| Legend Natrual Gas Iii, LP | Owner/operator | Katy, TX | | 1 |
| Legend Natural Gas Ii, LP | Owner/operator | Houston, TX | | 1 |
| Legend Natural Gas Iv, LP | Owner/operator | Fort Worth, TX | | 1 |
| Legends Pipeline Services LLC | Contractor | | | |
| Lehigh Cement Company LLC | Owner/operator | | | |
| Lemm Corporation - Operations | Owner/operator | Cordova, TN | | 1 |
| Lenox Municipal Gas System | Owner/operator | Lenox, IA | | 1 |
| Les Project Holdings, LLC | Owner/operator | Houston, TX | | |
| Letourneau Enterprises LLC | Contractor | | 1 | |
| Lewis Operating Company | Owner/operator | | | 1 |
| Lgot LP | Owner/operator | Gibson, LA | | 1 |
| Liberty | Owner/operator | | | 1 |
| Liberty Coating Company, LLC | Contractor | | | |
| Liberty Energy (georgia) Corp D/b/a Liberty Utilities Georgia | Owner/operator | Columbus, GA | | 1 |
| Liberty Energy (mid-States) Corp D/b/a Liberty Utilities - Central | Owner/operator | | | |
| Liberty Energy Future HLDNGS LLC | Owner/operator | | | 2 |
| Liberty Energy Services | Third-party inspection | Shenandoah, TX | | |
| Liberty Gas Storage, LLC | Owner/operator | | 4 | |
| Liberty Midstream Solutions, LLC | Owner/operator | Denver, CO | 1 | 3 |
| Liberty Natural Gas, LLC | Owner/operator | | | |
| Liberty Pipeline Group, LLC | Owner/operator | Houston, TX | | 1 |
| Liberty Pipeline Services | Third-party inspection | | 1 | |
| Liberty Power Innovations LLC | Owner/operator | Denver, CO | | 1 |
| Liberty Utilities (midstates Natural Gas) Corp. D/b/a Liberty Utilities | Owner/operator | Jackson, MO | | 1 |
| Liberty Utilities (new England Natural Gas Company) Corp | Owner/operator | Fall River, MA | | |
| Liberty Utilities (st. Lawrence Gas) Corp. | Owner/operator | Massena, NY | | 1 |
| Liberty Utilities Massachusetts | Owner/operator | | | |
| Lig Gas Company, LLC | Owner/operator | The Woodlands, TX | | 1 |
| Lightstone Generation LLC-Darby Power LLC | Owner/operator | | | |
| Lime Rock Resources III A LP | Owner/operator | Houston, TX | | 1 |
| Lime Rock Resources IV A LP | Owner/operator | Houston, TX | | 1 |
| Linc Gulf Coast Petroleum, Inc | Owner/operator | Houston, TX | | 1 |
| Lincoln Electric System | Owner/operator | Lincoln, NE | | 1 |
| Lincoln Generating Facility LLC | Owner/operator | Manhattan, IL | | 1 |
| Lincoln Manufacturing LLC | Pipe mill | | | |
| Lincoln Manufacturing Ohio | Pipe mill | | | |
| Lincoln Terminal Company | Owner/operator | | | 1 |
| Linde | Contractor, Owner/operator | Danbury, CT | 1 | 2 |
| Linde Gas Inc | Owner/operator | | | |
| Linde Gas North America, LLC | Owner/operator | Danbury, CT | | |
| Linder Oil Company | Owner/operator | | 1 | |
| Linder, John Operating Co., LLC | Owner/operator | | | 1 |
| Lindow Oil And Gas, LLC | Owner/operator | Tomball, TX | | 2 |
| Lindsey & Elliott | Owner/operator | Pikeville, KY | | 1 |
| Linn County Road Department | Owner/operator | Albany, OR | | 1 |
| Linn Energy | Owner/operator | | | 3 |
| Linn Operating, Inc | Owner/operator | Houston, TX | | 3 |
| Linn Western Operating, Inc | Owner/operator | Houston, TX | | 2 |
| Lion Elastomers Llc. | Owner/operator | Port Neches, TX | | 2 |
| Lion Oil CO | Owner/operator | | | 2 |