Company lists · Data refreshed September 2026

Top 25 Hydrogeological consultants worldwide

Name: Hydrogeological consultants worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 31,025 companies tracked

RevenueBase identified 31,025 hydrogeological consultants worldwide as of September 2026 and tracks 524,983 professional contacts across them, including 168,586 with verified work emails. The United States is the largest market and Belo Horizonte the largest hub.

This list covers hydrogeological 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 21, 2026. Country and city lists for hydrogeological 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 21, 2026 86% judged on-target in blind review

31,025Companies

524,983Contacts tracked

168,586Verified emails

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The 25 largest hydrogeological consultants worldwide

Ranked by team size

Top 25 of 31,025 hydrogeological consultants worldwide, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to hydrogeological consultants: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Tetra Tech	Indirect evidence	Pasadena, CA, United StatesHQ checked Sep 21, 2026	10001+	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 21, 2026
2	Tata Consulting Engineers	Partial evidence	Mumbai, IndiaHQ checked Sep 21, 2026	5,001-10,000	8,440 contacts →
	Partial evidence “Tata Consulting Engineers Limited (TCE) is the largest Indian private sector engineering and project consultancy and an emerging global leader in integrated engineering solutions.” Source: RevenueBase Database · checked Sep 21, 2026
3	Terracon	Indirect evidence	Olathe, KS, United StatesHQ checked Sep 21, 2026	5,001-10,000	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 21, 2026
4	Keller	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	5,001-10,000	3,960 contacts →
	Indirect evidence “Every day, people around the world live, work and play on ground prepared by Keller, the world's largest geotechnical specialist contractor.” Source: RevenueBase Database · checked Sep 21, 2026
5	Golder	Indirect evidence	Vancouver, BC, CanadaHQ checked Sep 21, 2026	5,001-10,000	3,167 contacts →
	Indirect evidence “Golder was acquired by WSP.” Source: RevenueBase Database · checked Sep 21, 2026
6	NIRAS	Indirect evidence	Allerød, DenmarkHQ checked Sep 21, 2026	1,001-5,000	2,699 contacts →
	Indirect evidence “At NIRAS, we engineer solutions for a shared future.” Source: RevenueBase Database · checked Sep 21, 2026
7	Brown And Caldwell	Indirect evidence	Walnut Creek, CA, United StatesHQ checked Sep 21, 2026	1,001-5,000	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 21, 2026
8	Geosyntec Consultants	Indirect evidence	Boca Raton, FL, United StatesHQ checked Sep 21, 2026	1,001-5,000	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 21, 2026
9	SRK Consulting	Partial evidence	Vancouver, CanadaHQ checked Sep 21, 2026	1,001-5,000	2,259 contacts →
	Partial evidence “SRK Consulting is an independent, international group providing specialised consultancy services.” Source: RevenueBase Database · checked Sep 21, 2026
10	Providence	Indirect evidence	Baton Rouge, LA, United StatesHQ checked Sep 21, 2026	n/a	2,232 contacts →
	Indirect evidence “Providence is an employee-owned engineering and environmental consulting firm.” Source: RevenueBase Database · checked Sep 21, 2026
11	ECS Group Of Companies	Indirect evidence	Chantilly, VA, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,210 contacts →
	Indirect evidence “ECS Group of Companies is a Chantilly, VA-based consulting engineering firm.” Source: RevenueBase Database · checked Sep 21, 2026
12	DRA Global	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 21, 2026	1,001-5,000	2,180 contacts →
	Indirect evidence “DRA Global Limited (DRA or the Group) is an international multi-disciplinary engineering, project delivery and operations management group, predominantly focused on the mining…” Source: RevenueBase Database · checked Sep 21, 2026
13	Langan Engineering & Environmental Services	Indirect evidence	Parsippany, NJ, United StatesHQ checked Sep 21, 2026	1,001-5,000	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 21, 2026
14	Civil & Environmental Consultants, INC	Partial evidence	Moon Township, PA, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,145 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 21, 2026
15	Hazen And Sawyer	Indirect evidence	New York, NY, United StatesHQ checked Sep 21, 2026	1,001-5,000	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 21, 2026
16	Englobe	Indirect evidence	Québec, QC, CanadaHQ checked Sep 21, 2026	1,001-5,000	1,852 contacts →
	Indirect evidence “Englobe is a leader in the fields of engineering, gesosciences, environmental management, asset integrity and quality management.” Source: RevenueBase Database · checked Sep 21, 2026
17	Burns & Mcdonnell India	Partial evidence	Vikhroli West, IndiaHQ checked Sep 21, 2026	1,001-5,000	1,724 contacts →
	Partial evidence “At Burns & McDonnell India, we are a diverse team of talented engineers with multidiscipline design and consultancy working across sectors in critical infrastructure: oil and gas…” Source: RevenueBase Database · checked Sep 21, 2026
18	Carollo Engineers	Indirect evidence	Walnut Creek, CA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,718 contacts →
	Indirect evidence “For more than 90 years, Carollo Engineers has been dedicated exclusively to water and wastewater solutions.” Source: RevenueBase Database · checked Sep 21, 2026
19	GEI Consultants, INC	Indirect evidence	Woburn, MA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,604 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 21, 2026
20	UES	Indirect evidence	Orlando, FL, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,595 contacts →
	Indirect evidence “UES provides professional engineering, environmental, testing and inspection services to clients across the United States.” Source: RevenueBase Database · checked Sep 21, 2026
21	Exponent	Indirect evidence	Menlo Park, CA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,560 contacts →
	Indirect evidence “In an era of accelerating change, Exponent is the only premium engineering and scientific consulting firm with the depth and breadth of expertise to solve our clients’ most…” Source: RevenueBase Database · checked Sep 21, 2026
22	Freese And Nichols	Indirect evidence	Fort Worth, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	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 21, 2026
23	DHI	Indirect evidence	Hørsholm, DenmarkHQ checked Sep 21, 2026	1,001-5,000	1,427 contacts →
	Indirect evidence “There is no substitute for water.” Source: RevenueBase Database · checked Sep 21, 2026
24	Antea Group Nederland	Indirect evidence	Heerenveen, NetherlandsHQ checked Sep 21, 2026	1,001-5,000	1,397 contacts →
	Indirect evidence “Antea Group is het thuis van 1800 trotse ingenieurs en adviseurs.” Source: RevenueBase Database · checked Sep 21, 2026
25	Ingetec	Indirect evidence	Bogota, ColombiaHQ checked Sep 21, 2026	1,001-5,000	1,358 contacts →
	Indirect evidence “Ingetec está conformado por un grupo de profesionales con alto nivel de especialización, quienes trabajan dentro de las diferentes gerencias y divisiones que componen la…” Source: RevenueBase Database · checked Sep 21, 2026

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 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 hydrogeological consultants.
Partial evidence: Its own public description names part of hydrogeological consultants, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name hydrogeological 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 31,025 hydrogeological consultants worldwide

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Hydrogeological consultants worldwide at a glance

As of Sep 21, 2026

32.1%Verified-email coverage

16.9Average contacts per company

1-10Median size (employees)

0.8%Largest-city concentration · Belo Horizonte

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

16,560

11-50

9,917

51-200

3,194

201-500

755

501-1,000

229

1,001-5,000

173

5,001-10,000

10001+

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 hydrogeological 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 hydrogeological consultants are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “hydrogeological 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 hydrogeological 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 hydrogeological 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, 168,586 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 21, 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 consultants by location

102 lists · largest first

Every Hydrogeological consultants list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

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 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 hydrogeological consultants are there worldwide?

RevenueBase identified 31,025 hydrogeological 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 hydrogeological consultants?

The United States leads with 4,224 companies, followed by Brazil (2,238) and Australia (2,059). Every hydrogeological consultants list by country and city is linked on this page.

Which city has the most hydrogeological consultants?

Belo Horizonte leads with 258 headquartered companies, followed by Sao Paulo (254) and Perth (206).

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 168,586 verified decision-maker contacts tracked across these 31,025 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 21, 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.