Company lists · Data refreshed September 2026

Top 25 Water quality management consultants based in the United States

RevenueBase identified 2,548 water quality management consultants headquartered in the United States as of September 2026 and tracks 73,159 professional contacts across them, including 33,948 with verified work emails. Houston is the largest hub.

This list covers water quality management 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 29, 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 29, 2026 86% judged on-target in blind review
2,548Companies
73,159Contacts tracked
33,948Verified emails
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The 25 largest water quality management consultants based in the United States

Ranked by team size
Top 25 of 2,548 water quality management consultants based in the United States, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to water quality management consultants: 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidencePasadena, CA, United StatesHQ checked Sep 29, 202610001+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 29, 2026
2Strong evidenceLoveland, CO, United StatesHQ checked Sep 29, 20261,001-5,0003,095 contacts →

Strong evidence

“At Hach, we ensure water quality for people around the world, and every associate plays a vital role in that mission.”

Source: RevenueBase Database · checked Sep 29, 2026
3Indirect evidenceWalnut Creek, CA, United StatesHQ checked Sep 29, 20261,001-5,0002,473 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 29, 2026
4Partial evidenceMoon Township, PA, United StatesHQ checked Sep 29, 20261,001-5,0002,145 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 29, 2026
5Indirect evidenceNew York, NY, United StatesHQ checked Sep 29, 20261,001-5,0002,100 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 29, 2026
6Partial evidenceWalnut Creek, CA, United StatesHQ checked Sep 29, 20261,001-5,0001,718 contacts →

Partial evidence

“For more than 90 years, Carollo Engineers has been dedicated exclusively to water and wastewater solutions.”

Source: RevenueBase Database · checked Sep 29, 2026
7Partial evidencePhoenix, AZ, United StatesHQ checked Sep 29, 20261,001-5,0001,629 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 29, 2026
8Indirect evidenceRockville, MD, United StatesHQ checked Sep 29, 20261,001-5,0001,137 contacts →

Indirect evidence

“Who is Apex?”

Source: RevenueBase Database · checked Sep 29, 2026
9Indirect evidenceMinneapolis, MN, United StatesHQ checked Sep 29, 20261,001-5,0001,088 contacts →

Indirect 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 29, 2026
10Partial evidenceDallas, TX, United StatesHQ checked Sep 29, 20261,001-5,000961 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 29, 2026
11Indirect evidenceDecatur, AL, United StatesHQ checked Sep 29, 20261,001-5,000956 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 29, 2026
12Indirect evidenceLafayette, LA, United StatesHQ checked Sep 29, 20261,001-5,000865 contacts →

Indirect evidence

“ATC Group Services LLC is now Atlas.”

Source: RevenueBase Database · checked Sep 29, 2026
13Indirect evidenceWilmington, DE, United StatesHQ checked Sep 29, 202610001+864 contacts →

Indirect evidence

“Chem-Aqua is a unique combination of knowledge, experience and stability.”

Source: RevenueBase Database · checked Sep 29, 2026
14Indirect evidenceDe Pere, WI, United StatesHQ checked Sep 29, 2026501-1,000781 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 29, 2026
15Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 29, 2026201-500578 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 29, 2026
16Strong evidenceLaramie, WY, United StatesHQ checked Sep 29, 2026501-1,000577 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 29, 2026
17Partial evidenceSalt Lake City, UT, United StatesHQ checked Sep 29, 2026501-1,000554 contacts →

Partial evidence

“WesTech Engineering, LLC designs, engineers, and manufactures water and wastewater treatment process equipment for mineral, industrial, and municipal applications worldwide.”

Source: RevenueBase Database · checked Sep 29, 2026
18Partial evidenceSeattle, WA, United StatesHQ checked Sep 29, 2026501-1,000479 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 29, 2026
19Strong evidenceVentura, CA, United StatesHQ checked Sep 29, 2026501-1,000479 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 29, 2026
20Indirect evidenceWall Township, NJ, United StatesHQ checked Sep 29, 2026201-500447 contacts →

Indirect evidence

“We are Groundwater & Environmental Services, Inc, better known as GES.”

Source: RevenueBase Database · checked Sep 29, 2026
21Partial evidenceIslandia, NY, United StatesHQ checked Sep 29, 2026201-500433 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 29, 2026
22Indirect evidenceCrystal Lake, IL, United StatesHQ checked Sep 29, 2026201-500385 contacts →

Indirect evidence

“Founded in 1946, Baxter & Woodman, Inc.”

Source: RevenueBase Database · checked Sep 29, 2026
23Indirect evidenceLiverpool, NY, United StatesHQ checked Sep 29, 2026201-500355 contacts →

Indirect evidence

“Barton & Loguidice is a multidisciplinary consulting firm providing technical services to public and private clients.”

Source: RevenueBase Database · checked Sep 29, 2026
24Indirect evidenceGrand Forks, ND, United StatesHQ checked Sep 29, 2026201-500339 contacts →

Indirect 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 29, 2026
25Indirect evidenceParlin, NJ, United StatesHQ checked Sep 29, 2026201-500336 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 29, 2026

Showing 25 of 2,548 water quality management consultants based in the United States

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Water quality management consultants based in the United States at a glance

As of Sep 29, 2026
46.4%Verified-email coverage
28.7Average contacts per company
11-50Median size (employees)
2.2%Largest-city concentration · Houston
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
1,253
11-50
933
51-200
277
201-500
41
501-1,000
8
1,001-5,000
18
5,001-10,000
4
10001+
5

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 2,548 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 quality management 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 “water quality management 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 water quality management 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 water quality management 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, 33,948 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 29, 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 quality management 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 water quality management 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 water quality management consultants are there based in the United States?

RevenueBase identified 2,548 water quality management 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?

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

Which city has the most water quality management consultants?

Houston leads with 55 headquartered companies, followed by New York (21) and Seattle (21).

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 33,948 verified decision-maker contacts tracked across these 2,548 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 29, 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.