All Other Pipeline Transportation (U.S.) — NAICS 48699

A Histometrics rollup primer for public- and private-market investors

Read this first — this is a single-child pass-through page. In the North American Industry Classification System (NAICS), the five-digit industry 48699 — All Other Pipeline Transportation contains exactly one six-digit national industry, 486990 (also "All Other Pipeline Transportation"). The two levels are, for practical purposes, the same thing: every firm, every mile of pipe, and every dollar of revenue counted at 48699 is counted at 486990. This page gives the level's own federal statistics and orients you; for the full treatment — the CO₂-pipeline network, the carbon-capture growth story, the company-by-company investable universe, the regulation, and the risks — see the child primer, NAICS 486990.

1. Overview

"All Other Pipeline Transportation" is the residual bucket of the U.S. pipeline sector: pipelines that move something other than crude oil, natural gas, or refined petroleum products. In practice that means carbon-dioxide (CO₂) pipelines (the dominant use by mileage and asset value), plus a small anhydrous-ammonia (fertilizer) network, and legacy or defunct coal-slurry and brine lines.[1]

Measured as a standalone industry it is tiny in headcount but strategically outsized: a roughly 5,300-mile CO₂ network already feeds carbon dioxide into aging oil fields to squeeze out more crude — a stable, toll-road-style cash machine — and on top of it sits a high-risk, high-reward build-out of new CO₂ pipelines for carbon capture and storage (CCS), driven by the federal Section 45Q tax credit and throttled by permitting and landowner fights rather than by money or technology.[6][8] There is no pure-play public company in this category; exposure comes bundled inside diversified energy, midstream, and industrial-gas firms, while the frontier CCS action lives in private markets. All of that detail belongs to the child primer.

2. What's inside — and why this level equals its one child

NAICS is a nested hierarchy: each five-digit NAICS industry breaks into one or more six-digit national industries. Most five-digit codes fan out into several children. This one does not — it has a single child:

When a five-digit industry has only one six-digit child, the U.S. Census Bureau defines the two to be coextensive — the child exists mainly to complete the six-digit numbering, not to carve the parent into pieces. So 48699 is 486990: the same establishments, the same firms, the same receipts. There is nothing at this level that the child does not already contain, which is why the rest of this page is short and points you downward.

Scope reminder (what falls in here): CO₂ pipelines, anhydrous-ammonia (fertilizer) lines, coal-slurry and other slurry lines, and brine.[1] What is excluded — and where most "pipeline" money actually sits: crude-oil pipelines (NAICS 486110), natural-gas pipeline transportation (486210), and refined-petroleum-product pipelines including liquefied petroleum gas / LPG (486910). Two products people loosely call "other pipelines" — natural gas liquids (NGLs) and hydrogen — mostly land in those other codes, not here, which is a big reason the federal numbers below look so small. The child primer walks through these boundary cases in detail.

3. Size (this level's rollup figures)

Because 48699 equals its one child, this level's federal statistics are the 486990 statistics. The figures below are our ingested ground-truth numbers for NAICS 48699. They combine two reference years and are not a single-year financial statement.

CR4/CR8 are the shares of revenue held by the largest four/eight firms. The market-concentration index — the Herfindahl-Hirschman Index (HHI) — is suppressed in the federal data (too few firms to publish without disclosing individual companies), so no HHI value is stated here. The concentration ratios tell the story regardless: four firms account for roughly 90% of reported revenue, and the top twenty account for all of it.[3] For reference, the U.S. Small Business Administration's small-business size standard for this industry is $46.0 million in average annual receipts.[4]

Undercount caveat — read before using these figures. The statistics badly understate the economic weight of "other" pipeline transportation, and the reasons all point back to how this category is measured. First, pipelines are capital-heavy and labor-light: a ~5,300-mile CO₂ network worth billions in steel-in-the-ground can be run by a couple hundred people, so headcount and payroll say little about scale.[2][6] Second, most CO₂-pipeline mileage is owned by diversified companies (ExxonMobil, Kinder Morgan, Occidental) whose primary federal classification sits elsewhere — oil-and-gas extraction, crude pipelines, refining — so their CO₂ activity is not captured under 486990/48699 at all. Third, much CO₂ is sold as a commodity to oil-field operators rather than booked as a transportation service, so that revenue lands in other line items. And fourth, County Business Patterns excludes non-employer and self-employed operators and most government facilities, so captive industrial lines and tiny operators drop out.[5] Treat the $374 million receipts figure as the floor of a residual bucket, not the size of the U.S. CO₂-transport economy. (Because ownership is so concentrated in a handful of individual companies, the small-operator undercount is modest here; the bigger distortion is the mis-classification of the majors.)

4. Investable universe — where value concentrates

With only one child, there is no "which sub-industry" allocation question at this level: all of the value sits in the single 486990 bucket, and within it, in CO₂ pipelines. There is no listed pure-play — the former closest thing, Denbury Inc., was acquired by ExxonMobil in 2023 — so public exposure comes as a small segment inside diversified majors and midstream operators, and dedicated new-build exposure lives in private markets. The child primer lays out the full company-by-company map (CO₂ incumbents, adjacent NGL/hydrogen operators, and private CCS developers) with tickers and roles; that detail is not repeated here.

5. How the money works

The economics are those of contracted, toll-road-style infrastructure — heavy upfront capital, then low operating cost and long-lived, fee-based cash flow — not a regulated-utility rate base, a real-estate cash-flow model, or a mining-cost model. Owners earn through transportation tariffs (a volumetric toll), reserved-capacity / take-or-pay commitments that make the cash flow durable, and — for the CO₂ incumbents specifically — CO₂ commodity sales and their own enhanced-oil-recovery production, which add real oil-price sensitivity. For new-build CCS projects the swing variable is not oil price but policy (45Q) and the ability to actually permit and build the route. The child primer works through the metrics that matter (throughput/utilization, contract coverage and tenor, customer concentration, tariff per unit, capex per mile).

6. Demand drivers

Demand at this level is the demand for its one child: chiefly oil-field enhanced oil recovery (EOR), which rises and falls with oil prices; the 45Q tax credit, which a 2025 law lifted to $85 per metric ton for EOR/utilization (to parity with permanent storage), materially improving CO₂-throughput economics; industrial carbon capture at ethanol, fertilizer, and gas-processing plants; depleting natural CO₂ domes that push the industry toward captured CO₂; and low-carbon-fuel markets that make Midwest ethanol producers want CCS pipelines at all. See the child primer for the full demand analysis and figures.[8]

7. Regulation

There is no single regulator; oversight depends on the product, the route, and whether a system is interstate or intrastate — and for CO₂ the framework is unusually fragmented, which is the single biggest reason projects stall. Federal pipeline safety sits with the Pipeline and Hazardous Materials Safety Administration (PHMSA); siting and eminent domain for interstate CO₂ lines have no federal framework and are fought state by state (South Dakota banned eminent domain for carbon pipelines in 2025); permanent underground storage uses the Environmental Protection Agency's Class VI injection wells; and the 45Q credit is administered by the IRS. The child primer covers each of these, and why permitting and land access are often as decisive for investors as engineering.[8]

8. Consolidation

The measured industry is textbook-concentrated (top four ≈ 90% of reported revenue) and recently grew more so, the defining move being ExxonMobil's 2023 acquisition of Denbury — which folded the largest independent CO₂ transport-and-storage network into a supermajor.[3] At the same time, the growth frontier has seen route-attrition rather than expansion: Navigator cancelled its entire 1,300-mile Heartland Greenway in 2023, and Summit Carbon Solutions has been repeatedly forced to shrink its route. Consolidation among incumbents plus attrition among newcomers — not greenfield build-out — is the current reality. Full detail is in the child primer.

9. Risks

The risk profile at this level is exactly the child's, dominated by permitting / eminent-domain / social-license risk — state route approval and landowner opposition can kill an economically sound project. Behind it sit public-safety concerns (CO₂ is a dense, odorless asphyxiant), volume/contract risk on high-fixed-cost assets, oil-price sensitivity for the EOR-linked incumbents, policy risk around 45Q and safety rules, construction/financing risk, stranded-asset risk on purpose-built lines, and classification/disclosure risk — a very small, opaque bucket buried inside larger companies. The child primer expands each.

10. How to invest & outlook

Because 48699 is 486990, there is nothing to invest in at this level distinct from the child. Public routes are diversified majors and midstream operators where CO₂/NGL/hydrogen transport is a modest segment — start with the asset, not the ticker, and read filings for the share of revenue from these lines, throughput and contracted-versus-uncontracted capacity, customer concentration, and safety liabilities. Private routes — infrastructure-fund- and venture-backed CCS developers — are where dedicated CO₂-pipeline exposure actually lives, as illiquid, project-finance-style bets with high dispersion between winners and cancelled projects.

Outlook. The macro setup is favorable on paper — the 2025 lift of the EOR credit to $85/ton and steadily falling CO₂ transport costs improve throughput economics — but the industry's growth now turns almost entirely on non-economic gates: state siting decisions, eminent-domain law, PHMSA safety rules, and community acceptance. The reasonable base case is a stable incumbent network with slow, contested expansion of captured-CO₂ capacity. For the complete company map, regulatory detail, and forward-looking judgment, read the child primer, NAICS 486990.

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Sources

1. U.S. Census Bureau. "NAICS 486990 — All Other Pipeline Transportation" (2022 definition and illustrative examples). https://www.census.gov/naics/?details=486990&year=2022
2. U.S. Census Bureau. County Business Patterns, NAICS 486990/48699 (establishments, employment, payroll), 2023. https://www.census.gov/programs-surveys/cbp.html
3. U.S. Census Bureau. Economic Census, concentration statistics for NAICS 486990/48699 (firms, receipts, CR4/CR8/CR20/CR50), 2022. https://data.census.gov/table/ECNSIZE2022.EC2200SIZECONCEN
4. U.S. Small Business Administration. "Table of Small Business Size Standards" (NAICS 486990 = $46.0M), 2023. https://www.sba.gov/document/support-table-size-standards
5. U.S. Census Bureau. "County Business Patterns Methodology" (coverage exclusions). https://www.census.gov/programs-surveys/cbp/technical-documentation/methodology.html
6. PHMSA (U.S. DOT). "Annual Report Mileage for Hazardous Liquid or Carbon Dioxide Systems" (~5,354 miles CO₂/other, 2022). https://www.phmsa.dot.gov/data-and-statistics/pipeline/annual-report-mileage-hazardous-liquid-or-carbon-dioxide-systems
7. Oil & Gas Journal / ExxonMobil. "ExxonMobil acquires Denbury" (announced July 2023, closed Nov. 2023, ~$4.9B; largest U.S. CO₂ network). 2023. https://www.ogj.com/general-interest/companies/article/14296369/exxonmobil-acquires-denbury
8. Congressional Research Service. "Carbon Dioxide (CO2) Pipelines: Safety, Siting, and Eminent Domain" (IN12575), 2025. https://www.congress.gov/crs-product/IN12575

Full sourcing for the underlying analysis — company filings, 45Q legislation, PHMSA safety actions, and the state-by-state permitting record — is in the child primer, NAICS 486990.