▾
The Small Business Administration (SBA) has established a small business size standard of $35,000,000 for NAICS code 221320 (Sewage Treatment Facilities), calculated based on receipts.
What is the legacy SIC equivalent for NAICS 221320? ▾
According to official Census Bureau concordance tables, NAICS code 221320 (Sewage Treatment Facilities) maps to legacy 1987 Standard Industrial Classification (SIC) codes: 4952 - Sewerage Systems.
Related Pages & Tools
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.
- NAICS 221320 to SIC Crosswalk — Bidirectional mapping to legacy SIC codes (Sewage Treatment Facilities).
- 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.