NAICS 221310 Quarterly Industry Report
Water Supply and Irrigation Systems
Comprehensive industry research for valuation professionals, business owners, buyers, and lenders
NAICS Code: 221310Sector: Utilities (22)Updated: Q1 2026
About This Report
This industry profile for Water Supply and Irrigation Systems (NAICS 221310) draws on data from the Bureau of Labor Statistics[6], U.S. Census Bureau, and SBA size standards database[7]. Published by Fair Market Value and updated quarterly, it provides valuation professionals, water utility analysts, and business brokers with current market data. The editorial analysis reflects the independent assessment of FairMarketValue.com's research team, with all quantitative claims sourced to publicly verifiable databases.
Industry Snapshot
Key metrics for the water supply and irrigation systems industry.
Industry Definition & Overview
Water Supply and Irrigation Systems (NAICS 221310) encompasses establishments primarily engaged in operating water treatment plants and water supply systems, including pumping stations, aqueducts, and distribution mains per the U.S. Census Bureau[5]. Water may serve drinking, irrigation, industrial, or other uses. This classification covers the full chain from raw water intake through treatment, storage, pumping, and pressurized delivery to customer taps.
About 4,492 companies operate nationally, employing roughly 38,510 workers per the Bureau of Labor Statistics[6]. American Water Works is the largest publicly traded U.S. water utility, serving 14 million people across 24 states. Essential Utilities serves three million water customers and 250,000 wastewater customers across eight states. Veolia serves drinking water to 95 million people globally. Most U.S. water systems are owned by municipal governments and tracked separately in the Census of Governments, making the private-sector establishment count an incomplete picture of total industry size.
Per the SBA Table of Size Standards[7], the size standard is $41.0 million in average annual receipts. EPA's Safe Drinking Water Act sets maximum contaminant levels and treatment technique requirements for public water systems. About 50,000 community water systems serve the U.S. population, though the vast majority serve fewer than 10,000 people. Aging distribution infrastructure creates water loss through pipe leaks, with the American Society of Civil Engineers estimating water main breaks at 250,000 per year. Lead service line replacement has become a regulatory priority following public health concerns, with the EPA's Lead and Copper Rule requiring utilities to identify and replace lead piping on accelerated timelines.
What's Included in This Industry
- Water treatment plant operations
- Distribution main and pump station management
- Reservoir and storage tank operations
- Water quality testing and monitoring
- Customer meter reading and billing
- Irrigation canal and system operation
- Fire hydrant maintenance and testing
- Lead service line replacement programs
- Leak detection and water loss reduction
- Emergency water supply and boil advisories
NAICS Classification Hierarchy
| Level | Description | Code |
|---|---|---|
| Sector | Utilities | 22 |
| Subsector | Utilities | 221 |
| Industry Group | Water, Sewage and Other Systems | 2213 |
| NAICS Industry | Water Supply and Irrigation Systems | 22131 |
| National Industry | Water Supply and Irrigation Systems | 221310 |
Related NAICS Codes
| Code | Description | Relationship |
|---|---|---|
| 221320 | Sewage Treatment Facilities | Sewage Treatment Facilities handle the wastewater side of the water cycle after customers use supplied water, with many utilities operating both water supply and wastewater treatment under combined management |
| 237110 | Water and Sewer Line and Related Structures Construction | Water and Sewer Line Construction builds distribution mains, service connections, and treatment plant structures that water supply systems need for infrastructure expansion and replacement |
| 541330 | Engineering Services | Engineering Services design water treatment plants, distribution systems, pump stations, and storage facilities during capital improvement projects and regulatory compliance upgrades |
| 221330 | Steam and Air-Conditioning Supply | Steam and Air-Conditioning Supply shares centralized utility distribution characteristics with water systems, both delivering commodity services through underground pipe networks to customer buildings |
| 562991 | Septic Tank and Related Services | Septic Tank Services provide decentralized wastewater management in areas without municipal sewer service, serving customers who rely on private wells and water supply alternatives |
| 541620 | Environmental Consulting Services | Environmental Consulting Services perform water quality assessments, source water protection studies, and regulatory compliance support for water utilities meeting Safe Drinking Water Act requirements |
Geographic Concentration
Top states by share of national establishments.
| # | State | % Est. | Total Est. |
|---|---|---|---|
| 1 | Texas | 15.7% | 694 |
| 2 | California | 11.0% | 489 |
| 3 | Mississippi | 7.3% | 323 |
| 4 | Florida | 6.4% | 285 |
| 5 | Pennsylvania | 4.1% | 180 |
| 6 | Louisiana | 3.6% | 161 |
| 7 | Washington | 3.0% | 133 |
| 8 | Colorado | 2.9% | 130 |
| 9 | Arizona | 2.8% | 125 |
| 10 | Indiana | 2.6% | 117 |
% Of Establishments
0%
16%
Source: County Business Patterns, U.S. Census Bureau[3]
SBA Lending Summary
432
Total SBA Loans
$191.4M
Total Loan Volume
$443K
Average Loan Size
12 yrs
Average Loan Term
10.40%
Average Interest Rate
4,104
Jobs Supported
Source: SBA 7(a) Program Data, U.S. Small Business Administration — FY 2025[4]
Key Insight: Per the SBA Table of Size Standards[7], Water Supply and Irrigation Systems (NAICS 221310) has a size standard of $41.0 million in average annual receipts for federal contracting purposes. SBA 7(a) loans[8] support treatment upgrades, pipe replacement, and working capital for qualifying operators. Small privately owned water systems serving rural communities represent a common small business profile. Additionally, 504/CDC loans[9] provide long-term, fixed-rate financing for major fixed assets such as real estate and equipment.
Top SBA Lenders
| # | Lender | Loans | Volume | Avg Loan |
|---|---|---|---|---|
| 1 | Newtek Bank, National Association | 48 | $63.2M | $1.3M |
| 2 | BOKF, National Association | 16 | $20.9M | $1.3M |
| 3 | Brookline Bank, a Division of Beacon Bank and Trust | 8 | $11.5M | $1.4M |
| 4 | Northeast Bank | 56 | $10.3M | $185K |
| 5 | First Internet Bank of Indiana | 8 | $10.2M | $1.3M |
Frequently Asked Questions
Common questions about this industry.
What companies operate water supply systems?
American Water Works serves 14 million people across 24 states, and Essential Utilities serves three million water customers. About 4,492 companies employ roughly 38,510 workers per the U.S. Census Bureau[5]. Most U.S. water systems are municipally owned rather than private.
How many water systems serve the U.S.?
About 50,000 community water systems serve the U.S. population, though the vast majority serve fewer than 10,000 people per the Bureau of Labor Statistics[6]. Private-sector systems represent a fraction of total utility count alongside municipal and government-owned operations.
What is the SBA size standard for Water Supply?
Per the SBA Table of Size Standards[7], NAICS 221310 has a size standard of $41.0 million in average annual receipts. This determines eligibility for SBA loans, federal contracting set-asides, and small business programs.
What NAICS codes are related to water supply?
Related codes include NAICS 221320 (Sewage Treatment), NAICS 237110 (Water Line Construction), NAICS 541330 (Engineering), NAICS 221330 (Steam Supply), and NAICS 541620 (Environmental Consulting) per the U.S. Census Bureau[5].
How is water quality regulated?
EPA's Safe Drinking Water Act sets maximum contaminant levels and treatment technique requirements for public water systems. State primacy agencies enforce federal standards and may set additional state-specific requirements for water quality protection.
What activities are included in NAICS 221310?
Core activities include water treatment, distribution main operations, reservoir management, water quality testing, meter reading, irrigation system operation, hydrant maintenance, lead pipe replacement, leak detection, and emergency supply per the U.S. Census Bureau[5].
Can water supply businesses get SBA loans?
Yes, firms meeting the $41.0 million size standard qualify for SBA 7(a) loans[8] covering treatment upgrades, pipe replacement, and working capital. Small privately owned rural water systems are common applicants.
Why is lead service line replacement a priority?
EPA's revised Lead and Copper Rule requires utilities to identify and replace lead service connections on accelerated timelines following public health concerns per the Bureau of Labor Statistics[6]. Lead exposure from aging water piping affects an estimated 9 million service lines nationwide that must be mapped and replaced.
Sources & References
Government datasets and editorial sources used in this report.
- [1]U.S. Bureau of Labor Statistics, Quarterly Census of Employment and Wages bls.gov
- [2]U.S. Census Bureau, Economic Census census.gov
- [3]U.S. Census Bureau, County Business Patterns census.gov
- [4]U.S. Small Business Administration, SBA 7(a) Loan Program Data data.sba.gov
- [5]U.S. Census Bureau census.gov
- [6]Bureau of Labor Statistics bls.gov
- [7]SBA Table of Size Standards sba.gov
- [8]SBA 7(a) loans sba.gov
- [9]504/CDC loans sba.gov
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