Company lists · Data refreshed September 2026

Top 25 Groundwater monitoring companies based in the United States

RevenueBase identified 327 groundwater monitoring companies headquartered in the United States as of September 2026 and tracks 6,505 professional contacts across them, including 3,145 with verified work emails. Houston is the largest hub.

This list covers groundwater monitoring 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
327Companies
6,505Contacts tracked
3,145Verified emails
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The 25 largest groundwater monitoring companies based in the United States

Ranked by team size
Top 25 of 327 groundwater monitoring 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 groundwater monitoring 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceLoveland, CO, United StatesHQ checked Sep 19, 20261,001-5,0003,095 contacts →

Indirect evidence

“At Hach, we ensure water quality for people around the world, and every associate plays a vital role in that mission.”

Source: RevenueBase Database · checked Sep 19, 2026
2Indirect evidenceWarrenville, IL, United StatesHQ checked Sep 19, 202651-200197 contacts →

Indirect evidence

“Phigenics is a leading provider of safe, smart, and superior water management programs aligned with ANSI/ASHRAE Standard 188 and Centers for Medicare & Medicaid Services (CMS) QSO…”

Source: RevenueBase Database · checked Sep 19, 2026
3Indirect evidenceStow, OH, United StatesHQ checked Sep 19, 202651-200176 contacts →

Indirect evidence

“EnviroScience is a team of over 150 expert biologists, commercial divers, environmental engineers, and environmental scientists that provides biomonitoring, environmental…”

Source: RevenueBase Database · checked Sep 19, 2026
4Strong evidenceFort Collins, CO, United StatesHQ checked Sep 19, 2026201-500170 contacts →

Strong evidence

“In-Situ simplifies water monitoring for surface water, coastal, groundwater, aquaculture, drinking water and wastewater applications with reliable, low-maintenance instrumentation…”

Source: RevenueBase Database · checked Sep 19, 2026
5Indirect evidenceFort Collins, CO, United StatesHQ checked Sep 19, 202651-200129 contacts →

Indirect evidence

“Ensero Solutions is an environmental consulting and remediation business with specific expertise in environmental assessments and permitting solutions, mine water management…”

Source: RevenueBase Database · checked Sep 19, 2026
6Indirect evidenceWharton, NJ, United StatesHQ checked Sep 19, 202651-200106 contacts →

Indirect evidence

“GWTT is one of the only U.S.”

Source: RevenueBase Database · checked Sep 19, 2026
7Indirect evidenceOrange, CA, United StatesHQ checked Sep 19, 202611-5096 contacts →

Indirect evidence

“EEC Environmental is a national environmental consulting firm that specializes in water, wastewater, stormwater, regulatory compliance, safety, and assessment and remediation of…”

Source: RevenueBase Database · checked Sep 19, 2026
8Indirect evidenceDenver, CO, United StatesHQ checked Sep 19, 202651-20083 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 19, 2026
9Indirect evidenceDavis, CA, United StatesHQ checked Sep 19, 202651-20079 contacts →

Indirect evidence

“Larry Walker Associates (LWA) is a privately owned firm headquartered in Davis, California, with offices in Berkeley, Yreka, Santa Monica, Ventura, San Diego, and Seattle, WA.”

Source: RevenueBase Database · checked Sep 19, 2026
10Indirect evidenceDexter, MI, United StatesHQ checked Sep 19, 202651-20071 contacts →

Indirect evidence

“QED Environmental Systems is the world's leading provider of environmental technology solutions.”

Source: RevenueBase Database · checked Sep 19, 2026
11Indirect evidenceFort Collins, CO, United StatesHQ checked Sep 19, 202651-20070 contacts →

Indirect evidence

“We deliver quality solutions with integrity and expertise, every time.”

Source: RevenueBase Database · checked Sep 19, 2026
12Partial evidencePortland, OR, United StatesHQ checked Sep 19, 202651-20066 contacts →

Partial evidence

“GSI Water Solutions, Inc, is a specialized groundwater, environmental, and water resources consulting firm.”

Source: RevenueBase Database · checked Sep 19, 2026
13Indirect evidenceSan Jose, CA, United StatesHQ checked Sep 19, 202651-20063 contacts →

Indirect evidence

“Blaine Tech Services performs environmental sampling and related field services.”

Source: RevenueBase Database · checked Sep 19, 2026
14Partial evidenceLittleton, CO, United StatesHQ checked Sep 19, 2026201-50057 contacts →

Partial evidence

“Headwater Companies, LLC is a collection of leading groundwater distributors.”

Source: RevenueBase Database · checked Sep 19, 2026
15Indirect evidenceSunnyvale, CA, United StatesHQ checked Sep 19, 202611-5047 contacts →

Indirect evidence

“KETOS is a vertically integrated water intelligence platform with intelligent hardware, bi-directional connectivity infrastructure, interactive software, and hassle-free services…”

Source: RevenueBase Database · checked Sep 19, 2026
16Indirect evidenceRockville, MD, United StatesHQ checked Sep 19, 202651-20045 contacts →

Indirect evidence

“S.S.”

Source: RevenueBase Database · checked Sep 19, 2026
17Indirect evidenceMishawaka, IN, United StatesHQ checked Sep 19, 202651-20044 contacts →

Indirect evidence

“Since 1973, Peerless-Midwest, Inc.”

Source: RevenueBase Database · checked Sep 19, 2026
18Partial evidenceWesterville, OH, United StatesHQ checked Sep 19, 202611-5043 contacts →

Partial evidence

“The National Ground Water Association is the hallmark organization for anyone affiliated with the groundwater industry.”

Source: RevenueBase Database · checked Sep 19, 2026
19Partial evidenceScottsdale, AZ, United StatesHQ checked Sep 19, 202611-5042 contacts →

Partial evidence

“Clear Creek Associates, a hydrogeological consulting company, was started in September to provide a very high level of expertise in groundwater science.”

Source: RevenueBase Database · checked Sep 19, 2026
20Indirect evidenceRockville, MD, United StatesHQ checked Sep 19, 202611-5040 contacts →

Indirect evidence

“At COLUMBIA Technologies, we're shaping the future of environmental safety and responsibility.”

Source: RevenueBase Database · checked Sep 19, 2026
21Indirect evidenceSignal Hill, CA, United StatesHQ checked Sep 19, 202651-20039 contacts →

Indirect evidence

“Gregg Drilling, LLC.(Gregg) offers a wide range of services for environmental, geotechnical and marine site investigation and remediation.”

Source: RevenueBase Database · checked Sep 19, 2026
22Indirect evidenceSan Diego, CA, United StatesHQ checked Sep 19, 202611-5037 contacts →

Indirect evidence

“Hargis + Associates, Inc.(H+A) is an employee-owned, environmental consulting and engineering firm founded in 1979 with a commitment to providing high-quality, cost-effective…”

Source: RevenueBase Database · checked Sep 19, 2026
23Indirect evidenceDetroit Lakes, MN, United StatesHQ checked Sep 19, 202651-20036 contacts →

Indirect evidence

“RMB Environmental Laboratories (RMB) is an independent, leading provider of comprehensive environmental testing solutions, founded in 1995.”

Source: RevenueBase Database · checked Sep 19, 2026
24Indirect evidenceHolt, MI, United StatesHQ checked Sep 19, 202651-20035 contacts →

Indirect evidence

“Fibertec Environmental Services is a full service environmental analytical laboratory, specializing in environmental analysis, subsurface investigations, and natural gas analysis.”

Source: RevenueBase Database · checked Sep 19, 2026
25Indirect evidenceCockeysville, MD, United StatesHQ checked Sep 19, 202611-5026 contacts →

Indirect evidence

“Company Overview: Carroll Water Systems has been locally owned and operated since 1983.”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 25 of 327 groundwater monitoring companies based in the United States

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Groundwater monitoring companies based in the United States at a glance

As of Sep 19, 2026
48.3%Verified-email coverage
19.9Average contacts per company
1-10Median size (employees)
1.8%Largest-city concentration · Houston
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
174
11-50
118
51-200
26
201-500
6
501-1,000
1
1,001-5,000
1

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 327 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 groundwater monitoring 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 “groundwater monitoring 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 groundwater monitoring 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 groundwater monitoring 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, 3,145 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.

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 groundwater monitoring 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 groundwater monitoring companies are there based in the United States?

RevenueBase identified 327 groundwater monitoring 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?

HACH, headquartered in Loveland, tops this list with the largest team on record.

Which city has the most groundwater monitoring companies?

Houston leads with 6 headquartered companies, followed by Miami (5) and Fort Collins (4).

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 3,145 verified decision-maker contacts tracked across these 327 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.