| Atlantic Contingency Constructors LLC | Baton Rouge | LA | $0 |
| Atlas Geosciences NW, LLC | Issaquah | WA | Subcontractor |
| Atoka, Inc. | Hot Springs | AR | $0 |
| A To Z Environmental Consulting, LLC | Sonoita | AZ | $0 |
| Aurora Research Associates LLC | Silver Lake | OH | Subcontractor |
| Avesi Inc. | Panama City Beach | FL | Subcontractor |
| Babbitt, Callie Whitfield | Rochester | NY | $0 |
| Bancroft Environmental Consulting LLC | Lubbock | TX | Subcontractor |
| Baranko Environmental, LLC | Dickinson | ND | $0 |
| Barclay Assessment Services LLC | Ponchatoula | LA | $0 |
| Barnes, Ferland And Associates, Inc. | Orlando | FL | $0 |
| BBC Environmental, Inc. | San Diego | CA | Subcontractor |
| Bec Environmental Inc. | Las Vegas | NV | Subcontractor |
| Behrens And Associates, Inc. | El Segundo | CA | $0 |
| Bercha International Inc. | Calgary | AB | $0 |
| Beyond Compliance Strategies, LLC | Oakland | CA | $0 |
| BH&M Environmental Consultants, Inc. | Memphis | TN | Subcontractor |
| Biebighauser Thomas | Morehead | KY | $0 |
| Big Apple Occupational Safety Inc. | New York | NY | $0 |
| Bioanalysts Inc. | Boise | ID | Subcontractor |
| Bioimpact, Inc. | Christiansted | VI | Subcontractor |
| Biological Monitoring Inc. | Blacksburg | VA | $0 |
| Biological Resources, LLC | Durango | CO | $0 |
| Biomaas Incorporated | San Francisco | CA | Subcontractor |
| Biome, Ecological And Wildlife Research, L.L.C. | Flagstaff | AZ | $0 |
| Bio-studies Inc. | Escondido | CA | Subcontractor |
| BKS Environmental Associates, Inc. | Gillette | WY | Subcontractor |
| Blackstone Environmental, Inc. | Stilwell | KS | Subcontractor |
| Blackwater Environmental Group, LLC | Hunt Valley | MD | Subcontractor |
| Bloomington Energy & Environmental Intelligence, LLC | Bloomington | IN | Subcontractor |
| Blue Mountain Environmental Consulting LLC | Fort Collins | CO | $0 |
| Bole Marcus | Wheatland | CA | $0 |
| Boreal Renewable Energy Development | Concord | MA | $0 |
| Brightfields, Inc. | Wilmington | DE | Subcontractor |
| Brisea International Development Inc. | Whippany | NJ | $0 |
| Brooks Environmental Consulting, LLC | Norwalk | CT | $0 |
| Brownfield Redevelopment Solutions Inc. | Medford | NJ | $0 |
| Brushy Fork Environmental Consulting Inc. | Trade | TN | $0 |
| Bubbleology Research International, Inc. | Solvang | CA | $0 |
| Buffalo Environmental Consultants Inc. | Niagara Falls | NY | $0 |
| Cache Environmental Laboratories, P.C. | Logan | UT | $0 |
| Caddis Environmental Consulting LLC | Crestone | CO | Subcontractor |
| Calstart, Inc. | Pasadena | CA | Subcontractor |
| Camas, LLC | Jacksonville | OR | Subcontractor |
| Cambrian Innovation Inc. | Boston | MA | $0 |
| Campbell Consulting Services Inc. | Yaphank | NY | Subcontractor |
| Canacre USA, LLC | Houston | TX | Subcontractor |
| Caribe Environmental Services Inc. | Caguas | PR | $0 |
| Cascadia Consulting Group, Inc. | Seattle | WA | $0 |
| Casc Engineering & Consulting Inc. | Colton | CA | $0 |
| Casey Greenstein | Homer | AK | $0 |
| Cashins & Associates, Inc. | Wakefield | MA | Subcontractor |
| Castle Environmental Consulting, LLC | Los Angeles | CA | Subcontractor |
| CCG-TTL Joint Venture, LLC | Columbus | OH | $0 |
| CDM Federal Programs Corporation | Pittsburgh | PA | Subcontractor |
| CDM Federal Services Inc. | Boston | MA | Subcontractor |
| CDW Consultants Inc. | Framingham | MA | $0 |
| Cedar Creek Associates, Inc. | Fort Collins | CO | $0 |
| Centennial Archaeology LLC | Fort Collins | CO | Subcontractor |
| Center For Climate Strategies Inc. | Washington | DC | Subcontractor |
| Center For Ecotechnology Inc. | Northampton | MA | $0 |
| Center For Watershed Protection, Inc. | Fulton | MD | Subcontractor |
| Centerline Strategy, LLC | Potomac | MD | $0 |
| Century Environmental Hygiene, LLC | Fort Collins | CO | Subcontractor |
| Ces Environmental Consultants Inc. | Whittier | CA | Subcontractor |
| Charles Hendrix | Harvest | AL | $0 |
| Chelonidata LLC | Berthoud | CO | Subcontractor |
| Chem Scope, Inc. | North Haven | CT | $0 |
| Chenega Reliable Services, LLC | Chantilly | VA | $0 |
| Chesapeake Environmental Management, Inc. | Bel Air | MD | $0 |
| Circlepoint | Oakland | CA | Subcontractor |
| Clay Point Associates Inc. | Williston | VT | $0 |
| Cleanfleets.net LLC | Sacramento | CA | $0 |
| Cleanhealth Environmental, LLC | Silver Spring | MD | $0 |
| Clean Properties Engineering, Inc. | Sudbury | MA | $0 |
| Clean Vapor Limited Liability Company | Blairstown | NJ | Subcontractor |
| CLF Ventures, Inc. | Boston | MA | $0 |
| Climate Focus North America, Inc. | Washington | DC | Subcontractor |
| Coastal 35 Consulting, Inc. | Atascadero | CA | Subcontractor |
| Coastal Environments Inc. | La Jolla | CA | $0 |
| Coastal Monitoring Associates LLC | San Diego | CA | Subcontractor |
| Coastal Science Associates Southern Affiliate, Inc. | Myrtle Beach | SC | Subcontractor |
| Coastwise Consulting, Inc. | Athens | GA | Subcontractor |
| Columbia Technologies, LLC | Rockville | MD | Subcontractor |
| Comite Resources, Inc. | Covington | LA | Subcontractor |
| Common Sense Environmental, Inc. | New Bedford | MA | $0 |
| Community Resilience Consulting, LLC | Lynchburg | VA | Subcontractor |
| Compass Ecospatial LLC | Ridgefield | WA | Subcontractor |
| Compliance Solution LLC | Honolulu | HI | $0 |
| Compliance Strategies & Solutions, Inc. | Pearland | TX | $0 |
| Condor Earth Technologies, Inc. | Sonora | CA | Subcontractor |
| Confluence Environmental Company | Seattle | WA | $0 |
| Conservation Southeast Incorporated | Andalusia | AL | $0 |
| Conservation Visions Incorporated | St Johns | NL | $0 |
| Consortium For Environmental Risk Management LLC | Hallowell | ME | $0 |
| Coranco Great Plains, Inc. | Wahoo | NE | $0 |
| Corona Environmental Consulting, LLC | Braintree | MA | Subcontractor |
| Corr Safety Professionals Inc. | West Chester | PA | Subcontractor |
| Courtney Fara | Gloucester | MA | $0 |
| Cox Environmental & Hydrogeologic LLC | Birmingham | AL | Subcontractor |
