221310 — Water Supply and Irrigation Systems
Description
This industry comprises establishments primarily engaged in operating water treatment plants and/or operating water supply systems. The water supply system may include pumping stations, aqueducts, and/or distribution mains. The water may be used for drinking, irrigation, or other uses.
Exclusions & Cross-References
- Establishments primarily engaged in irrigation project construction (except lawn) are classified in Industry
- 237110, Water and Sewer Line and Related Structures Construction;
- Establishments primarily engaged in installing lawn sprinkler systems are classified in Industry 238220,
- Plumbing, Heating, and Air-Conditioning Contractors;
- Establishments primarily engaged in lawn irrigation services are classified in Industry 561730,
- Landscaping Services;
- Establishments primarily engaged in retailing bottled water are classified in U.S. Industry 445298, All
- Other Specialty Food Retailers; and
- Government establishments primarily engaged in administering irrigation districts are classified in Industry
- 926130, Regulation and Administration of Communications, Electric, Gas, and Other Utilities.
Overview Facts
| NAICS Code | 221310 |
|---|---|
| Industry Title | Water Supply and Irrigation Systems |
| SBA Size Standard | $41,000,000 |
| U.S. Establishments | 4,554 (Census CBP, 2023) |
| IRS PBA Code | 221300 (rolled-up match) |
| Sectors Hierarchy | Sector 22 → 221 → 2213 |
| Source / Verified | US Census 2022 NAICS Manual, Census CBP / 2026-06-28 |
Legacy SIC Concordance
Trace the historical mapping chain from the 1987 Standard Industrial Classification (SIC) to the modern 2022 NAICS code format.
- SIC 4941 - Water Supply (via SIC1987:4941→NAICS1997:22131→2002:221310→2007:221310→2012:221310→2017:221310→2022:221310)
- SIC 4971 - Irrigation Systems (via SIC1987:4971→NAICS1997:22131→2002:221310→2007:221310→2012:221310→2017:221310→2022:221310)
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 M1NE — OPERATION OF WATER SUPPLY FACILITIES
Source: DoD DPCAP PSC Selection Tool (Ingested: 2026-06-29)
Related Resources & Compliance Guides
Further regulatory reference links for NAICS code 221310:
- 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 221310 a valid 2022 NAICS code?
NAICS 221310 is 'Water Supply and Irrigation Systems', a 2022 U.S. national industry under Sector 22 (Utilities); the SBA small-business size standard is $41,000,000.
What is the SBA size standard for NAICS 221310?
The SBA small business size standard for NAICS 221310 is $41,000,000 (based on receipts).
What is the legacy SIC code mapping for 221310?
NAICS code 221310 maps to the legacy 1987 SIC codes: 4941 - Water Supply, 4971 - Irrigation Systems.