| 1 | CH2M HILL PLATEAU REMEDIATION COMPANY | $7,065,250,860 | 1 | $7,065,250,860 | Jun 19, 2008 | Department of Energy |
| 2 | FLUOR-BWXT PORTSMOUTH LLC | $4,464,785,978 | 1 | $4,464,785,978 | Aug 16, 2010 | Department of Energy |
| 3 | SAVANNAH RIVER MISSION COMPLETION, LLC | $4,454,562,937 | 8 | $556,820,367 | May 05, 2026 | Department of Energy |
| 4 | UCOR LLC | $3,900,788,934 | 1 | $3,900,788,934 | Apr 29, 2011 | Department of Energy |
| 5 | CENTRAL PLATEAU CLEANUP COMPANY, LLC | $3,167,432,598 | 8 | $395,929,075 | Oct 01, 2024 | Department of Energy |
| 6 | UNITED CLEANUP OAK RIDGE LLC | $2,540,845,400 | 1 | $2,540,845,400 | May 17, 2023 | Department of Energy |
| 7 | IDAHO ENVIRONMENTAL COALITION LLC | $1,635,128,065 | 1 | $1,635,128,065 | Oct 01, 2023 | Department of Energy |
| 8 | CH2M HILL BWXT WEST VALLEY, LLC | $990,004,958 | 1 | $990,004,958 | Jul 01, 2011 | Department of Energy |
| 9 | SEVENSON ENVIRONMENTAL SERVICES, INC. | $886,887,743 | 30 | $29,562,925 | Mar 17, 2026 | Department of Defense |
| 10 | EA ENGINEERING, SCIENCE, AND TECHNOLOGY, IN… | $761,873,797 | 154 | $4,947,232 | Sep 26, 2027 | Environmental Protection … |
| 11 | NAVARRO RESEARCH AND ENGINEERING, INC. | $760,414,518 | 12 | $63,367,877 | Dec 01, 2025 | Department of Defense |
| 12 | NORTH WIND PORTAGE, INC. | $698,282,491 | 7 | $99,754,642 | May 02, 2024 | Department of Energy |
