Company lists · Data refreshed September 2026

Top 25 Environmental legal consultants based in the United States

RevenueBase identified 2,768 environmental legal consultants headquartered in the United States as of September 2026 and tracks 49,958 professional contacts across them, including 25,510 with verified work emails. Houston is the largest hub.

This list covers environmental legal consultants headquartered in the United States, 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 19, 2026.

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 19, 2026 86% judged on-target in blind review
2,768Companies
49,958Contacts tracked
25,510Verified emails
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The 25 largest environmental legal consultants based in the United States

Ranked by team size
Top 25 of 2,768 environmental legal consultants based in the United States, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to environmental legal 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidencePhoenix, AZ, United StatesHQ checked Sep 19, 20261,001-5,0001,629 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 19, 2026
2Partial evidenceLittle Rock, AR, United StatesHQ checked Sep 19, 20261,001-5,0001,529 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 19, 2026
3Indirect evidenceRockville, MD, United StatesHQ checked Sep 19, 20261,001-5,0001,137 contacts →

Indirect evidence

“Who is Apex?”

Source: RevenueBase Database · checked Sep 19, 2026
4Partial evidenceMinneapolis, MN, United StatesHQ checked Sep 19, 20261,001-5,0001,088 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 19, 2026
5Partial evidenceBrooklyn Park, MN, United StatesHQ checked Sep 19, 2026n/a982 contacts →

Partial evidence

“The Institute for Environmental Assessment, Inc.(IEA) is small business committed to providing trusted environmental safety consulting services for private and public…”

Source: RevenueBase Database · checked Sep 19, 2026
6Strong evidenceDallas, TX, United StatesHQ checked Sep 19, 20261,001-5,000961 contacts →

Strong 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 19, 2026
7Partial evidenceDecatur, AL, United StatesHQ checked Sep 19, 20261,001-5,000956 contacts →

Partial evidence

“Alliance is a new kind of environmental services company-powered by innovation, focused on service, and committed to client success.”

Source: RevenueBase Database · checked Sep 19, 2026
8Indirect evidenceLafayette, LA, United StatesHQ checked Sep 19, 20261,001-5,000865 contacts →

Indirect evidence

“ATC Group Services LLC is now Atlas.”

Source: RevenueBase Database · checked Sep 19, 2026
9Partial evidenceEncinitas, CA, United StatesHQ checked Sep 19, 2026501-1,000795 contacts →

Partial evidence

“Dudek is an environmental, planning, and engineering consulting firm.”

Source: RevenueBase Database · checked Sep 19, 2026
10Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 19, 2026501-1,000732 contacts →

Partial evidence

“ESA is a 100% employee-owned environmental consulting firm.”

Source: RevenueBase Database · checked Sep 19, 2026
11Partial evidenceSt Paul, MN, United StatesHQ checked Sep 19, 20261,001-5,000658 contacts →

Partial evidence

“Antea Group is an international engineering and environmental consulting firm specializing in full-service solutions in the fields of environment, health and safety, and…”

Source: RevenueBase Database · checked Sep 19, 2026
12Partial evidenceLaramie, WY, United StatesHQ checked Sep 19, 2026501-1,000577 contacts →

Partial evidence

“Headquartered in Laramie, Wyoming, Trihydro provides environmental consulting, engineering and surveying, air quality and process management, information technology, and water and…”

Source: RevenueBase Database · checked Sep 19, 2026
13Indirect evidenceBurlington, MA, United StatesHQ checked Sep 19, 2026501-1,000535 contacts →

Indirect evidence

“For 35 years we have been helping investors, lenders, owners, developers, contractors, and property managers reduce risk and optimize their built facilities, infrastructure and…”

Source: RevenueBase Database · checked Sep 19, 2026
14Partial evidenceKennesaw, GA, United StatesHQ checked Sep 19, 2026501-1,000518 contacts →

Partial evidence

“Established in 1996, NOVA was originally founded to provide Environmental Consulting, Geotechnical Engineering, and Construction Materials Testing and Inspection services to the…”

Source: RevenueBase Database · checked Sep 19, 2026
15Partial evidenceSeattle, WA, United StatesHQ checked Sep 19, 2026501-1,000479 contacts →

Partial evidence

“Headquartered in Seattle, Washington, Anchor QEA is a nationally recognized environmental science and engineering consulting firm specializing in aquatic, shoreline, and water…”

Source: RevenueBase Database · checked Sep 19, 2026
16Strong evidenceVentura, CA, United StatesHQ checked Sep 19, 2026501-1,000479 contacts →

Strong evidence

“Rincon Consultants is a multi-disciplinary environmental sciences, planning, and engineering consulting firm that provides quality professional services to government and industry.”

Source: RevenueBase Database · checked Sep 19, 2026
17Partial evidenceWall Township, NJ, United StatesHQ checked Sep 19, 2026201-500447 contacts →

Partial evidence

“We are Groundwater & Environmental Services, Inc, better known as GES.”

Source: RevenueBase Database · checked Sep 19, 2026
18Partial evidenceIslandia, NY, United StatesHQ checked Sep 19, 2026201-500433 contacts →

Partial evidence

“Founded 40 years ago, Roux is recognized for being a highly effective, client-focused environmental consulting and management firm.”

Source: RevenueBase Database · checked Sep 19, 2026
19Partial evidenceCheyenne, WY, United StatesHQ checked Sep 19, 2026201-500408 contacts →

Partial evidence

“WEST provides environmental and statistical consulting services and contract research nationally and internationally to industry, government, and private organizations.”

Source: RevenueBase Database · checked Sep 19, 2026
20Indirect evidenceLong Beach, CA, United StatesHQ checked Sep 19, 2026201-500375 contacts →

Indirect evidence

“P2S has brought forward-thinking, sustainable engineering solutions to California, the Pacific Northwest, and beyond, for over 30 years.”

Source: RevenueBase Database · checked Sep 19, 2026
21Partial evidenceParlin, NJ, United StatesHQ checked Sep 19, 2026201-500336 contacts →

Partial evidence

“CME Associates, with eight (8) office locations throughout New Jersey, provides a complete range of Environmental, Geotechnical, Engineering, Surveying and Planning services.”

Source: RevenueBase Database · checked Sep 19, 2026
22Partial evidenceIrvine, CA, United StatesHQ checked Sep 19, 2026201-500332 contacts →

Partial evidence

“LSA is a diversified environmental, transportation, and community planning firm that evolved from a small consulting firm.”

Source: RevenueBase Database · checked Sep 19, 2026
23Indirect evidenceWashington, DC, United StatesHQ checked Sep 19, 2026201-500328 contacts →

Indirect evidence

“Beveridge & Diamond’s 170+ lawyers in 7 U.S.”

Source: RevenueBase Database · checked Sep 19, 2026
24Partial evidenceGainesville, FL, United StatesHQ checked Sep 19, 2026201-500305 contacts →

Partial evidence

Environmental Consulting & Technology, Inc.(ECT) is a multi-disciplinary environmental and sustainability consulting firm delivering strategy, permitting, design, and management…”

Source: RevenueBase Database · checked Sep 19, 2026
25Indirect evidenceLancaster, NY, United StatesHQ checked Sep 19, 20265,001-10,000278 contacts →

Indirect evidence

“E&E is now WSP USA.”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 25 of 2,768 environmental legal consultants based in the United States

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Environmental legal consultants based in the United States at a glance

As of Sep 19, 2026
51.1%Verified-email coverage
18.0Average contacts per company
1-10Median size (employees)
2.0%Largest-city concentration · Houston
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
1,598
11-50
908
51-200
199
201-500
34
501-1,000
9
1,001-5,000
14
5,001-10,000
2
10001+
1

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 2,768 companies.

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 legal 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.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “environmental legal 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 environmental legal 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 environmental legal consultants, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
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, 25,510 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 19, 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.

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 legal 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 environmental legal consultants are there based in the United States?

RevenueBase identified 2,768 environmental legal consultants headquartered in the United States 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?

Swca Environmental Consultants, headquartered in Phoenix, tops this list with the largest team on record.

Which city has the most environmental legal consultants?

Houston leads with 56 headquartered companies, followed by Austin (38) and New York (34).

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 25,510 verified decision-maker contacts tracked across these 2,768 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 19, 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.