| Harris Miller Miller & Hanson Inc. | Burlington | MA | $19.9M |
| Four Peaks Environmental Science & Data Solutions LLC | Wenatchee | WA | $19.4M |
| Avanti Corporation | Alexandria | VA | $19.2M |
| Tetra Tech, Inc.King Of Prussia, PA · UEI JEG3QJSDMYG7 | King Of Prussia | PA | $19.1M |
| S.s. Papadopulos & Associates, Inc. | Rockville | MD | $19M |
| Air Resource Specialists, Inc. | Fort Collins | CO | $18.8M |
| WSP E&is GMBH | Frankfurt | | $18.7M |
| Q & A Diversified LLC | San Antonio | TX | $17.7M |
| Cardno - Amec Foster Wheeler Public Works Joint Venture | Charlottesville | VA | $17.7M |
| Hyperion Biotechnology, Inc. | San Antonio | TX | $17.5M |
| Alliant Corporation | Knoxville | TN | $17.4M |
| TRC Environmental Corporation | Windsor | CT | $17.1M |
| Seres-arcadis 8(a) JV2 LLC | Charleston | SC | $16.9M |
| Rmec Environmental, LLC | Bountiful | UT | $16.8M |
| Del Mar Environmental & Construction Services Inc. | Chula Vista | CA | $16.6M |
| Proferre, Inc. | Tamuning | GU | $16.1M |
| The Woods Hole Group, Inc. | Buzzards Bay | MA | $16.1M |
| LPS Kemron JV LLC | Anchorage | AK | $16M |
| Logan Simpson Design Inc. | Tempe | AZ | $15.6M |
| HDR Environmental, Operations And Construction, Inc. | Folsom | CA | $15.5M |
| Specpro-ayuda JV, LLC | Anchorage | AK | $15.3M |
| Potomac-hudson Engineering Inc. | Rockville | MD | $15.1M |
| Clark Group, LLC, The | Montpelier | VT | $14.9M |
| GRK Bhate JV, LLC | Englewood | CO | $14.4M |
| Brice Aptim JV LLC | Anchorage | AK | $14.3M |
| The NDN Sundance JV LLC | Jacksonville | FL | $14.3M |
| Copperhead Environmental Consulting Inc. | Paint Lick | KY | $14.1M |
| Tellus Civic Science Corporation | San Diego | CA | $14.1M |
| Harris Environmental Group Inc. | Tucson | AZ | $14.1M |
| Espinoza Cultural Services, LLC | La Jara | CO | $13.8M |
| Lg2-qri JV LLC | Jacksonville | FL | $13.7M |
| Phe-baker JV2, LLC | Rockville | MD | $13.6M |
| Gradco LLC | Boston | MA | $13.3M |
| DDC 4C, LLC | Scottsdale | AZ | $13.2M |
| Ses Inc. | Lenexa | KS | $13M |
| Real Model Solutions, Inc. | Ventura | CA | $12.7M |
| Anamar Environmental Consulting, Inc. | Alachua | FL | $12.7M |
| Bluestone - Burns & Mcdonnell JV | Malvern | PA | $12.4M |
| Cti Environmental Inc. | Long Beach | CA | $12.4M |
| Environmental Solutions & Innovations, Inc. | Cincinnati | OH | $12.4M |
| Terra Solutions & Services Inc. | Herlong | CA | $12.2M |
| Windborne Systems Inc. | Redwood City | CA | $12.2M |
| Environmental Synectics, Inc. | Sacramento | CA | $12.2M |
| Keres Consulting Inc. | Albuquerque | NM | $11.8M |
| Eas E&e JV, LLC | Richland | WA | $11.5M |
| Gold Wave Inc. | Darien | IL | $11.5M |
| Limno-tech Inc. | Ann Arbor | MI | $11.5M |
| Tetra Tech Inc.Atlanta, GA · UEI UC2RW42PNSF4 | Atlanta | GA | $11.4M |
| Pars Environmental Inc. | Robbinsville | NJ | $11.4M |
| Natural Resource Innovations GMBH | Heidelberg | | $11.4M |
| Aec-weston JV, LLC | Knoxville | TN | $11.2M |
| TRC Environmental Corp. | Raleigh | NC | $11.2M |
| Aarcher, Inc. | Annapolis | MD | $11.1M |
| Ones Whitetail Joint Venture LLC | Tulsa | OK | $11.1M |
| Ce2 Corporation, Inc. | Pleasanton | CA | $11M |
| Tetra Tech Inc.San Antonio, TX · UEI ZU7NSK3NW7Z4 | San Antonio | TX | $11M |
| Tahkox E2-whitetail LLC | Bartlesville | OK | $11M |
| Hamer Environmental Limited Partnership | Mount Vernon | WA | $10.5M |
| Environmental Resources Management Inc. | Malvern | PA | $10.5M |
| Ceg-mse 8a JV, LLC | Pottstown | PA | $10.5M |
| Kira Facilities Maintenance LLC | Lynnwood | WA | $10.3M |
| Cornerstone Environmental Consulting LLC | Flagstaff | AZ | $10.3M |
| Pg Environmental, LLC | Chantilly | VA | $10.3M |
| LG2 Environmental Solutions, Inc. | Jacksonville | FL | $9.98M |
| Environmental Cost Management, Inc. | Costa Mesa | CA | $9.96M |
| Tetra Tech, Inc.Lakewood, CO · UEI D8DGTTCQRRF8 | Lakewood | CO | $9.86M |
| Tridec Technologies, LLC | Huber Heights | OH | $9.86M |
| Sst-ageiss2 JV, LLC | Anchorage | AK | $9.83M |
| Environmental Testing And Consulting, Inc. | Romulus | MI | $9.55M |
| Exeter Associates, Inc. | Columbia | MD | $9.53M |
| Mass Tank Inspection Services LLC | Middleboro | MA | $9.51M |
| Envirosystems Management Inc. | Flagstaff | AZ | $9.42M |
| Mecx, Inc. | Houston | TX | $9.34M |
| Meca Consulting Inc. | Pleasanton | CA | $9.33M |
| Adanta, Inc. | Napa | CA | $9.27M |
| Scout-cardno Joint Venture LLC | Encinitas | CA | $9.22M |
| Apex Contracting & Consulting Inc. | Fallbrook | CA | $9.12M |
| Ero Resources Corporation | Lakewood | CO | $9.03M |
| Hazair Inc. | Henderson | NV | $8.76M |
| Composting Sme, LLC | Candler | NC | $8.69M |
| Abr, Inc. | Fairbanks | AK | $8.54M |
| Sol-ageiss LLC | Chandler | AZ | $8.52M |
| Gibs Geologen + Ingenieure GMBH & Co. Kg | Nuernberg | | $8.41M |
| Northland Research, Inc. | Flagstaff | AZ | $8.39M |
| Del Mar-trevet-jv LLC | Chula Vista | CA | $8.12M |
| Merkel & Associates, Inc. | San Diego | CA | $8.09M |
| Onerain Incorporated | Longmont | CO | $7.86M |
| Mantech-aecom Joint Venture | Herndon | VA | $7.8M |
| Applied Ecology Inc. | Melbourne | FL | $7.8M |
| Gsina-pacific JV LLC | Flemington | NJ | $7.75M |
| Boudreau Associates LLC | San Francisco | CA | $7.74M |
| Sp Cramer & Associates Inc. | West Sacramento | CA | $7.69M |
| Stantec Jacobs Buchart Horn Joint Venture | Charlottesville | VA | $7.69M |
| Oneida-stantec JV LLC | Milwaukee | WI | $7.58M |
| Recon Environmental,inc. | San Diego | CA | $7.57M |
| Ageiss Inc. | Lakewood | CO | $7.54M |
| Inya, Inc. | Diamond Bar | CA | $7.35M |
| Ross & Associates Environmental Consulting, Ltd. | Seattle | WA | $7.35M |
| Tanaq-mes 8(a) JV, LLC | Anchorage | AK | $7.31M |
| Swift River Versar Sb JV | Anchorage | AK | $7.25M |
