Company lists · Data refreshed September 2026
Top 25 Hydrogeology consultants worldwide
RevenueBase identified 14,358 hydrogeology consultants worldwide as of September 2026 and tracks 232,743 professional contacts across them, including 84,181 with verified work emails. The United States is the largest market and Belo Horizonte the largest hub.
This list covers hydrogeology consultants 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 20, 2026. Country and city lists for hydrogeology consultants 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 hydrogeology consultants worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 12,999 contacts → | ||||
Indirect evidence “Tetra Tech is the leader in water, environment and sustainable infrastructure, providing high-end technical and engineering services for projects worldwide.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 2 | 6,113 contacts → | ||||
Indirect evidence “Terracon is a 100 percent employee-owned consulting engineering firm providing quality services to clients.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 3 | 3,167 contacts → | ||||
Indirect evidence “Golder was acquired by WSP.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 4 | 2,473 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 20, 2026Thanks. The Data Team will review it. | |||||
| 5 | 2,393 contacts → | ||||
Indirect 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 20, 2026Thanks. The Data Team will review it. | |||||
| 6 | 2,259 contacts → | ||||
Partial evidence “SRK Consulting is an independent, international group providing specialised consultancy services.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 7 | 2,210 contacts → | ||||
Indirect evidence “ECS Group of Companies is a Chantilly, VA-based consulting engineering firm.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 8 | 2,177 contacts → | ||||
Indirect evidence “Langan's client-focused, highly entrepreneurial culture cultivates an environment of opportunities in which career growth and teamwork flourish.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 9 | 2,100 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 20, 2026Thanks. The Data Team will review it. | |||||
| 10 | 1,604 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 11 | 1,496 contacts → | ||||
Indirect evidence “Freese and Nichols is a professional planning, consulting and engineering firm serving clients across the United States.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 12 | 1,427 contacts → | ||||
Indirect evidence “There is no substitute for water.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 13 | 1,231 contacts → | ||||
Indirect evidence “Knight Piésold is an employee-owned, global consulting firm providing specialist services to the mining, power, water resources, and infrastructure industries.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 14 | 1,176 contacts → | ||||
Indirect evidence “Miljø er vores kernekompetence og vores ansvar.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 15 | 1,137 contacts → | ||||
Indirect evidence “Who is Apex?” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 16 | 1,088 contacts → | ||||
Indirect 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 20, 2026Thanks. The Data Team will review it. | |||||
| 17 | 1,021 contacts → | ||||
Indirect evidence “Deltares is an independent knowledge institute for applied research in the field of water and subsurface.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 18 | 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 20, 2026Thanks. The Data Team will review it. | |||||
| 19 | 958 contacts → | ||||
Indirect evidence “At Tonkin + Taylor, we’re dedicated to creating and sustaining a better world together.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 20 | 894 contacts → | ||||
Indirect evidence “M.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 21 | 880 contacts → | ||||
Partial 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 20, 2026Thanks. The Data Team will review it. | |||||
| 22 | 871 contacts → | ||||
Indirect 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 20, 2026Thanks. The Data Team will review it. | |||||
| 23 | 865 contacts → | ||||
Indirect evidence “ATC Group Services LLC is now Atlas.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 24 | 842 contacts → | ||||
Indirect evidence “Together with our strategic partners, we can address everything from supporting vulnerable customers, water quality, asset performance and leak detection, to integrated planning…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 25 | 798 contacts → | ||||
Indirect evidence “BGC Engineering is an international consulting firm that provides professional services in applied earth sciences.” Source: RevenueBase Database · checked Sep 20, 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: hydrogeology consultants. 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 hydrogeology consultants.
- Partial evidence
- Its own public description names part of hydrogeology consultants, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name hydrogeology consultants. 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 14,358 hydrogeology consultants worldwide
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Hydrogeology consultants worldwide at a glance
As of Sep 20, 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 hydrogeology consultants, 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 hydrogeology consultants are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “hydrogeology consultants”. 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 hydrogeology consultants), 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 hydrogeology consultants, 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, 84,181 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 20, 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.
Hydrogeology consultants by location
53 lists · largest firstEvery Hydrogeology consultants list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
- Hydrogeology consultants based in the United States2,906
- Hydrogeology consultants based in Brazil952
- Hydrogeology consultants based in Australia888
- Hydrogeology consultants based in Canada721
- Hydrogeology consultants based in the United Kingdom665
- Hydrogeology consultants based in France599
- Hydrogeology consultants based in Germany531
- Hydrogeology consultants based in India372
- Hydrogeology consultants based in Chile344
- Hydrogeology consultants based in Italy343
- Hydrogeology consultants based in Spain299
- Hydrogeology consultants based in South Africa265
- Hydrogeology consultants based in the Netherlands240
- Hydrogeology consultants based in Türkiye223
- Hydrogeology consultants based in Colombia217
- Hydrogeology consultants based in Peru204
- Hydrogeology consultants based in Indonesia153
- Hydrogeology consultants based in Switzerland150
- Hydrogeology consultants based in Mexico140
- Hydrogeology consultants based in New Zealand136
- Hydrogeology consultants based in Argentina122
- Hydrogeology consultants based in Poland93
- Hydrogeology consultants based in Sweden90
- Hydrogeology consultants based in Belgium81
- Hydrogeology consultants based in Portugal75
- Hydrogeology consultants based in Norway71
- Hydrogeology consultants based in Malaysia64
- Hydrogeology consultants based in Austria57
- Hydrogeology consultants based in Saudi Arabia57
- Hydrogeology consultants based in the United Arab Emirates57
- Hydrogeology consultants based in Greece56
- Hydrogeology consultants based in Denmark51
- Hydrogeology consultants based in Ireland43
- Hydrogeology consultants based in the Philippines40
- Hydrogeology consultants based in Israel27
Cities
- Hydrogeology consultants based in Belo Horizonte, Brazil147
- Hydrogeology consultants based in Houston, United States123
- Hydrogeology consultants based in Calgary, Canada114
- Hydrogeology consultants based in Sao Paulo, Brazil99
- Hydrogeology consultants based in Perth, Australia98
- Hydrogeology consultants based in Sydney, Australia71
- Hydrogeology consultants based in Brisbane, Australia63
- Hydrogeology consultants based in Ankara, Türkiye59
- Hydrogeology consultants based in Melbourne, Australia52
- Hydrogeology consultants based in Rio De Janeiro, Brazil50
- Hydrogeology consultants based in Denver, United States47
- Hydrogeology consultants based in Porto Alegre, Brazil35
- Hydrogeology consultants based in Toronto, Canada35
- Hydrogeology consultants based in Vancouver, Canada32
- Hydrogeology consultants based in Edmonton, Canada31
- Hydrogeology consultants based in Austin, United States27
- Hydrogeology consultants based in Portland, United States26
- Hydrogeology consultants based in Tampa, United States25
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 hydrogeology consultants, 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 hydrogeology consultants are there worldwide?
RevenueBase identified 14,358 hydrogeology consultants 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?
Tetra Tech, headquartered in Pasadena, tops this list with the largest team on record.
Which country has the most hydrogeology consultants?
The United States leads with 2,906 companies, followed by Brazil (952) and Australia (888). Every hydrogeology consultants list by country and city is linked on this page.
Which city has the most hydrogeology consultants?
Belo Horizonte leads with 147 headquartered companies, followed by Houston (123) and Calgary (114).
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 84,181 verified decision-maker contacts tracked across these 14,358 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 20, 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.