Company lists · Data refreshed September 2026

Top 25 Environmental consultant firms worldwide

Name: Environmental consultant firms worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 24,774 companies tracked

RevenueBase identified 24,774 environmental consultant firms worldwide as of September 2026 and tracks 404,849 professional contacts across them, including 155,660 with verified work emails. The United States is the largest market and Sao Paulo the largest hub.

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

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

24,774Companies

404,849Contacts tracked

155,660Verified emails

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The 25 largest environmental consultant firms worldwide

Ranked by team size

Top 25 of 24,774 environmental consultant firms worldwide, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to environmental consultant firms: 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	Stantec	Indirect evidence	Edmonton, AB, CanadaHQ checked Sep 21, 2026	10001+	28,416 contacts →
	Indirect evidence “Stantec empowers clients, people, and communities to rise to the world’s greatest challenges at a time when the world faces more unprecedented concerns than ever before.” Source: RevenueBase Database · checked Sep 21, 2026
2	Tetra Tech	Partial evidence	Pasadena, CA, United StatesHQ checked Sep 21, 2026	10001+	12,999 contacts →
	Partial 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
3	WSP In The U.S	Partial evidence	New York, NY, United StatesHQ checked Sep 21, 2026	10001+	9,318 contacts →
	Partial evidence “What if you could shape built and natural environments – and the future of those that use them?” Source: RevenueBase Database · checked Sep 21, 2026
4	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
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	APTIM	Partial evidence	Baton Rouge, LA, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,639 contacts →
	Partial evidence “APTIM enhances the quality of the environment, wellbeing of people, resilience of communities, and opportunity for employees to make a difference, not just a living.” 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	Partial evidence	Boca Raton, FL, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,393 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 21, 2026
9	Providence	Partial evidence	Baton Rouge, LA, United StatesHQ checked Sep 21, 2026	n/a	2,232 contacts →
	Partial evidence “Providence is an employee-owned engineering and environmental consulting firm.” Source: RevenueBase Database · checked Sep 21, 2026
10	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
11	Langan Engineering & Environmental Services	Partial evidence	Parsippany, NJ, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,177 contacts →
	Partial 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
12	Civil & Environmental Consultants, INC	Strong evidence	Moon Township, PA, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,145 contacts →
	Strong 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
13	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
14	LJA	Indirect evidence	Houston, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,932 contacts →
	Indirect evidence “Employee-Owned.” Source: RevenueBase Database · checked Sep 21, 2026
15	Swca Environmental Consultants	Partial evidence	Phoenix, AZ, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,629 contacts →
	Partial evidence “Founded on a commitment to sound science and creative solutions, SWCA is a leader in environmental and management consulting services.” Source: RevenueBase Database · checked Sep 21, 2026
16	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
17	UES	Partial evidence	Orlando, FL, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,595 contacts →
	Partial evidence “UES provides professional engineering, environmental, testing and inspection services to clients across the United States.” Source: RevenueBase Database · checked Sep 21, 2026
18	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
19	Montrose Environmental Group	Partial evidence	Little Rock, AR, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,529 contacts →
	Partial evidence “Onterris (formerly Montrose Environmental Group) was one of the first to see environmental responsibility as not just an imperative but as a strategic asset.” Source: RevenueBase Database · checked Sep 21, 2026
20	Weston Solutions, INC	Partial evidence	West Chester, PA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,441 contacts →
	Partial evidence “Weston Solutions, Inc.(Weston) is a 100% employee-owned environmental and infrastructure services firm committed to safety and providing measurable client value.” Source: RevenueBase Database · checked Sep 21, 2026
21	Partner Engineering & Science, INC	Indirect evidence	Torrance, CA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,358 contacts →
	Indirect evidence “Partner Assessment Corp.” Source: RevenueBase Database · checked Sep 21, 2026
22	RSK Group	Partial evidence	Helsby, United KingdomHQ checked Sep 21, 2026	10001+	1,255 contacts →
	Partial evidence “RSK Group is a global leader in the delivery of environmental and engineering solutions.” Source: RevenueBase Database · checked Sep 21, 2026
23	Knight Piesold	Indirect evidence	Denver, CO, United StatesHQ checked Sep 21, 2026	1,001-5,000	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 21, 2026
24	Dillon Consulting Limited	Partial evidence	Toronto, ON, CanadaHQ checked Sep 21, 2026	1,001-5,000	1,227 contacts →
	Partial evidence “Dillon is a proudly Canadian, employee-owned, professional consulting firm with over 1,100 employees specializing in planning, engineering, environmental science and management.” Source: RevenueBase Database · checked Sep 21, 2026
25	DGE Danmark	Indirect evidence	Højbjerg, DenmarkHQ checked Sep 21, 2026	n/a	1,176 contacts →
	Indirect evidence “Miljø er vores kernekompetence og vores ansvar.” 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: environmental consultant 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 environmental consultant firms.
Partial evidence: Its own public description names part of environmental consultant firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name environmental consultant 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 24,774 environmental consultant firms worldwide

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Environmental consultant firms worldwide at a glance

As of Sep 21, 2026

38.4%Verified-email coverage

16.3Average contacts per company

1-10Median size (employees)

1.5%Largest-city concentration · Sao Paulo

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

15,281

11-50

7,090

51-200

1,689

201-500

398

501-1,000

1,001-5,000

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 environmental consultant 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: Every country. Country and city lists for environmental consultant firms are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “environmental consultant 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 environmental consultant 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 environmental consultant 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, 155,660 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.

Environmental consultant firms by location

89 lists · largest first

Every Environmental consultant firms 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 environmental consultant 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 environmental consultant firms are there worldwide?

RevenueBase identified 24,774 environmental consultant 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?

Stantec, headquartered in Edmonton, tops this list with the largest team on record.

Which country has the most environmental consultant firms?

The United States leads with 5,126 companies, followed by Brazil (3,312) and Canada (996). Every environmental consultant firms list by country and city is linked on this page.

Which city has the most environmental consultant firms?

Sao Paulo leads with 366 headquartered companies, followed by Belo Horizonte (169) and Lima (155).

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 155,660 verified decision-maker contacts tracked across these 24,774 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.