Top 28 Contractors in PSC B502: Air Quality Analysis, Aug 2025–Jul 2026

Full ranking

Rank	Contractor	Net obligations	Share	Trend
1	Air Resource Specialists, Inc. Top agencies DOI (Department of the Interior)	$4,403,514	34.7%	Rank history: #4 in FY2021, #2 in FY2022, #1 in FY2023, #1 in FY2024 and #2 in FY2025; unchanged since Aug 2024–Jul 2025.
2	University of California, Davis Top agencies DOI (Department of the Interior)	$2,722,726	21.5%	Rank history: not on the FY2021–FY2024 lists and #1 in FY2025; unchanged since Aug 2024–Jul 2025.
3	General Dynamics Corporation Through General Dynamics Information Technology, Inc. Top agencies EPA (Environmental Protection Agency)	$2,421,781	19.1%	Rank history: not on the FY2021–FY2023 lists, #3 in FY2024 and #3 in FY2025; unchanged since Aug 2024–Jul 2025.
4	Nevada System of Higher Education Top agencies DOI (Department of the Interior)	$773,310	6.1%	Rank history: not on the FY2021 list, #5 in FY2022, #4 in FY2023, #4 in FY2024 and #4 in FY2025; unchanged since Aug 2024–Jul 2025.
5	H & L Environmental Services, LLC Top agencies USAF (Department of the Air Force)	$743,605	5.9%	Rank history: not on the FY2021–FY2024 lists and #5 in FY2025; unchanged since Aug 2024–Jul 2025.
6	Research Triangle Institute Top agencies DOI (Department of the Interior)	$420,075	3.3%	Rank history: #6 in FY2021, #6 in FY2022, #7 in FY2023, #5 in FY2024 and #6 in FY2025; unchanged since Aug 2024–Jul 2025.
7	WSP USA Environment & Infrastructure Inc. Top agencies DOI (Department of the Interior)	$252,707	2.0%	Rank history: not on the FY2021–FY2024 lists and #7 in FY2025; new, not ranked in Aug 2024–Jul 2025.
8	Trine Environmental Inc. Top agencies VA (Department of Veterans Affairs)	$128,636	1.0%	Rank history: not on the FY2021 list, #25 in FY2022, not on the FY2023 list, #27 in FY2024 and #8 in FY2025; up 1 since Aug 2024–Jul 2025.
9	MES Service Company, LLC Top agencies Navy (Department of the Navy)	$126,000	1.0%	Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
10	I-2-I Solutions, Inc. Top agencies Navy (Department of the Navy)	$91,000	0.7%	Rank history: not on the FY2021–FY2024 lists and #11 in FY2025; new, not ranked in Aug 2024–Jul 2025.
11	Mabbett & Associates, Inc. Top agencies VA (Department of Veterans Affairs)	$66,823	0.5%	Rank history: #23 in FY2021, #19 in FY2022, not on the FY2023 list, #10 in FY2024 and #9 in FY2025; down 1 since Aug 2024–Jul 2025.
12	Environmental Consulting Group, Inc. Top agencies Treasury (Department of the Treasury)	$42,777	0.3%	Rank history: #13 in FY2021, #13 in FY2022, #16 in FY2023, #13 in FY2024 and not on the FY2025 list; new, not ranked in Aug 2024–Jul 2025.
13	Janicke GBR Ingenieurbüro FÜR Umweltphysik Top agencies DOT (Department of Transportation)	$40,250	0.3%	Rank history: not on the FY2021–FY2023 lists, #18 in FY2024 and #16 in FY2025; up 2 since Aug 2024–Jul 2025.
14	State Board for Community Colleges & OCC Top agencies Army (Department of the Army)	$39,325	0.3%	Rank history: not on the FY2021–FY2024 lists and #15 in FY2025; unchanged since Aug 2024–Jul 2025.
15	Consolidated Analytical Systems Inc. Top agencies EPA (Environmental Protection Agency)	$38,466	0.3%	Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
16	Texas Commission On Environmental Quality Top agencies USAF (Department of the Air Force)	$22,994	0.2%	Rank history: not on the FY2021–FY2024 lists and #18 in FY2025; new, not ranked in Aug 2024–Jul 2025.
17	Aehs Incorporated Top agencies DHA (Defense Health Agency)	$20,771	0.2%	Rank history: #35 in FY2021, #11 in FY2022, #15 in FY2023, #11 in FY2024 and #13 in FY2025; down 6 since Aug 2024–Jul 2025.
18	August Mack Environmental, Inc. Top agencies DFAS (Defense Finance and Accounting Service)	$14,000	0.1%	Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
19	Sage-Efs JV Top agencies VA (Department of Veterans Affairs)	$13,661	0.1%	Rank history: not on the FY2021 list, #30 in FY2022, not on the FY2023 list, #30 in FY2024 and #31 in FY2025; up 9 since Aug 2024–Jul 2025.
20	Spectral Platforms Inc. Top agencies HHS (Department of Health and Human Services)	$13,499	0.1%	Rank history: not on the FY2021–FY2022 lists, #8 in FY2023, #15 in FY2024 and #23 in FY2025; new, not ranked in Aug 2024–Jul 2025.
21	Eastern New Mexico University Top agencies Army (Department of the Army)	$13,277	0.1%	Rank history: not on the FY2021–FY2024 lists and #21 in FY2025; down 2 since Aug 2024–Jul 2025.
22	Coterie Environmental LLC Top agencies Army (Department of the Army)	$12,757	0.1%	Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
23	Clearair, Inc. Top agencies Navy (Department of the Navy)	$10,990	0.1%	Rank history: not on the FY2021–FY2024 lists and #24 in FY2025; new, not ranked in Aug 2024–Jul 2025.
24	Titan Environmental Solutions, Inc. Top agencies Navy (Department of the Navy)	$9,536	0.1%	Rank history: not on the FY2021 list, #33 in FY2022, not on the FY2023 list, #25 in FY2024 and #25 in FY2025; down 1 since Aug 2024–Jul 2025.
25	SGS North America Inc. Top agencies DOI (Department of the Interior)	$4,795	<0.1%	Rank history: not on the FY2021–FY2024 lists and #27 in FY2025; new, not ranked in Aug 2024–Jul 2025.
26	Ati, Inc. Top agencies NARA (National Archives and Records Administration)	$2,508	<0.1%	Rank history: not on the FY2021–FY2023 lists, #31 in FY2024 and not on the FY2025 list; new, not ranked in Aug 2024–Jul 2025.
27	Tri Airtesting Inc. Top agencies Navy (Department of the Navy)	$2,112	<0.1%	Rank history: not on the FY2021–FY2024 lists and #33 in FY2025; up 5 since Aug 2024–Jul 2025.
28	North Carolina Department of Environmental Quality Top agencies DOJ (Department of Justice)	$1,304	<0.1%	Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.

How this ranking works

• Source: every contract action FPDS records (as published on SAM.gov) in the period, as GovTribe received it.
• Amounts are net obligations: what was obligated, less what was deobligated. Shares are of $12.7 million obligated before deobligations, so they never pass 100%.
• Parent companies: each action counts under the ultimate parent its award record names, or under the awardee when it names none, so no dollar counts twice. An awardee whose own actions mostly name no parent, and that no other company's actions name as their parent, rolls up its SAM.gov registration's chain of parent companies: it counts under the first company there that other companies' actions name as their parent, or under the parent most of a company's own actions name, whichever comes first; with neither, under the highest company in the chain with federal contracts of its own. Joint ventures stay companies of their own. Parents of the same name (Inc., LLC and the like aside) count as one company, since FPDS records a company's parent under more than one UEI over time. GovTribe corrects a few parents and names by hand; see the corrections.
• Period: the trailing 12 months end with the last month that ended at least 90 days ago, because the Department of Defense reports its contract actions to FPDS about 90 days late. The list is rebuilt each night.
• Rank changes compare with Aug 2024–Jul 2025. "New" marks a company outside that period's top 500, and "Returned" one of those that was on an earlier fiscal year's list.
• Rank lines show each company's rank on every fiscal year's list since FY2021, #1 at the top, on a scale that gives the top of the list more room. A dashed stretch spans years it wasn't on the list.
• Placeholder recipients FPDS uses when it names no company ("Miscellaneous Foreign Contractors" and the like) aren't ranked.

Quick answers