Totalizing Fluid Meter and Counting Device Manufacturing (U.S.)

NAICS 2022 code 334514 — an investor's primer

1. Overview

This is the industry that makes the meters your water and gas utility reads to bill you — plus a grab-bag of related counting devices like parking meters, taxi meters, transit fare boxes, and vehicle dashboard gauges. In plain terms: devices that measure and register (total up) how much fluid has flowed, or how many of something has passed.[4]

Why an investor should care: this is a small manufacturing niche — roughly $5.3 billion of U.S. factory shipments in 2022 and about 11,900 workers[1][2] — but it sits at the center of a large, policy-driven upgrade cycle. Utilities across the country are swapping tens of millions of old mechanical meters for "smart" meters that report readings wirelessly, and each new endpoint pulls along recurring software and communications revenue for decades. The demand is unusually steady because it is driven by regulated utility budgets and mandated replacement schedules, not the consumer economy.

Public vs. private ways in. There is one clean public pure-play — Badger Meter — and one broad public metering specialist, Itron. Beyond those, most of the biggest names are divisions of large diversified public companies (Roper Technologies owns Neptune; Xylem owns Sensus; Hubbell owns Aclara; Honeywell owns Elster), so buying the "industry" often means buying a conglomerate. Several other leaders (Diehl Metering, Kamstrup, Master Meter) are privately held. Details in Section 4.

2. What it is and how it's structured

Scope. The U.S. Census Bureau defines NAICS 334514 as establishments that manufacture totalizing fluid meters and counting devices — mechanical, electromechanical, and electronic. The common functional thread is accumulated measurement: gallons or cubic feet consumed, miles traveled, elapsed parking time, fares or passengers counted — rather than merely an instantaneous flow rate. Typical products: water consumption meters, gas consumption meters, parking meters, taxi meters, fare-collection equipment, impeller- and counter-driven flow meters, and motor-vehicle gauges (speedometers, tachometers, oil-pressure and water-temperature gauges).[4] (NAICS stands for the North American Industry Classification System, the government's standard scheme for grouping businesses.)

Census classifies establishments, not consolidated companies, so a diversified manufacturer can have only some plants counted in 334514. This distinction makes many commercial "totalizing fluid meter market" estimates incomparable with the official industry figures.

What it excludes — this matters, because a lot of what people loosely call "metering" is not in this code:

• Electricity meters are classified in NAICS 334515 (instruments for measuring and testing electricity and electrical signals), not here.[5] So Itron's electric meters and Landis+Gyr's business sit outside 334514 even though water and gas meters sit inside it.

• Industrial process instruments — pressure gauges, controllers, and flow devices that measure and control industrial process variables — are in NAICS 334513.[5]

• Other measuring and controlling devices not elsewhere classified fall into the catch-all NAICS 334519.[5]

• AMI network software, data platforms, and communications services are counted as software and services, not manufacturing — an important reason the factory-shipment figure understates the real business (see Section 3).

Product evolution. A conventional fluid meter uses displacement, turbine, or other mechanical motion to turn a register. Newer static meters use ultrasonic or electromagnetic sensing, with fewer moving parts. "Smart" products add a digital register, radio or cellular endpoint, battery, communications network, meter-data-management software, analytics, and a customer portal. EPA describes water AMI as smart meters plus communications and data-management tools that automatically collect, transmit, and analyze usage data in near real time.[21]

Production inputs. Manufacturing combines metal or polymer meter bodies, precision measurement elements, seals, registers, printed circuit boards, microprocessors, radios, and batteries, followed by calibration, environmental testing, and certification. Badger Meter, for example, identifies castings made from brass, aluminum, stainless steel, cast iron, and bismuth, along with plastic resin, glass, microprocessors, and electronic subassemblies as principal inputs, and relies on single suppliers for some brass castings, resins, and electronic subassemblies.[6]

Ownership mix. The federal data count 163 firms operating 156 establishments[1][2] — a "big fish, many minnows" structure. A handful of large plants (many of them subsidiaries of multibillion-dollar public companies) dominate output, while dozens of small specialist shops make up a long tail. Ownership is overwhelmingly corporate, not government or sole-proprietor; there is no meaningful cottage-industry or public-sector-operator distortion here.

Sales model. Large utility projects are usually sold through specifications, competitive tenders, and multi-year deployment schedules. Major utilities are served directly; smaller utilities often buy through distributors, representatives, and systems integrators. Itron describes a mix of internal and outsourced manufacture and uses direct sales for large utilities but distributors, agents, and partners for smaller systems; its backlog can move materially with the timing of large project awards, component availability, and customer rescheduling.[7]

3. How big it is

From our federal figures (the ground truth for this primer):

That works out to average pay of roughly $82,000 per worker and about $443,000 of shipments per worker[1][2] — a moderately capital- and technology-intensive manufacturing profile, not a low-wage assembly business.

Concentration. The four largest firms account for 32.3% of receipts, the top eight for 49.4%, the top 20 for 73.9%, and the top 50 for 93.2%.[2] Yet the Herfindahl-Hirschman Index (HHI — a standard concentration gauge that squares each firm's market share and sums them) is just 422.6[2], well below the 1,500 the U.S. Department of Justice treats as the start of "moderate concentration." The apparent contradiction is the point: a few leaders hold about half the market, but none is individually dominant, and a large tail of small firms drags the HHI down.

The undercount caveat — read this. The $5.3 billion figure is domestic factory shipments of hardware only, and it materially understates the economic reality of this industry for three reasons:

1. Software and services are booked elsewhere. The value of a modern smart-meter deployment is increasingly in the network, the software subscription, and the data analytics — revenue that lands in software/services line items, not in this manufacturing code. Independent market trackers put the North American water-metering market well above the hardware-shipment figure once these are included.[11][13]

2. Imports aren't in it. Meters made abroad (Germany's Diehl and Kamstrup, Chinese suppliers) and sold into the U.S. don't appear in domestic shipments; some U.S. output is also exported.

3. Most output is embedded in conglomerates. Because Neptune, Sensus, Aclara, and Elster are segments of Roper, Xylem, Hubbell, and Honeywell, the industry's true scale and profitability are hard to see in standalone terms — the plants are counted here, but the franchise value shows up in parent-company financials.

4. The investable universe

There is no U.S. pure-play counting-device stock, and no dedicated ETF (exchange-traded fund) for this NAICS code. Exposure comes through water-technology and utility-hardware names. The cleanest plays are Badger Meter and Itron; the rest carry meaningful metering operations inside a larger company.

Public companies with meaningful exposure

Scale figures are revenue unless noted; market caps are approximate mid-2026 values and move with share prices.[18]

Major private and foreign owners

• Diehl Metering (Germany) and Kamstrup (Denmark) — large privately held water/heat-metering makers active in the U.S.[12]

• Master Meter, Metron-Farnier — U.S. privately held water-meter specialists.

• Sensus International — Xylem's non-North-American metering unit, sold to private-equity firm AURELIUS in 2025 (Xylem kept the North American Sensus business).[10]

• IPS Group and Flowbird — privately held makers of smart parking meters (the "counting device" corner of the code).

5. How the money works

Owners in this industry make money in three layers, and the mix is shifting in a way that favors the leaders.

Layer 1 — the meter (hardware). A utility buys a physical meter that must be accurate, tamper- resistant, and long-lived (residential water meters last 15–20 years). Historically this was a low-margin, commoditized hardware sale competed largely on price. Key hardware economics: input costs (brass and copper for water meters, electronics and — critically — long-life lithium batteries that must run 15–20 years without a service call), capacity utilization at a small number of plants, and backlog, because large utility rollouts are booked as multi-year orders (Itron reported a backlog of roughly $4.7 billion entering 2025[7]).

Layer 2 — the radio and the network (AMI/AMR). Adding a communications endpoint turns a dumb meter into a smart one. AMR (automatic meter reading) lets a truck drive by and collect readings; AMI (advanced metering infrastructure) sends readings continuously over a fixed radio-frequency (RF) network or a cellular link (NB-IoT / LTE-M — low-power cellular standards for the Internet of Things, or IoT). This layer commands higher prices and creates switching costs, because once a utility standardizes on a vendor's network it is expensive to change.

Layer 3 — software and data (recurring). The most valuable and fastest-growing layer: billing integration, leak-detection analytics, pressure and water-quality monitoring, and customer portals, increasingly sold as software-as-a-service (SaaS) subscriptions or "network-as-a-service." This is the classic razor-and-blades model — sell the endpoint, then earn recurring revenue off the installed base for years — and it is why the leaders are steadily lifting margins. The segment-level economics are visible at Itron: Device Solutions gross margin was 31.2% in 2025, compared with 39.1% for Networked Solutions and 39.6% for Outcomes (analytics and managed services); company-wide gross and operating margins were 37.7% and 13.2%, respectively.[7]

Badger Meter shows the economics of a more water-focused franchise. On $916.7 million of 2025 sales it reported gross profit of ~$382 million and operating earnings of ~$183 million, equivalent to gross and operating margins of approximately 41.7% and 20.0% — well above a typical metal-bending manufacturer, precisely because software, monitoring, and recurring revenue are a rising share of the mix.[6]

Profitability moves with product mix, factory utilization, pricing, commodities, semiconductor availability, project timing, and the ratio of hardware to software. Xylem's Measurement and Control Solutions segment illustrates the volatility: its 2025 operating margin was 11.7%, down from 13.2% in 2024, with management attributing pressure to unfavorable mix, inflation, strategic investment, and acquired-intangible amortization, partly offset by productivity, price, and volume.[8]

Why it's less cyclical than most manufacturing. Demand is anchored to (a) regulated utility capital budgets and (b) a mandatory replacement clock — mechanical meters lose accuracy as they age, and an inaccurate meter is lost revenue for the utility, so meters get replaced on a schedule almost regardless of the broader economy. Municipal water demand is less economically sensitive than automotive or industrial capital equipment, though it is not fully noncyclical — utilities can defer replacements and AMI conversions when rates, debt capacity, or grant funding are constrained. The main volatility is project timing (a big city rollout can slip a quarter or two) rather than end-demand collapse.

6. What drives demand

• The AMR/AMI upgrade cycle. At the end of 2022, North America had roughly 86.5 million active water endpoints with automated reading (~75% of meters), but only about 38 million were the more advanced AMI type — roughly one-third AMI penetration.[14] The multi-year migration from mechanical/AMR to smart cellular AMI is the single biggest growth lever, and analysts project the AMI water segment growing at a high-single-to-double-digit annual rate through the early 2030s.[13] (For comparison, U.S. electric AMI installations reached 140.5 million in 2024 while one-way electric AMR fell to 19.3 million[24] — but electric meters are classified in NAICS 334515, not here.)

• Aging infrastructure and non-revenue water. Much of the U.S. water grid is 40–80 years old. Utilities lose large volumes to leaks and under-registering meters ("non-revenue water"); smart meters and network sensors find those losses, which pays for the upgrade.[11] EPA's latest assessment identifies $625 billion of U.S. drinking-water infrastructure need over 20 years, including $422.9 billion for distribution and transmission — of which metering upgrades are one component.[22]

• Water scarcity and conservation, especially across the drought-prone West, where per-customer usage data supports conservation pricing and drought response.

• Labor savings — automated reads eliminate manual meter-reading routes.

• Federal and state funding. The 2021 Bipartisan Infrastructure Law (also called the Infrastructure Investment and Jobs Act) directs more than $50 billion through the EPA (Environmental Protection Agency), largely via State Revolving Funds — including $15 billion earmarked for lead service-line replacement, work that frequently triggers meter upgrades at the same time.[15] Separately, USDA's Water and Waste Disposal program provides ongoing financing for rural drinking-water and wastewater systems in communities that often cannot obtain reasonable commercial credit.[23]

• Regulatory mandates on meter accuracy and lead-free materials (Section 7).

• Gas and parking niches. Gas metering demand is driven by safety and remote shut-off features; parking/transit demand by the shift to cashless, dynamically priced systems.

7. Regulation

This is a standards-and-certification business more than a heavily licensed one, but the barriers are real and act as a moat.

• Lead-free materials (federal). Under the Safe Drinking Water Act (SDWA), wetted components of drinking-water meters must be effectively lead-free — no more than a 0.25% weighted average across wetted surfaces — and uncertified plumbing products may not be used for potable water.[27] Compliance is verified to NSF/ANSI/CAN 61 (material safety and leaching) and NSF/ANSI/CAN 372 (lead content).[16][28]

• Performance standards. Water meters are built to AWWA (American Water Works Association) C700-series standards for accuracy, pressure, and durability.[16] NIST Handbook 44 (current edition 2026) supplies specifications and tolerances for commercial liquid-measuring devices, vehicle-tank meters, gas-vapor meters, water meters, mass-flow meters, odometers, taximeters, and timing devices; enforcement is generally through state weights-and-measures regimes.[26]

• Weights-and-measures certification. Because meters are used for commercial billing, they need accuracy certification under the NTEP (National Type Evaluation Program), run through the National Conference on Weights and Measures with NIST (National Institute of Standards and Technology), plus state weights-and-measures approval.[17]

• Gas meters follow ANSI B109-series accuracy standards.

• Radio spectrum. Wireless endpoints must meet FCC (Federal Communications Commission) rules for licensed or unlicensed radio operation.

• Domestic-content rules (BABA). The Build America, Buy America Act (BABA) ordinarily requires federally assisted manufactured products to be made in the United States with domestic components exceeding 55% of component cost. EPA found that an AMI water-meter system can contain upwards of 50 components and that transmitters, circuit boards, electronics, batteries, and endpoints were particularly difficult to source domestically.[27] As a result, EPA and Interior issued an AMI water-meter nonavailability waiver running from December 20, 2024 through December 19, 2027, because fully compliant supply was not available.[27] That waiver reduces near-term project friction but also shows the industry's dependence on foreign electronics and the risk of later localization costs.

• Cybersecurity and data privacy. As meters join utility networks, AMI systems face growing scrutiny over network security and customer-usage data. GAO reports that increasingly connected operational technology has expanded water-sector cyber exposure and identifies incomplete risk- assessment requirements across some systems.[28] In AWWA's 2025 survey of 3,575 water professionals, 73% rated cybersecurity very to critically important.[25]

• Trade policy. Tariffs on imported components and finished meters (including Section 301 duties on Chinese goods) and on metals like brass affect input costs; to date the largest U.S. players have reported the impact as manageable but a live watch-item.[18]

Note that the end customers — water and gas utilities — are themselves regulated by state public utility commissions (PUCs), which must approve rate recovery of metering investments. That approval process shapes the pace and size of orders. In AWWA's 2025 survey, financing capital improvements ranked as the leading challenge for water professionals.[25]

8. Competitive dynamics and consolidation

The industry has been reshaped by two forces. First, roll-up by diversified industrials: Roper acquired Neptune, Xylem acquired Sensus, Hubbell acquired Aclara, and Honeywell owns Elster — each folding a metering brand into a larger platform.[9][10] Second, a shift from hardware to platform, where competition is moving away from meter unit price toward lifecycle value: integrated analytics, subscription software, and networks that can be upgraded by firmware rather than by sending a truck. Vendors now stress firmware-upgradable endpoints and software-defined radios specifically to protect utilities' investments from protocol obsolescence — and to lock in the installed base.[11]

Once installed, meter bodies, registers, endpoints, network protocols, and software create switching costs. A utility may be nominally "meter agnostic," but interoperability, retraining, spare-parts inventories, billing integration, and radio coverage favor incumbent vendors. An EPA case study of a utility with 45,000 AMI radios illustrates both the scale of a deployment and the continued coexistence of Neptune, Badger, and Sensus meters within one system.[21]

Badger Meter has been the most visible consolidator on the technology side, using acquisitions (s::can water-quality monitoring; SmartCover sewer/collection-network monitoring) to extend from metering into broader distribution-network intelligence — repositioning itself as a data provider, not just a meter maker.[11]

The competitive moats are durable: certification requirements, entrenched utility relationships, long replacement cycles that reward incumbents, and switching costs once a network is installed. The main competitive threats are foreign meter makers (Diehl, Kamstrup) winning open tenders on price, and the ever-present risk that a rival's network technology leapfrogs an incumbent's.

9. Risks

• Lumpy project timing. Revenue can swing with the start/stop of large municipal rollouts and utility budget cycles; a delayed city contract dents a quarter.

• Municipal finance and interest rates. Utilities fund meter programs with budgets and municipal borrowing; higher rates or tight budgets can slow orders.

• Input costs and supply chain. Copper/brass prices, semiconductor availability, and — uniquely here — long-life battery supply (a 20-year battery is a hard engineering and sourcing problem) all hit margins. Tariffs add uncertainty.[18]

• Technology/protocol obsolescence. A utility or vendor that bets on the wrong communications standard can strand a large network investment; this fear both drives and slows purchases.

• Cybersecurity. A breach of an AMI network is a reputational and operational risk for vendors and utilities alike. GAO has flagged incomplete risk-assessment requirements in some water systems.[28]

• Margin compression on hardware from foreign and low-cost competition, partly offset by the software mix shift.

• Concentration on regulated utility capex — a single end-market. A pullback in water/gas utility spending has no consumer offset.

• Dependence on federal funding continuity — a wind-down of infrastructure-law money could soften a tailwind (though the replacement cycle persists regardless).

• BABA localization risk. The current AMI water-meter waiver expires December 2027; if domestic supply cannot scale by then, federally funded projects face sourcing constraints or vendors face new localization costs.[27]

10. How to invest, and the outlook

Public-market routes.

• Pure-play: Badger Meter (BMI) is the cleanest listed exposure to smart water metering and the software mix-shift — but it typically trades at a premium valuation, so the growth is not cheap.[6][18]

• Broad metering specialist: Itron (ITRI) spans water, gas, and electric meters plus grid-edge networks; more diversified, more tied to electric-utility spending, and historically more volatile in execution.[7]

• Diversified owners: Xylem (XYL), Roper (ROP), Hubbell (HUBB), Honeywell (HON), and Mueller Water Products (MWA) give indirect, diluted exposure inside larger businesses — useful if you want the theme with less single-niche risk.[8][9][19]

• Funds: there is no meter-specific ETF, but broad water ETFs (for example Invesco Water Resources, First Trust Water, Invesco S&P Global Water) hold Xylem, Badger Meter, and Mueller among their top constituents, offering thematic exposure with diversification.

Private-market routes. Much of the industry is not publicly investable: Diehl, Kamstrup, and Master Meter are private, and Sensus's international arm went to private equity (AURELIUS) in 2025 — illustrating that private equity and strategic acquirers, not public listings, are how many of these assets change hands.[10][12] Private-market exposure is available through specialty meter manufacturers, register and endpoint suppliers, utility distributors, installation contractors, AMI systems integrators, meter-data-management software, and leak-detection platforms. The most attractive targets generally combine certified hardware and installed-base access with recurring software or service revenue. Diligence should separate true recurring revenue from deployment-period maintenance, test protocol openness and interoperability, quantify sole-source electronics and battery exposure, examine BABA compliance after the current waiver expires, and map revenue by water, gas, automotive, and counting-device application.

Outlook (forward-looking judgment). The structural setup is favorable. With AMI penetration in U.S. water still only around one-third[14], there is a long runway to convert the remaining mechanical and drive-by meters to smart cellular endpoints, and each conversion seeds recurring software revenue. Federal infrastructure funding, lead-line replacement work, drought pressure, and aging pipes all reinforce the replacement cycle, and the ongoing shift from hardware to subscription software should keep lifting margins for the leaders. The near-term swing factors to watch are project timing and utility budgets, copper and battery input costs, tariff developments, BABA waiver expiration, and the pace at which federal water money actually reaches local systems. Net: a small, unglamorous manufacturing niche with utility-grade demand stability and a genuine, multi-year digital-upgrade tailwind — attractive for investors who prize durability over excitement, with valuation (for the pure-plays) the main thing to get right.

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Sources

1. U.S. Census Bureau. County Business Patterns 2023, NAICS 334514 (establishments, employment, annual and first-quarter payroll). https://www.census.gov/programs-surveys/cbp.html

2. U.S. Census Bureau. 2022 Economic Census — Concentration by Largest Firms, NAICS 334514 (receipts, firm count, CR4/CR8/CR20/CR50, HHI). https://www.census.gov/programs-surveys/economic-census.html

3. U.S. Small Business Administration. Table of Small Business Size Standards, NAICS 334514 (2023). https://www.sba.gov/document/support-table-size-standards

4. U.S. Census Bureau / NAICS. 2022 NAICS Definition — 334514 Totalizing Fluid Meter and Counting Device Manufacturing (2022). https://www.census.gov/naics/?input=334514&year=2022

5. IBISWorld / U.S. Census Bureau. NAICS 334513, 334515, and 334519 definitions (industry boundaries and exclusions) (2022). https://www.ibisworld.com/classifications/naics/334515/

6. U.S. Securities and Exchange Commission. Badger Meter, Inc. Form 10-K, FY 2025 (2026). https://www.sec.gov/Archives/edgar/data/9092/000119312526054739/bmi-20251231.htm

7. U.S. Securities and Exchange Commission. Itron, Inc. Form 10-K, FY 2025 (2026). https://www.sec.gov/Archives/edgar/data/780571/000078057126000033/itri-20251231.htm

8. U.S. Securities and Exchange Commission. Xylem Inc. Form 10-K, FY 2025 (2026). https://www.sec.gov/Archives/edgar/data/1524472/000152447226000012/xyl-20251231.htm

9. U.S. Securities and Exchange Commission. Roper Technologies, Inc. Form 10-K, FY 2025 (2026). https://www.sec.gov/Archives/edgar/data/882835/000088283526000009/rop-20251231.htm

10. Xylem Inc. / AURELIUS. Xylem Announces Sale of Metering Assets Outside North America; retains North American Sensus (2025). https://www.xylem.com/en-us/about-xylem/newsroom/press-releases/xylem-announces-sale-of-metering-assets-outside-north-america/

11. Mordor Intelligence. United States Water Meter Market — Size, Companies, Consolidation (2025). https://www.mordorintelligence.com/industry-reports/united-states-water-meter-market

12. MarketsandMarkets / GlobeNewswire. Smart Water Metering Market — key players (Badger, Sensus/Xylem, Itron, Diehl, Kamstrup) (2025). https://www.marketsandmarkets.com/ResearchInsight/smart-water-metering-market.asp

13. GMInsights. AMI Water Meter Market Statistics, 2025–2034 (market size and growth) (2025). https://www.gminsights.com/industry-analysis/ami-water-meter-market

14. Berg Insight (via Mordor Intelligence). North American water metering endpoints — ~86.5M active AMR/AMI endpoints, ~38M AMI (~33% AMI penetration), end-2022 (2023). https://www.mordorintelligence.com/industry-reports/united-states-water-meter-market

15. U.S. Environmental Protection Agency. Water Infrastructure Investments / Bipartisan Infrastructure Law — $50B+ to EPA, $15B lead service lines (2022–2023). https://www.epa.gov/infrastructure/water-infrastructure-investments

16. NSF International / AWWA. NSF/ANSI 61, NSF/ANSI 372 lead-free certification and AWWA water-meter standards under the Safe Drinking Water Act. https://info.nsf.org/Certified/PwsComponents/

17. National Conference on Weights and Measures. National Type Evaluation Program (NTEP) — accuracy certification for commercial meters. https://www.ncwm.com/ntep

18. companiesmarketcap.com. Badger Meter (BMI) and Itron (ITRI) market capitalization and revenue, mid-2026. https://companiesmarketcap.com/badger-meter/marketcap/

19. Mueller Water Products, Inc. Mueller Systems metering and Mi.Net AMI. (2024). https://www.muellerwaterproducts.com/water-technology/metering

20. Honeywell International Inc. Honeywell Elster gas metering products. (2025). https://process.honeywell.com/us/en/site/elster-instromet

21. U.S. Environmental Protection Agency. WaterSense Advanced Metering Infrastructure Webinar (2026). https://www.epa.gov/system/files/documents/2026-02/watersense_webinar_ami_jan_28_2026_0.pdf

22. U.S. Environmental Protection Agency. Seventh Drinking Water Infrastructure Needs Survey and Assessment — $625B need over 20 years (2023). https://www.epa.gov/dwsrf/epas-7th-drinking-water-infrastructure-needs-survey-and-assessment

23. U.S. Department of Agriculture. Water and Waste Disposal Loan and Grant Program. https://www.rd.usda.gov/programs-services/water-environmental-programs/water-waste-disposal-loan-grant-program

24. U.S. Energy Information Administration. Electric Power Annual, Table 10.05 (electric AMI/AMR installations, 2024). https://www.eia.gov/electricity/annual/table.php?t=epa_10_05.html

25. American Water Works Association. 2025 State of the Water Industry (capital funding challenges, cybersecurity priorities). https://www.awwa.org/AWWA-Articles/capital-funding-emerges-as-top-challenge-in-awwas-state-of-the-water-industry-report/

26. National Institute of Standards and Technology. Handbook 44 (2026 edition) — specifications and tolerances for commercial measuring devices. https://www.nist.gov/pml/owm/nist-handbook-44-current-edition

27. U.S. Environmental Protection Agency / U.S. Department of the Interior. AMI Water Meter Nonavailability Waiver (Dec 2024–Dec 2027) and BABA Manufacturer Guidance. https://www.epa.gov/system/files/documents/2024-12/doi-epa-joint-ami-water-meter-non-availability-waiver.pdf

28. U.S. Government Accountability Office. Water-Sector Cybersecurity Review (GAO-26-109159) (2026). https://www.gao.gov/products/gao-26-109159