SIC 4971 — Irrigation Systems
Official OSHA SIC Manual Definition
Establishments primarily engaged in operating water supply systems for the purpose of irrigation. Establishments primarily engaged in operating irrigation systems for others, but which do not themselves provide water, are classified in Agricultural Services, Industry 0721.
Description & Classification
SIC code 4971 representing 'Irrigation Systems' is an industry category in the Standard Industrial Classification (SIC) system under U.S. OSHA and Federal procurement registers.
Modern NAICS Crosswalk
Trace the modern equivalent classifications in the 2022 North American Industry Classification System (NAICS) database:
- NAICS 221310 - Water Supply and Irrigation Systems (via SIC1987:4971→NAICS1997:22131→2002:221310→2007:221310→2012:221310→2017:221310→2022:221310)
Classification Details
| SIC Code | 4971 |
|---|---|
| Industry Title | Irrigation Systems |
| Division | Division E: Transportation, Communications, Electric, Gas, and Sanitary Services |
| Major Group | Major Group 49: Electric, Gas, and Sanitary Services |
| JSON Endpoint | View as JSON · API → |
| Source / Verified | US Census 1987 SIC Concordance / 2026-08-08 |
SIC vs NAICS Compliance & Common Mismatches
Legacy SIC code 4971 classifies commercial operations based on primary end-product or service output under the 1987 federal framework. In contrast, modern 2022 NAICS codes group establishments based on production process inputs.
When submitting public disclosures to SEC EDGAR or determining OSHA workplace safety log recordkeeping exemptions (29 CFR Part 1904), rely strictly on the official OSHA 4-digit SIC classification rather than an automated commercial translation.
💡 Expert Guidance: SIC to NAICS Conversion
Common Compliance Mistake: Many contractors and B2B analysts confuse legacy 4-digit SIC codes like 4971 with modern 6-digit NAICS codes. Ensure that you use the correct active 2022 NAICS code (e.g. from the crosswalk below) when submitting representations on SAM.gov, as federal contracting officers only accept modern NAICS codes.
Related Pages & Tools
Further regulatory reference links for legacy SIC code 4971:
- SIC Codes Complete Compliance Guide — Detailed history and active legal applications of the SIC classification framework.
- Why Legacy SIC Codes Persist Guide — How credit systems and the SEC still rely on SIC metadata.
- SIC ↔ NAICS Crosswalk Tool — Trace industrial code conversions dynamically.
- SIC 4971 to NAICS Crosswalk — Bidirectional mapping to modern NAICS codes (Irrigation Systems).
- SIC Major Group 49 Hub — View other legacy industries in this business division.
Frequently Asked Questions (FAQ)
What industry sector is represented by legacy SIC code 4971? ▾
Legacy SIC code 4971 represents 'Irrigation Systems', categorized under Division Division E: Transportation, Communications, Electric, Gas, and Sanitary Services and Major Group Major Group 49: Electric, Gas, and Sanitary Services. The Standard Industrial Classification (SIC) system was developed in the late 1930s.
What is the modern 2022 NAICS equivalent for legacy SIC 4971? ▾
Legacy SIC code 4971 maps to the modern 2022 NAICS industry classifications: NAICS 221310 (Water Supply and Irrigation Systems). Mappings are resolved transitively across successive updates to handle splits.
Why do credit agencies and banks still reference legacy SIC code 4971? ▾
Registries like Dun & Bradstreet, insurance underwriters, and private platforms retain SIC code 4971 because their historical financial risk data and scoring models are indexed using the legacy 4-digit SIC framework.
Does the SEC EDGAR system allow searching public filings by SIC 4971? ▾
Yes. The SEC Division of Corporation Finance assigns a primary 4-digit SIC code to public companies. You can search the EDGAR database using SIC code 4971 to group reporting peer firms.
How do OSHA safety recordkeeping rules apply to SIC code 4971? ▾
Under 29 CFR Part 1904 safety regulations, OSHA references legacy SIC codes including 4971 to determine if a physical establishment is required to maintain daily injury logs (Form 300) or is partially exempt.
What is the structural difference between SIC 4971 and NAICS codes? ▾
SIC code 4971 classifies establishments based on their final product output or market destination (what they sell), while modern NAICS codes classify them based on production processes and inputs (how they work).
What are the typical business activities classified under legacy SIC 4971? ▾
Typical business activities classified under legacy SIC 4971 are the operations associated with 'Irrigation Systems'. Mapped modern NAICS codes can be referenced for specific current examples.
Is legacy SIC code 4971 uniform across all 50 U.S. states? ▾
Yes, the Standard Industrial Classification (SIC) system, including code 4971, was published as a federal standard and remains uniform nationwide. It is still referenced by various state workers' compensation boards and departments of labor.
Sources & References
- U.S. Department of Labor (OSHA): OSHA Standard Industrial Classification (SIC) Manual — Code 4971
- U.S. Census Bureau: 1987 SIC to 2022 NAICS Concordance Tables
- Federal Reserve Board: Industrial Production & Capacity Utilization Classifications
- Internal Revenue Service (IRS): Schedule C Principal Business Activity (PBA) Industry Concordance
- Office of Management and Budget (OMB): Standard Industrial Classification Systems Governance