Top 100 Contractors in PSC B510: Environmental Studies and Assessments, Aug 2025–Jul 2026
Parent companies by net contract obligations Aug 1, 2025 – Jul 31, 2026 Code page on GovTribe
The latest 12 months. See the newest fiscal year's list: Top Contractors in PSC B510: Environmental Studies and Assessments, FY2025.
The top 10 won 56% of PSC B510 contract dollars from August 2025 through July 2026
Ranking facts
- Contract obligations
- $250,726,496 Net of deobligations, by contracts coded PSC B510
- Contractors
- 204 Parent companies with an obligation
- Largest contractor
- Amentum Holdings, Inc. $38.9 million, 14.4% of obligations
- Data as of
Contract actions from FPDS (SAM.gov). How the rankings work · Download all 100 rows as CSV · Free to reuse with credit to GovTribe (CC BY 4.0)
Full ranking
| Rank | Contractor | Net obligations | Share | Trend |
|---|---|---|---|---|
| 1 |
Amentum Holdings, Inc.
Top agencies
|
$38,867,641 | ||
| 2 | $28,352,696 | |||
| 3 |
Gulf South Research Corp
|
$26,485,754 | ||
| 4 | $12,050,946 | |||
| 5 | $8,887,899 | |||
| 6 | $8,731,862 | |||
| 7 | $8,393,259 | |||
| 8 | $6,934,351 | |||
| 9 |
Kfs, LLC
Top agencies
|
$6,635,104 | ||
| 10 |
Hdr, Inc.
Top agencies
|
$5,892,853 | ||
| 11 |
Jacobs Engineering Group Inc.
Top agencies
|
$5,465,312 | ||
| 12 | $5,291,875 | |||
| 13 |
Ardl Inc.
Top agencies
|
$5,108,588 | ||
| 14 | $5,051,141 | |||
| 15 | $4,980,197 | |||
| 16 |
WSP USA Solutions Inc
|
$4,750,146 | ||
| 17 |
Dawson Mcg, Inc.
Top agencies
|
$4,635,519 | ||
| 18 |
Rmec Environmental Inc
Top agencies
|
$3,419,660 | ||
| 19 | $3,295,805 | |||
| 20 |
Pb&A / CSS JV, Llc.
Top agencies
|
$2,881,471 | ||
| 21 | $2,791,569 | |||
| 22 |
MBK Engineers
Top agencies
|
$2,467,103 | ||
| 23 |
Kemron Environmental Services Inc.
Top agencies
|
$2,435,278 | ||
| 24 |
Sundance Consultants, LLC
Top agencies
|
$2,432,433 | ||
| 25 | $1,858,945 | |||
| 26 | $1,792,560 | |||
| 27 | $1,759,547 | |||
| 28 | $1,735,877 | |||
| 29 |
Avid Core LLC
Top agencies
|
$1,634,791 | ||
| 30 |
R Ward & Associates Inc.
Top agencies
|
$1,446,581 | ||
| 31 | $1,267,912 | |||
| 32 |
Ocean Associates Inc.
Top agencies
|
$1,262,815 | ||
| 33 | $1,247,287 | |||
| 34 | $1,118,722 | |||
| 35 | $1,111,753 | |||
| 36 |
Southeastern Archaeological Research LLC
Top agencies
|
$1,091,020 | ||
| 37 | $1,080,247 | |||
| 38 |
Star Geoenvironmental LLC
Top agencies
|
$1,054,384 | ||
| 39 | $990,371 | |||
| 40 | $948,594 | |||
| 41 |
EA Engineering Science and Technology Inc. PBC
Top agencies
|
$947,269 | ||
| 42 |
Swca Incorporated
Top agencies
|
$923,834 | ||
| 43 | $897,925 | |||
| 44 |
Chloeta Holdings LLC
Top agencies
|
$896,128 | ||
| 45 | $878,651 | |||
| 46 |
Mtsa II JV LLC
Top agencies
|
$864,775 | ||
| 47 |
ICF International Inc.
|
$831,549 | ||
| 48 | $791,926 | |||
| 49 | $762,900 | |||
| 50 |
Chugai Technos Corporation
Top agencies
|
$732,900 | ||
| 51 | $644,835 | |||
| 52 |
Paleowest LLC
Top agencies
|
$631,886 | ||
| 53 | $626,577 | |||
| 54 |
Alaska Biomap, Inc.
Top agencies
|
$580,435 | ||
| 55 |
ASM Affiliates Inc.
Top agencies
|
$545,000 | ||
| 56 | $503,285 | |||
| 57 |
Ecoquants LLC
Top agencies
|
$500,000 | ||
| 58 |
Heliotech
Top agencies
|
$467,093 | ||
| 59 |
Hydrogeologic, Inc.
Top agencies
|
$456,449 | ||
| 60 | $439,814 | |||
| 61 |
Ecological Associates, Inc.
Top agencies
|
$415,148 | ||
| 62 | $400,000 | |||
| 63 | $380,111 | |||
| 64 | $370,337 | |||
| 65 |
Ironwood Consulting Inc.
Top agencies
|
$369,145 | ||
| 66 | $368,700 | |||
| 67 | $351,597 | |||
| 68 |
Water & Air Research, Inc.
Top agencies
|
$350,280 | ||
| 69 |
Seva EHS Inc
Top agencies
|
$317,610 | ||
| 70 | $316,520 | |||
| 71 | $314,904 | |||
| 72 | $300,548 | |||
| 73 |
Kgsne JV II LLC
Top agencies
|
$300,080 | ||
| 74 | $295,734 | |||
| 75 |
TDA Research, Inc.
Top agencies
|
$295,592 | ||
| 76 |
OCH JV
Top agencies
|
$294,106 | ||
| 77 |
S&K Mission Support, LLC
Top agencies
|
$283,836 | ||
| 78 | $270,336 | |||
| 79 |
Oneida Environmental, LLC
Top agencies
|
$267,601 | ||
| 80 |
SES Inc.
Top agencies
|
$266,300 | ||
| 81 |
DAV Energy Solutions, Inc.
Top agencies
|
$259,000 | ||
| 82 | $257,606 | |||
| 83 |
Cherokee Nation
Top agencies
|
$254,217 | ||
| 84 |
Avanti Corporation
Top agencies
|
$251,667 | ||
| 85 |
Advista
Top agencies
|
$248,711 | ||
| 86 | $244,745 | |||
| 87 |
Bromgrove Limited
Top agencies
|
$243,882 | ||
| 88 |
Deloitte
Top agencies
|
$238,217 | ||
| 89 |
Swift River Versar JV
Top agencies
|
$220,617 | ||
| 90 |
Atkinsrealis USA Inc.
Top agencies
|
$215,245 | ||
| 91 | $213,154 | |||
| 92 |
Solv LLC
Top agencies
|
$209,252 | ||
| 93 |
Aerialzeus, LLC
Top agencies
|
$195,000 | ||
| 94 |
One Network Enterprises Inc.
Top agencies
|
$189,950 | ||
| 95 | $188,680 | |||
| 96 | $186,905 | |||
| 97 |
Relife Recycling S.R.L.
Top agencies
|
$185,854 | ||
| 98 | $182,062 | |||
| 99 | $178,050 | |||
| 100 | $177,039 |
Show 75 more
100 of 204 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 $269 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
Who were the top 10 PSC B510 contractors in Aug 2025–Jul 2026?
1. Amentum Holdings, Inc. ($38.9M), 2. Vernadero Group Inc. ($28.4M), 3. Gulf South Research Corp ($26.5M), 4. Environmental Restoration LLC ($12.1M), 5. Tierra Right of Way Services Ltd ($8.89M), 6. Dawson Solutions LLC ($8.73M), 7. ECO & Associates, Inc. ($8.39M), 8. Eastern Research Group Inc. ($6.93M), 9. Kfs, LLC ($6.64M), 10. Hdr, Inc. ($5.89M).
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