Company lists · Data refreshed September 2026

Top 25 Wastewater treatment plant builders based in the United States

RevenueBase identified 765 wastewater treatment plant builders headquartered in the United States as of September 2026 and tracks 14,275 professional contacts across them, including 6,568 with verified work emails. Houston is the largest hub.

This list covers wastewater treatment plant builders 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 22, 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 22, 2026 86% judged on-target in blind review
765Companies
14,275Contacts tracked
6,568Verified emails
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The 25 largest wastewater treatment plant builders based in the United States

Ranked by team size
Top 25 of 765 wastewater treatment plant builders based in the United States, ranked by team size, largest first. Data refreshed Sep 22, 2026. RevenueBase Smart Search rates how each company's information relates to wastewater treatment plant builders: 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 evidenceWalnut Creek, CA, United StatesHQ checked Sep 22, 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 22, 2026
2Strong evidenceSalt Lake City, UT, United StatesHQ checked Sep 22, 2026501-1,000554 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 22, 2026
3Strong evidenceWaukegan, IL, United StatesHQ checked Sep 22, 2026201-500389 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 22, 2026
4Strong evidenceOld Saybrook, CT, United StatesHQ checked Sep 22, 2026501-1,000295 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 22, 2026
5Indirect evidenceDenver, NC, United StatesHQ checked Sep 22, 2026201-500243 contacts →

Indirect evidence

“HUBER Technology, LLC, the U.S.”

Source: RevenueBase Database · checked Sep 22, 2026
6Indirect evidenceLoves Park, IL, United StatesHQ checked Sep 22, 202651-200207 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 22, 2026
7Partial evidenceMinneapolis, MN, United StatesHQ checked Sep 22, 2026201-500195 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 22, 2026
8Strong evidenceCoraopolis, PA, United StatesHQ checked Sep 22, 2026201-500185 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 22, 2026
9Indirect evidencePhoenix, AZ, United StatesHQ checked Sep 22, 2026201-500178 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 22, 2026
10Strong evidenceLenexa, KS, United StatesHQ checked Sep 22, 2026201-500172 contacts →

Strong evidence

“S&L delivers long-lasting, reliable and easy-to-operate wastewater pumping and treatment systems for municipal, federal, and industrial-commercial applications.”

Source: RevenueBase Database · checked Sep 22, 2026
11Partial evidenceSutherlin, OR, United StatesHQ checked Sep 22, 2026201-500170 contacts →

Partial evidence

“Nobody wants to worry about whether their wastewater is contaminating nearby rivers, streams, and wells.”

Source: RevenueBase Database · checked Sep 22, 2026
12Partial evidenceBothell, WA, United StatesHQ checked Sep 22, 202651-200136 contacts →

Partial evidence

“RH2 is an innovative, full-service engineering firm specializing in water and wastewater related projects.”

Source: RevenueBase Database · checked Sep 22, 2026
13Indirect evidenceScottsdale, AZ, United StatesHQ checked Sep 22, 202651-200135 contacts →

Indirect evidence

“Water Works Engineers is a leading civil and environmental engineering firm specializing in innovative and sustainable solutions for water infrastructure projects across the…”

Source: RevenueBase Database · checked Sep 22, 2026
14Strong evidenceAnaheim, CA, United StatesHQ checked Sep 22, 202651-200133 contacts →

Strong evidence

“Tomorrow Water is an innovative environmental solutions company specializing in both wastewater and organic waste treatment.”

Source: RevenueBase Database · checked Sep 22, 2026
15Indirect evidenceDeerwood, MN, United StatesHQ checked Sep 22, 2026201-500125 contacts →

Indirect evidence

“At Rice Lake Construction Group, we know water.”

Source: RevenueBase Database · checked Sep 22, 2026
16Indirect evidenceEscondido, CA, United StatesHQ checked Sep 22, 2026201-500122 contacts →

Indirect evidence

“Headquartered in Escondido, California, Filanc is an award-winning, general engineering and design-build contractor that solely constructs, renovates, and expands water and…”

Source: RevenueBase Database · checked Sep 22, 2026
17Indirect evidenceLivermore, CA, United StatesHQ checked Sep 22, 2026201-500112 contacts →

Indirect evidence

“Over the past 45 years, GSE Construction has completed more than projects as a general engineering contractor.”

Source: RevenueBase Database · checked Sep 22, 2026
18Indirect evidenceLoveland, OH, United StatesHQ checked Sep 22, 202611-50111 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 22, 2026
19Indirect evidenceWharton, NJ, United StatesHQ checked Sep 22, 202651-200106 contacts →

Indirect evidence

“GWTT is one of the only U.S.”

Source: RevenueBase Database · checked Sep 22, 2026
20Strong evidenceOklahoma City, OK, United StatesHQ checked Sep 22, 202651-20097 contacts →

Strong evidence

“At World Water Works, we strive to provide industrial and municipal customers with proven and cost-effective wastewater treatment solutions that deliver superior effluent quality.”

Source: RevenueBase Database · checked Sep 22, 2026
21Indirect evidencePuyallup, WA, United StatesHQ checked Sep 22, 2026201-50097 contacts →

Indirect evidence

“Northwest Cascade is a growing company with a variety of related businesses that serve construction and environmental needs.”

Source: RevenueBase Database · checked Sep 22, 2026
22Indirect evidenceElliston, VA, United StatesHQ checked Sep 22, 202651-20095 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 22, 2026
23Strong evidenceDallas, TX, United StatesHQ checked Sep 22, 202651-20092 contacts →

Strong evidence

“Gupta & Associates, Inc.(GAI) was established in Dallas, Texas in January to provide electrical and instrumentation control services for water treatment and wastewater treatment…”

Source: RevenueBase Database · checked Sep 22, 2026
24Indirect evidenceEnglewood, CO, United StatesHQ checked Sep 22, 2026201-50091 contacts →

Indirect evidence

“Western Summit Constructors, Inc.”

Source: RevenueBase Database · checked Sep 22, 2026
25Indirect evidenceMonroe, NC, United StatesHQ checked Sep 22, 202651-20089 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 22, 2026

Showing 25 of 765 wastewater treatment plant builders based in the United States

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Wastewater treatment plant builders based in the United States at a glance

As of Sep 22, 2026
46.0%Verified-email coverage
18.7Average contacts per company
11-50Median size (employees)
2.7%Largest-city concentration · Houston
Sep 22, 2026Page data refreshed

Companies by employee count

1-10
275
11-50
309
51-200
136
201-500
32
501-1,000
6
1,001-5,000
2
5,001-10,000
2
10001+
2

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 765 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 plant builders, 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 plant builders”. 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 plant builders), 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 plant builders, 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, 6,568 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 22, 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.

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 plant builders, 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 plant builders are there based in the United States?

RevenueBase identified 765 wastewater treatment plant builders 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 plant builders?

Houston leads with 21 headquartered companies, followed by Austin (8) and Charlotte (7).

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 6,568 verified decision-maker contacts tracked across these 765 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 22, 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.