| Walter Scott Jr. Energy Center | Berkshire Hathaway | 5,752,624 | |
| Louisa | Berkshire Hathaway | 3,691,041 | |
| Ottumwa | Berkshire Hathaway | 3,426,759 | |
| CF Industries Nitrogen, LLC-Port Neal Nitrogen Complex | CF Industries | 3,191,237 | |
| ADM CORN PROCESSING | Archer Daniels Midland | 2,746,519 | |
| ADM CORN PROCESSING | Archer Daniels Midland | 1,945,777 | |
| Sutherland | Alliant Energy | 1,522,582 | |
| Iowa Fertilizer Company | Koch Industries | 1,350,065 | |
| George Neal North | Berkshire Hathaway | 1,322,337 | |
| Emery Station | Alliant Energy | 1,201,117 | |
| Koch Fertilizer Ft. Dodge, LLC | Koch Industries | 1,025,233 | |
| George Neal South | George Neal South | 963,695 | |
| Davenport Plant | Summit Materials | 841,277 | |
| Greater Des Moines Energy Center | Berkshire Hathaway | 839,556 | |
| Muscatine | Muscatine Power & Water | 679,632 | |
| Prairie Creek | Alliant Energy | 594,742 | |
| EQUISTAR CHEMICALS LP | LyondellBasell Industries | 502,998 | |
| GRAIN PROCESSING CORP | Kent Corp. | 464,185 | |
| LEHIGH CEMENT CO LLC | Heidelberg Materials | 446,400 | |
| CARGILL INC - EDDYVILLE | Cargill | 399,264 | |
| ROQUETTE AMERICA INC | Roquette | 351,512 | |
| SSAB Iowa Inc. | SSAB | 295,476 | |
| Arconic US LLC | Apollo Global Management | 269,183 | |
| Ames | City of Ames, IA | 236,925 | |
| Cargill, Incorporated | Cargill | 233,855 | |
| HOMELAND ENERGY SOLUTIONS LLC | HOMELAND ENERGY SOLUTIONS LLC | 229,718 | |
| Valero Renewable Fuels LLC Charles City | Valero Energy | 201,940 | |
| Poet Biorefining Fairbank LLC | Poet LLC | 196,145 | |
| Valero Fort Dodge Plant | Valero Energy | 195,687 | |
| LITTLE SIOUX CORN PROCESSORS, LLC | Little Sioux Corn Processors LLLP | 193,904 | |
| Valero Hartley Plant | Valero Energy | 192,779 | |
| VALERO ALBERT CITY PLANT | Valero Energy | 189,653 | |
| Carmeuse Davenport | Carmeuse | 186,934 | |
| POET Biorefining- Menlo, LLC | Poet LLC | 180,626 | |
| Elite Octane | ELITE OCTANE LLC | 177,746 | |
| POET Biorefining Shell Rock, LLC. | Poet LLC | 174,101 | |
| BIG RIVER UNITED ENERGY LLC | Growmark | 174,051 | |
| BLACK HAWK COUNTY SANITARY LANDFILL | Black Hawk County, IA | 173,456 | |
| GOLDEN GRAIN ENERGY, LLC | Golden Grain Energy LLC | 169,762 | |
| BIG RIVER RESOURCES WEST BURLINGTON LLC | Growmark | 164,883 | |
| LOUIS DREYFUS COMMODITIES GRAND JUNCTION LLC | Louis Dreyfus | 163,739 | |
| POET Biorefining- Arthur, LLC | Poet LLC | 159,570 | |
| ABSOLUTE ENERGY LLC | ABSOLUTE ENERGY LLC | 151,261 | |
| UNIV OF IOWA MAIN PWR PLANT | University Of Iowa | 148,016 | |
| IOWA STATE UNIVERSITY/ ISU HEATING PLANT | Iowa State University Of Science & Technology | 146,726 | |
| SOUTHWEST IOWA RENEWABLE ENERGY | SOUTHWEST IOWA RENEWABLE ENERGY | 145,413 | |
| POET Biorefining- Iowa Falls, LLC | Poet LLC | 142,205 | |
| Exira Station | WESTERN MINNESOTA MUNICIPAL POWER AGENCY | 131,628 | |
| PINE LAKE CORN PROCESSORS | Innovative Ag Services | 124,046 | |
| Bunge | Bunge | 112,309 | |
| POET BIOREFINING | Poet LLC | 111,870 | |
| Valero Lakota Plant | Valero Energy | 111,809 | |
| PINNACLE ETHANOL LLC d/b/a POET BIOREFINING - CORNING | Poet LLC | 110,033 | |
| ADM SOYBEAN PROCESSING - DES MOINES | Archer Daniels Midland | 108,458 | |
| POET BIOREFINING - GOWRIE, LLC | Poet LLC | 107,851 | |
| AHN Heartland Ingredients | Ajinomoto | 104,073 | |
| POET Biorefining - Hanlontown LLC | Poet LLC | 102,352 | |
| LINCOLNWAY ENERGY LLC | Lincolnway Energy | 101,232 | |
| GREEN PLAINS SHENANDOAH LLC | Green Plains Inc. | 101,170 | |
| GUARDIAN INDUSTRIES - DeWitt | Koch Industries | 98,146 | |
| Poet Biorefining Ashton | Poet LLC | 94,566 | |
| CARGILL INC-CEDAR RAPIDS | Cargill | 92,119 | |
| SIOUXLAND ENERGY COOPERATIVE | SIOUXLAND ENERGY COOPERATIVE | 87,511 | |
| CORN LP | CORN LP | 87,144 | |
| VOYAGER ETHANOL LLC | Poet LLC | 85,822 | |
| ALLIANCE PIPELINE L.P. - MANCHESTER | Pembina Pipeline Corp. | 82,855 | |
| Loess Hills Regional Sanitary Landfill | Waste Connections Inc. | 82,200 | |
| Cedar Rapids/Linn County Solid Waste Agency Site #2 | Linn County, IA | 80,661 | |
| Poet Biorefining-Coon Rapids | Poet LLC | 79,543 | |
| MidAmerican Energy Local Gas Distribution Company | Berkshire Hathaway | 77,042 | |
| LANDFILL OF NORTH IOWA | Cerro Gordo County, IA | 76,499 | |
| GREEN PLAINS SUPERIOR LLC | Green Plains Inc. | 75,855 | |
| US GYPSUM - SPERRY PLANT | Knauf | 74,570 | |
| Bayer CropScience LP | Bayer | 73,944 | |
| TYSON FRESH MEATS INC | Tyson Foods | 73,268 | |
| THE ANDERSONS MARATHON HOLDINGS LLC | Andersons Inc. | 72,860 | |
| QUAD CNTY CORN PROCESSORS | QUAD COUNTY CORN PROCESSORS | 70,827 | |
| AG PROCESSING INC-EAGLE GROVE | Ag Processing Inc. | 70,515 | |
| GREEN VALLEY CHEMICAL CORP | Green Valley Chemical | 65,745 | |
| Ag Processing Inc | Ag Processing Inc. | 65,183 | |
| NORTHERN NATURAL GAS CO-OGDEN COMPRESSOR | Berkshire Hathaway | 64,527 | |
| DES MOINES COUNTY REGIONAL SOLID WASTE COMMISSION | Des Moines County, IA | 61,585 | |
| METRO METHANE RECOVERY FACILITY | METRO WASTE AUTHORITY | 61,540 | |
| Northwest Ia. Area Solid Waste Agency | Northwest Iowa Area Solid Waste Agency | 61,034 | |
| Cargill Incorporated | Cargill | 60,937 | |
| Cargill Incorporated | Cargill | 60,583 | |
| UNIVERSITY OF NORTHERN IOWA - POWER PLANT/MAIN CAMPUS | University Of Northern Iowa | 59,125 | |
| INGREDION INCORPORATED | Ingredion | 56,565 | |
| GREAT RIVER REGIONAL WASTE AUTHORITY SANITARY LANDFILL | Great River Regional Waste Authority | 54,367 | |
| SOUTH CENTRAL IOWA SOLID WASTE AGENCY SCISWA | South Central Iowa Solid Waste Agency | 53,314 | |
| Cedar Rapids/Linn County Solid Waste Agency Site #1 | Linn County, IA | 53,053 | |
| NCIRSWA Sanitary Landfill | North Central Iowa Regional Solid Waste Agency | 52,033 | |
| Plymouth Energy LLC | Lakeview Energy | 51,991 | |
| JBS SWIFT | JBS | 51,697 | |
| NGPL Station 107 Emerson, IA | Kinder Morgan | 50,807 | |
| Boone County Sanitary Landfill | Boone County, IA | 50,275 | |
| Novelis ALR Aluminum LLC (Davenport Casting) | Aditya Birla Group | 49,269 | |
| TYSON FRESH MEATS, INC. - WATERLOO | Tyson Foods | 48,704 | |
| SMITHFIELD FRESH MEATS CORP-DENISON | WH Group | 48,539 | |
| Gold Bond - FTD Plant | National Gypsum | 46,496 | |
| TYSON FRESH MEATS INC-PERRY | Tyson Foods | 46,152 | |
| GNRL MILLS | General Mills | 45,114 | |
| JOHN DEERE FNDRY WATERLOO | Deere | 45,076 | |
| CARROLL COUNTY SOLID WASTE MANAGEMENT COMMISSION | Carroll County Solid Waste Management Commission | 44,800 | |
| CENTRAL DISPOSAL SYSTEMS INC | Waste Management Inc. | 44,514 | |
| Georgia-Pacific Gypsum LLC - Fort Dodge | Koch Industries | 44,224 | |
| NGPL Station 109 Harper, IA | Kinder Morgan | 43,096 | |
| JBS Swift Food | JBS | 42,757 | |
| CITY OF MUSCATINE LANDFILL | Muscatine County, IA | 42,669 | |
| BRIDGESTONE AMERICAS TIRE OPERATIONS, LLC | Bridgestone | 41,169 | |
| CLINTON COUNTY SANITARY LANDFILL (EAST) | Clinton County, IA | 39,638 | |
| OTTUMWA / WAPELLO COUNTY SANITARY LANDFILL | Ottumwa-Wapello Solid Waste Commission | 39,467 | |
| Mahaska County Sanitary Landfill - Binns and Stevens Site | Mahaska County, IA | 38,422 | |
| US ARMY IOWA ARMY AMMUNITION PLANT-AMERICAN ORDNANCE LLC | Day & Zimmerman | 37,272 | |
| GELITA USA | GELITA | 37,117 | |
| Redfield UGS and Compressor Station | Berkshire Hathaway | 36,491 | |
| Shell Rock Soy Processing | Shell Rock Soy Processing, LLC | 36,489 | |
| Summit Lake | CENTRAL IOWA POWER COOPERATIVE | 36,040 | |
| WINNESHIEK COUNTY SANITARY LANDFILL | Winneshiek County, IA | 35,734 | |
| Cargill Incorporated | Cargill | 35,611 | |
| GERDAU AMERISTEEL US INC | Gerdau | 31,887 | |
| Marshall County Sanitary Landfill | Marshall County, IA | 31,812 | |
| Nestle Purina Petcare Co. | Nestle | 31,501 | |
| NGPL Station 204 Columbus Junction, IA | Kinder Morgan | 31,369 | |
| ANR Pipeline Birmingham CS | TC Energy | 30,814 | |
| South Central Iowa Landfill | South Central Iowa Landfill Agency | 30,252 | |
| USDA-NATIONAL ANIMAL DISEASE CENTER | U.S. Government | 28,205 | |
| AG PROCESSING INC-SHELDON | Ag Processing Inc. | 27,848 | |
| Tyson Fresh Meats | Tyson Foods | 27,655 | |
| Potters Industries, Inc. - Muscatine, IA | The Jordan Company | 27,523 | |
| QUAKER MFG LLC | PepsiCo | 27,403 | |
| City of Newton Sanitary Landfill | City of Newton, IA | 26,974 | |
| IOWA CITY SANITARY LANDFILL | City of Iowa City, IA | 26,465 | |
| AG PROCESSING INC | Ag Processing Inc. | 23,462 | |
| PB LEINER USA | Tessenderlo | 22,012 | |
| Interstate Power & Light Gas Distribution | Alliant Energy | 21,371 | |
| TITAN TIRE CORP | Titan International | 18,635 | |
| Burlington (IA) | Alliant Energy | 18,575 | |
| DICKINSON LANDFILL INC | Waste Management Inc. | 15,753 | |
| DUBUQUE METROPOLITAN SANITARY LANDFILL | Dubuque Metropolitan Area Solid Waste Agency | 15,419 | |
| Pleasant Hill Energy Center | Berkshire Hathaway | 13,374 | |
| Oakland Compressor Station | Berkshire Hathaway | 12,857 | |
| Waterloo Compressor Station | Berkshire Hathaway | 12,578 | |
| Sycamore Combustion Turbine | Berkshire Hathaway | 11,320 | |
| Streeter Station | CEDAR FALLS UTILITIES | 10,497 | |
| NGPL Station 108 Truro, IA | Kinder Morgan | 10,242 | |
| Northern Natural Gas - Ventura Compressor Station | Berkshire Hathaway | 9,164 | |
| MidAmerican Energy Company Local Natural Gas Distribution Company - South Dakota | Berkshire Hathaway | 8,706 | |
| Electrifarm | Berkshire Hathaway | 8,694 | |
| SCOTT AREA SANITARY LANDFILL | Scott County, IA | 8,185 | |
| ANR Pipeline Lineville CS | TC Energy | 7,995 | |
| Tama Paperboard, LLC | Greif Inc. | 7,353 | |
| MidAmerican Energy Company Local Natural Gas Distribution Company - Illinois | Berkshire Hathaway | 7,229 | |
| Earl F Wisdom | CORN BELT POWER COOPERATIVE | 6,001 | |
| MidAmerican Energy Company | Berkshire Hathaway | 5,275 | |
| Dayton Avenue Substation | City of Ames, IA | 1,856 | |
| Cedar Falls Municipal Gas Utility | CEDAR FALLS UTILITIES | 1,156 | |
| Lansing | Alliant Energy | 1,091 | |
| MidAmerican Energy Company Local Natural Gas Distribution Company - Nebraska | Berkshire Hathaway | 910 | |