| Long Ridge Energy Generation OPSB case 19-1742-GA-BLN | Long Ridge Energy Generation LLC | OH | | |
| Longboard LNG | Longboard TerminalCo, LLC | HI | | |
| Longhorn Pipeline | | TX | | |
| Longwall Mine Panel 2C G150 8" Pipeline Excavation | Blue Racer Midstream, LLC | WV | | |
| Longwall Mine Panel 3C G150 8" Pipeline Excavation | Blue Racer Midstream, LLC | WV | | |
| Longwall Mine Panel 4C G150 8" Pipeline Excavation | Blue Racer Midstream, LLC | WV | | |
| Longwall Mining Panel M1 Project | Texas Eastern Transmission, LP | PA | Started 2026 | |
| Longwall Mining Panel M2/M3 Project | Texas Eastern Transmission, LP | PA | | |
| Longwell to Fracslap Pipeline | Eqt Production | WV | | |
| Lost Creek Storage Replacements 2025 | Eastern Gas Transmission and Storage, Inc. | WV | | |
| Lost Creek Storage Replacements 2026 | Eastern Gas Transmission and Storage, Inc. | WV | | |
| Lost Creek Storage Replacements H-20847 | Eastern Gas Transmission and Storage, Inc. | WV | | |
| Lost River Compressor Station Replacement | Columbia Gas Transmission, LLC | WV | | |
| Loudon Expansion Project | East Tennessee Nat Gas Co | TN | 2016 | |
| Louisiana Connector Amendment Project | Port Arthur Pipeline LLC | LA | | |
| Louisiana Connector Extension Project | Port Arthur Pipeline LLC | | | |
| Louisiana Deepwater Link Project | TENNESSEE GAS PIPELINE COMPANY | LA | 2006–2007 | |
| Louisiana Energy Access Project (LEAP) Expansion Phase 3 | Dte | LA | In service 2024 | |
| Louisiana Energy Access Project (LEAP) Expansion Phase 4 | Dte | LA | In service 2025 | |
| Louisiana Energy Gateway | Williams | LA | In service 2025 | |
| Louisiana Energy Gateway (LEG) | Energy Transfer | LA | In service 2025 | |
| Louisiana Gas Service coastal use permit P20000691 pipeline | Louisiana Gas Service Co | LA | | |
| Louisiana LNG | Driftwood LNG LLC | LA | | |
| Louisiana LNG Energy PF14-17 | Louisiana LNG Energy, LLC | | | |
| Louisiana Line 1 Pipe Replacement Project | Natural Gas Pipeline Company of America LLC | | | |
| Louisiana Line Expansion Project | Natural Gas Pipeline Co. of America | LA, TX | In service 2008 | |
| Louisiana State Gas coastal use permit P20090442 pipeline | Louisiana State Gas LLC | LA | | |
| Louisiana XPress Project | Columbia Gulf Transmission, LLC/Louisiana XPress Project | LA | In service 2022 | |
| Lousiana Energy Access Project (LEAP) Expansion Phase 1 | Dte | LA | In service 2023 | |
| Lousiana Energy Access Project (LEAP) Expansion Phase 2 | Dte | LA | In service 2023 | |