Company lists · Data refreshed September 2026

Top 25 Environmental consulting firms based in Houston, United States

Name: Environmental consulting firms based in Houston, United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 12, 2026 149 companies tracked

RevenueBase identified 149 environmental consulting firms headquartered in Houston, United States as of September 2026 and tracks 7,793 professional contacts across them, including 4,117 with verified work emails and 3,518 with mobile numbers. Houston is the largest hub.

This list covers environmental consulting firms headquartered in Houston, 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 12, 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 12, 2026 86% judged on-target in blind review

149Companies

7,793Contacts tracked

4,117Verified emails

3,518Mobile numbers

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The 25 largest environmental consulting firms based in Houston, United States

Ranked by team size

Top 25 of 149 environmental consulting firms based in Houston, United States, ranked by team size, largest first. Data refreshed Sep 12, 2026. RevenueBase Smart Search rates how each company's information relates to environmental 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	LJA	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	1,001-5,000	1,932 contacts →
	Indirect evidence “Employee-Owned.” Source: RevenueBase Database · checked Sep 12, 2026
2	Rimkus	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	1,001-5,000	1,184 contacts →
	Indirect evidence “Consultants.” Source: RevenueBase Database · checked Sep 12, 2026
3	Bge, INC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	1,001-5,000	1,112 contacts →
	Indirect evidence “Ranked No.” Source: RevenueBase Database · checked Sep 12, 2026
4	VLS Environmental Solutions, LLC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	1,001-5,000	481 contacts →
	Indirect evidence “At VLS, we address your company’s most significant hurdles with waste management and compliance through sustainable solutions.” Source: RevenueBase Database · checked Sep 12, 2026
5	Lockwood, Andrews & Newnam, Inc. LAN	Partial evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	201-500	461 contacts →
	Partial evidence “Lockwood, Andrews & Newnam, Inc.(LAN) is a full-service consulting firm offering planning, engineering and program management services.” Source: RevenueBase Database · checked Sep 12, 2026
6	GSI Environmental INC	Strong evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	201-500	259 contacts →
	Strong evidence “GSI Environmental, Inc.(GSI), is an environmental engineering and science consulting firm committed to measuring, analyzing, and solving complex environmental problems around the…” Source: RevenueBase Database · checked Sep 12, 2026
7	NEW Tech Global	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	51-200	245 contacts →
	Indirect evidence “New Tech Global (NTG) is comprised of 5 different business units: New Tech Global Ventures: Upstream Oil & Gas consultancy services, and W-2 professional placement services for…” Source: RevenueBase Database · checked Sep 12, 2026
8	Shah Smith & Associates, INC	Partial evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	51-200	134 contacts →
	Partial evidence “Shah Smith & Associates, Inc.(SSA) is a 120+ employee Mechanical, Electrical, and Plumbing (MEP) consulting engineering firm with offices in Houston, Austin & Dallas.” Source: RevenueBase Database · checked Sep 12, 2026
9	Milestone Environmental	Partial evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	201-500	128 contacts →
	Partial evidence “Milestone Environmental is a leading environmental infrastructure and services company delivering reliable, safe, compliant and best-in-class waste management solutions.” Source: RevenueBase Database · checked Sep 12, 2026
10	Edge Engineering And Science, LLC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	51-200	116 contacts →
	Indirect evidence “Edge Engineering & Science, LLC (EDGE) is a privately owned professional services firm headquartered in Houston, Texas.” Source: RevenueBase Database · checked Sep 12, 2026
11	Perennial Environmental Services	Partial evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	51-200	102 contacts →
	Partial evidence “Perennial Environmental Services, LLC, has been providing technical environmental solutions and management with fresh perspectives and unparalleled efficiency since 2003.” Source: RevenueBase Database · checked Sep 12, 2026
12	Aarc Environmental	Partial evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	51-200	63 contacts →
	Partial evidence “As a leader in the environmental compliance services industry, AARC does more than just meeting the needs of clients today.” Source: RevenueBase Database · checked Sep 12, 2026
13	RCP INC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	51-200	63 contacts →
	Indirect evidence “RCP is the regulatory compliance and risk management expert for pipelines, facilities, and terminal operations.” Source: RevenueBase Database · checked Sep 12, 2026
14	Sage ATC Environmental Consulting	Strong evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	201-500	63 contacts →
	Strong evidence “Sage ATC Environmental Consulting is now Atlas.” Source: RevenueBase Database · checked Sep 12, 2026
15	Spirit Environmental Montrose Environmental Group	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	51-200	54 contacts →
	Indirect evidence “In July of 2024, Spirit was acquired by Onterris.” Source: RevenueBase Database · checked Sep 12, 2026
16	Pilko & Associates	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	11-50	50 contacts →
	Indirect evidence “We are the trusted Advisor to corporate officers and boards on mitigating Operational/EHS Risks and unlocking value for global energy, chemical and industrial companies.” Source: RevenueBase Database · checked Sep 12, 2026
17	Riner Engineering, Inc., A UES Company	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	51-200	47 contacts →
	Indirect evidence “Riner Engineering became part of the UES family of companies in June 2023, combining our local expertise with UES’s nationwide presence and resources.” Source: RevenueBase Database · checked Sep 12, 2026
18	International Safety Systems, INC	Partial evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	11-50	46 contacts →
	Partial evidence “International Safety Systems, Inc.(ISS) is a consulting company providing cost effective and high quality industrial hygiene and safety services to 35+ countries from its offices…” Source: RevenueBase Database · checked Sep 12, 2026
19	RPT Alliance LLC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	11-50	43 contacts →
	Indirect evidence “As of December 8, 2025, RTP Alliance has been acquired by by Bowman.” Source: RevenueBase Database · checked Sep 12, 2026
20	J Connor Consulting, INC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	51-200	39 contacts →
	Indirect evidence “The Company J.” Source: RevenueBase Database · checked Sep 12, 2026
21	RSB Environmental, An Alliance Technical Group Company	Strong evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	11-50	38 contacts →
	Strong evidence “RSB Environmental, an Alliance Technical Group company, is a full-service environmental engineering consulting firm, specializing in environmental health and safety services and…” Source: RevenueBase Database · checked Sep 12, 2026
22	Phase Engineering, LLC	Strong evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	11-50	34 contacts →
	Strong evidence “Phase Engineering, LLC, was founded in 1993 and is a leading engineering and environmental consulting firm, serving clients nationwide to deliver trusted environmental solutions.” Source: RevenueBase Database · checked Sep 12, 2026
23	Hollaway Environmental Communications Services, INC	Partial evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	11-50	33 contacts →
	Partial evidence “Hollaway Environmental + Communication Services, an SBE/DBE/WBE/HUB firm, bridges two worlds that are uniquely connected: Environmental Services and Communications Services.” Source: RevenueBase Database · checked Sep 12, 2026
24	UES Professional Solutions 64, LLC	Strong evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	11-50	31 contacts →
	Strong evidence “Environmental Consulting and Engineering InControl Technologies was established in 1997 to provide high-end quality environmental consulting services to owners of commercial and…” Source: RevenueBase Database · checked Sep 12, 2026
25	Ikon Environmental Solutions, LP	Partial evidence	Houston, TX, United StatesHQ checked Sep 12, 2026	11-50	24 contacts →
	Partial evidence “IKON Environmental Solutions, LP (IKON) provides clients with unique solutions to environmental needs.” Source: RevenueBase Database · checked Sep 12, 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: environmental consulting firms. 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 environmental consulting firms.
Partial evidence: Its own public description names part of environmental consulting firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name environmental consulting firms. 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 149 environmental consulting firms based in Houston, United States

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Environmental consulting firms based in Houston, United States at a glance

As of Sep 12, 2026

52.8%Verified-email coverage

45.1%Mobile-number coverage

52.3Average contacts per company

1-10Median size (employees)

89.3%Largest-city concentration · Houston

Sep 12, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

1,001-5,000

Freshness & accuracy

How recently the business emails were verified and the company information checked

Email last verified

Median 14.0d

3,4840–30

58631–60

1761–90

490–180

26180+

Company record updated

Median 62.0d

00–30

3,88031–60

2,77161–90

68690–180

456180+

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 environmental 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.
What qualifies: Companies headquartered in Houston, United States whose own description of what they do matches “environmental 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 environmental 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 environmental consulting firms, and records with no verified work email. Companies headquartered outside Houston 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, 4,117 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 12, 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.

Environmental consulting firms by metro in the United States

Environmental consulting firms in Houston133
Environmental consulting firms in New York117
Environmental consulting firms in Seattle80
Environmental consulting firms in Washington76
Environmental consulting firms in Portland70
Environmental consulting firms in Denver66
Environmental consulting firms in Los Angeles63

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 environmental 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 environmental consulting firms are there based in Houston, United States?

RevenueBase identified 149 environmental consulting firms headquartered in Houston, 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?

LJA, headquartered in Houston, tops this list with the largest team on record.

Which city has the most environmental consulting firms?

Houston leads with 133 headquartered companies, followed by New York (117) and Seattle (80).

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 4,117 verified decision-maker contacts tracked across these 149 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 12, 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.