Company lists · Data refreshed September 2026
Top 25 Wastewater system design engineers worldwide
RevenueBase identified 750 wastewater system design engineers worldwide as of September 2026 and tracks 9,894 professional contacts across them, including 4,179 with verified work emails. The United States is the largest market and Tehran the largest hub.
This list covers wastewater system design engineers worldwide, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 22, 2026. Country and city lists for wastewater system design engineers follow the table.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest wastewater system design engineers worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 1,718 contacts → | ||||
Strong evidence “For more than 90 years, Carollo Engineers has been dedicated exclusively to water and wastewater solutions.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 2 | 879 contacts → | ||||
Partial evidence “MWH Treatment is a leading Design and Build non-infrastructure solution provider in the UK water sector, with a water sector heritage dating back to 1820.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 3 | 632 contacts → | ||||
Partial evidence “Since its establishment, Ward & Burke has sought to develop and adopt the ideals and aspirations to civil engineering construction and currently delivers class leading, reliable…” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 4 | 323 contacts → | ||||
Strong evidence “Since 2009, Enviro has combined engineering excellence with a commitment to sustainability in water and wastewater solutions across India." Enviro Infra Engineers Limited stands…” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 5 | 315 contacts → | ||||
Partial evidence “Tata & Howard is a 100% employee owned, award-winning, specialized consulting engineering firm dedicated to providing superior client service coupled with delivering…” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 6 | 191 contacts → | ||||
Partial evidence “HNB ENGINEERS PVT.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 7 | 147 contacts → | ||||
Strong evidence “At Atlan Stormwater, we draw on more than 45 years’ experience in the design, testing and manufacture of water treatment systems that are utilised in over 45 countries.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 8 | 137 contacts → | ||||
Partial evidence “Severn Trent Services offer a range of services to municipal and industrial clients, including the Ministry of Defence and the Coal Authority, for design, build and operation of…” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 9 | 136 contacts → | ||||
Strong evidence “RH2 is an innovative, full-service engineering firm specializing in water and wastewater related projects.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 10 | 135 contacts → | ||||
Partial evidence “Water Works Engineers is a leading civil and environmental engineering firm specializing in innovative and sustainable solutions for water infrastructure projects across the…” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 11 | 112 contacts → | ||||
Partial evidence “Over the past 45 years, GSE Construction has completed more than projects as a general engineering contractor.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 12 | 101 contacts → | ||||
Strong evidence “Today, Jones & Henry Engineers, Ltd, continues to provide high quality consulting services in water, wastewater, storm water, and civil engineering to municipalities and…” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 13 | 94 contacts → | ||||
Strong evidence “CMP Consulting Group is a multi-disciplinary Engineering firm specialising in design, project management and construction phase services for the Water Industry.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 14 | 91 contacts → | ||||
Indirect evidence “STA aiuta le Società di Gestione del Servizio Idrico e le Piccole, Medie e Grandi Industrie a progettare, costruire e gestire impianti di trattamento delle acque reflue, primarie…” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 15 | 79 contacts → | ||||
Partial evidence “The objective of A&S is to provide municipal engineering services, with focus on water districts, municipalities, and land development.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 16 | 78 contacts → | ||||
Indirect evidence “Water: It’s a human thing.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 17 | 72 contacts → | ||||
Indirect evidence “A Rotária do Brasil é uma empresa de Engenharia especializada em projetos, implantação e operação de sistemas de tratamento de efluentes/esgotos e água potável.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 18 | 57 contacts → | ||||
Partial evidence “At Right Group, our experienced team has collectively propelled us to the forefront as the leading provider of Electrical and Mechanical Engineering solutions in the water and…” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 19 | 56 contacts → | ||||
Strong evidence “Tritech is an industry leader in integrated design, project management, and construction services for water and wastewater infrastructure projects.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 20 | 54 contacts → | ||||
Strong evidence “AQUA Engineering (AQUA) is a civil engineering firm specializing in municipal engineering, water resources, water and wastewater treatment design, and environmental services.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 21 | 50 contacts → | ||||
Partial evidence “ACO Grupo Iberia now offers, together with ACO Remosa-a family-run company with a long-standing presence in the market and now part of the ACO Group-systems and services to…” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 22 | 49 contacts → | ||||
Indirect evidence “The position I hold is a one person GIS department.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 23 | 47 contacts → | ||||
Strong evidence “NCS is an experienced water and wastewater engineering consulting firm with offices in Arizona, Maryland, Nevada, New Mexico and California.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 24 | 40 contacts → | ||||
Indirect evidence “For over 90 years Bosman Watermanagement has been recognized for it's expertise in water management; including wind watermills, small pumping units, large capacity pumping…” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
| 25 | 37 contacts → | ||||
Indirect evidence “Empresa especialista en tratamiento de aguas residuales y sistemas de potabilización de agua.” Source: RevenueBase Database · checked Sep 22, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: wastewater system design engineers. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names wastewater system design engineers.
- Partial evidence
- Its own public description names part of wastewater system design engineers, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name wastewater system design engineers. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 750 wastewater system design engineers worldwide
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Wastewater system design engineers worldwide at a glance
As of Sep 22, 2026Companies by employee count
Email recency is reported on each country list linked below.
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among wastewater system design engineers, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
- Coverage
- Every country. Country and city lists for wastewater system design engineers are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “wastewater system design engineers”. Matching reads each company's description, not its industry code or its name.
- RevenueBase Smart Search
- RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names wastewater system design engineers), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
- What we exclude
- Companies whose own description does not clearly place them among wastewater system design engineers, and records with no verified work email.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every listed company carries at least one verified work email, 4,179 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 22, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
Wastewater system design engineers by location
3 lists · largest firstEvery Wastewater system design engineers list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
Frequently asked
What is RevenueBase Smart Search?
RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names wastewater system design engineers, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.
How many wastewater system design engineers are there worldwide?
RevenueBase identified 750 wastewater system design engineers worldwide as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
Carollo Engineers, headquartered in Walnut Creek, tops this list with the largest team on record.
Which country has the most wastewater system design engineers?
The United States leads with 186 companies, followed by Germany (35) and the United Kingdom (29). Every wastewater system design engineers list by country and city is linked on this page.
Which city has the most wastewater system design engineers?
Tehran leads with 19 headquartered companies, followed by Houston (6) and Pune (6).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 4,179 verified decision-maker contacts tracked across these 750 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 22, 2026.
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About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.