Company lists · Data refreshed September 2026

Top 25 Environmental audit companies based in the United States

Name: Environmental audit companies based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 19, 2026 445 companies tracked

RevenueBase identified 445 environmental audit companies headquartered in the United States as of September 2026 and tracks 6,109 professional contacts across them, including 3,186 with verified work emails. Houston is the largest hub.

This list covers environmental audit companies 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

445Companies

6,109Contacts tracked

3,186Verified emails

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The 25 largest environmental audit companies based in the United States

Ranked by team size

Top 25 of 445 environmental audit companies 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 audit companies: 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	Alliance Technical Group	Partial evidence	Decatur, AL, United StatesHQ checked Sep 19, 2026	1,001-5,000	956 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
2	ROUX	Partial evidence	Islandia, NY, United StatesHQ checked Sep 19, 2026	201-500	433 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
3	Cleanair Engineering	Indirect evidence	Palatine, IL, United StatesHQ checked Sep 19, 2026	51-200	152 contacts →
	Indirect evidence “Since its founding in 1972, CleanAir has an established reputation for excellence on projects of all sizes, ranging from boiler, APC equipment and cooling tower efficiency testing…” Source: RevenueBase Database · checked Sep 19, 2026
4	Mostardi Platt	Partial evidence	Elmhurst, IL, United StatesHQ checked Sep 19, 2026	51-200	140 contacts →
	Partial evidence “Since the passage of original environmental legislation nearly four decades ago, both private and public industry have turned to Mostardi Platt for guidance in complying with air…” Source: RevenueBase Database · checked Sep 19, 2026
5	Ensolum, LLC	Partial evidence	Dallas, TX, United StatesHQ checked Sep 19, 2026	51-200	136 contacts →
	Partial evidence “OUR MISSION is to combine sustainable environmental solutions with forward-thinking, cost-effective, innovative, and value-added technologies that balance our clients’ economic…” Source: RevenueBase Database · checked Sep 19, 2026
6	Hart & Hickman, PC	Partial evidence	Charlotte, NC, United StatesHQ checked Sep 19, 2026	51-200	103 contacts →
	Partial evidence “Hart & Hickman PC provides environmental consulting services to commercial, industrial, and governmental clients throughout the Southeast US.” Source: RevenueBase Database · checked Sep 19, 2026
7	Chambers Group, INC	Partial evidence	Costa Mesa, CA, United StatesHQ checked Sep 19, 2026	51-200	98 contacts →
	Partial evidence “Public agencies and businesses have been relying on Chambers Group to keep them in compliance with applicable federal, state, and/or local environmental laws, regulations, and…” Source: RevenueBase Database · checked Sep 19, 2026
8	A-Tech Consulting, INC	Indirect evidence	Orange, CA, United StatesHQ checked Sep 19, 2026	51-200	97 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 19, 2026
9	Aspen Environmental Group	Partial evidence	Agoura Hills, CA, United StatesHQ checked Sep 19, 2026	51-200	94 contacts →
	Partial evidence “Aspen Environmental Group is an expert interdisciplinary environmental impact analysis firm, specializing in the management of environmental assessment efforts under CEQA, NEPA…” Source: RevenueBase Database · checked Sep 19, 2026
10	Yorke Engineering, LLC	Indirect evidence	San Juan Capistrano, CA, United StatesHQ checked Sep 19, 2026	51-200	92 contacts →
	Indirect evidence “Yorke Engineering, LLC (Yorke) was founded in 1996 and specializes in air quality, waste, storm water and industrial hygiene/safety services.” Source: RevenueBase Database · checked Sep 19, 2026
11	Cgrs INC	Indirect evidence	Fort Collins, CO, United StatesHQ checked Sep 19, 2026	51-200	70 contacts →
	Indirect evidence “We deliver quality solutions with integrity and expertise, every time.” Source: RevenueBase Database · checked Sep 19, 2026
12	Chemicalsafety	Partial evidence	Las Vegas, NV, United StatesHQ checked Sep 19, 2026	51-200	67 contacts →
	Partial evidence “ChemicalSafety provides industry-leading environmental technology for chemical, facility, and hazardous waste management, as well as compliance with local, national and…” Source: RevenueBase Database · checked Sep 19, 2026
13	Seres Engineering & Services, LLC	Partial evidence	Charleston, SC, United StatesHQ checked Sep 19, 2026	51-200	65 contacts →
	Partial evidence “Seres Engineering & Services, LLC (SERES) is a minority-owned small business environmental services and consulting firm established in 2007 with a highly experienced…” Source: RevenueBase Database · checked Sep 19, 2026
14	Aarc Environmental	Partial evidence	Houston, TX, United StatesHQ checked Sep 19, 2026	51-200	63 contacts →
	Partial evidence “As a leader in the environmental compliance services industry, AARC does more than just meeting the needs of clients today.” Source: RevenueBase Database · checked Sep 19, 2026
15	Sage ATC Environmental Consulting	Partial evidence	Houston, TX, United StatesHQ checked Sep 19, 2026	201-500	63 contacts →
	Partial evidence “Sage ATC Environmental Consulting is now Atlas.” Source: RevenueBase Database · checked Sep 19, 2026
16	LEW Environmental	Partial evidence	Mine Hill, NJ, United StatesHQ checked Sep 19, 2026	51-200	59 contacts →
	Partial evidence “THE ENVIRONMENTAL COMPANY LEW Environmental Services is proud to be part of the Mainline Environmental family of companies, alongside our sister organizations HSE Consulting and…” Source: RevenueBase Database · checked Sep 19, 2026
17	Ecolsciences, INC	Partial evidence	Rockaway, United StatesHQ checked Sep 19, 2026	11-50	53 contacts →
	Partial evidence “EcolSciences, Inc, was founded in 1973 in response to the growing need for responsible environmental planning, as mandated by NEPA, The National Environmental Policy Act.” Source: RevenueBase Database · checked Sep 19, 2026
18	ONE Environmental Group, LLC	Partial evidence	Midlothian, VA, United StatesHQ checked Sep 19, 2026	11-50	52 contacts →
	Partial evidence “ONE offers environmental consulting and industrial services to commercial, industrial, and government clients that are regulated by environmental state and federal regulations or…” Source: RevenueBase Database · checked Sep 19, 2026
19	GEL Engineering, LLC	Partial evidence	Charleston, SC, United StatesHQ checked Sep 19, 2026	51-200	52 contacts →
	Partial evidence “GEL Engineering and GEL Engineering of NC provide environmental, engineering, surveying, and emissions testing services to our valued clients throughout the southeast and beyond.” Source: RevenueBase Database · checked Sep 19, 2026
20	Integrated Environmental Solutions, LLC	Partial evidence	Mckinney, TX, United StatesHQ checked Sep 19, 2026	51-200	51 contacts →
	Partial evidence “Integrated Environmental Solutions, LLC.(IES) is a Small, Woman-Owned Business Enterprise with corporate headquarters centrally located in the Dallas/Fort Worth Metroplex in…” Source: RevenueBase Database · checked Sep 19, 2026
21	Spheros Environmental	Partial evidence	Denver, CO, United StatesHQ checked Sep 19, 2026	201-500	48 contacts →
	Partial evidence “Environmental insight for complex real-world decisions Spheros Environmental helps clients make clear, defensible decisions in complex environments.” Source: RevenueBase Database · checked Sep 19, 2026
22	7g Environmental Compliance Management	Partial evidence	Tallahassee, FL, United StatesHQ checked Sep 19, 2026	51-200	48 contacts →
	Partial evidence “7G Environmental Compliance Management (7G) is an environmental consulting firm headquartered in Tallahassee, Florida.” Source: RevenueBase Database · checked Sep 19, 2026
23	Environmental Assessment Services, LLC	Partial evidence	Richland, WA, United StatesHQ checked Sep 19, 2026	51-200	47 contacts →
	Partial evidence “Environmental Assessment Services, LLC (EAS) is a member of the KOMAN Family of Companies.” Source: RevenueBase Database · checked Sep 19, 2026
24	Whitetail Environmental LLC	Partial evidence	Jay, OK, United StatesHQ checked Sep 19, 2026	51-200	45 contacts →
	Partial evidence “Whitetail Environmental, LLC is a Small Business Administration (SBA)-certified 8(a), Native American-owned small disadvantaged business.” Source: RevenueBase Database · checked Sep 19, 2026
25	Enviroservices & Training Center	Partial evidence	Honolulu, HI, United StatesHQ checked Sep 19, 2026	51-200	44 contacts →
	Partial evidence “We Are a Full-Service Environmental Consultancy.” Source: RevenueBase Database · checked Sep 19, 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 audit companies. 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 audit companies.
Partial evidence: Its own public description names part of environmental audit companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name environmental audit companies. 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 445 environmental audit companies based in the United States

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Environmental audit companies based in the United States at a glance

As of Sep 19, 2026

52.2%Verified-email coverage

13.7Average contacts per company

1-10Median size (employees)

3.4%Largest-city concentration · Houston

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

246

11-50

154

51-200

201-500

1,001-5,000

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 445 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 audit companies, 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 audit companies”. 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 audit companies), 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 audit companies, 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, 3,186 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 audit companies, 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 audit companies are there based in the United States?

RevenueBase identified 445 environmental audit companies 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?

Alliance Technical Group, headquartered in Decatur, tops this list with the largest team on record.

Which city has the most environmental audit companies?

Houston leads with 15 headquartered companies, followed by Dallas (9) and Seattle (7).

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 3,186 verified decision-maker contacts tracked across these 445 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.