Company lists · Data refreshed September 2026

Top 25 Wastewater engineering companies based in the United States

Name: Wastewater engineering companies based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 19, 2026 1,854 companies tracked

RevenueBase identified 1,854 wastewater engineering companies headquartered in the United States as of September 2026 and tracks 66,875 professional contacts across them, including 26,564 with verified work emails. Houston is the largest hub.

This list covers wastewater engineering companies 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 19, 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 19, 2026 86% judged on-target in blind review

1,854Companies

66,875Contacts tracked

26,564Verified emails

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The 25 largest wastewater engineering companies based in the United States

Ranked by team size

Top 25 of 1,854 wastewater engineering companies based in the United States, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to wastewater engineering companies: 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 19, 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 19, 2026
2	CDM Smith	Indirect evidence	Boston, MA, United StatesHQ checked Sep 19, 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 19, 2026
3	Evoqua Water Technologies	Indirect evidence	Washington, DC, United StatesHQ checked Sep 19, 2026	10001+	2,639 contacts →
	Indirect evidence “Evoqua has now joined Xylem.” Source: RevenueBase Database · checked Sep 19, 2026
4	Brown And Caldwell	Indirect evidence	Walnut Creek, CA, United StatesHQ checked Sep 19, 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 19, 2026
5	Hazen And Sawyer	Indirect evidence	New York, NY, United StatesHQ checked Sep 19, 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 19, 2026
6	Carollo Engineers	Partial evidence	Walnut Creek, CA, United StatesHQ checked Sep 19, 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 19, 2026
7	Garney Construction	Partial evidence	North Kansas City, MO, United StatesHQ checked Sep 19, 2026	1,001-5,000	1,009 contacts →
	Partial evidence “Garney Construction is a national leader in water and wastewater construction.” Source: RevenueBase Database · checked Sep 19, 2026
8	Aquatech	Indirect evidence	Canonsburg, PA, United StatesHQ checked Sep 19, 2026	501-1,000	903 contacts →
	Indirect 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 19, 2026
9	Chem-Aqua, INC	Indirect evidence	Wilmington, DE, United StatesHQ checked Sep 19, 2026	10001+	864 contacts →
	Indirect evidence “Chem-Aqua is a unique combination of knowledge, experience and stability.” Source: RevenueBase Database · checked Sep 19, 2026
10	Gradiant	Indirect evidence	Woburn, MA, United StatesHQ checked Sep 19, 2026	1,001-5,000	813 contacts →
	Indirect evidence “Gradiant is a Different Kind of Water Company.” Source: RevenueBase Database · checked Sep 19, 2026
11	Kennedy Jenks	Partial evidence	San Francisco, CA, United StatesHQ checked Sep 19, 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 19, 2026
12	Westech Engineering	Strong evidence	Salt Lake City, UT, United StatesHQ checked Sep 19, 2026	501-1,000	554 contacts →
	Strong 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 19, 2026
13	MWH	Indirect evidence	Broomfield, CO, United StatesHQ checked Sep 19, 2026	501-1,000	428 contacts →
	Indirect evidence “As a leading U.S.” Source: RevenueBase Database · checked Sep 19, 2026
14	Liquid Environmental Solutions	Partial evidence	Irving, TX, United StatesHQ checked Sep 19, 2026	501-1,000	427 contacts →
	Partial evidence “Liquid Environmental Solutions - the largest, exclusively non-hazardous US wastewater collection and disposal company, is known for innovation and leadership in protecting…” Source: RevenueBase Database · checked Sep 19, 2026
15	Wright-Pierce	Strong evidence	Topsham, ME, United StatesHQ checked Sep 19, 2026	201-500	402 contacts →
	Strong evidence “Wright-Pierce is an award-winning, multidiscipline engineering firm that has been providing drinking water, wastewater, and civil infrastructure services since 1947.” Source: RevenueBase Database · checked Sep 19, 2026
16	UCC Environmental	Partial evidence	Waukegan, IL, United StatesHQ checked Sep 19, 2026	201-500	389 contacts →
	Partial evidence “UCC Environmental (UCC) is a global leader in environmental solutions for solids handling, wastewater treatment and pollution control technologies in power generation and other…” Source: RevenueBase Database · checked Sep 19, 2026
17	Baxter & Woodman	Indirect evidence	Crystal Lake, IL, United StatesHQ checked Sep 19, 2026	201-500	385 contacts →
	Indirect evidence “Founded in 1946, Baxter & Woodman, Inc.” Source: RevenueBase Database · checked Sep 19, 2026
18	Ae2s Advanced Engineering And Environmental Services, LLC	Partial evidence	Grand Forks, ND, United StatesHQ checked Sep 19, 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 19, 2026
19	Parkson Corporation	Partial evidence	Fort Lauderdale, FL, United StatesHQ checked Sep 19, 2026	51-200	317 contacts →
	Partial evidence “Parkson Corporation is a supplier of innovative, cost effective solutions for potable water, process water, and industrial and municipal wastewater treatment.” Source: RevenueBase Database · checked Sep 19, 2026
20	Tata & Howard, INC	Partial evidence	Marlborough, MA, United StatesHQ checked Sep 19, 2026	51-200	315 contacts →
	Partial evidence “Tata & Howard is a 100% employee owned, award-winning, specialized consulting engineering firm dedicated to providing superior client service coupled with delivering…” Source: RevenueBase Database · checked Sep 19, 2026
21	Infiltrator Water Technologies Decentralized Wastewater Treatment Solutions	Partial evidence	Old Saybrook, CT, United StatesHQ checked Sep 19, 2026	501-1,000	295 contacts →
	Partial evidence “Protecting the environment with innovative wastewater treatment solutions for over 35 years, Infiltrator is the leading manufacturer of onsite wastewater treatment products in…” Source: RevenueBase Database · checked Sep 19, 2026
22	West Yost	Partial evidence	Davis, CA, United StatesHQ checked Sep 19, 2026	201-500	279 contacts →
	Partial evidence “West Yost is a water-focused consulting engineering firm ranked by Fortune Magazine as one of the “Best Small and Medium Workplaces in Consulting and Professional Services” 2023 -…” Source: RevenueBase Database · checked Sep 19, 2026
23	Keystone Clearwater Solutions	Indirect evidence	Hershey, PA, United StatesHQ checked Sep 19, 2026	501-1,000	268 contacts →
	Indirect evidence “Keystone Clearwater Solutions is moving water forward with engineered solutions for safer, more efficient water transfer, water management, and environmental services.” Source: RevenueBase Database · checked Sep 19, 2026
24	Culligan By Waterco	Indirect evidence	Lombard, IL, United StatesHQ checked Sep 19, 2026	501-1,000	265 contacts →
	Indirect evidence “Culligan has over 80 years of experience in the design and distribution of water treatment systems for residential, commercial and industrial applications.” Source: RevenueBase Database · checked Sep 19, 2026
25	Valicor	Indirect evidence	Monroe, OH, United StatesHQ checked Sep 19, 2026	201-500	254 contacts →
	Indirect evidence “Valicor is a trusted partner for sustainable waste management solutions.” Source: RevenueBase Database · checked Sep 19, 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 engineering companies. 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 engineering companies.
Partial evidence: Its own public description names part of wastewater engineering companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name wastewater engineering companies. 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 1,854 wastewater engineering companies based in the United States

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Wastewater engineering companies based in the United States at a glance

As of Sep 19, 2026

39.7%Verified-email coverage

36.1Average contacts per company

11-50Median size (employees)

2.8%Largest-city concentration · Houston

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

751

11-50

725

51-200

275

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 1,854 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 wastewater engineering companies, 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 “wastewater engineering companies”. 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 engineering companies), 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 engineering companies, 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, 26,564 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 19, 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 engineering companies by metro

Wastewater engineering companies in Houston51

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 engineering companies, 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 engineering companies are there based in the United States?

RevenueBase identified 1,854 wastewater engineering companies 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 wastewater engineering companies?

Houston leads with 51 headquartered companies, followed by Austin (19) and Charlotte (16).

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 26,564 verified decision-maker contacts tracked across these 1,854 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 19, 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.