Company lists · Data refreshed September 2026

Top 25 Wastewater consulting firms worldwide

Name: Wastewater consulting firms worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 29, 2026 15,595 companies tracked

RevenueBase identified 15,595 wastewater consulting firms worldwide as of September 2026 and tracks 488,968 professional contacts across them, including 172,146 with verified work emails. The United States is the largest market and Sao Paulo the largest hub.

This list covers wastewater 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 wastewater 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

15,595Companies

488,968Contacts tracked

172,146Verified emails

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The 25 largest wastewater consulting firms worldwide

Ranked by team size

Top 25 of 15,595 wastewater 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 wastewater 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	AECOM	Indirect evidence	Dallas, TX, United StatesHQ checked Sep 29, 2026	10001+	63,914 contacts →
	Indirect evidence “AECOM is the global infrastructure leader, committed to delivering a better world.” Source: RevenueBase Database · checked Sep 29, 2026
2	Stantec	Indirect evidence	Edmonton, AB, CanadaHQ checked Sep 29, 2026	10001+	28,416 contacts →
	Indirect evidence “Stantec empowers clients, people, and communities to rise to the world’s greatest challenges at a time when the world faces more unprecedented concerns than ever before.” Source: RevenueBase Database · checked Sep 29, 2026
3	SUEZ	Indirect evidence	Paris, FranceHQ checked Sep 29, 2026	10001+	21,549 contacts →
	Indirect evidence “We provide essential services in the water and waste sectors to preserve resources and improve quality of life wherever we operate.” Source: RevenueBase Database · checked Sep 29, 2026
4	GHD	Indirect evidence	Sydney, AustraliaHQ checked Sep 29, 2026	10001+	14,572 contacts →
	Indirect evidence “We are committed to addressing the world’s biggest challenges in the areas of water, energy and communities.” Source: RevenueBase Database · checked Sep 29, 2026
5	Tetra Tech	Indirect evidence	Pasadena, CA, United StatesHQ checked Sep 29, 2026	10001+	12,999 contacts →
	Indirect 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
6	CDM Smith	Indirect evidence	Boston, MA, United StatesHQ checked Sep 29, 2026	5,001-10,000	7,527 contacts →
	Indirect evidence “CDM Smith is shaping what’s next, now, with world class solutions in water, environment, transportation and energy to public and private clients worldwide.” Source: RevenueBase Database · checked Sep 29, 2026
7	Terracon	Partial evidence	Olathe, KS, United StatesHQ checked Sep 29, 2026	5,001-10,000	6,113 contacts →
	Partial evidence “Terracon is a 100 percent employee-owned consulting engineering firm providing quality services to clients.” Source: RevenueBase Database · checked Sep 29, 2026
8	ION Exchange India LTD	Indirect evidence	Mumbai, IndiaHQ checked Sep 29, 2026	1,001-5,000	3,810 contacts →
	Indirect evidence “At Ion Exchange India, we bring you total environment solutions - water treatment, liquid waste treatment & recycle, air pollution control, solid & hazardous waste management and…” Source: RevenueBase Database · checked Sep 29, 2026
9	STV	Indirect evidence	New York, NY, United StatesHQ checked Sep 29, 2026	1,001-5,000	3,556 contacts →
	Indirect evidence “STV offers professional services for the infrastructure that powers our lives.” Source: RevenueBase Database · checked Sep 29, 2026
10	Golder	Indirect evidence	Vancouver, BC, CanadaHQ checked Sep 29, 2026	5,001-10,000	3,167 contacts →
	Indirect evidence “Golder was acquired by WSP.” Source: RevenueBase Database · checked Sep 29, 2026
11	APTIM	Indirect evidence	Baton Rouge, LA, United StatesHQ checked Sep 29, 2026	1,001-5,000	2,639 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
12	Brown And Caldwell	Indirect evidence	Walnut Creek, CA, United StatesHQ checked Sep 29, 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 29, 2026
13	Geosyntec Consultants	Partial evidence	Boca Raton, FL, United StatesHQ checked Sep 29, 2026	1,001-5,000	2,393 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
14	VA Tech Wabag LTD	Indirect evidence	Wabag House, IndiaHQ checked Sep 29, 2026	1,001-5,000	2,375 contacts →
	Indirect evidence “WABAG, a global leader in the water industry, is backed by rich experience spanning over 100 years.” Source: RevenueBase Database · checked Sep 29, 2026
15	Providence	Partial evidence	Baton Rouge, LA, United StatesHQ checked Sep 29, 2026	n/a	2,232 contacts →
	Partial evidence “Providence is an employee-owned engineering and environmental consulting firm.” Source: RevenueBase Database · checked Sep 29, 2026
16	Civil & Environmental Consultants, INC	Partial evidence	Moon Township, PA, United StatesHQ checked Sep 29, 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 29, 2026
17	Olsson	Indirect evidence	Lincoln, NE, United StatesHQ checked Sep 29, 2026	1,001-5,000	2,108 contacts →
	Indirect evidence “Olsson is an engineering firm made up of people who craft expert solutions and designs that improve communities.” Source: RevenueBase Database · checked Sep 29, 2026
18	Hazen And Sawyer	Indirect evidence	New York, NY, United StatesHQ checked Sep 29, 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 29, 2026
19	ILF Consulting Engineers	Partial evidence	FranceHQ checked Sep 29, 2026	1,001-5,000	1,747 contacts →
	Partial evidence “The ILF Group (ILF) is an international engineering and consulting firm that helps its clients successfully execute technically demanding industrial and infrastructure projects.” Source: RevenueBase Database · checked Sep 29, 2026
20	Burns & Mcdonnell India	Indirect evidence	Vikhroli West, IndiaHQ checked Sep 29, 2026	1,001-5,000	1,724 contacts →
	Indirect evidence “At Burns & McDonnell India, we are a diverse team of talented engineers with multidiscipline design and consultancy working across sectors in critical infrastructure: oil and gas…” Source: RevenueBase Database · checked Sep 29, 2026
21	Carollo Engineers	Partial evidence	Walnut Creek, CA, United StatesHQ checked Sep 29, 2026	1,001-5,000	1,718 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
22	Bowman Consulting	Indirect evidence	Reston, VA, United StatesHQ checked Sep 29, 2026	1,001-5,000	1,666 contacts →
	Indirect evidence “Headquartered in Reston, Virginia, Bowman is a national engineering services firm delivering infrastructure solutions to customers who own, develop and maintain the built…” Source: RevenueBase Database · checked Sep 29, 2026
23	CHA Consulting, INC	Partial evidence	Albany, NY, United StatesHQ checked Sep 29, 2026	1,001-5,000	1,639 contacts →
	Partial evidence “CHA Consulting, Inc.(CHA) is an innovative, full-service engineering, design, consulting, and program/construction management firm providing a wide range of technology-enhanced…” Source: RevenueBase Database · checked Sep 29, 2026
24	Swca Environmental Consultants	Partial evidence	Phoenix, AZ, United StatesHQ checked Sep 29, 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 29, 2026
25	GEI Consultants, INC	Indirect evidence	Woburn, MA, United StatesHQ checked Sep 29, 2026	1,001-5,000	1,604 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 29, 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: wastewater 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 wastewater consulting firms.
Partial evidence: Its own public description names part of wastewater consulting firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name wastewater 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 15,595 wastewater consulting firms worldwide

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Wastewater consulting firms worldwide at a glance

As of Sep 29, 2026

35.2%Verified-email coverage

31.4Average contacts per company

11-50Median size (employees)

0.8%Largest-city concentration · Sao Paulo

Sep 29, 2026Page data refreshed

Companies by employee count

1-10

7,224

11-50

5,307

51-200

1,983

201-500

592

501-1,000

181

1,001-5,000

163

5,001-10,000

10001+

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 wastewater 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 wastewater consulting firms are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “wastewater 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 wastewater 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 wastewater 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, 172,146 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.

Wastewater consulting firms by location

74 lists · largest first

Every Wastewater 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 wastewater 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 wastewater consulting firms are there worldwide?

RevenueBase identified 15,595 wastewater 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 wastewater consulting firms?

The United States leads with 3,631 companies, followed by Brazil (1,161) and India (1,126). Every wastewater consulting firms list by country and city is linked on this page.

Which city has the most wastewater consulting firms?

Sao Paulo leads with 130 headquartered companies, followed by Tehran (118) and Pune (113).

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 172,146 verified decision-maker contacts tracked across these 15,595 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.