Company lists · Data refreshed September 2026
Top 25 Marine environmental consultancies based in the United States
RevenueBase identified 2,416 marine environmental consultancies headquartered in the United States as of September 2026 and tracks 48,165 professional contacts across them, including 21,426 with verified work emails. Houston is the largest hub.
This list covers marine environmental consultancies 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 14, 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 marine environmental consultancies based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 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 14, 2026Thanks. The Data Team will review it. | |||||
| 2 | 1,529 contacts → | ||||
Partial 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 14, 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 14, 2026Thanks. The Data Team will review it. | |||||
| 4 | 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 14, 2026Thanks. The Data Team will review it. | |||||
| 5 | 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 14, 2026Thanks. The Data Team will review it. | |||||
| 6 | 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 14, 2026Thanks. The Data Team will review it. | |||||
| 7 | 865 contacts → | ||||
Indirect evidence “ATC Group Services LLC is now Atlas.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 8 | 781 contacts → | ||||
Indirect evidence “By combining science, engineering, and technology with a true collaborative spirit, Foth has delivered innovative solutions to our clients since 1938.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 9 | 732 contacts → | ||||
Partial evidence “ESA is a 100% employee-owned environmental consulting firm.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 10 | 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 14, 2026Thanks. The Data Team will review it. | |||||
| 11 | 504 contacts → | ||||
Indirect evidence “BSC Group, Inc.(BSC) is a multidisciplinary consulting firm with a staff of more than 200 professionals and offices in Boston, Worcester, Andover, and West Yarmouth, MA, as well…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 12 | 479 contacts → | ||||
Partial evidence “Headquartered in Seattle, Washington, Anchor QEA is a nationally recognized environmental science and engineering consulting firm specializing in aquatic, shoreline, and water…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 13 | 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 14, 2026Thanks. The Data Team will review it. | |||||
| 14 | 447 contacts → | ||||
Partial evidence “We are Groundwater & Environmental Services, Inc, better known as GES.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 15 | 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 14, 2026Thanks. The Data Team will review it. | |||||
| 16 | 408 contacts → | ||||
Partial evidence “WEST provides environmental and statistical consulting services and contract research nationally and internationally to industry, government, and private organizations.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 17 | 305 contacts → | ||||
Partial evidence “Environmental Consulting & Technology, Inc.(ECT) is a multi-disciplinary environmental and sustainability consulting firm delivering strategy, permitting, design, and management…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 18 | 304 contacts → | ||||
Partial evidence “Drew Marine is a global leader in maritime water treatment, fuel management, refrigerant compliance, cleaning solutions, and technical services trusted by ship owners, operators…” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 19 | 299 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 20 | 278 contacts → | ||||
Indirect evidence “E&E is now WSP USA.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 21 | 277 contacts → | ||||
Partial evidence “Resolve Marine, a global leader in vessel salvage, emergency response, compliance and specialized marine services, has served and supported clients and projects for 40 years.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 22 | 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 14, 2026Thanks. The Data Team will review it. | |||||
| 23 | 241 contacts → | ||||
Indirect evidence “At Brennan, our people are our top priority.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 24 | 238 contacts → | ||||
Partial evidence “Environmental Works, Inc.(EWI) offers truly comprehensive environmental solutions for a variety of industries, businesses, and municipalities.” Source: RevenueBase Database · checked Sep 14, 2026Thanks. The Data Team will review it. | |||||
| 25 | 236 contacts → | ||||
Partial evidence “Ballard Marine Construction (Ballard) is a specialty marine and underwater contractor.” Source: RevenueBase Database · checked Sep 14, 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: marine environmental consultancies. 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 marine environmental consultancies.
- Partial evidence
- Its own public description names part of marine environmental consultancies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name marine environmental consultancies. 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 2,416 marine environmental consultancies based in the United States
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Marine environmental consultancies based in the United States at a glance
As of Sep 14, 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 2,416 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 marine environmental consultancies, 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 “marine environmental consultancies”. 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 marine environmental consultancies), 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 marine environmental consultancies, 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, 21,426 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 14, 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.
Marine environmental consultancies 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 marine environmental consultancies, 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 marine environmental consultancies are there based in the United States?
RevenueBase identified 2,416 marine environmental consultancies 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 marine environmental consultancies?
Houston leads with 97 headquartered companies, followed by Seattle (48) and Miami (33).
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 21,426 verified decision-maker contacts tracked across these 2,416 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 14, 2026.
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Marine environmental consultancies by geography
- Marine environmental consultancies based in Brisbane, Australia
- Marine environmental consultancies based in Melbourne, Australia
- Marine environmental consultancies based in Perth, Australia
- Marine environmental consultancies based in Sydney, Australia
- Marine environmental consultancies based in Belo Horizonte, Brazil
- Marine environmental consultancies based in Campinas, Brazil
- Marine environmental consultancies based in Curitiba, Brazil
- Marine environmental consultancies based in Porto Alegre, Brazil
- Marine environmental consultancies based in Rio De Janeiro, Brazil
- Marine environmental consultancies based in Santos, Brazil
- Marine environmental consultancies based in Sao Paulo, Brazil
- Marine environmental consultancies based in Calgary, Canada
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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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