Top 100 Contractors in PSC B510: Environmental Studies and Assessments, FY2025

Name: Top 100 Contractors in PSC B510: Environmental Studies and Assessments, FY2025
Creator: GovTribe

Parent companies by net contract obligations Oct 1, 2024 – Sep 30, 2025 Code page on GovTribe

The top 10 won 58% of FY2025 PSC B510 contract dollars

Contract obligations: $224,994,258 Net of deobligations, by contracts coded PSC B510
Contractors: 227 Parent companies with an obligation
Largest contractor: Amentum Holdings, Inc. $62.6 million, 24.3% of obligations
Data as of: Oct 14, 2026

Contract actions from FPDS (SAM.gov). How the rankings work · Download all 100 rows as CSV

Full ranking

Rank	Contractor	Net obligations	Share	Trend
1	Amentum Holdings, Inc. Through Amentum Services, Inc. Top agencies Army (Department of the Army)	$62,625,373	24.3%	Rank history: not on the FY2021–FY2023 lists and #36 in FY2024; up 35 since FY2024.
2	Tetra Tech, Inc. 3 awardees Top agencies EPA (Environmental Protection Agency) DOE (Department of Energy)	$21,569,308	8.4%	Rank history: #7 in FY2021, #2 in FY2022, #1 in FY2023 and #3 in FY2024; up 1 since FY2024.
3	Gulf South Research Corp Top agencies DHS (Department of Homeland Security) Army (Department of the Army) DOT (Department of Transportation)	$16,143,034	6.3%	Rank history: not on the FY2021–FY2022 lists, #41 in FY2023 and not on the FY2024 list; returned.
4	Hdr, Inc. 2 awardees, including HDR Environmental, Operations and Construction, Inc. Top agencies Navy (Department of the Navy)	$12,334,188	4.8%	Rank history: #83 in FY2021, #47 in FY2022, #31 in FY2023 and #4 in FY2024; unchanged since FY2024.
5	Vernadero Group Inc. Top agencies DHS (Department of Homeland Security)	$8,802,913	3.4%	Rank history: #95 in FY2021 and not on the FY2022–FY2024 lists; returned.
6	Eastern Research Group Inc. Top agencies EPA (Environmental Protection Agency) DOI (Department of the Interior)	$7,156,129	2.8%	Rank history: #2 in FY2021, #12 in FY2022, #13 in FY2023 and #7 in FY2024; up 1 since FY2024.
7	Dawson Solutions LLC Top agencies DHS (Department of Homeland Security) USDA (Department of Agriculture)	$6,240,913	2.4%	Rank history: not on the FY2021–FY2022 lists, #22 in FY2023 and #42 in FY2024; up 35 since FY2024.
8	Jacobs Government Services Company Through Jacobs Engineering Group Inc. Top agencies Army (Department of the Army)	$5,500,717	2.1%	Rank history: not on the FY2021–FY2023 lists and #10 in FY2024; up 2 since FY2024.
9	University of California, Davis Top agencies EPA (Environmental Protection Agency)	$5,265,591	2.0%	Rank history: not on the FY2021–FY2023 lists and #23 in FY2024; up 14 since FY2024.
10	Consolidated Safety Services Incorporated Top agencies EPA (Environmental Protection Agency)	$5,046,137	2.0%	Rank history: #9 in FY2021, #14 in FY2022, #15 in FY2023 and #15 in FY2024; up 5 since FY2024.
11	Kgsne JV II LLC Top agencies EPA (Environmental Protection Agency)	$4,972,718	1.9%	Rank history: not on the FY2021 list, #10 in FY2022, #17 in FY2023 and #22 in FY2024; up 11 since FY2024.
12	Dawson Mcg, Inc. Top agencies DHS (Department of Homeland Security)	$4,393,646	1.7%	Rank history: not on the FY2021–FY2024 lists; new.
13	Neptune and Company, Incorporated Top agencies DOE (Department of Energy)	$4,138,273	1.6%	Rank history: #61 in FY2021, #52 in FY2022, #18 in FY2023 and #28 in FY2024; up 15 since FY2024.
14	Golder Europe Service Centre SRL 2 awardees, including WSP USA Solutions Inc. and WSP Italia S.R.L. Top agencies DOE (Department of Energy) GSA (General Services Administration) Army (Department of the Army)	$4,121,095	1.6%	Rank history: not on the FY2021–FY2022 lists, #25 in FY2023 and #18 in FY2024; up 4 since FY2024.
15	Southeastern Archaeological Research Inc. Top agencies Army (Department of the Army)	$3,687,448	1.4%	Rank history: #23 in FY2021, #35 in FY2022, #48 in FY2023 and #54 in FY2024; up 39 since FY2024.
16	Rmec Environmental Inc Top agencies Army (Department of the Army)	$3,480,648	1.4%	Rank history: not on the FY2021–FY2022 lists, #20 in FY2023 and #17 in FY2024; up 1 since FY2024.
17	Pe Ayuda Joint Venture LLC Top agencies Army (Department of the Army)	$3,330,993	1.3%	Rank history: not on the FY2021–FY2022 lists, #4 in FY2023 and not on the FY2024 list; up 85 since FY2024.
18	Anamar Environmental Consulting, Inc. Top agencies Army (Department of the Army)	$2,811,123	1.1%	Rank history: #18 in FY2021, #28 in FY2022, #32 in FY2023 and #33 in FY2024; up 15 since FY2024.
19	Ciri Development Corporation Through North Wind Resource Consulting LLC Top agencies DOI (Department of the Interior)	$2,791,569	1.1%	Rank history: not on the FY2021–FY2022 lists, #27 in FY2023 and not on the FY2024 list; returned.
20	Stantec Inc. 2 awardees, including Stantec Consulting Services Inc. Top agencies DOI (Department of the Interior) HHS (Department of Health and Human Services)	$2,218,679	0.9%	Rank history: not on the FY2021–FY2022 lists, #12 in FY2023 and #31 in FY2024; up 11 since FY2024.
21	Environmental Testing and Consulting, Inc. Top agencies Army (Department of the Army) GSA (General Services Administration)	$1,887,332	0.7%	Rank history: not on the FY2021 list, #27 in FY2022, #30 in FY2023 and #30 in FY2024; up 9 since FY2024.
22	Kfs, LLC Top agencies Army (Department of the Army)	$1,859,941	0.7%	Rank history: not on the FY2021–FY2024 lists; new.
23	LRS Federal LLC Top agencies VA (Department of Veterans Affairs)	$1,830,208	0.7%	Rank history: not on the FY2021–FY2023 lists and #82 in FY2024; up 59 since FY2024.
24	Avid Core LLC Top agencies DHS (Department of Homeland Security)	$1,786,285	0.7%	Rank history: not on the FY2021–FY2022 lists, #35 in FY2023 and #37 in FY2024; up 13 since FY2024.
25	Environmental Science Corporation Top agencies Army (Department of the Army)	$1,526,760	0.6%	Rank history: #36 in FY2021, #36 in FY2022, #46 in FY2023 and #62 in FY2024; up 37 since FY2024.
26	Pond & Company Top agencies USAF (Department of the Air Force)	$1,516,045	0.6%	Rank history: not on the FY2021–FY2024 lists; new.
27	LG2 Environmental Solutions, Inc. Top agencies Army (Department of the Army)	$1,495,940	0.6%	Rank history: #20 in FY2021, #57 in FY2022, #49 in FY2023 and #69 in FY2024; up 42 since FY2024.
28	Tierra Right of Way Services Ltd Top agencies DHS (Department of Homeland Security)	$1,485,590	0.6%	Rank history: not on the FY2021–FY2024 lists; new.
29	Environmental Assessment Services, LLC Top agencies Army (Department of the Army)	$1,477,654	0.6%	Rank history: not on the FY2021–FY2024 lists; up 139 since FY2024.
30	AECOM 2 awardees, including Environmental Management & Planning Solutions LLC and AECOM Italia S.P.A. Top agencies DOI (Department of the Interior) Army (Department of the Army)	$1,449,728	0.6%	Rank history: #22 in FY2021, #5 in FY2022, #3 in FY2023 and #12 in FY2024; down 18 since FY2024.
31	R Ward & Associates Inc. Top agencies Army (Department of the Army)	$1,446,581	0.6%	Rank history: not on the FY2021–FY2024 lists; new.
32	Ardl Inc. Top agencies Army (Department of the Army) EPA (Environmental Protection Agency)	$1,371,784	0.5%	Rank history: not on the FY2021 list, #39 in FY2022, #28 in FY2023 and not on the FY2024 list; up 98 since FY2024.
33	Environmental Science Services Inc. Top agencies Army (Department of the Army)	$1,359,427	0.5%	Rank history: not on the FY2021–FY2024 lists; up 269 since FY2024.
34	Hana Resources, Inc. Top agencies Army (Department of the Army)	$1,149,764	0.4%	Rank history: not on the FY2021–FY2024 lists; new.
35	EA Engineering Science and Technology Inc. PBC Top agencies EPA (Environmental Protection Agency) DOT (Department of Transportation)	$1,126,165	0.4%	Rank history: not on the FY2021–FY2023 lists and #34 in FY2024; down 1 since FY2024.
36	S C & A Inc. Top agencies DOE (Department of Energy) NRC (Nuclear Regulatory Commission)	$1,091,709	0.4%	Rank history: #54 in FY2021, not on the FY2022–FY2023 lists and #35 in FY2024; down 1 since FY2024.
37	Paleowest LLC Top agencies Army (Department of the Army)	$1,090,930	0.4%	Rank history: #99 in FY2021, not on the FY2022–FY2023 lists and #94 in FY2024; up 57 since FY2024.
38	Horsley Witten Group, Inc. Top agencies EPA (Environmental Protection Agency)	$1,090,194	0.4%	Rank history: #12 in FY2021, #41 in FY2022, #40 in FY2023 and #32 in FY2024; down 6 since FY2024.
39	Green Water Solutions, LLC Top agencies IBWC (International Boundary and Water Commission U.S.-Mexico)	$1,080,247	0.4%	Rank history: not on the FY2021–FY2024 lists; new.
40	Blue World Research Institute Inc. Top agencies DOI (Department of the Interior)	$1,078,364	0.4%	Rank history: #24 in FY2021, #72 in FY2022, #16 in FY2023 and #38 in FY2024; down 2 since FY2024.
41	Global Consulting Inc. Top agencies HHS (Department of Health and Human Services)	$1,010,458	0.4%	Rank history: #67 in FY2021, #73 in FY2022, #65 in FY2023 and #53 in FY2024; up 12 since FY2024.
42	Ahtna Global LLC Top agencies Army (Department of the Army)	$990,415	0.4%	Rank history: not on the FY2021–FY2023 lists and #73 in FY2024; up 31 since FY2024.
43	Converge Federal Solutions JV, LLC Top agencies Army (Department of the Army)	$975,248	0.4%	Rank history: not on the FY2021–FY2022 lists, #50 in FY2023 and #49 in FY2024; up 6 since FY2024.
44	Chloeta Holdings LLC Top agencies USDA (Department of Agriculture) USAF (Department of the Air Force)	$921,036	0.4%	Rank history: not on the FY2021–FY2023 lists and #75 in FY2024; up 31 since FY2024.
45	Chugai Technos Corporation Top agencies Navy (Department of the Navy)	$879,782	0.3%	Rank history: not on the FY2021–FY2024 lists; new.
46	Hawaii International Environmental Services Inc. Top agencies Army (Department of the Army)	$879,421	0.3%	Rank history: not on the FY2021–FY2024 lists; up 103 since FY2024.
47	Watercourse Engineering, Inc. Top agencies DOI (Department of the Interior)	$875,812	0.3%	Rank history: not on the FY2021–FY2023 lists and #89 in FY2024; up 42 since FY2024.
48	Ocean Associates Inc. Top agencies Commerce (Department of Commerce)	$853,485	0.3%	Rank history: not on the FY2021–FY2023 lists and #76 in FY2024; up 28 since FY2024.
49	Marstel-Day, LLC Top agencies DOI (Department of the Interior) USAF (Department of the Air Force) Navy (Department of the Navy)	$712,393	0.3%	Rank history: #88 in FY2021, #58 in FY2022, #47 in FY2023 and #77 in FY2024; up 28 since FY2024.
50	Hydrogeologic, Inc. Top agencies EPA (Environmental Protection Agency) Army (Department of the Army)	$661,489	0.3%	Rank history: not on the FY2021–FY2023 lists and #59 in FY2024; up 9 since FY2024.
51	Truescape Limited Top agencies DOI (Department of the Interior)	$585,000	0.2%	Rank history: not on the FY2021 list, #43 in FY2022, not on the FY2023 list and #48 in FY2024; down 3 since FY2024.
52	National Institute of Building Sciences Top agencies EPA (Environmental Protection Agency)	$546,899	0.2%	Rank history: not on the FY2021–FY2023 lists and #84 in FY2024; up 32 since FY2024.
53	MBK Engineers Top agencies DOI (Department of the Interior)	$540,000	0.2%	Rank history: #58 in FY2021, #69 in FY2022, #67 in FY2023 and #13 in FY2024; down 40 since FY2024.
54	AECOM Technical Services, Inc. Top agencies DOI (Department of the Interior)	$532,919	0.2%	Rank history: not on the FY2021–FY2023 lists and #5 in FY2024; down 49 since FY2024.
55	Ironwood Consulting Inc. Top agencies DOI (Department of the Interior)	$506,941	0.2%	Rank history: not on the FY2021–FY2024 lists; new.
56	Ecoquants LLC Top agencies DOI (Department of the Interior)	$500,000	0.2%	Rank history: not on the FY2021–FY2022 lists, #94 in FY2023 and not on the FY2024 list; returned.
57	Swca Incorporated Top agencies DOI (Department of the Interior)	$464,706	0.2%	Rank history: not on the FY2021–FY2023 lists and #29 in FY2024; down 28 since FY2024.
58	Water & Air Research, Inc. Top agencies Army (Department of the Army)	$454,448	0.2%	Rank history: #59 in FY2021, #88 in FY2022, #100 in FY2023 and #71 in FY2024; up 13 since FY2024.
59	Mabbett & Associates, Inc. Top agencies VA (Department of Veterans Affairs) EPA (Environmental Protection Agency) USDA (Department of Agriculture)	$445,400	0.2%	Rank history: #39 in FY2021, #33 in FY2022, not on the FY2023 list and #55 in FY2024; down 4 since FY2024.
60	Raven Environmental Services, Inc. Top agencies USDA (Department of Agriculture)	$439,814	0.2%	Rank history: not on the FY2021–FY2024 lists; up 65 since FY2024.
61	Heliotech Top agencies EPA (Environmental Protection Agency)	$427,846	0.2%	Rank history: not on the FY2021–FY2024 lists; up 192 since FY2024.
62	Cherokee Nation Environmental Solutions, L.L.C. Top agencies Army (Department of the Army)	$331,393	0.1%	Rank history: not on the FY2021–FY2022 lists, #33 in FY2023 and #51 in FY2024; down 11 since FY2024.
63	Bureau Veritas Technical Assessments LLC Top agencies USDA (Department of Agriculture)	$329,300	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
64	ERO Resources Corporation Top agencies DOI (Department of the Interior)	$320,696	0.1%	Rank history: not on the FY2021 list, #60 in FY2022, #39 in FY2023 and #46 in FY2024; down 18 since FY2024.
65	HDR and Tehama Joint Venture Top agencies USAF (Department of the Air Force)	$314,904	0.1%	Rank history: not on the FY2021–FY2024 lists; up 52 since FY2024.
66	Stillwater Ecosystem Watershed & Riverine Sciences Top agencies DOI (Department of the Interior)	$312,045	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
67	Bluestone Environmental Group, Inc. Top agencies Army (Department of the Army)	$298,854	0.1%	Rank history: not on the FY2021 list, #83 in FY2022, #73 in FY2023 and not on the FY2024 list; up 41 since FY2024.
68	TDA Research, Inc. Top agencies Navy (Department of the Navy)	$295,592	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
69	OCH JV Top agencies EPA (Environmental Protection Agency)	$294,106	0.1%	Rank history: #66 in FY2021 and not on the FY2022–FY2024 lists; up 36 since FY2024.
70	Oneida Environmental, LLC Top agencies Navy (Department of the Navy)	$280,600	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
71	Al Department Environmental Management Top agencies NASA (National Aeronautics and Space Administration)	$272,000	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
72	New South Associates, Inc. Top agencies DOI (Department of the Interior)	$270,336	0.1%	Rank history: not on the FY2021–FY2024 lists; up 203 since FY2024.
73	Environmental Cost Management, Inc. Top agencies DOI (Department of the Interior) USDA (Department of Agriculture)	$259,500	0.1%	Rank history: not on the FY2021 list, #97 in FY2022, not on the FY2023 list and #85 in FY2024; up 12 since FY2024.
74	Minatoishi Palumbo Architects, Inc. Top agencies Army (Department of the Army)	$259,164	0.1%	Rank history: not on the FY2021–FY2023 lists and #1 in FY2024; down 73 since FY2024.
75	DAV Energy Solutions, Inc. Top agencies Army (Department of the Army)	$259,000	0.1%	Rank history: not on the FY2021–FY2024 lists; up 206 since FY2024.
76	SES Inc. Top agencies USDA (Department of Agriculture)	$253,575	0.1%	Rank history: not on the FY2021–FY2024 lists; up 37 since FY2024.
77	Advista Top agencies DOS (Department of State)	$248,711	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
78	Rock Leaf Water Environmental LLC Top agencies USDA (Department of Agriculture)	$245,185	0.1%	Rank history: not on the FY2021–FY2024 lists; up 51 since FY2024.
79	Hsg, LLC Top agencies DOI (Department of the Interior) GSA (General Services Administration)	$239,596	0.1%	Rank history: #78 in FY2021 and not on the FY2022–FY2024 lists; up 238 since FY2024.
80	Alaska Biomap, Inc. Top agencies DOI (Department of the Interior)	$226,441	0.1%	Rank history: not on the FY2021–FY2024 lists; up 81 since FY2024.
81	Swift River Versar JV Top agencies Navy (Department of the Navy)	$220,617	0.1%	Rank history: #45 in FY2021, #38 in FY2022, #44 in FY2023 and #24 in FY2024; down 57 since FY2024.
82	Silva Silva International, LLC Top agencies IBWC (International Boundary and Water Commission U.S.-Mexico)	$218,019	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
83	Atkinsrealis USA Inc. Top agencies DOI (Department of the Interior)	$215,245	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
84	Vanasse Hangen Brustlin Inc. Top agencies DOI (Department of the Interior)	$213,154	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
85	Solv LLC Top agencies DOI (Department of the Interior)	$212,991	0.1%	Rank history: not on the FY2021–FY2022 lists, #61 in FY2023 and not on the FY2024 list; up 58 since FY2024.
86	Johnson, Mirmiran & Thompson, Inc. Top agencies GSA (General Services Administration)	$204,408	0.1%	Rank history: not on the FY2021–FY2022 lists, #66 in FY2023 and #78 in FY2024; down 8 since FY2024.
87	Aerialzeus, LLC Top agencies DOI (Department of the Interior)	$195,000	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
88	Bromgrove Limited Top agencies USAF (Department of the Air Force)	$194,705	0.1%	Rank history: not on the FY2021–FY2024 lists; up 63 since FY2024.
89	Florida Department of Environmental Protection Top agencies NASA (National Aeronautics and Space Administration)	$190,783	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
90	Blue Yonder Inc. Through TRC Environmental Corporation Top agencies EPA (Environmental Protection Agency)	$189,950	0.1%	Rank history: not on the FY2021–FY2024 lists; up 47 since FY2024.
91	Phase Associates LLC Top agencies DOI (Department of the Interior)	$189,610	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
92	Cultural Resource Analysts, Inc. Top agencies DOT (Department of Transportation)	$186,905	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
93	Ivl, Institut FÜR Vegetationskunde UND Landschaftsökologie H. Schott UND Partner Landschaftsökologen Top agencies Army (Department of the Army)	$178,050	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
94	R. Christopher Goodwin & Associates, Inc. Top agencies DOT (Department of Transportation)	$177,406	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
95	WSP USA Environment & Infrastructure Inc. Top agencies DOI (Department of the Interior)	$165,326	0.1%	Rank history: not on the FY2021–FY2022 lists, #96 in FY2023 and not on the FY2024 list; returned.
96	Bay Area Environmental Research Institute Top agencies DOI (Department of the Interior)	$164,344	0.1%	Rank history: not on the FY2021–FY2024 lists; up 16 since FY2024.
97	Dong Myung Enterprise Co., Ltd. Top agencies USAF (Department of the Air Force)	$161,200	0.1%	Rank history: not on the FY2021 list, #48 in FY2022 and not on the FY2023–FY2024 lists; up 12 since FY2024.
98	RNA - Ricerca Natura API S.R.L. Top agencies Army (Department of the Army)	$158,785	0.1%	Rank history: not on the FY2021 list, #99 in FY2022 and not on the FY2023–FY2024 lists; up 37 since FY2024.
99	San Pasqual Band of Diegueno Mission Indians of California Top agencies IBWC (International Boundary and Water Commission U.S.-Mexico)	$150,920	0.1%	Rank history: not on the FY2021–FY2024 lists; new.
100	Olshesky Design Group, LLC Top agencies HHS (Department of Health and Human Services)	$149,881	0.1%	Rank history: not on the FY2021–FY2023 lists and #88 in FY2024; down 12 since FY2024.

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100 of 227 contractors listed here. See the rest on GovTribe.

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 $258 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. 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.
Fiscal year 2025 ran Oct 1, 2024 – Sep 30, 2025. The Department of Defense reports its contract actions to FPDS about 90 days late, so a fiscal year is ranked once they're in, in February, and the list doesn't change after.
Rank changes compare with FY2024. "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. The step from FY2024 takes the color of the rank change beside it.
Placeholder recipients FPDS uses when it names no company ("Miscellaneous Foreign Contractors" and the like) aren't ranked.

Quick answers

Who were the top 10 PSC B510 contractors in FY2025?

1. Amentum Holdings, Inc. ($62.6M), 2. Tetra Tech, Inc. ($21.6M), 3. Gulf South Research Corp ($16.1M), 4. Hdr, Inc. ($12.3M), 5. Vernadero Group Inc. ($8.8M), 6. Eastern Research Group Inc. ($7.16M), 7. Dawson Solutions LLC ($6.24M), 8. Jacobs Government Services Company ($5.5M), 9. University of California, Davis ($5.27M), 10. Consolidated Safety Services Incorporated ($5.05M).

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