Company lists · Data refreshed September 2026

Top 25 Wastewater treatment companies based in the United States

Name: Wastewater treatment 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 16, 2026 1,840 companies tracked

RevenueBase identified 1,840 wastewater treatment companies headquartered in the United States as of September 2026 and tracks 38,071 professional contacts across them, including 16,269 with verified work emails. Houston is the largest hub.

This list covers wastewater treatment 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 16, 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 16, 2026 86% judged on-target in blind review

1,840Companies

38,071Contacts tracked

16,269Verified emails

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The 25 largest wastewater treatment companies based in the United States

Ranked by team size

Top 25 of 1,840 wastewater treatment companies based in the United States, ranked by team size, largest first. Data refreshed Sep 16, 2026. RevenueBase Smart Search rates how each company's information relates to wastewater treatment 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	Carollo Engineers	Partial evidence	Walnut Creek, CA, United StatesHQ checked Sep 16, 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 16, 2026
2	Chemtreat	Indirect evidence	Glen Allen, VA, United StatesHQ checked Sep 16, 2026	1,001-5,000	1,404 contacts →
	Indirect evidence “At ChemTreat, we understand that water is a vital resource for our planet.” Source: RevenueBase Database · checked Sep 16, 2026
3	Inframark	Indirect evidence	Horsham, PA, United StatesHQ checked Sep 16, 2026	1,001-5,000	973 contacts →
	Indirect evidence “As an Azuria owned company, Inframark is a widely recognized leader in Water Infrastructure Operations and Infrastructure Management Services.” Source: RevenueBase Database · checked Sep 16, 2026
4	Aquatech	Indirect evidence	Canonsburg, PA, United StatesHQ checked Sep 16, 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 16, 2026
5	Crystal Clean	Indirect evidence	Hoffman Estates, IL, United StatesHQ checked Sep 16, 2026	1,001-5,000	899 contacts →
	Indirect evidence “Crystal Clean is a national leader in the environmental services market, providing the smart alternative.” Source: RevenueBase Database · checked Sep 16, 2026
6	Gradiant	Indirect evidence	Woburn, MA, United StatesHQ checked Sep 16, 2026	1,001-5,000	813 contacts →
	Indirect evidence “Gradiant is a Different Kind of Water Company.” Source: RevenueBase Database · checked Sep 16, 2026
7	Westech Engineering	Strong evidence	Salt Lake City, UT, United StatesHQ checked Sep 16, 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 16, 2026
8	HRSD	Indirect evidence	Virginia Beach, VA, United StatesHQ checked Sep 16, 2026	501-1,000	526 contacts →
	Indirect evidence “Welcome.” Source: RevenueBase Database · checked Sep 16, 2026
9	Liquid Environmental Solutions	Partial evidence	Irving, TX, United StatesHQ checked Sep 16, 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 16, 2026
10	UCC Environmental	Strong evidence	Waukegan, IL, United StatesHQ checked Sep 16, 2026	201-500	389 contacts →
	Strong 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 16, 2026
11	North Texas Municipal Water District	Partial evidence	Wylie, TX, United StatesHQ checked Sep 16, 2026	501-1,000	369 contacts →
	Partial evidence “About Us: The North Texas Municipal Water District (NTMWD) is a regional provider of water, wastewater and solid waste disposal services.” Source: RevenueBase Database · checked Sep 16, 2026
12	Parkson Corporation	Strong evidence	Fort Lauderdale, FL, United StatesHQ checked Sep 16, 2026	51-200	317 contacts →
	Strong 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 16, 2026
13	Infiltrator Water Technologies Decentralized Wastewater Treatment Solutions	Strong evidence	Old Saybrook, CT, United StatesHQ checked Sep 16, 2026	501-1,000	295 contacts →
	Strong 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 16, 2026
14	Culligan By Waterco	Partial evidence	Lombard, IL, United StatesHQ checked Sep 16, 2026	501-1,000	265 contacts →
	Partial 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 16, 2026
15	Toho Water Authority	Partial evidence	Kissimmee, FL, United StatesHQ checked Sep 16, 2026	501-1,000	256 contacts →
	Partial evidence “Toho Water Authority was established in 2003 by a special act of the Florida legislature and provides a full range of water, wastewater and reclaimed water services to its…” Source: RevenueBase Database · checked Sep 16, 2026
16	Valicor	Indirect evidence	Monroe, OH, United StatesHQ checked Sep 16, 2026	201-500	254 contacts →
	Indirect evidence “Valicor is a trusted partner for sustainable waste management solutions.” Source: RevenueBase Database · checked Sep 16, 2026
17	Huber Technology US	Indirect evidence	Denver, NC, United StatesHQ checked Sep 16, 2026	201-500	243 contacts →
	Indirect evidence “HUBER Technology, LLC, the U.S.” Source: RevenueBase Database · checked Sep 16, 2026
18	Alcosan	Partial evidence	Pittsburgh, PA, United StatesHQ checked Sep 16, 2026	201-500	242 contacts →
	Partial evidence “ALCOSAN is one of the Pittsburgh region’s premiere environmental and public health organizations, treating wastewater for 83 Allegheny County communities, including the City of…” Source: RevenueBase Database · checked Sep 16, 2026
19	Usabluebook	Partial evidence	Waukegan, IL, United StatesHQ checked Sep 16, 2026	5,001-10,000	241 contacts →
	Partial evidence “Rely on USABlueBook for everything you need for water and wastewater operations and maintenance.” Source: RevenueBase Database · checked Sep 16, 2026
20	Superior Environmental Solutions, LLC	Indirect evidence	Cincinnati, OH, United StatesHQ checked Sep 16, 2026	501-1,000	225 contacts →
	Indirect evidence “Superior Environmental Solutions, LLC (SES) is an industrial cleaning service company founded in response to the growing need for a superior and cost effective service provider.” Source: RevenueBase Database · checked Sep 16, 2026
21	Aqua-Aerobic Systems, INC	Indirect evidence	Loves Park, IL, United StatesHQ checked Sep 16, 2026	51-200	207 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 16, 2026
22	Stage 3 Separation	Indirect evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	201-500	205 contacts →
	Indirect evidence “Stage 3 Separation is North America’s leading service provider for fluid conservation, solids control and waste mitigation.” Source: RevenueBase Database · checked Sep 16, 2026
23	Fluence Corporation	Partial evidence	Minneapolis, MN, United StatesHQ checked Sep 16, 2026	201-500	195 contacts →
	Partial evidence “Formed in 2017 following the consolidation of independent water treatment solution providers Emefcy and RWL Water, Fluence Corporation was established with the vision of becoming…” Source: RevenueBase Database · checked Sep 16, 2026
24	Newterra	Strong evidence	Coraopolis, PA, United StatesHQ checked Sep 16, 2026	201-500	185 contacts →
	Strong evidence “Newterra designs, engineers, manufactures, and services environmental, water and wastewater treatment solutions that assure great performance, superb reliability, and the highest…” Source: RevenueBase Database · checked Sep 16, 2026
25	Felix Construction Company	Indirect evidence	Phoenix, AZ, United StatesHQ checked Sep 16, 2026	201-500	178 contacts →
	Indirect evidence “Felix Construction Company is a general engineering contractor and construction management company with a specific focus on: Water production facilities, well sites, booster pump…” Source: RevenueBase Database · checked Sep 16, 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 treatment 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 treatment companies.
Partial evidence: Its own public description names part of wastewater treatment companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name wastewater treatment 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 1,840 wastewater treatment companies based in the United States

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Wastewater treatment companies based in the United States at a glance

As of Sep 16, 2026

42.7%Verified-email coverage

20.7Average contacts per company

11-50Median size (employees)

2.8%Largest-city concentration · Houston

Sep 16, 2026Page data refreshed

Companies by employee count

1-10

728

11-50

687

51-200

294

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 1,840 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 treatment 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 treatment 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 treatment 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 treatment 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, 16,269 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 16, 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 treatment companies by metro

Wastewater treatment 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 treatment 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 treatment companies are there based in the United States?

RevenueBase identified 1,840 wastewater treatment 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?

Carollo Engineers, headquartered in Walnut Creek, tops this list with the largest team on record.

Which city has the most wastewater treatment companies?

Houston leads with 51 headquartered companies, followed by Charlotte (14) and Phoenix (14).

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 16,269 verified decision-maker contacts tracked across these 1,840 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 16, 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.