Company lists · Data refreshed September 2026

Top 25 Environmental compliance consulting firms based in the United States

Name: Environmental compliance consulting firms based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 2, 2026 3,054 companies tracked

RevenueBase identified 3,054 company matches for environmental compliance consulting firms associated with the United States as of September 2026 and tracks 57,877 professional contacts across them, including 26,942 with verified work emails and 26,209 with mobile numbers. Houston is the largest hub.

This list covers company matches for environmental compliance consulting firms associated with the United States, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed September 2, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 RevenueBase SmartSearch · Exact Recorded Sep 2, 2026 How this list was built

3,054Companies

57,877Contacts tracked

26,942Verified emails

26,209Mobile numbers

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The 25 largest environmental compliance consulting firms based in the United States

Ranked by team size

Top 25 of 3,054 company matches for environmental compliance consulting firms based in the United States, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 2, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#	Company	RevenueBase SmartSearch	Headquarters	Employees	Contacts
1	Civil & Environmental Consultants, INC	Exact match	Martinsburg, WV, United States	1,001-5,000	2,152 contacts →
	Exact match “Civil & Environmental Consultants, Inc.(CEC) provides comprehensive market-oriented consulting services that advance the strategic business objectives of its clients.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
2	Swca Environmental Consultants	Exact match	Phoenix, AZ, United States	1,001-5,000	1,618 contacts →
	Exact match “Founded on a commitment to sound science and creative solutions, SWCA is a leader in environmental and management consulting services.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
3	Montrose Environmental Group	Exact match	Little Rock, AR, United States	1,001-5,000	1,516 contacts →
	Exact match “Onterris (formerly Montrose Environmental Group) was one of the first to see environmental responsibility as not just an imperative but as a strategic asset.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
4	SCS Engineers	Exact match	Long Beach, CA, United States	1,001-5,000	1,191 contacts →
	Exact match “SCS Engineers delivers environmental solutions by combining long-term experience with compliance and technological expertise.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
5	Apex Companies	Exact match	Rockville, MD, United States	1,001-5,000	1,146 contacts →
	Exact match “Who is Apex?” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
6	Barr Engineering CO	Exact match	Washington, United States	1,001-5,000	1,098 contacts →
	Exact match “Barr provides engineering and environmental consulting services to clients across the Midwest, throughout the Americas, and around the world.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
7	Trinity Consultants	Exact match	Dallas, TX, United States	1,001-5,000	949 contacts →
	Exact match “Trinity Consultants is a global team of experts helping organizations solve complex challenges in environmental compliance, ecological protection, infrastructure performance, and…” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
8	Alliance Technical Group	Exact match	Pittsburgh, PA, United States	1,001-5,000	946 contacts →
	Exact match “Alliance is a new kind of environmental services company-powered by innovation, focused on service, and committed to client success.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
9	ATC Group Services LLC	Exact match	Sharonville, OH, United States	1,001-5,000	868 contacts →
	Exact match “ATC Group Services LLC is now Atlas.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
10	The Foth Companies	Exact match	Marion, MA, United States	501-1,000	790 contacts →
	Exact match “By combining science, engineering, and technology with a true collaborative spirit, Foth has delivered innovative solutions to our clients since 1938.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
11	Environmental Science Associates	Exact match	Petaluma, CA, United States	501-1,000	725 contacts →
	Exact match “ESA is a 100% employee-owned environmental consulting firm.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
12	Antea Group USA	Exact match	White Plains, NY, United States	1,001-5,000	658 contacts →
	Exact match “Antea Group is an international engineering and environmental consulting firm specializing in full-service solutions in the fields of environment, health and safety, and…” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
13	Trihydro Corporation	Exact match	Rock Springs, WY, United States	501-1,000	571 contacts →
	Exact match “Headquartered in Laramie, Wyoming, Trihydro provides environmental consulting, engineering and surveying, air quality and process management, information technology, and water and…” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
14	Rincon Consultants	Exact match	San Diego, CA, United States	501-1,000	483 contacts →
	Exact match “Rincon Consultants is a multi-disciplinary environmental sciences, planning, and engineering consulting firm that provides quality professional services to government and industry.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
15	Anchor QEA	Exact match	Columbia, MD, United States	501-1,000	478 contacts →
	Exact match “Headquartered in Seattle, Washington, Anchor QEA is a nationally recognized environmental science and engineering consulting firm specializing in aquatic, shoreline, and water…” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
16	VLS Environmental Solutions, LLC	Exact match	Houston, TX, United States	1,001-5,000	477 contacts →
	Exact match “At VLS, we address your company’s most significant hurdles with waste management and compliance through sustainable solutions.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
17	Enhesa	Exact match	Arlington, VA, United States	201-500	463 contacts →
	Exact match “At Enhesa we empower the world’s largest businesses to achieve compliance, manage risk, and drive sustainability with clear, actionable insights.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
18	Groundwater & Environmental Services, INC	Exact match	Amherst, NY, United States	201-500	452 contacts →
	Exact match “We are Groundwater & Environmental Services, Inc, better known as GES.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
19	ROUX	Exact match	Houston, TX, United States	201-500	435 contacts →
	Exact match “Founded 40 years ago, Roux is recognized for being a highly effective, client-focused environmental consulting and management firm.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
20	P2s	Exact match	Irvine, CA, United States	201-500	370 contacts →
	Exact match “P2S has brought forward-thinking, sustainable engineering solutions to California, the Pacific Northwest, and beyond, for over 30 years.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
21	LSA	Exact match	Roseville, CA, United States	201-500	331 contacts →
	Exact match “LSA is a diversified environmental, transportation, and community planning firm that evolved from a small consulting firm.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
22	All4	Exact match	Philadelphia, PA, United States	201-500	330 contacts →
	Exact match “ALL4 is a global consulting firm committed to shaping a sustainable future through innovative environmental, health, and safety (EHS) and digital solutions.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
23	Environmental Consulting & Technology, Inc. ECT	Exact match	Tampa, FL, United States	201-500	303 contacts →
	Exact match “Environmental Consulting & Technology, Inc.(ECT) is a multi-disciplinary environmental and sustainability consulting firm delivering strategy, permitting, design, and management…” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
24	Ecology And Environment, INC	Exact match	Lancaster, NY, United States	5,001-10,000	277 contacts →
	Exact match “E&E is now WSP USA.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase
25	Wetland Studies And Solutions, Inc. Wssi , A Davey Tree Company	Exact match	Gainesville, VA, United States	201-500	267 contacts →
	Exact match “For more than 30 years, WSSI has been the trusted partner in environmental, regulatory, cultural resources, and water resources engineering consulting.” Recorded in the RevenueBase company graph · Sep 2, 2026 · View company records in RevenueBase

RevenueBase SmartSearch

Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.

This list uses Exact for “environmental compliance consulting firms”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.

Showing 25 of 3,054 environmental compliance consulting firms based in the United States

See the full list, filter by size, metro and specialty, and access 26,942 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Environmental compliance consulting firms based in the United States at a glance

As of Sep 2, 2026

46.6%Verified-email coverage

45.3%Mobile-number coverage

19.0Average contacts per company

1-10Median size (employees)

1.9%Largest-city concentration · Houston

Sep 2, 2026Page data refreshed

Companies by employee count

1-10

1,698

11-50

1,021

51-200

255

201-500

501-1,000

1,001-5,000

5,001-10,000

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies: Company records associated with the United States whose business descriptions match “environmental compliance consulting firms” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch: Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview: The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality: RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 26,942 professional contacts with verified work emails across the full matched dataset. 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 2, 2026. Lists refresh periodically as the graph is re-checked.
Record context: Company records and descriptions can change. Check the company's website for its current services and locations.

Environmental compliance consulting firms by metro

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “environmental compliance consulting firms”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many environmental compliance consulting firms are there based in the United States?

RevenueBase identified 3,054 company matches for environmental compliance consulting firms associated with the United States as of September 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Civil & Environmental Consultants, INC tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most environmental compliance consulting firms?

Houston leads with 59 company records, followed by New York (39) and Denver (32).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 26,942 professional contacts with verified work emails tracked across these 3,054 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 2, 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 SmartSearch, 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.