Company lists · Data refreshed September 2026

Top 25 Environmental liability law firms based in Washington, United States

Name: Environmental liability law firms 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 65 companies tracked

RevenueBase identified 65 environmental liability law firms headquartered in Washington, United States as of September 2026 and tracks 6,557 professional contacts across them, including 4,469 with verified work emails. Across the United States, New York is the largest hub for this category (83 companies); Washington has 65.

This list covers environmental liability law firms 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

65Companies

6,557Contacts tracked

4,469Verified emails

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The 25 largest environmental liability law firms based in Washington, United States

Ranked by team size

Top 25 of 65 environmental liability law firms 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 liability law 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	Arnold & Porter	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1,001-5,000	2,333 contacts →
	Indirect evidence “Arnold & Porter combines sophisticated regulatory, litigation, and transactional capabilities to resolve clients’ most complex issues.” Source: RevenueBase Database · checked Sep 28, 2026
2	Venable LLP	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1,001-5,000	1,790 contacts →
	Partial evidence “Committed to Your Success – As a law firm of more than 900 professionals, Venable delivers legal services globally in every area of regulatory compliance, government affairs…” Source: RevenueBase Database · checked Sep 28, 2026
3	Wiley Rein LLP	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	501-1,000	576 contacts →
	Indirect evidence “Founded in 1983, Wiley is a dominant presence in the nation’s capital.” Source: RevenueBase Database · checked Sep 28, 2026
4	Beveridge & Diamond PC	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	201-500	328 contacts →
	Indirect evidence “Beveridge & Diamond’s 170+ lawyers in 7 U.S.” Source: RevenueBase Database · checked Sep 28, 2026
5	Hausfeld	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	201-500	267 contacts →
	Indirect evidence “Hausfeld successfully resolves disputes for its clients, driven by its bold approach and pioneering experience.” Source: RevenueBase Database · checked Sep 28, 2026
6	Keller And Heckman LLP	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	230 contacts →
	Partial evidence “Keller and Heckman, founded in 1962, has a broad practice in the areas of regulatory law, public policy, and litigation, serving both domestic and international clients.” Source: RevenueBase Database · checked Sep 28, 2026
7	VAN Ness Feldman LLP	Strong evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	174 contacts →
	Strong evidence “Van Ness Feldman is a nationally recognized mid-sized law firm specializing in the areas of energy, environment, and natural resources law and policy, with offices in Washington…” Source: RevenueBase Database · checked Sep 28, 2026
8	Zuckerman Spaeder LLP	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	155 contacts →
	Indirect evidence “Zuckerman Spaeder LLP is consistently recognized as a leading national litigation boutique.” Source: RevenueBase Database · checked Sep 28, 2026
9	Hollingsworth LLP	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	112 contacts →
	Indirect evidence “Hollingsworth LLP is among the nation’s leading litigation firms.” Source: RevenueBase Database · checked Sep 28, 2026
10	Holtzman Vogel	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	80 contacts →
	Indirect evidence “HOLTZMAN VOGEL PROTECTS THE HIGHEST PROFILE VOICES IN BUSINESS, POLITICS AND ADVOCACY For 25 years, Holtzman Vogel has represented Fortune 500 companies, non-profits, high net…” Source: RevenueBase Database · checked Sep 28, 2026
11	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
12	Conn Maciel Carey LLP	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	46 contacts →
	Partial evidence “Conn Maciel Carey LLP is a boutique law firm focused on Labor & Employment, Workplace Safety - OSHA/MSHA, and Litigation.” Source: RevenueBase Database · checked Sep 28, 2026
13	John & Hengerer LLP	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	n/a	46 contacts →
	Indirect evidence “John & Hengerer LLP represents and advises energy companies, inlcuding natural gas producers, importers, processors, and marketers; gas and liquids pipeline operators; gas storage…” Source: RevenueBase Database · checked Sep 28, 2026
14	Bergeson & Campbell, P.C	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	40 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
15	Duncan, Weinberg, Genzer & Pembroke, P.C. Dwgp	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	28 contacts →
	Indirect evidence “Since its founding in 1971, DWG & P, has provided a broad range of counseling, regulatory, litigation and legislative services to clients in every region of the country.” Source: RevenueBase Database · checked Sep 28, 2026
16	Gilbert LLP	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	51-200	27 contacts →
	Partial evidence “Gilbert LLP is a Washington, DC-based law firm with expertise in risk management, insurance recovery, litigation, and strategic consulting.” Source: RevenueBase Database · checked Sep 28, 2026
17	E&w LAW	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	18 contacts →
	Partial evidence “At Earth & Water, we are more than lawyers – we’re strategic advisors with unique experience who advance our clients’ interests across a broad range of environmental and business…” Source: RevenueBase Database · checked Sep 28, 2026
18	Harkins Cunningham LLP	Strong evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	18 contacts →
	Strong evidence “Harkins Cunningham LLP is a law firm engaged in optimizing risk and opportunities in complex matters in highly regulated and politicized environments.” Source: RevenueBase Database · checked Sep 28, 2026
19	Rock Creek Energy Group, LLP	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	17 contacts →
	Indirect evidence “Rock Creek Energy Group is a group of diverse and like-minded professionals with a shared passion – Energy.” Source: RevenueBase Database · checked Sep 28, 2026
20	Terris, Pravlik & Millian, LLP	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	15 contacts →
	Indirect evidence “Terris, Pravlik & Millian, LLP was founded by Bruce J.” Source: RevenueBase Database · checked Sep 28, 2026
21	Mason LLP	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	14 contacts →
	Indirect evidence “Mason LLP is a civil litigation firm representing plaintiffs who have been injured or harmed by corporate misconduct.” Source: RevenueBase Database · checked Sep 28, 2026
22	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
23	Akrivis LAW Group, Pllc	Partial evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	1-10	10 contacts →
	Partial evidence “A Washington, DC based law firm with offices in New York and Miami focusing on international trade compliance & enforcement, white collar defense & litigation, international…” Source: RevenueBase Database · checked Sep 28, 2026
24	Harmon, Curran, Spielberg & Eisenberg, LLP	Indirect evidence	Washington, DC, United StatesHQ checked Sep 28, 2026	11-50	9 contacts →
	Indirect evidence “For more than forty years, we at Harmon, Curran, Spielberg + Eisenberg, LLP, have served the legal needs of individuals and organizations to help them advance social, economic and…” Source: RevenueBase Database · checked Sep 28, 2026
25	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

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 liability law 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 liability law firms.
Partial evidence: Its own public description names part of environmental liability law firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name environmental liability law 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 65 environmental liability law firms based in Washington, United States

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Environmental liability law firms based in Washington, United States at a glance

As of Sep 28, 2026

68.2%Verified-email coverage

100.9Average contacts per company

1-10Median size (employees)

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

1,001-5,000

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 65 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 liability law 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 Washington, United States whose own description of what they do matches “environmental liability law 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 liability law 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 liability law firms, 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, 4,469 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 liability law firms 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 liability law 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 liability law firms are there based in Washington, United States?

RevenueBase identified 65 environmental liability law firms 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?

Arnold & Porter, headquartered in Washington, tops this list with the largest team on record.

Which city in the United States has the most environmental liability law firms?

New York leads the United States with 83 headquartered companies, followed by Houston (77) and Washington (65).

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 4,469 verified decision-maker contacts tracked across these 65 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.