| Indian Mound | Gas processing plant | Young County, TX | Advance NGL, Inc. | In service |
| Indian Mound Gas Plant | Gas processing plant | Young County, TX | | |
| Indian Springs Gas Plant | Gas processing plant | Polk County, TX | Enterprise Products Operating LP | In service |
| Indian Springs Plant | Gas processing plant | Polk County, TX | | |
| Indian Village Plant | Gas processing plant | Allen Parish, LA | JP Oil Company, LLC | In service |
| Industrial Axle Shawnee Plant | Gas processing plant | Pottawatomie County, OK | Industrial Axle Co LLC | |
| Ingalls Compressor Station | Compressor station | Payne County, OK | Skye Ok LLC | |
| Ingersoll Compressor Station | Compressor station | Alfalfa County, OK | ET Gathering & Processing, LLC | |
| Inland Fuel Bridgeport terminal | Terminal | CT | Inland Fuel | |
| Inland Fuel Terminals Tiverton | Terminal | RI | Inland Fuel Terminals | |
| Interconnect Compressor Station | Compressor station | Logan County, OK | Nemaha Gas Gathering LLC | |
| Intercontinental Terminals Deer Park | Terminal | TX | Intercontinental Terminals CO | |
| Intercontinental Terminals Itc Pasadena | Terminal | TX | Intercontinental Terminals CO | |
| Intergulf Marine LLC terminal | Terminal | TX | Intergulf Corporation | |
| International Matex Tank Terminals ST Rose | Terminal | LA | International- Matex Tank Terminals LLC | |
| Intl Matex Tank Terminals Avondale | Terminal | LA | International- Matex Tank Terminals LLC | |
| Intl Matex Tank Terminals Chesapeake | Terminal | VA | International- Matex Tank Terminals LLC | |
| Intl Matex Tank Terminals Gretna | Terminal | LA | International- Matex Tank Terminals LLC | |
| Intl Matex Tank Terminals Imtt Il Joliet Facility | Terminal | IL | International- Matex Tank Terminals LLC | |
| Intl Matex Tank Terminals Richmond | Terminal | VA | International- Matex Tank Terminals LLC | |
| Io 9 Iodine Production Plant | Gas processing plant | Kingfisher County, OK | Iofina Resources Inc | |
| Iochem Plant | Gas processing plant | Dewey County, OK | Iochem Corporation | |
| Ira | Underground storage | St. Clair County, MI | Consumers Energy Inc | In service |
| Iron Horse Midstream Crusader Compressor Station | Compressor station | Canadian County, OK | Iron Horse Midstream, LLC | |
| Iron Horse Processing Plant | Gas processing plant | Grady County, OK | Iron Horse Midstream, LLC | |
| Ironhouse 19/20 CTB | Compressor station | NM | Coterra Energy Operating Co. | |
| Ironhouse 24 CTB | Compressor station | NM | Coterra Energy Operating Co. | |
| Irving Oil Terminals Portsmouth Marine | Terminal | NH | Irving Oil Terminals Inc | |
| Irving Oil Terminals Revere Marine Terminal | Terminal | MA | Irving Oil Terminals Inc | |
| Irving Oil Terminals Searsport Marine | Terminal | ME | Irving Oil Terminals Inc | |
| Island Energy SVCS Downstream Kapolei terminal | Terminal | HI | Island Energy Services Downstream | |
| Island Energy Services Downstream Hilo terminal | Terminal | HI | Island Energy Services Downstream | |
| Island Energy Services Downstream Honolulu terminal | Terminal | HI | Island Energy Services Downstream | |
| Island Energy Services Downstream Kahului terminal | Terminal | HI | Island Energy Services Downstream | |
| Island Energy Services Downstream Port Allen terminal | Terminal | HI | Island Energy Services Downstream | |
| Island Petroleum terminal | Terminal | HI | Island Petroleum Inc | |
| Isti Plant Services Cherokee Facility | Gas processing plant | Tulsa County, OK | Isti PLT SVC | |
| Ivanhoe Compressor Station | Compressor station | Beaver County, OK | ET Gathering & Processing, LLC | |
| J D Streett & 1st Street terminal | Terminal | MO | J D Streett & Co Inc | |
| J Ellen Booster Station | Compressor station | Caddo County, OK | Bounty Transfer LLC | |
| J F Bell 4 CDP | Compressor station | NM | Hilcorp Energy Company | |
| J T Russell & Sons Albemarle terminal | Terminal | NC | J T Russell & Sons Inc | |
| JC Davidson A 1 CDP | Compressor station | NM | Hilcorp Energy Company | |
| JC Gordon B 2 CDP | Compressor station | NM | Hilcorp Energy Company | |
| JC Gordon D 2 CDP | Compressor station | NM | Hilcorp Energy Company | |
| JD Streett & Lemay terminal | Terminal | MO | JD Streett & Co Inc | |
| JPT384 | Compressor station | Panola County, TX | | |
| Jackson Booster Station | Compressor station | NM | DCP Operating Company, LP | |
| Jackson Compressor Station | Compressor station | Roger Mills County, OK | Markwest Oklahoma Gas Company, LLC | |
| Jackson Gas Storage | Underground storage | Rankin County, MS | Gulf South Pipeline Company, LLC | In service |