Company lists · Data verified August 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 Verified Aug 28, 2026 3,054 companies tracked

There are 3,054 environmental compliance consulting firms headquartered in the United States (RevenueBase, August 2026). RevenueBase 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 environmental compliance consulting firms headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Data current as of August 28, 2026.

3,054Companies

57,877Contacts tracked

26,942Verified emails

26,209Mobile numbers

Unlock all 3,054 companies Free account · no credit card · 2 minutes

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

Ranked by team size

Top 25 of 3,054 environmental compliance consulting firms based in the United States, ranked by team size, largest first. Data verified Aug 28, 2026. Click a count to unlock that company's people.
#	Company	HQ	Employees	Contacts	Verified emails
1	Civil & Environmental Consultants, INC	Martinsburg, WV	1,001-5,000	2,152	945
2	Swca Environmental Consultants	Phoenix, AZ	1,001-5,000	1,618	1,159
3	Montrose Environmental Group	Little Rock, AR	1,001-5,000	1,516	846
4	SCS Engineers	Long Beach, CA	1,001-5,000	1,191	675
5	Apex Companies	Rockville, MD	1,001-5,000	1,146	591
6	Barr Engineering CO	Washington	1,001-5,000	1,098	828
7	Trinity Consultants	Dallas, TX	1,001-5,000	949	615
8	Alliance Technical Group	Pittsburgh, PA	1,001-5,000	946	549
9	ATC Group Services LLC	Sharonville, OH	1,001-5,000	868	278
10	The Foth Companies	Marion, MA	501-1,000	790	537
11	Environmental Science Associates	Petaluma, CA	501-1,000	725	517
12	Antea Group USA	White Plains, NY	1,001-5,000	658	6
13	Trihydro Corporation	Rock Springs, WY	501-1,000	571	361
14	Rincon Consultants	San Diego, CA	501-1,000	483	312
15	Anchor QEA	Columbia, MD	501-1,000	478	329
16	VLS Environmental Solutions, LLC	Houston, TX	1,001-5,000	477	303
17	Enhesa	Arlington, VA	201-500	463	370
18	Groundwater & Environmental Services, INC	Amherst, NY	201-500	452	229
19	ROUX	Houston, TX	201-500	435	311
20	P2s	Irvine, CA	201-500	370	208
21	LSA	Roseville, CA	201-500	331	120
22	All4	Philadelphia, PA	201-500	330	237
23	Environmental Consulting & Technology, Inc. ECT	Tampa, FL	201-500	303	176
24	Ecology And Environment, INC	Lancaster, NY	5,001-10,000	277	19
25	Wetland Studies And Solutions, Inc. Wssi , A Davey Tree Company	Gainesville, VA	201-500	267	179

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 get verified emails and direct dials for all 26,942 reachable decision-makers.

Free account · no credit card

See all 3,054 companies

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

As of Aug 28, 2026

1-10Median size (employees)

HoustonLargest hub · 59 HQs

26,209Contacts with mobile numbers

0Emails re-verified in last 30 days

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

Environmental compliance consulting firms by metro

Metro	Companies
Environmental compliance consulting firms in Houston	59
Environmental compliance consulting firms in New York	39
Environmental compliance consulting firms in Denver	32
Environmental compliance consulting firms in Austin	31
Environmental compliance consulting firms in Phoenix	31
Environmental compliance consulting firms in San Diego	27
Environmental compliance consulting firms in Seattle	26

How this list was built

Source: The RevenueBase company graph: 21.3 million companies and 398.9 million professional contacts resolved from primary sources.
Inclusion: Companies whose own business descriptions match “environmental compliance consulting firms”, with match quality audited by blind human judging, and headquartered in the United States.
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: Contact records re-verify on a rolling cadence; 0 contacts on this list were re-verified in the last 30 days.
Refresh: Lists are refreshed periodically as the underlying company graph is re-verified. Last verified Aug 28, 2026.

Frequently asked

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

There are 3,054 environmental compliance consulting firms headquartered in the United States as of August 2026 (RevenueBase).

What is the largest company on this list?

Civil & Environmental Consultants, INC, headquartered in Martinsburg, tops this list with the largest team on record.

Which city has the most environmental compliance consulting firms?

Houston leads with 59 headquartered companies, 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 the top results, verified emails and direct dials included. Upgrading unlocks all 26,942 verified decision-maker contacts tracked across these 3,054 companies.

How current is this list?

The list is refreshed periodically as the underlying company graph is re-verified. It was last verified on August 28, 2026.

Ready to reach these companies? Verified emails and direct dials for all 3,054 environmental compliance consulting firms based in the United States. Start with a free account, no credit card.

Get the full list

Related lists

Environmental compliance consulting firms by geography

Browse the directory

Browse: Companies home · All United States lists · All Environmental compliance consulting firms lists · New lists

About this data

RevenueBase is a B2B contact data platform. Its company graph covers 21.3 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, the same data that powers RevenueBase's B2B data products and the free research portal.