Company lists · Data refreshed September 2026

Top 25 Sustainable IT consulting firms based in the United States

Name: Sustainable IT consulting firms based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 6, 2026 1,828 companies tracked

RevenueBase identified 1,828 sustainable IT consulting firms headquartered in the United States as of September 2026 and tracks 28,479 professional contacts across them, including 12,970 with verified work emails and 11,437 with mobile numbers. New York is the largest hub.

This list covers sustainable IT consulting firms 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 6, 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 6, 2026 86% judged on-target in blind review

1,828Companies

28,479Contacts tracked

12,970Verified emails

11,437Mobile numbers

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The 25 largest sustainable IT consulting firms based in the United States

Ranked by team size

Top 25 of 1,828 sustainable IT consulting firms based in the United States, ranked by team size, largest first. Data refreshed Sep 6, 2026. RevenueBase Smart Search rates how each company's information relates to sustainable IT 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	WSP In The U.S	Indirect evidence	New York, NY, United StatesHQ checked Sep 6, 2026	10001+	9,318 contacts →
	“What if you could shape built and natural environments – and the future of those that use them?” Source: company website · checked Sep 6, 2026
2	Swca Environmental Consultants	Partial evidence	Phoenix, AZ, United StatesHQ checked Sep 6, 2026	1,001-5,000	1,629 contacts →
	“Founded on a commitment to sound science and creative solutions, SWCA is a leader in environmental and management consulting services.” Source: company website · checked Sep 6, 2026
3	Adec Innovations	Indirect evidence	Irvine, CA, United StatesHQ checked Sep 6, 2026	1,001-5,000	1,304 contacts →
	“ADEC Innovations seamlessly delivers fully integrated, cost-effective industry expertise, business process & data management, and software services.” Source: company website · checked Sep 6, 2026
4	OLA	Strong evidence	Austin, TX, United StatesHQ checked Sep 6, 2026	n/a	1,145 contacts →
	“OLA Sustainability, LLC OLA Sustainability is a consulting firm that focuses on integrating sustainable practices into commercial and multifamily design projects.” Source: company website · checked Sep 6, 2026
5	The Cadmus Group	Partial evidence	Arlington, OR, United StatesHQ checked Sep 6, 2026	1,001-5,000	700 contacts →
	“Cadmus is a technology-empowered global strategic consulting firm that helps clients achieve their goals through transformative digital solutions and expertise across domains.” Source: company website · checked Sep 6, 2026
6	Uniqus Consultech INC	Strong evidence	San Jose, CA, United StatesHQ checked Sep 6, 2026	501-1,000	675 contacts →
	“Uniqus Consultech is an AI and global tech-enabled consulting company that specializes in Accounting & Reporting Consulting, Governance, Risk & Compliance, Sustainability &…” Source: company website · checked Sep 6, 2026
7	Antea Group USA	Partial evidence	St Paul, MN, United StatesHQ checked Sep 6, 2026	1,001-5,000	658 contacts →
	“Antea Group is an international engineering and environmental consulting firm specializing in full-service solutions in the fields of environment, health and safety, and…” Source: company website · checked Sep 6, 2026
8	P2s	Partial evidence	Long Beach, CA, United StatesHQ checked Sep 6, 2026	201-500	375 contacts →
	“P2S has brought forward-thinking, sustainable engineering solutions to California, the Pacific Northwest, and beyond, for over 30 years.” Source: company website · checked Sep 6, 2026
9	Environmental Consulting & Technology, Inc. ECT	Strong evidence	Gainesville, FL, United StatesHQ checked Sep 6, 2026	201-500	305 contacts →
	“Environmental Consulting & Technology, Inc.(ECT) is a multi-disciplinary environmental and sustainability consulting firm delivering strategy, permitting, design, and management…” Source: company website · checked Sep 6, 2026
10	Csrs, A Westwood Company	Indirect evidence	Baton Rouge, LA, United StatesHQ checked Sep 6, 2026	51-200	305 contacts →
	“CSRS was acquired by Westwood Professional Services on June 30, 2025.” Source: company website · checked Sep 6, 2026
11	Cascade Energy	Indirect evidence	Portland, OR, United StatesHQ checked Sep 6, 2026	201-500	288 contacts →
	“At Cascade Energy, we believe in better.” Source: company website · checked Sep 6, 2026
12	PEG	Partial evidence	Fairfax, VA, United StatesHQ checked Sep 6, 2026	201-500	214 contacts →
	“PEG presents a comprehensive capacity for the evaluation and understanding of a broad base of energy and environmental sustainability related programs, policies and initiatives.” Source: company website · checked Sep 6, 2026
13	Delaware North America	Partial evidence	Dallas, TX, United StatesHQ checked Sep 6, 2026	5,001-10,000	213 contacts →
	“delaware is a fast-growing, global company that delivers advanced solutions and services to organizations striving for a sustainable, competitive advantage.” Source: company website · checked Sep 6, 2026
14	Plateau GRP	Partial evidence	Fairfax, VA, United StatesHQ checked Sep 6, 2026	51-200	192 contacts →
	“Plateau Grp provides innovative and agile IT solutions to customer challenges.” Source: company website · checked Sep 6, 2026
15	SUMAC	Strong evidence	Chicago, IL, United StatesHQ checked Sep 6, 2026	51-200	183 contacts →
	“SUMAC is an architecture, engineering, and consulting firm that promotes sustainability as the key element to increasing the profitability of our clients and partners.” Source: company website · checked Sep 6, 2026
16	Keramida INC	Strong evidence	Indianapolis, IN, United StatesHQ checked Sep 6, 2026	51-200	152 contacts →
	“Founded in 1988, KERAMIDA is a multidisciplinary Sustainability, EHS & Engineering consulting firm grounded in evidence-based research and development.” Source: company website · checked Sep 6, 2026
17	Quest Resource Management Group, A Qrhc Company Nasdaq Qrhc	Partial evidence	The Colony, TX, United StatesHQ checked Sep 6, 2026	51-200	147 contacts →
	“Quest Resource Management Group, a subsidiary of Quest Resource Holding Corporation (Nasdaq: QRHC), is a full-service environmental consulting and management company headquartered…” Source: company website · checked Sep 6, 2026
18	STOK	Indirect evidence	San Francisco, CA, United StatesHQ checked Sep 6, 2026	51-200	141 contacts →
	“Stok leads organizations to decarbonize now.” Source: company website · checked Sep 6, 2026
19	Four Seasons Environmental, INC	Indirect evidence	Monroe, OH, United StatesHQ checked Sep 6, 2026	201-500	134 contacts →
	Source: company website · checked Sep 6, 2026
20	Onepointfive Opf.Degree	Partial evidence	New York, NY, United StatesHQ checked Sep 6, 2026	11-50	133 contacts →
	“At OnePointFive we solve your sustainability focused business challenges by empowering your organization with expert-led solutions, embedded training, and cutting edge tools to…” Source: company website · checked Sep 6, 2026
21	Hastings	Partial evidence	Nashville, TN, United StatesHQ checked Sep 6, 2026	51-200	126 contacts →
	“Since our founding in 1985, HASTINGS has been deeply committed to design and community, producing award-winning sustainable design that positively impacts our clients and the…” Source: company website · checked Sep 6, 2026
22	Cascadia Consulting Group	Strong evidence	Seattle, WA, United StatesHQ checked Sep 6, 2026	51-200	110 contacts →
	“Cascadia Consulting Group is a majority women-owned consulting firm specializing in environmental and sustainability solutions.” Source: company website · checked Sep 6, 2026
23	Techlaw	Partial evidence	Chantilly, VA, United StatesHQ checked Sep 6, 2026	201-500	104 contacts →
	“Established in 1983, TechLaw provides environmental and management consulting services to the public sector nationwide.” Source: company website · checked Sep 6, 2026
24	Citadel EHS	Strong evidence	Glendale, CA, United StatesHQ checked Sep 6, 2026	51-200	102 contacts →
	“Founded in 1993, Citadel EHS provides comprehensive environmental, health, safety, and sustainability consulting solutions to meet the needs of both the public and private sectors.” Source: company website · checked Sep 6, 2026
25	Environ Energy	Partial evidence	New York, NY, United StatesHQ checked Sep 6, 2026	51-200	98 contacts →
	“Environ Energy is a leader in accelerating global sustainable energy transformation for more than 30 years.” Source: company website · checked Sep 6, 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: sustainable IT 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 sustainable IT consulting firms.
Partial evidence: Its own public description names part of sustainable IT consulting firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name sustainable IT 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 1,828 sustainable IT consulting firms based in the United States

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Sustainable IT consulting firms based in the United States at a glance

As of Sep 6, 2026

45.5%Verified-email coverage

40.2%Mobile-number coverage

15.6Average contacts per company

1-10Median size (employees)

5.7%Largest-city concentration · New York

Sep 6, 2026Page data refreshed

Companies by employee count

1-10

1,363

11-50

342

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Freshness & accuracy

How recently the business emails on this list were verified

Email last verified

11,9360–30

88531–60

261–90

390–180

144180+

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 sustainable IT 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 the United States whose own description of what they do matches “sustainable IT 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 sustainable IT 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 sustainable IT consulting firms, 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, 12,970 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 6, 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.

Sustainable IT consulting firms by metro

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 sustainable IT 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 sustainable IT consulting firms are there based in the United States?

RevenueBase identified 1,828 sustainable IT consulting firms 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?

WSP In The U.S, headquartered in New York, tops this list with the largest team on record.

Which city has the most sustainable IT consulting firms?

New York leads with 104 headquartered companies, followed by Chicago (54) and Washington (50).

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 12,970 verified decision-maker contacts tracked across these 1,828 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 6, 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.