Company lists · Data refreshed September 2026

Top 25 Water security consulting firms worldwide

RevenueBase identified 4,326 water security consulting firms worldwide as of September 2026 and tracks 164,156 professional contacts across them, including 61,090 with verified work emails. The United States is the largest market and Tehran the largest hub.

This list covers water security consulting firms worldwide, 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. Country and city lists for water security consulting firms follow the table.

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
4,326Companies
164,156Contacts tracked
61,090Verified emails
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The 25 largest water security consulting firms worldwide

Ranked by team size
Top 25 of 4,326 water security consulting firms worldwide, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to water security 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceDallas, TX, United StatesHQ checked Sep 29, 202610001+63,914 contacts →

Indirect evidence

“AECOM is the global infrastructure leader, committed to delivering a better world.”

Source: RevenueBase Database · checked Sep 29, 2026
2Partial 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
3Partial evidencePittsburgh, PA, United StatesHQ checked Sep 29, 20265,001-10,0004,362 contacts →

Partial evidence

“Michael Baker International is a leading provider of engineering, consulting, and technology services spanning four Verticals: Infrastructure, Places and Facilities, Federal and…”

Source: RevenueBase Database · checked Sep 29, 2026
4Indirect evidenceBaton Rouge, LA, United StatesHQ checked Sep 29, 20261,001-5,0002,639 contacts →

Indirect evidence

“APTIM enhances the quality of the environment, wellbeing of people, resilience of communities, and opportunity for employees to make a difference, not just a living.”

Source: RevenueBase Database · checked Sep 29, 2026
5Indirect 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
6Partial evidenceBoca Raton, FL, United StatesHQ checked Sep 29, 20261,001-5,0002,393 contacts →

Partial evidence

“Geosyntec is a consulting and engineering firm that works with private and public sector clients to address new ventures and complex problems involving our environment, natural…”

Source: RevenueBase Database · checked Sep 29, 2026
7Indirect 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
8Partial 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
9Partial evidenceFort Worth, TX, United StatesHQ checked Sep 29, 20261,001-5,0001,496 contacts →

Partial evidence

“Freese and Nichols is a professional planning, consulting and engineering firm serving clients across the United States.”

Source: RevenueBase Database · checked Sep 29, 2026
10Partial evidenceHørsholm, DenmarkHQ checked Sep 29, 20261,001-5,0001,427 contacts →

Partial evidence

“There is no substitute for water.”

Source: RevenueBase Database · checked Sep 29, 2026
11Indirect evidenceMorrisville, NC, United StatesHQ checked Sep 29, 2026501-1,0001,175 contacts →

Indirect evidence

“IEM is a professional services firm dedicated to building a safe, secure, and resilient world.”

Source: RevenueBase Database · checked Sep 29, 2026
12Indirect evidenceGurugram, IndiaHQ checked Sep 29, 20261,001-5,0001,144 contacts →

Indirect evidence

“At Voyants, we don't just design infrastructure, we sculpt the future.”

Source: RevenueBase Database · checked Sep 29, 2026
13Indirect evidenceTampa, FL, United StatesHQ checked Sep 29, 20261,001-5,0001,139 contacts →

Indirect evidence

“At Verdantas, we blend engineering and environmental science together with advanced technology and world-renowned labs to create solutions with the big picture in mind.”

Source: RevenueBase Database · checked Sep 29, 2026
14Indirect 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
15Indirect evidenceBurlington, MA, United StatesHQ checked Sep 29, 2026501-1,0001,124 contacts →

Indirect evidence

“Haley & Aldrich is committed to solving our clients’ most meaningful challenges in the built and natural environments.”

Source: RevenueBase Database · checked Sep 29, 2026
16Indirect evidenceVitacura, ChileHQ checked Sep 29, 202610001+988 contacts →

Indirect evidence

“WSP en una empresa líder en servicios profesionales de consultoría en recursos hídricos, ingeniería, medio ambiente y sustentabilidad.”

Source: RevenueBase Database · checked Sep 29, 2026
17Partial evidenceCanonsburg, PA, United StatesHQ checked Sep 29, 2026501-1,000903 contacts →

Partial evidence

“Aquatech enables the world's most recognized companies to solve complex challenges in water reuse, desalination, minimal and zero liquid discharge, and critical minerals…”

Source: RevenueBase Database · checked Sep 29, 2026
18Partial evidenceRedhill, United KingdomHQ checked Sep 29, 2026501-1,000842 contacts →

Partial evidence

“Together with our strategic partners, we can address everything from supporting vulnerable customers, water quality, asset performance and leak detection, to integrated planning…”

Source: RevenueBase Database · checked Sep 29, 2026
19Indirect 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
20Indirect evidenceOlivet, FranceHQ checked Sep 29, 20261,001-5,000737 contacts →

Indirect evidence

“Antea Group est une société internationale d’ingénierie et de conseil en environnement.”

Source: RevenueBase Database · checked Sep 29, 2026
21Indirect evidenceAhmedabad, IndiaHQ checked Sep 29, 20261,001-5,000712 contacts →

Indirect evidence

“In the wake of the devastation caused by the earthquake in Gujarat in 2001, MaRS was established with the objective to provide assistance and aid to the local & state governing…”

Source: RevenueBase Database · checked Sep 29, 2026
22Indirect evidenceMedellín | Bogotá | Lima | Miami | Nueva Delhi, ColombiaHQ checked Sep 29, 20261,001-5,000709 contacts →

Indirect evidence

“Over six decades offering our consultancy services locally and internationally, based on ethical principles and commitments, always through honest, socially responsible actions…”

Source: RevenueBase Database · checked Sep 29, 2026
23Indirect evidenceLondon, United KingdomHQ checked Sep 29, 20261,001-5,000670 contacts →

Indirect evidence

“Click the 'Follow' button and explore careers at Ricardo on our 'Jobs' and 'Life' tabs and at careers.ricardo.com.”

Source: RevenueBase Database · checked Sep 29, 2026
24Indirect evidenceSao Paulo, BrazilHQ checked Sep 29, 2026201-500615 contacts →

Indirect evidence

“Uma equipe multidisciplinar de profissionais permanentemente à sua disposição.”

Source: RevenueBase Database · checked Sep 29, 2026
25Partial evidenceDoetinchem, NetherlandsHQ checked Sep 29, 20261,001-5,000609 contacts →

Partial evidence

“Founded in 1904, Nijhuis Saur Industries provides solid and adaptive solutions for sustainable and resilient water use, energy- and resource recovery.”

Source: RevenueBase Database · checked Sep 29, 2026

Showing 25 of 4,326 water security consulting firms worldwide

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Water security consulting firms worldwide at a glance

As of Sep 29, 2026
37.2%Verified-email coverage
37.9Average contacts per company
1-10Median size (employees)
0.8%Largest-city concentration · Tehran
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
2,456
11-50
1,256
51-200
399
201-500
106
501-1,000
39
1,001-5,000
34
5,001-10,000
10
10001+
8

Email recency is reported on each country list linked below.

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 security 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.
Coverage
Every country. Country and city lists for water security consulting firms are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “water security 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 security 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 security consulting firms, and records with no verified work email.
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, 61,090 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 security consulting firms by location

22 lists · largest first

Every Water security consulting firms list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

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 security 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 security consulting firms are there worldwide?

RevenueBase identified 4,326 water security consulting firms worldwide 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?

AECOM, headquartered in Dallas, tops this list with the largest team on record.

Which country has the most water security consulting firms?

The United States leads with 972 companies, followed by Australia (207) and France (199). Every water security consulting firms list by country and city is linked on this page.

Which city has the most water security consulting firms?

Tehran leads with 34 headquartered companies, followed by Sao Paulo (33) and Paris (26).

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 61,090 verified decision-maker contacts tracked across these 4,326 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.