Company lists · Data refreshed September 2026
Top 25 Air quality engineering consultants based in the United States
RevenueBase identified 1,580 air quality engineering consultants headquartered in the United States as of September 2026 and tracks 30,049 professional contacts across them, including 14,253 with verified work emails. Houston is the largest hub.
This list covers air quality engineering consultants 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.
The 25 largest air quality engineering consultants based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 2,145 contacts → | ||||
Partial 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, 2026Thanks. The Data Team will review it. | |||||
| 2 | 1,629 contacts → | ||||
Indirect 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 30, 2026Thanks. The Data Team will review it. | |||||
| 3 | 1,088 contacts → | ||||
Partial evidence “Barr provides engineering and environmental consulting services to clients across the Midwest, throughout the Americas, and around the world.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 4 | 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 30, 2026Thanks. The Data Team will review it. | |||||
| 5 | 865 contacts → | ||||
Indirect evidence “ATC Group Services LLC is now Atlas.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 6 | 806 contacts → | ||||
Partial evidence “AAF International clean air products and systems offer the most comprehensive clean air solutions available in the world.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 7 | 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 30, 2026Thanks. The Data Team will review it. | |||||
| 8 | 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, 2026Thanks. The Data Team will review it. | |||||
| 9 | 479 contacts → | ||||
Strong 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 30, 2026Thanks. The Data Team will review it. | |||||
| 10 | 447 contacts → | ||||
Indirect evidence “We are Groundwater & Environmental Services, Inc, better known as GES.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 11 | 433 contacts → | ||||
Indirect 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 30, 2026Thanks. The Data Team will review it. | |||||
| 12 | 331 contacts → | ||||
Indirect evidence “ALL4 is a global consulting firm committed to shaping a sustainable future through innovative environmental, health, and safety (EHS) and digital solutions.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 13 | 278 contacts → | ||||
Indirect evidence “E&E is now WSP USA.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 14 | 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 30, 2026Thanks. The Data Team will review it. | |||||
| 15 | 189 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 16 | 172 contacts → | ||||
Indirect evidence “With a staff of over 150 employees in the San Francisco, Sacramento, Los Angeles, San Diego, Modesto, Bakersfield, Fresno, Portland, Chicago, and Grand Rapids offices, Forensic…” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 17 | 166 contacts → | ||||
Partial evidence “Terraphase offers cost-effective solutions to complex environmental and engineering challenges.” Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 18 | 166 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 19 | 155 contacts → | ||||
Indirect 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 30, 2026Thanks. The Data Team will review it. | |||||
| 20 | 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, 2026Thanks. The Data Team will review it. | |||||
| 21 | 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 30, 2026Thanks. The Data Team will review it. | |||||
| 22 | 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, 2026Thanks. The Data Team will review it. | |||||
| 23 | 142 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 30, 2026Thanks. The Data Team will review it. | |||||
| 24 | 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, 2026Thanks. The Data Team will review it. | |||||
| 25 | 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, 2026Thanks. The Data Team will review it. | |||||
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 quality engineering consultants. 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 quality engineering consultants.
- Partial evidence
- Its own public description names part of air quality engineering consultants, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name air quality engineering consultants. 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 1,580 air quality engineering consultants based in the United States
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Air quality engineering consultants based in the United States at a glance
As of Sep 30, 2026Companies by employee count
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 1,580 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 quality engineering consultants, 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 quality engineering consultants”. 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 quality engineering consultants), 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 quality engineering consultants, 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, 14,253 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 quality engineering consultants by metro
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 quality engineering consultants, 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 quality engineering consultants are there based in the United States?
RevenueBase identified 1,580 air quality engineering consultants 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 quality engineering consultants?
Houston leads with 44 headquartered companies, followed by Austin (18) and New York (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 14,253 verified decision-maker contacts tracked across these 1,580 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.
Ready to reach these companies? Verified emails and direct dials for all 1,580 air quality engineering consultants based in the United States. Start with a free account, no credit card.
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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.
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