Company lists · Data refreshed September 2026

Top 25 Stormwater compliance consulting firms worldwide

RevenueBase identified 2,534 stormwater compliance consulting firms worldwide as of September 2026 and tracks 61,591 professional contacts across them, including 27,507 with verified work emails and 22,582 with mobile numbers. The United States is the largest market and Houston the largest hub.

This list covers stormwater compliance 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 6, 2026. Country and city lists for stormwater compliance 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 6, 2026 86% judged on-target in blind review
2,534Companies
61,591Contacts tracked
27,507Verified emails
22,582Mobile numbers
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The 25 largest stormwater compliance consulting firms worldwide

Ranked by team size
Top 25 of 2,534 stormwater compliance consulting firms worldwide, ranked by team size, largest first. Data refreshed Sep 6, 2026. RevenueBase Smart Search rates how each company's information relates to stormwater compliance 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 evidencePasadena, CA, United StatesHQ checked Sep 6, 202610001+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 6, 2026
2Indirect evidenceWalnut Creek, CA, United StatesHQ checked Sep 6, 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 6, 2026
3Partial evidenceMoon Township, PA, United StatesHQ checked Sep 6, 20261,001-5,0002,145 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 6, 2026
4Indirect evidenceNew York, NY, United StatesHQ checked Sep 6, 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 6, 2026
5Partial evidenceFort Worth, TX, United StatesHQ checked Sep 6, 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 6, 2026
6Indirect evidenceRockville, MD, United StatesHQ checked Sep 6, 20261,001-5,0001,137 contacts →

Indirect evidence

“Who is Apex?”

Source: RevenueBase Database · checked Sep 6, 2026
7Indirect evidenceVitacura, ChileHQ checked Sep 6, 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 6, 2026
8Partial evidenceDallas, TX, United StatesHQ checked Sep 6, 20261,001-5,000961 contacts →

Partial evidence

“Trinity Consultants is a global team of experts helping organizations solve complex challenges in environmental compliance, ecological protection, infrastructure performance, and…”

Source: RevenueBase Database · checked Sep 6, 2026
9Indirect evidenceLafayette, LA, United StatesHQ checked Sep 6, 20261,001-5,000865 contacts →

Indirect evidence

“ATC Group Services LLC is now Atlas.”

Source: RevenueBase Database · checked Sep 6, 2026
10Indirect evidenceRedhill, United KingdomHQ checked Sep 6, 2026501-1,000842 contacts →

Indirect 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 6, 2026
11Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 6, 2026501-1,000732 contacts →

Partial evidence

“ESA is a 100% employee-owned environmental consulting firm.”

Source: RevenueBase Database · checked Sep 6, 2026
12Partial evidenceLaramie, WY, United StatesHQ checked Sep 6, 2026501-1,000577 contacts →

Partial evidence

“Headquartered in Laramie, Wyoming, Trihydro provides environmental consulting, engineering and surveying, air quality and process management, information technology, and water and…”

Source: RevenueBase Database · checked Sep 6, 2026
13Partial evidenceSeattle, WA, United StatesHQ checked Sep 6, 2026501-1,000479 contacts →

Partial evidence

“Headquartered in Seattle, Washington, Anchor QEA is a nationally recognized environmental science and engineering consulting firm specializing in aquatic, shoreline, and water…”

Source: RevenueBase Database · checked Sep 6, 2026
14Partial evidenceVentura, CA, United StatesHQ checked Sep 6, 2026501-1,000479 contacts →

Partial evidence

“Rincon Consultants is a multi-disciplinary environmental sciences, planning, and engineering consulting firm that provides quality professional services to government and industry.”

Source: RevenueBase Database · checked Sep 6, 2026
15Indirect evidenceWall Township, NJ, United StatesHQ checked Sep 6, 2026201-500447 contacts →

Indirect evidence

“We are Groundwater & Environmental Services, Inc, better known as GES.”

Source: RevenueBase Database · checked Sep 6, 2026
16Partial evidenceIslandia, NY, United StatesHQ checked Sep 6, 2026201-500433 contacts →

Partial evidence

“Founded 40 years ago, Roux is recognized for being a highly effective, client-focused environmental consulting and management firm.”

Source: RevenueBase Database · checked Sep 6, 2026
17Indirect evidenceHarrisburg, PA, United StatesHQ checked Sep 6, 2026201-500371 contacts →

Indirect evidence

“HRG assists with the planning, design, and management of community infrastructure.”

Source: RevenueBase Database · checked Sep 6, 2026
18Partial evidenceMarlborough, MA, United StatesHQ checked Sep 6, 202651-200315 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 6, 2026
19Partial evidenceGainesville, VA, United StatesHQ checked Sep 6, 2026201-500268 contacts →

Partial evidence

“For more than 30 years, WSSI has been the trusted partner in environmental, regulatory, cultural resources, and water resources engineering consulting.”

Source: RevenueBase Database · checked Sep 6, 2026
20Indirect evidenceBloomfield Hills, MI, United StatesHQ checked Sep 6, 2026201-500250 contacts →

Indirect evidence

“Celebrating years of innovation and design, HRC provides professional engineering, environmental engineering, and architectural services to municipal, industrial and private…”

Source: RevenueBase Database · checked Sep 6, 2026
21Indirect evidenceSpringfield, MO, United StatesHQ checked Sep 6, 2026201-500238 contacts →

Indirect evidence

“Environmental Works, Inc.(EWI) offers truly comprehensive environmental solutions for a variety of industries, businesses, and municipalities.”

Source: RevenueBase Database · checked Sep 6, 2026
22Indirect evidenceGoiânia, BrazilHQ checked Sep 6, 2026201-500234 contacts →

Indirect evidence

“A GAP Ambiental oferece serviços para pequenas, médias e grandes empresas em diversas áreas que vão desde o licenciamento ao acompanhamento da execução de projetos.”

Source: RevenueBase Database · checked Sep 6, 2026
23Indirect evidenceOttawa, ON, CanadaHQ checked Sep 6, 2026201-500210 contacts →

Indirect evidence

“Since 1976, BluMetric has been delivering innovative and sustainable solutions to complex environmental challenges.”

Source: RevenueBase Database · checked Sep 6, 2026
24Partial evidenceLa Mesa, CA, United StatesHQ checked Sep 6, 2026201-500199 contacts →

Partial evidence

“HELIX Environmental Planning, Inc.(HELIX) is an employee-owned, environmental consulting firm established in 1991 and with offices in San Diego, Los Angeles, Orange, Riverside…”

Source: RevenueBase Database · checked Sep 6, 2026
25Indirect evidenceBedford, NH, United StatesHQ checked Sep 6, 2026201-500189 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 6, 2026

Showing 25 of 2,534 stormwater compliance consulting firms worldwide

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Stormwater compliance consulting firms worldwide at a glance

As of Sep 6, 2026
44.7%Verified-email coverage
36.7%Mobile-number coverage
24.3Average contacts per company
1-10Median size (employees)
1.6%Largest-city concentration · Houston
Sep 6, 2026Page data refreshed

Companies by employee count

1-10
1,471
11-50
809
51-200
183
201-500
35
501-1,000
11
1,001-5,000
12
10001+
2

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 stormwater compliance 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
10 countries, largest first: the United States, Brazil, Canada, France, Australia, India, Germany, the United Kingdom, Chile, Italy. Country and city lists for stormwater compliance consulting firms are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “stormwater compliance 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 stormwater compliance 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 stormwater compliance 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, 27,507 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 between September 6, 2026 and September 14, 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.

Stormwater compliance consulting firms by location

11 lists · largest first

Every Stormwater compliance 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 stormwater compliance 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 stormwater compliance consulting firms are there worldwide?

RevenueBase identified 2,534 stormwater compliance 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?

Tetra Tech, headquartered in Pasadena, tops this list with the largest team on record.

Which country has the most stormwater compliance consulting firms?

The United States leads with 1,778 companies, followed by Brazil (213) and Canada (109). Every stormwater compliance consulting firms list by country and city is linked on this page.

Which city has the most stormwater compliance consulting firms?

Houston leads with 40 headquartered companies, followed by Sao Paulo (23) and Seattle (22).

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 27,507 verified decision-maker contacts tracked across these 2,534 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled from the company graph between September 6, 2026 and September 14, 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.