Utility System Construction (NAICS 2371)

A rollup primer for public-market and private investors

What this page is. In the North American Industry Classification System (NAICS) — the U.S. government's standard scheme for grouping businesses — the four-digit industry group 2371 sits inside subsector 237 (Heavy and Civil Engineering Construction), which sits inside sector 23 (Construction). Unlike its two single-child siblings, 2371 has three distinct children with genuinely different economics. This page's job is to compare them — relative size, growth direction, ownership, and how to invest — and then give the level's own ground-truth federal figures. For company-by-company detail, contract mechanics, and full diligence checklists, follow the links to the three child primers.

1. Overview

Utility System Construction is the heavy-civil business of building, expanding, hardening, and repairing the three great networks that make modern life run: the pipes that move water and sewage, the lines and stations that move oil and gas, and the wires, towers, and cables that move electricity and data.[1] These are the contractors — crews, excavators, welders, linemen, pipe and cable in the ground or on towers. They are not the utilities, pipeline companies, or telecom carriers that own the systems and bill customers for what flows through them; those asset-owners sit in separate NAICS codes (electric/gas utilities in 2211, pipeline transportation in 486, carriers in subsector 517).[1][4][5][6]

It is a project-based, fee-for-work industry: firms make money by winning contracts and executing them, not by owning a rate base or collecting rents. And it is enormous — at roughly $204 billion in annual receipts, 2371 is the largest industry group in heavy-civil construction, funded overwhelmingly by the capital budgets of utilities, pipeline owners, telecom carriers, and governments.[2] Every one of those customers is now in an unusually heavy investment phase, which is why this whole group has moved to the center of the infrastructure-investing conversation.

The distinctive thing about looking at 2371 as a group, rather than at one child, is the contrast: its three children differ sharply in size, capital intensity, who owns the builders, how you can get exposure, and — most of all — what drives their demand and how durable it is.

2. What's inside — the three children and how they differ

2371 breaks into three six-digit national industries. Each has its own full primer; the numbers behind this table are consolidated in Section 3.

Contrast at a glance:

The differences that matter for an investor:

• Size and momentum diverge. Power & communication line is by itself half the group and is the one riding a clear structural boom.[6] Water is steadier and more non-discretionary but gated by public budgets and a looming infrastructure-funding cliff.[4] Oil & gas is the smallest and the most cyclical — lumpy megaproject waves that arrive and vanish with permitting.[5]
• Firm scale is completely different. Average revenue per firm runs about $5.5 million in water (a true small-business industry), $18.6 million in power/communication, and $24.6 million in oil & gas (the fewest firms, by far the largest each).[2][4][5][6] That scale gap tracks straight through to concentration (Section 8).
• Ownership access is different. Water is the hardest to own directly (the cleanest listed exposure is pipe/valve makers and regulated utilities, not contractors); power/communication has the richest set of listed contractors; oil & gas splits between listed diversified builders and private megaproject giants.[4][5][6]
• What crosses over. A handful of diversified contractors — Quanta, MasTec, Primoris — appear in two or all three children. That overlap is exactly why the group is investable as a theme even though no single company equals it: buying one of these names is buying a slice of the whole utility-construction super-cycle at once.[5][6]

3. How big it is (this level's rollup figures)

These are our ground-truth federal statistics for NAICS 2371, with the three children broken out so the mix is visible. Receipts, firm counts, and concentration come from the 2022 Economic Census (EC); establishments, employment, and payroll come from County Business Patterns (CBP) 2023. The two programs use different years and definitions, so do not treat every row as one clean "market size."

Sources: rollup column is our ground-truth extract for 2371;[2][3] child columns from the three child primers.[4][5][6]

Three quick reads:

• The group is big, and skilled-labor-heavy. More than 627,000 paid employees and a $54.7 billion payroll — pay per worker (~$87,000) runs well above construction-sector norms because the work needs welders, equipment operators, and linemen, often unionized and on heavy overtime.[3][5][6]
• Water and oil & gas employ almost identical headcounts (~167,000 each) yet water bills $13 billion more. That is the capital-intensity gap: pipeline megaprojects are fewer, larger, and more equipment-and-materials-heavy per worker, spread across far fewer firms.[4][5]
• The group is near-atomistic. The four largest firms hold just 11.7% of receipts (top 50, only 37.5%), and the HHI of 63.1 is a tiny fraction of the 1,500 mark below which regulators call a market "unconcentrated."[2] Notably, the group's HHI (63) is lower than two of its three children's (oil & gas 174, power 156) — combining three sub-markets whose leaders only partly overlap dilutes any one firm's share of the whole. This is one of the most fragmented industry groups in the U.S. economy.

Undercount caveat — read this. The $203.85 billion counts private contractors with employees only. It misses three large pools of real build-and-maintain activity: (1) government and utility "force-account" work — municipal water crews, and electric/gas utilities' and telecom carriers' own linemen and pipefitters, whose labor is counted under government or under NAICS 2211/517, not here;[4][6] (2) nonemployer firms — the self-employed and one-person outfits excluded from CBP, which matter most in the highly fragmented water segment where small and individually run ownership dominates;[4] and (3) some megaproject spending booked elsewhere, because the giant diversified builders of the largest pipelines (Kiewit, Bechtel) carry a primary NAICS classification under other codes.[5] True national utility-construction activity is therefore materially larger than the measured $203.85 billion.

4. The investable universe (where value concentrates)

There is no single public company whose revenue equals this group — the work is local, project-based, and heavily private and municipal. Public exposure runs through contractors that straddle several NAICS codes, so the golden rule is to judge every name by the share of its revenue actually tied to utility construction, not by headline size. Value concentrates in five layers, and where each layer sits across the three children is the useful map:

• Diversified heavy-civil contractors — the span-the-group names. Quanta Services (PWR), MasTec (MTZ), and Primoris (PRIM) each self-perform across power, pipeline, and/or water; Quanta is the clear leader in power/communication and a major pipeline builder.[5][6] These are the cleanest single-ticker proxies for the whole 2371 super-cycle. Add Granite (GVA), Sterling Infrastructure (STRL), and Southland Holdings (SLND) on the water-and-civil side.[4]
• Segment specialists. Dycom (DY) — fiber/communications; MYR Group (MYRG) — near pure-play electric transmission and distribution (T&D); IES Holdings (IESC) and Centuri Holdings (CTRI) — utility services.[6]
• Products, equipment, and distribution (cleaner "theme" exposure, but not contractor economics). Water-side: Core & Main (CNM), Mueller Water Products (MWA), Xylem (XYL), NWPX Infrastructure (NWPX).[4]
• Asset-owner proxies (the customers whose budgets fund the builders). Regulated water utilities American Water Works (AWK) and Essential Utilities (WTRG); midstream pipeline owners (Williams, Kinder Morgan, Energy Transfer, ONEOK, Enbridge); and electric utilities generally.[4][5]
• Private and private-equity-backed builders. Much of the actual work — and nearly all of the largest water and pipeline jobs — is built privately: Kiewit, Bechtel, Michels, Black & Veatch, Burns & McDonnell, Garney, Pike, and PE platforms such as Artera (power/gas) and Azuria Water Solutions (formerly Aegion; trenchless water rehabilitation). Reachable through private equity, private credit, or as project counterparties.[4][5][6]

Full company tables and segment revenues live in each child primer.

5. How the money works

The economics are the same type across all three children — volume-and-execution contracting, not utility rent — with the same handful of levers, so learn them once:

• Backlog is the headline leading indicator. Signed-but-not-yet-built work, watched alongside book-to-bill. Revenue is recognized over a project's life as work progresses.[5][6]
• Contract mix sets the risk. Fixed-price / lump-sum contracts (competitively bid megaprojects) carry the most margin upside and the most risk — cost overruns from weather, rock, inflation, and delay land on the builder. Master Service Agreements (MSAs) — time-and-materials frameworks for recurring maintenance, integrity, and replacement work — are the lower-margin "annuity" that keeps crews busy between big jobs.[5][6]
• Margins are thin. Mid-single to low-double-digit operating/EBITDA margins are normal (EBITDA = earnings before interest, taxes, depreciation, and amortization); Quanta's underground/pipeline segment ran about 5.7% operating margin in 2024.[5] Recurring rehab/maintenance work — especially trenchless water relining — tends to be the higher-margin, more differentiated slice.[4]
• Cash lags reported revenue because of retainage (money held back until completion), mobilization costs, and slow public-owner payments — a real strain on smaller firms.[4]

Crucially, do not value these contractors with the tools built for their customers: regulated-utility rate base, real-estate FFO, and mining cost measures belong to the asset-owners, not their builders.[4][5]

6. What drives demand

Demand is simply the capital budgets of the utilities, pipeline owners, telecom carriers, and governments that own the systems — and all three of those spigots are open at once, for different reasons:

• Power & communication (the biggest driver). After ~20 years of flat U.S. electricity demand, load is rising again on AI/data centers, reshoring, and electrification. Utilities have answered with the largest capital wave in the sector's history — on the order of $1.3–1.4 trillion planned for 2025–2030[9][10] — plus grid hardening, renewable interconnection queues, and a federally funded fiber build anchored by the $42.45 billion Broadband Equity, Access, and Deployment (BEAD) program.[11]
• Water & sewer (durable, partly mandated). Aging pipe (much 50–100+ years old), a roughly $1.25 trillion 20-year federal capital need (drinking water plus wastewater), a federal lead-service-line replacement mandate, emerging PFAS treatment, and the Infrastructure Investment and Jobs Act (IIJA) funding surge routed through State Revolving Funds.[4][7] Non-discretionary need, but lumpy and gated by local budgets.
• Oil & gas pipeline (cyclical, currently strong). The U.S. Energy Information Administration (EIA) expects roughly 44.9 billion cubic feet per day of new gas pipeline capacity in 2026–27, about 70% already under construction, pulled by LNG exports, gas-fired power for data centers, and industrial reshoring — with steadier integrity/replacement work underneath.[8]

The common thread: aging infrastructure plus a once-in-a-generation build-out of electricity, water, and connectivity. The differences are in durability — power and water demand is structural and long, oil-and-gas volume is more sensitive to commodity cycles and the energy transition.

7. Regulation

Contractors are lightly regulated as businesses; what sets how much gets built is the regulation of their customers. The layers differ by child but rhyme:

• Water & sewer: the Safe Drinking Water Act (SDWA) and Clean Water Act (CWA), overflow consent decrees, the Lead and Copper Rule Improvements (LCRI), and the funding/loan programs (State Revolving Funds, Water Infrastructure Finance and Innovation Act, WIFIA) — here regulation largely creates the work.[4]
• Oil & gas pipeline: permitting is the single biggest external variable — a Certificate of Public Convenience and Necessity from the Federal Energy Regulatory Commission (FERC), safety oversight by the Pipeline and Hazardous Materials Safety Administration (PHMSA), and CWA Section 404 water-crossing permits from the U.S. Army Corps of Engineers. Builders carry no permitting risk on their own balance sheet, but their revenue timing is hostage to whether customers' projects clear FERC and the courts.[5]
• Power & communication: FERC governs interstate transmission (Order No. 1920 on planning/cost allocation; Order No. 1977 on backstop siting), the North American Electric Reliability Corporation (NERC) sets reliability standards, and state public utility commissions (PUCs) approve utility spending and rate recovery — the real day-to-day spigot on demand.[6]

Cutting across all three: worker-safety rules (Occupational Safety and Health Administration, OSHA — trenching, and 29 CFR 1926 Subpart V for electrical work), prevailing-wage rules (Davis-Bacon), and domestic-content rules (Build America, Buy America / American Iron and Steel) that apply to federally funded work.[4][6]

8. Consolidation

The pattern is identical across all three children and thus across the group: fragmented at the base, consolidating at the top. The base is thousands of small, local firms — work stays local because crews, equipment, permits, bonding, and site knowledge travel poorly. The top is a handful of national consolidators (Quanta, MasTec, Primoris) and private-equity platforms (Artera in power/gas, Azuria in water) that roll up regional specialists to gain crews, licenses, MSAs, bonding capacity, and multi-region and storm-response reach.[4][5][6]

The concentration figures show how early this still is: at the group level, CR4 is only 11.7% and HHI just 63.1, with the water child near-atomistic (CR4 4.2%) and even the more consolidated oil-and-gas and power children still below a 22% top-four share.[2] Even the single largest public contractor's relevant U.S. revenue is a modest slice of the group — meaning the runway for consolidators is long. The cautionary flip side is that scale does not guarantee survival: one bad fixed-price megaproject has sunk large specialists before (Welded Construction, a top pipeline builder, went bankrupt in 2018).[5]

9. Risks

The children share a common risk spine, with each tilting toward one hazard:

• Dependence on customers' capital budgets. Every dollar of demand is someone else's capex or a government appropriation. Water's signature risk is a funding cliff — much IIJA water money is being obligated through roughly 2026.[4] Oil & gas's is extreme cyclicality plus permitting/litigation — Keystone XL's 2021 cancellation cut ~1,000 union jobs almost overnight, and Mountain Valley Pipeline ran from ~$3.5B to ~$7.85B through a decade of court fights.[5] Power's is policy and demand-durability — reliance on federal broadband/tax-credit programs and on AI-data-center power demand actually materializing.[6]
• Skilled-labor scarcity is the constraint that can cap the whole boom — most acute in power, where a large share of experienced linemen are near retirement and apprenticeship pipelines can't keep pace.[6]
• Fixed-price execution risk — overruns hit the contractor, not the customer — plus input-cost inflation, equipment lead times (notably large transformers on the power side), and cash-conversion strain on smaller firms.[4][5][6]
• Permitting, interconnection, and siting delays push awarded work into later periods across all three, and are the biggest external bottleneck for oil & gas and power.[5][6]

10. How to invest and the outlook

The playbook. Start with exposure, not the ticker. For any listed name, ask how much revenue is genuinely utility construction, whether it is self-performed field work versus design/engineering/products/utility rate recovery, and what its backlog quality, contract-type mix, margin history, cash conversion, and bonding capacity look like (backlog is not reported on a standard basis, so don't compare it mechanically across companies).[6]

• Public — one-ticker theme exposure: the diversified span-the-group contractors (PWR, MTZ, PRIM), which capture power, pipeline, and/or water at once.[5][6] Segment plays: DY (fiber), MYRG (electric T&D), CTRI/IESC (utility services). Cleaner "theme" tilts via products/utilities (CNM, MWA, XYL; AWK, WTRG), and broad infrastructure or water exchange-traded funds (ETFs — baskets that trade like a single share; e.g., PAVE for infrastructure, PHO/FIW/CGW for water — check current holdings).[4][6]
• Private: most of the industry is private. Reach it through private-equity and infrastructure funds, platform/add-on acquisitions, private credit, equipment financing — and, for the water segment specifically, the municipal bonds that fund the projects.[4][5][6]

Outlook. Rarely have all three utility grids been in a heavy build-out at the same time. The power/communication child is riding the strongest and most durable tailwind (load growth, the $1.3–1.4 trillion utility super-cycle, fiber); water offers the longest, partly mandated replacement visibility but is gated by public budgets; oil & gas has a favorable near-term volume outlook that is more cyclical and carries the long-run transition question.[7][8][9][10] Across all three, the demand backdrop is not the swing factor — conversion is. Whether this super-cycle turns into profit will hinge on skilled labor, permitting and interconnection, materials and equipment lead times, fixed-price discipline, and cash collection far more than on demand. The tailwind is real and multi-year; the cleanest way to own it is a diversified contractor with proven execution, and the winners will be separated from the losers on the ground, not on the order book. For full company detail, contract mechanics, and diligence checklists, see the three child primers (237110, 237120, 237130).

---

Sources

1. U.S. Census Bureau, 2022 NAICS Definitions — Industry Group 2371 "Utility System Construction" and its three national industries (237110 water & sewer, 237120 oil & gas pipeline, 237130 power & communication line); cross-references to owner codes 2211, 486, and subsector 517. https://www.census.gov/naics/?year=2022&details=2371
2. U.S. Census Bureau, 2022 Economic Census — Concentration of Largest Firms (EC2200SIZECONCEN), NAICS 2371: receipts $203.855B, 17,649 firms, CR4 11.7%, CR8 18.3%, CR20 29.4%, CR50 37.5%, HHI 63.1. (Histometrics ground-truth federal statistics extract.) https://data.census.gov/table/ECNSIZE2022.EC2200SIZECONCEN
3. U.S. Census Bureau, County Business Patterns 2023, NAICS 2371: 20,109 establishments, 627,151 employees, $54.675B annual payroll, $12.897B first-quarter payroll. (Histometrics ground-truth federal statistics extract.) https://www.census.gov/programs-surveys/cbp.html
4. Histometrics child primer — NAICS 237110 / 23711, Water and Sewer Line and Related Structures Construction (receipts $56.9B; 10,380 firms; CR4 4.2%, HHI ~11; EPA ~$1.25T 20-year need; lead-service-line and PFAS drivers; investable universe and private/PE roll-up detail).
5. Histometrics child primer — NAICS 237120 / 23712, Oil and Gas Pipeline and Related Structures Construction (receipts $44.07B; 1,790 firms; CR4 21.6%, HHI 173.6; Quanta ~5.7% pipeline operating margin; Keystone XL and Mountain Valley Pipeline case studies; private megaproject builders).
6. Histometrics child primer — NAICS 237130 / 23713, Power and Communication Line and Related Structures Construction (receipts $102.9B; 5,526 firms; CR4 19.2%, HHI 156.2; utility capex super-cycle; BEAD fiber; linemen-shortage risk; full listed-contractor menu).
7. U.S. Environmental Protection Agency, drinking-water and clean-water infrastructure needs surveys (combined ~$1.25 trillion 20-year capital need), as cited in the 237110 primer.
8. U.S. Energy Information Administration, "Most planned natural gas pipeline capacity additions in 2026 and 2027 originate in Texas" (~44.9 Bcf/d, ~70% under construction), 2026, as cited in the 237120 primer. https://www.eia.gov/todayinenergy/detail.php?id=67707
9. S&P Global Market Intelligence, "Surging Energy Demand Puts US Utility Capex Forecast Near $1.3T in 2026–30," 2026, as cited in the 237130 primer.
10. Edison Electric Institute / Electric Perspectives, "Electric Companies to Invest $1.4T," 2026, as cited in the 237130 primer.
11. National Telecommunications and Information Administration, "Broadband Equity, Access, and Deployment (BEAD) Program ($42.45B)," 2025, as cited in the 237130 primer. https://broadbandusa.ntia.doc.gov/funding-programs/broadband-equity-access-and-deployment-bead-program

Company-, funding-, and regulation-level citations are carried in full by the three child primers (237110, 237120, 237130); this rollup cites the federal figures specific to the 2371 level plus the cross-child themes it synthesizes.