Company lists · Data refreshed September 2026

Top 25 Air permit engineering firms based in the United States

Name: Air permit engineering 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 30, 2026 810 companies tracked

RevenueBase identified 810 air permit engineering firms headquartered in the United States as of September 2026 and tracks 13,026 professional contacts across them, including 5,678 with verified work emails. Houston is the largest hub.

This list covers air permit engineering 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 30, 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 30, 2026 86% judged on-target in blind review

810Companies

13,026Contacts tracked

5,678Verified emails

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The 25 largest air permit engineering firms based in the United States

Ranked by team size

Top 25 of 810 air permit engineering firms based in the United States, ranked by team size, largest first. Data refreshed Sep 30, 2026. RevenueBase Smart Search rates how each company's information relates to air permit engineering 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	Civil & Environmental Consultants, INC	Indirect evidence	Moon Township, PA, United StatesHQ checked Sep 30, 2026	1,001-5,000	2,145 contacts →
	Indirect evidence “Civil & Environmental Consultants, Inc.(CEC) provides comprehensive market-oriented consulting services that advance the strategic business objectives of its clients.” Source: RevenueBase Database · checked Sep 30, 2026
2	ATC Group Services LLC	Indirect evidence	Lafayette, LA, United StatesHQ checked Sep 30, 2026	1,001-5,000	865 contacts →
	Indirect evidence “ATC Group Services LLC is now Atlas.” Source: RevenueBase Database · checked Sep 30, 2026
3	Trihydro Corporation	Strong evidence	Laramie, WY, United StatesHQ checked Sep 30, 2026	501-1,000	577 contacts →
	Strong 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 30, 2026
4	Jva, INC	Partial evidence	Boulder, CO, United StatesHQ checked Sep 30, 2026	51-200	258 contacts →
	Partial evidence “JVA, Incorporated is an employee-owned consulting engineering firm with offices in Boulder, Fort Collins, Winter Park, Glenwood Springs, and Denver, Colorado.” Source: RevenueBase Database · checked Sep 30, 2026
5	Ecorp Consulting, INC	Indirect evidence	Rocklin, CA, United StatesHQ checked Sep 30, 2026	51-200	166 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 30, 2026
6	Verdantas Flow Labs	Indirect evidence	Holden, MA, United StatesHQ checked Sep 30, 2026	51-200	154 contacts →
	Indirect evidence “Since 1894, Verdantas Flow Labs (formerly Alden) has been a recognized leader in the field of applied fluid dynamic consulting.” Source: RevenueBase Database · checked Sep 30, 2026
7	Cleanair Engineering	Indirect evidence	Palatine, IL, United StatesHQ checked Sep 30, 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 30, 2026
8	Mostardi Platt	Partial evidence	Elmhurst, IL, United StatesHQ checked Sep 30, 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 30, 2026
9	Ensolum, LLC	Indirect evidence	Dallas, TX, United StatesHQ checked Sep 30, 2026	51-200	136 contacts →
	Indirect 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 30, 2026
10	Skelly And Loy, Inc., A Terracon Company	Indirect evidence	Harrisburg, PA, United StatesHQ checked Sep 30, 2026	51-200	108 contacts →
	Indirect evidence “Established in 1969, Skelly and Loy is a privately owned, mid-sized corporation with 6 Mid-Atlantic offices.” Source: RevenueBase Database · checked Sep 30, 2026
11	Broadbent & Associates, INC	Partial evidence	Henderson, NV, United StatesHQ checked Sep 30, 2026	51-200	106 contacts →
	Partial evidence “Broadbent & Associates, Inc.(Broadbent) is an established environmental, water resources, and civil engineering firm.” Source: RevenueBase Database · checked Sep 30, 2026
12	Chambers Group, INC	Indirect evidence	Costa Mesa, CA, United StatesHQ checked Sep 30, 2026	51-200	98 contacts →
	Indirect 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 30, 2026
13	A-Tech Consulting, INC	Indirect evidence	Orange, CA, United StatesHQ checked Sep 30, 2026	51-200	97 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 30, 2026
14	Aspen Environmental Group	Indirect evidence	Agoura Hills, CA, United StatesHQ checked Sep 30, 2026	51-200	94 contacts →
	Indirect 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 30, 2026
15	Yorke Engineering, LLC	Strong evidence	San Juan Capistrano, CA, United StatesHQ checked Sep 30, 2026	51-200	92 contacts →
	Strong 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 30, 2026
16	Alliance Consulting Engineers, INC	Partial evidence	Columbia, SC, United StatesHQ checked Sep 30, 2026	11-50	77 contacts →
	Partial evidence “Professional Civil and Environmental Engineering Firm providing Technical Consulting Services to County Governments, Municipalities, Industry, School Districts, Healthcare…” Source: RevenueBase Database · checked Sep 30, 2026
17	Occupational Services, INC	Indirect evidence	San Diego, CA, United StatesHQ checked Sep 30, 2026	11-50	74 contacts →
	Indirect evidence “Occupational Services, Incorporated is a San Diego-based professional consulting firm providing services in the areas of environmental compliance, occupational health and safety…” Source: RevenueBase Database · checked Sep 30, 2026
18	Cgrs INC	Indirect evidence	Fort Collins, CO, United StatesHQ checked Sep 30, 2026	51-200	70 contacts →
	Indirect evidence “We deliver quality solutions with integrity and expertise, every time.” Source: RevenueBase Database · checked Sep 30, 2026
19	HMMH	Partial evidence	Burlington, MA, United StatesHQ checked Sep 30, 2026	51-200	68 contacts →
	Partial evidence “HMMH is an international leader in environmental noise and vibration control, air quality analysis, airport and airspace planning, and climate and energy solutions.” Source: RevenueBase Database · checked Sep 30, 2026
20	AIR Hygiene International, INC	Partial evidence	Tulsa, United StatesHQ checked Sep 30, 2026	11-50	68 contacts →
	Partial evidence “AIR HYGIENE is known for providing professional services which include the following:* Providing superior, cost saving services to our clients!* High quality emission testing…” Source: RevenueBase Database · checked Sep 30, 2026
21	Environmental Design International INC	Indirect evidence	Chicago, IL, United StatesHQ checked Sep 30, 2026	51-200	68 contacts →
	Indirect evidence “Clients can trust Environmental Design International inc.(EDI) to be responsive, demonstrate technical excellence, adhere to the demands of budgets and schedules, and offer…” Source: RevenueBase Database · checked Sep 30, 2026
22	Aarc Environmental	Indirect evidence	Houston, TX, United StatesHQ checked Sep 30, 2026	51-200	63 contacts →
	Indirect 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 30, 2026
23	IVI INC	Partial evidence	Greenville, WI, United StatesHQ checked Sep 30, 2026	51-200	62 contacts →
	Partial evidence “Since 1993, IVI has used technology and experience as fuel for developing innovative air quality solutions.” Source: RevenueBase Database · checked Sep 30, 2026
24	Voltair INC	Partial evidence	Tampa, FL, United StatesHQ checked Sep 30, 2026	51-200	62 contacts →
	Partial evidence “VoltAir is a minority-owned engineering firm providing mechanical, electrical, plumbing and fire protection engineering design and commissioning with offices located in Texas and…” Source: RevenueBase Database · checked Sep 30, 2026
25	LEW Environmental	Indirect evidence	Mine Hill, NJ, United StatesHQ checked Sep 30, 2026	51-200	59 contacts →
	Indirect 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 30, 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: air permit engineering 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 air permit engineering firms.
Partial evidence: Its own public description names part of air permit engineering firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name air permit engineering 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 810 air permit engineering firms based in the United States

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Air permit engineering firms based in the United States at a glance

As of Sep 30, 2026

43.6%Verified-email coverage

16.1Average contacts per company

1-10Median size (employees)

3.7%Largest-city concentration · Houston

Sep 30, 2026Page data refreshed

Companies by employee count

1-10

440

11-50

305

51-200

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 810 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 air permit engineering 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 “air permit engineering 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 air permit engineering 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 air permit engineering 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, 5,678 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 30, 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.

Air permit engineering firms by metro

Air permit engineering firms in Houston30

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 air permit engineering 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 air permit engineering firms are there based in the United States?

RevenueBase identified 810 air permit engineering 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?

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

Which city has the most air permit engineering firms?

Houston leads with 30 headquartered companies, followed by Austin (11) and Dallas (10).

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 5,678 verified decision-maker contacts tracked across these 810 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 30, 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.