Company lists · Data refreshed September 2026

Top 25 Environmental consulting firms for construction based in Washington, United States

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

Compiled by the RevenueBase Data Team Data refreshed Sep 28, 2026 44 companies tracked

RevenueBase identified 44 environmental consulting firms for construction headquartered in Washington, United States as of September 2026 and tracks 513 professional contacts across them, including 264 with verified work emails. Across the United States, New York is the largest hub for this category (173 companies); Washington has 44.

This list covers environmental consulting firms for construction headquartered in Washington, 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 28, 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 28, 2026 86% judged on-target in blind review

44Companies

513Contacts tracked

264Verified emails

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The 25 largest environmental consulting firms for construction based in Washington, United States

Ranked by team size

Top 25 of 44 environmental consulting firms for construction based in Washington, United States, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to environmental consulting firms for construction: 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	Delon Hampton & Associates, Chartered	Strong evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	72 contacts →
	Strong evidence “Delon Hampton & Associates, Chartered (DHA), is a professional consulting engineering firm specializing in civil and structural engineering, as well as program and construction…” Source: RevenueBase Database · checked Sep 28, 2026
2	Peer Consultants, P.C	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	71 contacts →
	Indirect evidence “In 1978, PEER was established under Dr.” Source: RevenueBase Database · checked Sep 28, 2026
3	Baumann Consulting	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	63 contacts →
	Partial evidence “Baumann Consulting is driven to deliver solutions for a carbon-neutral real estate industry.” Source: RevenueBase Database · checked Sep 28, 2026
4	Soil And Land USE Technology	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	30 contacts →
	Indirect evidence “SaLUT is a client-focused company.” Source: RevenueBase Database · checked Sep 28, 2026
5	Kumi Construction Management Corporation	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	26 contacts →
	Partial evidence “KUMI Construction Management Corp, founded in 2007 and based in Washington, D.C, with an office in Baltimore, is a certified MDOT/DBE/SBE/MBE firm recognized by several public…” Source: RevenueBase Database · checked Sep 28, 2026
6	SZ PM Consultants, INC	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	24 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
7	Northbridge	Partial evidence	Washington, United StatesHQ checked Sep 28, 2026	11-50	24 contacts →
	Partial evidence “At Northbridge, we provide our clients with the tools and expertise to help solve complex financial, policy, and environmental challenges.” Source: RevenueBase Database · checked Sep 28, 2026
8	Bfa, INC	Partial evidence	Washington, MO, United StatesHQ checked Sep 28, 2026	11-50	19 contacts →
	Partial evidence “BFA is a consulting civil engineering firm located in downtown Washington, Missouri.” Source: RevenueBase Database · checked Sep 28, 2026
9	Interagency INC	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	19 contacts →
	Partial evidence “InterAgency provides preconstruction consulting for the Washington Metro Area’s most complex and challenging infrastructure projects.” Source: RevenueBase Database · checked Sep 28, 2026
10	The Clark Group LLC	Strong evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	19 contacts →
	Strong evidence “The Clark Group is an environmental policy consulting firm that provides a broad range of services to government, private and nonprofit clients.” Source: RevenueBase Database · checked Sep 28, 2026
11	Harshman CE Group, LLC	Partial evidence	Washington, PA, United StatesHQ checked Sep 28, 2026	11-50	19 contacts →
	Partial evidence “We are a full service Professional Engineering consulting firm providing civil site and infrastructure design, professional land surveying, facility design, and permitting support…” Source: RevenueBase Database · checked Sep 28, 2026
12	Numark Associates, INC	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	15 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
13	TSG Consulting	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	11 contacts →
	Indirect evidence “For over 30 years, TSG has provided companies around the world with regulatory guidance and scientific expertise.” Source: RevenueBase Database · checked Sep 28, 2026
14	Brockerhoff Environmental Services	Indirect evidence	Washington, NJ, United StatesHQ checked Sep 28, 2026	11-50	9 contacts →
	Indirect evidence “Since 2007, BES has combined innovative technology with cost-effective and focused strategies to deliver effective remediation services for our clients.” Source: RevenueBase Database · checked Sep 28, 2026
15	DRM International, INC	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	7 contacts →
	Partial evidence “DRM International, Inc,(DRM) is a leading DIsadvantaged Business Enterprise (DBE) professional engineering consulting firm offering engineering, architectural, planning…” Source: RevenueBase Database · checked Sep 28, 2026
16	Modulus	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	7 contacts →
	Partial evidence “Modulus is a minority-owned MBE, SBE and DBE consulting firm based in Washington, DC, which provides services to the Northeast Region.” Source: RevenueBase Database · checked Sep 28, 2026
17	Allen-Norris Permitting And Inspections	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	7 contacts →
	Partial evidence “Allen-Norris Permitting and Inspections is a minority, woman-owned construction management firm uniquely positioned to provide architectural, engineering, compliance, permitting…” Source: RevenueBase Database · checked Sep 28, 2026
18	Energy Shrink, LLC	Strong evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	6 contacts →
	Strong evidence “Energy Shrink is an environmental consulting practice specialized in sustainability and energy efficiency in buildings, that is, high-performance or green buildings.” Source: RevenueBase Database · checked Sep 28, 2026
19	Core Engineers Consulting Group	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	5 contacts →
	Partial evidence “CORE Engineers Consulting Group (CORE Group) is a Washington DC based engineering firm specializing in code consulting and fire protection engineering for the building and…” Source: RevenueBase Database · checked Sep 28, 2026
20	Deborah Brosnan & Associates	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	4 contacts →
	Indirect evidence “Leading and innovative company that finding solutions, bridging gaps and driving positive action for clients and the planet.” Source: RevenueBase Database · checked Sep 28, 2026
21	Warwick Group Consultants, LLC	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	3 contacts →
	Partial evidence “Warwick Group Consultants is the Nation's premier consulting firm for local governments with coastal projects involving beach nourishment, dredging, aquatic ecosystem restoration…” Source: RevenueBase Database · checked Sep 28, 2026
22	Greening Urban LLC	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	3 contacts →
	Indirect evidence “Greening Urban is a civil engineering firm with built projects in Washington, D.C; Maryland; and Virginia.” Source: RevenueBase Database · checked Sep 28, 2026
23	The Impact Group, LLC	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	2 contacts →
	Partial evidence “The Impact Group, LLC supports the mission and strategic goals of our customers in Engineering, Construction, and Information Technology.” Source: RevenueBase Database · checked Sep 28, 2026
24	Balaton Builders	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	2 contacts →
	Indirect evidence “Balaton Builders is a licensed and insured family-owned company that has been serving residential and commercial markets in Washington DC, Northern Virginia and Maryland for more…” Source: RevenueBase Database · checked Sep 28, 2026
25	Empower Infrastructure	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	2 contacts →
	Indirect evidence “EMPOWER INFRASTRUCTURE LLC is registered as CBE, SBE, and DBE for Washington DC, DDOT, Virginia, VDOT, and WMATA.” Source: RevenueBase Database · checked Sep 28, 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 for construction. 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 for construction.
Partial evidence: Its own public description names part of environmental consulting firms for construction, 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 for construction. 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 44 environmental consulting firms for construction based in Washington, United States

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Environmental consulting firms for construction based in Washington, United States at a glance

As of Sep 28, 2026

51.5%Verified-email coverage

11.7Average contacts per company

1-10Median size (employees)

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

Email recency for this list is measured across the whole United States list rather than for Washington, so it is reported there. Company counts and contact totals on this page are exact for Washington, over 44 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 environmental consulting firms for construction, 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 Washington, United States whose own description of what they do matches “environmental consulting firms for construction”. 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 for construction), 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 for construction, and records with no verified work email. Companies headquartered outside Washington 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, 264 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 28, 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 for construction by metro in the United States

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 for construction, 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 for construction are there based in Washington, United States?

RevenueBase identified 44 environmental consulting firms for construction headquartered in Washington, 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?

Delon Hampton & Associates, Chartered, headquartered in Washington, tops this list with the largest team on record.

Which city in the United States has the most environmental consulting firms for construction?

New York leads the United States with 173 headquartered companies, followed by Houston (170) and Austin (79). Washington has 44.

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 264 verified decision-maker contacts tracked across these 44 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 28, 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.