Company lists · Data refreshed September 2026

Top 25 Water compliance consulting firms based in the United States

Name: Water 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 14, 2026 2,220 companies tracked

RevenueBase identified 2,220 water compliance consulting firms headquartered in the United States as of September 2026 and tracks 60,865 professional contacts across them, including 28,527 with verified work emails. Houston is the largest hub.

This list covers water 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 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 14, 2026 86% judged on-target in blind review

2,220Companies

60,865Contacts tracked

28,527Verified emails

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

Ranked by team size

Top 25 of 2,220 water compliance consulting firms based in the United States, ranked by team size, largest first. Data refreshed Sep 14, 2026. RevenueBase Smart Search rates how each company's information relates to water 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	Tetra Tech	Partial evidence	Pasadena, CA, United StatesHQ checked Sep 14, 2026	10001+	12,999 contacts →
	Partial evidence “Tetra Tech is the leader in water, environment and sustainable infrastructure, providing high-end technical and engineering services for projects worldwide.” Source: RevenueBase Database · checked Sep 14, 2026
2	Brown And Caldwell	Indirect evidence	Walnut Creek, CA, United StatesHQ checked Sep 14, 2026	1,001-5,000	2,473 contacts →
	Indirect evidence “Headquartered in Walnut Creek, Calif, Brown and Caldwell is an employee-owned firm with 2,100+ professionals serving clients locally and globally from 52 locations.” Source: RevenueBase Database · checked Sep 14, 2026
3	Civil & Environmental Consultants, INC	Partial evidence	Moon Township, PA, United StatesHQ checked Sep 14, 2026	1,001-5,000	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 14, 2026
4	Hazen And Sawyer	Indirect evidence	New York, NY, United StatesHQ checked Sep 14, 2026	1,001-5,000	2,100 contacts →
	Indirect evidence “As Hazen marks 75 years, we celebrate a legacy of absolute commitment to our clients while delivering the best technical work available anywhere.” Source: RevenueBase Database · checked Sep 14, 2026
5	Swca Environmental Consultants	Partial evidence	Phoenix, AZ, United StatesHQ checked Sep 14, 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 14, 2026
6	Apex Companies	Indirect evidence	Rockville, MD, United StatesHQ checked Sep 14, 2026	1,001-5,000	1,137 contacts →
	Indirect evidence “Who is Apex?” Source: RevenueBase Database · checked Sep 14, 2026
7	Barr Engineering CO	Partial evidence	Minneapolis, MN, United StatesHQ checked Sep 14, 2026	1,001-5,000	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, 2026
8	Trinity Consultants	Partial evidence	Dallas, TX, United StatesHQ checked Sep 14, 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 14, 2026
9	Alliance Technical Group	Indirect evidence	Decatur, AL, United StatesHQ checked Sep 14, 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 14, 2026
10	ATC Group Services LLC	Indirect evidence	Lafayette, LA, United StatesHQ checked Sep 14, 2026	1,001-5,000	865 contacts →
	Indirect evidence “ATC Group Services LLC is now Atlas.” Source: RevenueBase Database · checked Sep 14, 2026
11	Antea Group USA	Partial evidence	St Paul, MN, United StatesHQ checked Sep 14, 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 14, 2026
12	Kennedy Jenks	Partial evidence	San Francisco, CA, United StatesHQ checked Sep 14, 2026	201-500	578 contacts →
	Partial evidence “For over 100 years, Kennedy Jenks has provided engineering and scientific solutions for innovative water and environmental projects.” Source: RevenueBase Database · checked Sep 14, 2026
13	Trihydro Corporation	Strong evidence	Laramie, WY, United StatesHQ checked Sep 14, 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 14, 2026
14	Anchor QEA	Strong evidence	Seattle, WA, United StatesHQ checked Sep 14, 2026	501-1,000	479 contacts →
	Strong 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, 2026
15	Rincon Consultants	Partial evidence	Ventura, CA, United StatesHQ checked Sep 14, 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 14, 2026
16	Groundwater & Environmental Services, INC	Indirect evidence	Wall Township, NJ, United StatesHQ checked Sep 14, 2026	201-500	447 contacts →
	Indirect evidence “We are Groundwater & Environmental Services, Inc, better known as GES.” Source: RevenueBase Database · checked Sep 14, 2026
17	ROUX	Partial evidence	Islandia, NY, United StatesHQ checked Sep 14, 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 14, 2026
18	Barton & Loguidice	Partial evidence	Liverpool, NY, United StatesHQ checked Sep 14, 2026	201-500	355 contacts →
	Partial evidence “Barton & Loguidice is a multidisciplinary consulting firm providing technical services to public and private clients.” Source: RevenueBase Database · checked Sep 14, 2026
19	Ae2s Advanced Engineering And Environmental Services, LLC	Partial evidence	Grand Forks, ND, United StatesHQ checked Sep 14, 2026	201-500	339 contacts →
	Partial evidence “AE2S is a specialized civil/environmental consulting engineering firm that provides professional services and our unique brand of extreme client service to clients in the upper…” Source: RevenueBase Database · checked Sep 14, 2026
20	CME Associates	Indirect evidence	Parlin, NJ, United StatesHQ checked Sep 14, 2026	201-500	336 contacts →
	Indirect evidence “CME Associates, with eight (8) office locations throughout New Jersey, provides a complete range of Environmental, Geotechnical, Engineering, Surveying and Planning services.” Source: RevenueBase Database · checked Sep 14, 2026
21	Environmental Consulting & Technology, Inc. ECT	Partial evidence	Gainesville, FL, United StatesHQ checked Sep 14, 2026	201-500	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, 2026
22	Wetland Studies And Solutions, Inc. Wssi , A Davey Tree Company	Strong evidence	Gainesville, VA, United StatesHQ checked Sep 14, 2026	201-500	268 contacts →
	Strong evidence “For more than 30 years, WSSI has been the trusted partner in environmental, regulatory, cultural resources, and water resources engineering consulting.” Source: RevenueBase Database · checked Sep 14, 2026
23	GSI Environmental INC	Partial evidence	Houston, TX, United StatesHQ checked Sep 14, 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 14, 2026
24	Environmental Works, INC	Indirect evidence	Springfield, MO, United StatesHQ checked Sep 14, 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 14, 2026
25	Metiri Group	Indirect evidence	Clovis, CA, United StatesHQ checked Sep 14, 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 14, 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: water 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 water compliance consulting firms.
Partial evidence: Its own public description names part of water 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 water 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 2,220 water compliance consulting firms based in the United States

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

As of Sep 14, 2026

46.9%Verified-email coverage

27.4Average contacts per company

1-10Median size (employees)

2.3%Largest-city concentration · Houston

Sep 14, 2026Page data refreshed

Companies by employee count

1-10

1,159

11-50

781

51-200

212

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

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 2,220 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 water 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 “water 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 water 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 water 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, 28,527 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.

Water compliance consulting firms by metro

Water compliance consulting firms in Houston50

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

RevenueBase identified 2,220 water 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?

Tetra Tech, headquartered in Pasadena, tops this list with the largest team on record.

Which city has the most water compliance consulting firms?

Houston leads with 50 headquartered companies, followed by Denver (24) and Seattle (24).

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 28,527 verified decision-maker contacts tracked across these 2,220 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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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.