Company lists · Data refreshed September 2026
Top 25 Hydrogeological consulting firms worldwide
RevenueBase identified 9,686 hydrogeological consulting firms worldwide as of September 2026 and tracks 192,692 professional contacts across them, including 72,555 with verified work emails and 38,799 with mobile numbers. The United States is the largest market and Belo Horizonte the largest hub.
This list covers hydrogeological consulting firms 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 3, 2026. Country and city lists for hydrogeological consulting firms 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 hydrogeological consulting firms worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 6,024 contacts → | ||||
Partial evidence “Terracon is a 100 percent employee-owned consulting engineering firm providing quality services to clients.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 2 | 3,183 contacts → | ||||
Indirect evidence “Golder was acquired by WSP.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 3 | 2,455 contacts → | ||||
Indirect evidence “Headquartered in Walnut Creek, Calif, Brown and Caldwell is an employee-owned firm with 2,100+ professionals serving clients locally and globally from 52 locations.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 4 | 2,392 contacts → | ||||
Partial evidence “Geosyntec is a consulting and engineering firm that works with private and public sector clients to address new ventures and complex problems involving our environment, natural…” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 5 | 2,258 contacts → | ||||
Partial evidence “SRK Consulting is an independent, international group providing specialised consultancy services.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 6 | 2,201 contacts → | ||||
Partial evidence “ECS Group of Companies is a Chantilly, VA-based consulting engineering firm.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 7 | 2,152 contacts → | ||||
Partial evidence “Civil & Environmental Consultants, Inc.(CEC) provides comprehensive market-oriented consulting services that advance the strategic business objectives of its clients.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 8 | 2,105 contacts → | ||||
Indirect evidence “As Hazen marks 75 years, we celebrate a legacy of absolute commitment to our clients while delivering the best technical work available anywhere.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 9 | 1,577 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 10 | 1,461 contacts → | ||||
Partial evidence “Freese and Nichols is a professional planning, consulting and engineering firm serving clients across the United States.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 11 | 1,415 contacts → | ||||
Indirect evidence “There is no substitute for water.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 12 | 1,175 contacts → | ||||
Indirect evidence “Miljø er vores kernekompetence og vores ansvar.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 13 | 1,146 contacts → | ||||
Indirect evidence “Who is Apex?” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 14 | 1,127 contacts → | ||||
Indirect evidence “At Verdantas, we blend engineering and environmental science together with advanced technology and world-renowned labs to create solutions with the big picture in mind.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 15 | 1,098 contacts → | ||||
Partial evidence “Barr provides engineering and environmental consulting services to clients across the Midwest, throughout the Americas, and around the world.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 16 | 988 contacts → | ||||
Indirect evidence “WSP en una empresa líder en servicios profesionales de consultoría en recursos hídricos, ingeniería, medio ambiente y sustentabilidad.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 17 | 952 contacts → | ||||
Indirect evidence “At Tonkin + Taylor, we’re dedicated to creating and sustaining a better world together.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 18 | 949 contacts → | ||||
Indirect evidence “Trinity Consultants is a global team of experts helping organizations solve complex challenges in environmental compliance, ecological protection, infrastructure performance, and…” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 19 | 894 contacts → | ||||
Indirect evidence “M.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 20 | 872 contacts → | ||||
Indirect evidence “Founded in 1964 as a soils and foundations specialty consultant, GZA GeoEnvironmental, Inc.(GZA) has grown into a full-service company providing its clients with highly…” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 21 | 870 contacts → | ||||
Partial evidence “KCB is a global engineering, geosciences, and environmental consulting firm driven by Passion, Integrity and a commitment to Excellence.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 22 | 868 contacts → | ||||
Indirect evidence “ATC Group Services LLC is now Atlas.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 23 | 807 contacts → | ||||
Partial evidence “We are Pares & Alvarez, our extensive experience and the recognition of our clients makes us one of the leading Engineering Companies in environmental, consulting, engineering and…” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 24 | 792 contacts → | ||||
Partial evidence “Dudek is an environmental, planning, and engineering consulting firm.” Source: RevenueBase Database · checked Sep 3, 2026Thanks. The Data Team will review it. | |||||
| 25 | 790 contacts → | ||||
Partial evidence “BGC Engineering is an international consulting firm that provides professional services in applied earth sciences.” Source: RevenueBase Database · checked Sep 3, 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: hydrogeological consulting firms. 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 hydrogeological consulting firms.
- Partial evidence
- Its own public description names part of hydrogeological consulting firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name hydrogeological consulting firms. 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 9,686 hydrogeological consulting firms worldwide
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Hydrogeological consulting firms worldwide at a glance
As of Sep 3, 2026Companies by employee count
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 hydrogeological consulting firms, 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
- 33 countries, largest first: the United States, Brazil, Canada, Australia, France, Germany, the United Kingdom, Italy, Chile, India and 23 more. Country and city lists for hydrogeological consulting firms are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “hydrogeological consulting firms”. 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 hydrogeological consulting firms), 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 hydrogeological consulting firms, 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, 72,555 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 between September 3, 2026 and September 14, 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.
Hydrogeological consulting firms by location
52 lists · largest firstEvery Hydrogeological consulting firms list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
- Hydrogeological consulting firms based in the United States2,065
- Hydrogeological consulting firms based in Brazil1,144
- Hydrogeological consulting firms based in Canada617
- Hydrogeological consulting firms based in Australia600
- Hydrogeological consulting firms based in France575
- Hydrogeological consulting firms based in Germany486
- Hydrogeological consulting firms based in the United Kingdom406
- Hydrogeological consulting firms based in Italy355
- Hydrogeological consulting firms based in Chile346
- Hydrogeological consulting firms based in India343
- Hydrogeological consulting firms based in Spain304
- Hydrogeological consulting firms based in Colombia254
- Hydrogeological consulting firms based in South Africa246
- Hydrogeological consulting firms based in Türkiye225
- Hydrogeological consulting firms based in Peru219
- Hydrogeological consulting firms based in the Netherlands191
- Hydrogeological consulting firms based in Switzerland148
- Hydrogeological consulting firms based in Mexico146
- Hydrogeological consulting firms based in Indonesia133
- Hydrogeological consulting firms based in Argentina129
- Hydrogeological consulting firms based in Poland82
- Hydrogeological consulting firms based in Sweden79
- Hydrogeological consulting firms based in New Zealand76
- Hydrogeological consulting firms based in Portugal74
- Hydrogeological consulting firms based in Belgium68
- Hydrogeological consulting firms based in Austria59
- Hydrogeological consulting firms based in Greece59
- Hydrogeological consulting firms based in Saudi Arabia58
- Hydrogeological consulting firms based in Norway51
- Hydrogeological consulting firms based in the United Arab Emirates44
- Hydrogeological consulting firms based in Denmark38
- Hydrogeological consulting firms based in Israel35
- Hydrogeological consulting firms based in Ireland31
Cities
- Hydrogeological consulting firms based in Belo Horizonte, Brazil155
- Hydrogeological consulting firms based in Sao Paulo, Brazil121
- Hydrogeological consulting firms based in Calgary, Canada91
- Hydrogeological consulting firms based in Houston, United States75
- Hydrogeological consulting firms based in Rio De Janeiro, Brazil59
- Hydrogeological consulting firms based in Perth, Australia56
- Hydrogeological consulting firms based in Madrid, Spain55
- Hydrogeological consulting firms based in Sydney, Australia50
- Hydrogeological consulting firms based in Curitiba, Brazil42
- Hydrogeological consulting firms based in Denver, United States37
- Hydrogeological consulting firms based in Melbourne, Australia36
- Hydrogeological consulting firms based in Johannesburg, South Africa35
- Hydrogeological consulting firms based in Porto Alegre, Brazil35
- Hydrogeological consulting firms based in Vancouver, Canada34
- Hydrogeological consulting firms based in Paris, France33
- Hydrogeological consulting firms based in Brisbane, Australia32
- Hydrogeological consulting firms based in Toronto, Canada30
- Hydrogeological consulting firms based in Edmonton, Canada26
- Hydrogeological consulting firms based in Montreal, Canada25
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 hydrogeological consulting firms, 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 hydrogeological consulting firms are there worldwide?
RevenueBase identified 9,686 hydrogeological consulting firms 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?
Terracon, headquartered in Tustin, tops this list with the largest team on record.
Which country has the most hydrogeological consulting firms?
The United States leads with 2,065 companies, followed by Brazil (1,144) and Canada (617). Every hydrogeological consulting firms list by country and city is linked on this page.
Which city has the most hydrogeological consulting firms?
Belo Horizonte leads with 157 headquartered companies, followed by Sao Paulo (120) and Lima (88).
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 72,555 verified decision-maker contacts tracked across these 9,686 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled from the company graph between September 3, 2026 and September 14, 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.