Company lists · Data refreshed September 2026

Top 25 Hydrogeology companies based in the United States

RevenueBase identified 3,115 company matches for hydrogeology companies associated with the United States as of September 2026 and tracks 141,143 professional contacts across them, including 53,180 with verified work emails. Houston is the largest hub.

This list covers company matches for hydrogeology companies associated with the United States, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed September 21, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 RevenueBase SmartSearch · Exact Recorded Sep 21, 2026 How this list was built
3,115Companies
141,143Contacts tracked
53,180Verified emails
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The 25 largest hydrogeology companies based in the United States

Ranked by team size
Top 25 of 3,115 company matches for hydrogeology companies based in the United States, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 21, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchHouston, TX, United StatesHQ recorded Sep 21, 202610001+53,380 contacts →

Exact match

“We collaborate and engineer solutions to maximize asset value for our customers.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
2Exact matchPasadena, CA, United StatesHQ recorded Sep 21, 202610001+12,999 contacts →

Exact match

“Tetra Tech is the leader in water, environment and sustainable infrastructure, providing high-end technical and engineering services for projects worldwide.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
3Exact matchOlathe, KS, United StatesHQ recorded Sep 21, 20265,001-10,0006,113 contacts →

Exact match

“Terracon is a 100 percent employee-owned consulting engineering firm providing quality services to clients.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
4Exact matchWalnut Creek, CA, United StatesHQ recorded Sep 21, 20261,001-5,0002,473 contacts →

Exact match

“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.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
5Exact matchChantilly, VA, United StatesHQ recorded Sep 21, 20261,001-5,0002,210 contacts →

Exact match

“ECS Group of Companies is a Chantilly, VA-based consulting engineering firm.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
6Exact matchParsippany, NJ, United StatesHQ recorded Sep 21, 20261,001-5,0002,177 contacts →

Exact match

“Langan's client-focused, highly entrepreneurial culture cultivates an environment of opportunities in which career growth and teamwork flourish.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
7Exact matchNew York, NY, United StatesHQ recorded Sep 21, 20261,001-5,0002,100 contacts →

Exact match

“As Hazen marks 75 years, we celebrate a legacy of absolute commitment to our clients while delivering the best technical work available anywhere.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
8Exact matchGainesville, TX, United StatesHQ recorded Sep 21, 20261,001-5,0001,605 contacts →

Exact match

“Select is a leader in water management and chemical technology to our customers in the oil and gas industry, as well as in other industrial applications.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
9Exact matchKaty, TX, United StatesHQ recorded Sep 21, 20261,001-5,0001,244 contacts →

Exact match

“Newpark Fluids Systems is the world’s leading pure-play oil & gas and geothermal fluid solutions provider.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
10Exact matchDenver, CO, United StatesHQ recorded Sep 21, 20261,001-5,0001,231 contacts →

Exact match

“Knight Piésold is an employee-owned, global consulting firm providing specialist services to the mining, power, water resources, and infrastructure industries.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
11Exact matchPortland, ME, United StatesHQ recorded Sep 21, 20261,001-5,0001,060 contacts →

Exact match

“Woodard & Curran is more than just a consulting firm – we are an employee-owned integrated science, engineering, design-build, and operations company specializing in water and…”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
12Exact matchCanonsburg, PA, United StatesHQ recorded Sep 21, 2026501-1,000903 contacts →

Exact match

“Aquatech enables the world's most recognized companies to solve complex challenges in water reuse, desalination, minimal and zero liquid discharge, and critical minerals…”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
13Exact matchNorwood, MA, United StatesHQ recorded Sep 21, 2026501-1,000880 contacts →

Exact match

“Founded in 1964 as a soils and foundations specialty consultant, GZA GeoEnvironmental, Inc.(GZA) has grown into a full-service company providing its clients with highly…”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
14Exact matchIrvine, CA, United StatesHQ recorded Sep 21, 20261,001-5,000760 contacts →

Exact match

“At Shimmick (NASDAQ: SHIM), we’re shaping the future of sustainable infrastructure through innovative solutions that advance communities and protect our environment.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
15Exact matchGlen Allen, VA, United StatesHQ recorded Sep 21, 2026501-1,000707 contacts →

Exact match

“Schnabel is a trusted partner in building the foundation for project success.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
16Exact matchSan Antonio, TX, United StatesHQ recorded Sep 21, 2026501-1,000582 contacts →

Exact match

“Founded in 1968, Raba Kistner Inc.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
17Exact matchSan Francisco, CA, United StatesHQ recorded Sep 21, 2026201-500578 contacts →

Exact match

“For over 100 years, Kennedy Jenks has provided engineering and scientific solutions for innovative water and environmental projects.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
18Exact matchLaramie, WY, United StatesHQ recorded Sep 21, 2026501-1,000577 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
19Exact matchKennesaw, GA, United StatesHQ recorded Sep 21, 2026501-1,000518 contacts →

Exact match

“Established in 1996, NOVA was originally founded to provide Environmental Consulting, Geotechnical Engineering, and Construction Materials Testing and Inspection services to the…”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
20Exact matchSeattle, WA, United StatesHQ recorded Sep 21, 2026501-1,000479 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
21Exact matchRedmond, WA, United StatesHQ recorded Sep 21, 2026201-500479 contacts →

Exact match

Recorded description not available.

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
22Exact matchSan Diego, CA, United StatesHQ recorded Sep 21, 2026501-1,000449 contacts →

Exact match

“Ninyo & Moore was acquired by SOCOTEC US.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
23Exact matchBroomfield, CO, United StatesHQ recorded Sep 21, 2026501-1,000428 contacts →

Exact match

“As a leading U.S.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
24Exact matchHouston, TX, United StatesHQ recorded Sep 21, 2026501-1,000379 contacts →

Exact match

“Express Energy Services, a leading oilfield services company, is active in every major hydrocarbon basin in the United States and is a premier provider of products and services…”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
25Exact matchParlin, NJ, United StatesHQ recorded Sep 21, 2026201-500336 contacts →

Exact match

“CME Associates, with eight (8) office locations throughout New Jersey, provides a complete range of Environmental, Geotechnical, Engineering, Surveying and Planning services.”

Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase

Showing 25 of 3,115 hydrogeology companies based in the United States

See the full list, filter by size, metro and specialty, and access 53,180 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Hydrogeology companies based in the United States at a glance

As of Sep 21, 2026
37.7%Verified-email coverage
45.3Average contacts per company
11-50Median size (employees)
6.2%Largest-city concentration · Houston
Sep 21, 2026Page data refreshed

Companies by employee count

1-10
1,492
11-50
1,121
51-200
373
201-500
75
501-1,000
16
1,001-5,000
22
5,001-10,000
4
10001+
5

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 3,115 companies.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Company records associated with the United States whose business descriptions match “hydrogeology companies” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 53,180 professional contacts with verified work emails across the full matched dataset. 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 21, 2026. Lists refresh periodically as the graph is re-checked.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “hydrogeology companies”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many hydrogeology companies are there based in the United States?

RevenueBase identified 3,115 company matches for hydrogeology companies associated with the United States as of September 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Halliburton tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most hydrogeology companies?

Houston leads with 192 company records, followed by Denver (55) and Austin (35).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 53,180 professional contacts with verified work emails tracked across these 3,115 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 21, 2026.

Ready to reach these companies? Verified emails and direct dials for all 3,115 hydrogeology companies based in the United States. Start with a free account, no credit card.

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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 SmartSearch, 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.