| Company | Booth | |
| Chainbridge Technologies | 350 | |
| CK Associates | 313 | |
| Clean Earth Systems | 115 | |
| Clean Gulf Associates | 401 | |
| CLEAN GULF Sales Office | 653 | |
| Clean Harbors | 237 | |
| Cliff Berry Inc. | 525 | |
| Crawford & Company | 327 | |
| CRUCIAL, Inc. | 209 | |
| Crystal Clean | 212 | |
| CSA Ocean Sciences Inc. | 530 | |
| CTEH, LLC | 200 | |
Alabama Department of Environmental Management
Florida Department of Environmental Protection
Mississippi Department of Environmental Quality