| Columbia Gulf Trans coastal use permit P19971300 pipeline | Columbia Gulf Trans | LA | | |
| Columbia Gulf Transimission coastal use permit P20130361 pipeline | Columbia Gulf Transimission | LA | | |
| Columbia Gulf Transm coastal use permit P19970072 pipeline | Columbia Gulf Transm | LA | | |
| Columbia Gulf Transmission CP06-81 | Columbia Gulf Transmission, LLC | | | |
| Columbia Gulf Transmission CP08-149 | Columbia Gulf Transmission, LLC | LA | | |
| Columbia Gulf Transmission CP19-10 | Columbia Gulf Transmission, LLC | LA | | |
| Columbia Gulf Transmission CP26-141 | Columbia Gulf Transmission, LLC | | | |
| Columbia Gulf Transmission Mainline 1999 Project | Columbia Gulf Transmission, LLC | MS, TN | In service 1999 | |
| Columbia Gulf Transmission Mainline 300 Replacement Project | Columbia Gulf Transmission, LLC | KY | In service 2021 | |
| Columbia Gulf Transmission coastal use permit P20041396 pipeline | Columbia Gulf Transmission, LLC | LA | | |
| Columbia Gulf Transmission coastal use permit P20110258 pipeline | Columbia Gulf Transmission, LLC | LA | | |
| Columbia Gulf Transmission coastal use permit P20111177 pipeline | Columbia Gulf Transmission, LLC | LA | | |
| Columbia Gulf Transmission coastal use permit P20150210 pipeline | Columbia Gulf Transmission, LLC | LA | | |
| Columbia Line A-5 Replacement Project | Columbia Gas Transmission, LLC | NY | | |
| Columbia Pipeline East Side Expansion Project | Columbia Pipeline | NJ | 2015 | |
| Columbia Waynesburg Compressor Station (Line 1570 Project) | Columbia Gas Transmission, LLC | PA | | |
| Columbia to Eastover Project | Dominion Carolina Gas Transmission, LLC | SC | 2016 | |
| Columbus 3 Storage Pipelines | Bluewater Gas Storage | MI | In service 2004 | |
| Columbus Branch Replacement Project | Northern Natural Gas Company | | Started 2026 | |
| Columbus City I/W Well Relocation Project | Natural Gas Pipeline Company of America LLC | | | |
| Columbus HP Casing Project | Columbia Gas of Ohio | OH | | |
| Comanche II Plant | Brazos Midstream | TX | In service 2018 | |
| Comanche Trail Pipeline | Energy Transfer | TX | In service 2017 | |
| Commonwealth Energy Connector Project | Transcontinental Gas Pipe Line Company, LLC | VA | 2024–2025 | |
| Commonwealth LNG | Commonwealth LNG, LLC | LA | | |
| Commonwealth LNG Expansion Project | Commonwealth LNG Expansion, LLC | LA | | |
| Compressor Station 105 Unit Addition | Transcontinental Gas Pipe Line Company, LLC | AL | In service 2025 | |
| Compressor Station 11A | Tennessee Gas Pipeline Company, L.L.C. | TX | | |
| Compressor Station 17 | Transcontinental Gas Pipe Line Company, LLC | TX | | |
| Compressor Station 196 | | | | |