Company lists · Data refreshed September 2026

Top 25 Epa compliance consulting firms based in the United States

Name: Epa 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 28, 2026 1,693 companies tracked

RevenueBase identified 1,693 epa compliance consulting firms headquartered in the United States as of September 2026 and tracks 31,151 professional contacts across them, including 14,897 with verified work emails. Houston is the largest hub.

This list covers epa 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. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 28, 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 28, 2026 86% judged on-target in blind review

1,693Companies

31,151Contacts tracked

14,897Verified emails

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

Ranked by team size

Top 25 of 1,693 epa compliance consulting firms based in the United States, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to epa compliance consulting 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	Swca Environmental Consultants	Partial evidence	Phoenix, AZ, United StatesHQ checked Sep 28, 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 28, 2026
2	Montrose Environmental Group	Indirect evidence	Little Rock, AR, United StatesHQ checked Sep 28, 2026	1,001-5,000	1,529 contacts →
	Indirect 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 28, 2026
3	Apex Companies	Indirect evidence	Rockville, MD, United StatesHQ checked Sep 28, 2026	1,001-5,000	1,137 contacts →
	Indirect evidence “Who is Apex?” Source: RevenueBase Database · checked Sep 28, 2026
4	IEA	Partial evidence	Brooklyn Park, MN, United StatesHQ checked Sep 28, 2026	n/a	982 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 28, 2026
5	Trinity Consultants	Partial evidence	Dallas, TX, United StatesHQ checked Sep 28, 2026	1,001-5,000	961 contacts →
	Partial 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 28, 2026
6	Alliance Technical Group	Indirect evidence	Decatur, AL, United StatesHQ checked Sep 28, 2026	1,001-5,000	956 contacts →
	Indirect 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 28, 2026
7	Antea Group USA	Partial evidence	St Paul, MN, United StatesHQ checked Sep 28, 2026	1,001-5,000	658 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 28, 2026
8	Rincon Consultants	Partial evidence	Ventura, CA, United StatesHQ checked Sep 28, 2026	501-1,000	479 contacts →
	Partial 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 28, 2026
9	Groundwater & Environmental Services, INC	Indirect evidence	Wall Township, NJ, United StatesHQ checked Sep 28, 2026	201-500	447 contacts →
	Indirect evidence “We are Groundwater & Environmental Services, Inc, better known as GES.” Source: RevenueBase Database · checked Sep 28, 2026
10	ROUX	Partial evidence	Islandia, NY, United StatesHQ checked Sep 28, 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 28, 2026
11	GSI Environmental INC	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	201-500	259 contacts →
	Partial evidence “GSI Environmental, Inc.(GSI), is an environmental engineering and science consulting firm committed to measuring, analyzing, and solving complex environmental problems around the…” Source: RevenueBase Database · checked Sep 28, 2026
12	Environmental Works, INC	Indirect evidence	Springfield, MO, United StatesHQ checked Sep 28, 2026	201-500	238 contacts →
	Indirect evidence “Environmental Works, Inc.(EWI) offers truly comprehensive environmental solutions for a variety of industries, businesses, and municipalities.” Source: RevenueBase Database · checked Sep 28, 2026
13	Metiri Group	Indirect evidence	Clovis, CA, United StatesHQ checked Sep 28, 2026	n/a	233 contacts →
	Indirect evidence “Appl Inc is an environmental services company based out of 908 N Temperance Ave, Clovis, CA, United States.” Source: RevenueBase Database · checked Sep 28, 2026
14	Tanknology	Partial evidence	Austin, TX, United StatesHQ checked Sep 28, 2026	201-500	232 contacts →
	Partial evidence “Tanknology is the world's largest provider of tank testing and environmental compliance services for petroleum systems.” Source: RevenueBase Database · checked Sep 28, 2026
15	Patriot Environmental Services	Indirect evidence	Signal Hill, CA, United StatesHQ checked Sep 28, 2026	201-500	223 contacts →
	Indirect evidence “Patriot Environmental Services, a Crystal Clean company, is a leading environmental service provider with clients throughout the Southwestern United States.” Source: RevenueBase Database · checked Sep 28, 2026
16	Kleinschmidt Associates	Indirect evidence	Pittsfield, ME, United StatesHQ checked Sep 28, 2026	201-500	218 contacts →
	Indirect evidence “At Kleinschmidt, we work primarily with energy companies and government agencies in North America to protect and enhance the environment without compromising performance.” Source: RevenueBase Database · checked Sep 28, 2026
17	August Mack Environmental, INC	Indirect evidence	Indianapolis, IN, United StatesHQ checked Sep 28, 2026	51-200	210 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
18	Normandeau Associates, INC	Indirect evidence	Bedford, NH, United StatesHQ checked Sep 28, 2026	201-500	189 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
19	Terraphase Engineering INC	Indirect evidence	Oakland, CA, United StatesHQ checked Sep 28, 2026	201-500	166 contacts →
	Indirect evidence “Terraphase offers cost-effective solutions to complex environmental and engineering challenges.” Source: RevenueBase Database · checked Sep 28, 2026
20	Ecorp Consulting, INC	Indirect evidence	Rocklin, CA, United StatesHQ checked Sep 28, 2026	51-200	166 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
21	HRP Associates, INC	Partial evidence	Farmington, CT, United StatesHQ checked Sep 28, 2026	51-200	155 contacts →
	Partial evidence “For 40 years, the consulting engineers at HRP have worked together with our clients to assure that they reach their intended business goals and achieve the right solutions to…” Source: RevenueBase Database · checked Sep 28, 2026
22	Keramida INC	Partial evidence	Indianapolis, IN, United StatesHQ checked Sep 28, 2026	51-200	152 contacts →
	Partial evidence “Founded in 1988, KERAMIDA is a multidisciplinary Sustainability, EHS & Engineering consulting firm grounded in evidence-based research and development.” Source: RevenueBase Database · checked Sep 28, 2026
23	Cleanair Engineering	Indirect evidence	Palatine, IL, United StatesHQ checked Sep 28, 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 28, 2026
24	Quest Resource Management Group, A Qrhc Company Nasdaq Qrhc	Partial evidence	The Colony, TX, United StatesHQ checked Sep 28, 2026	51-200	147 contacts →
	Partial evidence “Quest Resource Management Group, a subsidiary of Quest Resource Holding Corporation (Nasdaq: QRHC), is a full-service environmental consulting and management company headquartered…” Source: RevenueBase Database · checked Sep 28, 2026
25	Mostardi Platt	Indirect evidence	Elmhurst, IL, United StatesHQ checked Sep 28, 2026	51-200	140 contacts →
	Indirect 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 28, 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: epa compliance consulting 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 epa compliance consulting firms.
Partial evidence: Its own public description names part of epa compliance consulting firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name epa compliance consulting 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 1,693 epa compliance consulting firms based in the United States

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

As of Sep 28, 2026

47.8%Verified-email coverage

18.4Average contacts per company

1-10Median size (employees)

2.7%Largest-city concentration · Houston

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

947

11-50

575

51-200

134

201-500

501-1,000

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 1,693 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 epa compliance consulting 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.
What qualifies: Companies headquartered in the United States whose own description of what they do matches “epa compliance consulting 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 epa compliance consulting 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 epa compliance consulting firms, 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, 14,897 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 28, 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.

Epa compliance consulting firms by metro

Epa compliance consulting firms in Houston45

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 epa compliance consulting 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 epa compliance consulting firms are there based in the United States?

RevenueBase identified 1,693 epa compliance consulting firms 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 epa compliance consulting firms?

Houston leads with 45 headquartered companies, followed by Austin (22) and Tampa (18).

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 14,897 verified decision-maker contacts tracked across these 1,693 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 28, 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.