| 1 | Hansen-Welldo-Service Inc. | 33 | 117 | 138 |
| 2 | Sierra Exploration Drilling Co. Inc. | 23 | 180 | 803 |
| 3 | Thomas Murphy Pump & Well | 22 | 55 | 55 |
| 4 | Pacific Coast Well Drilling Inc. | 21 | 31 | 338 |
| 5 | Cascade Well Co. | 15 | 60 | 371 |
| 6 | Barbour Well Inc. | 14 | 15 | 32 |
| 7 | Beks Acquisition Inc. | 13 | 16 | 465 |
| 8 | Layne Christensen Company | 12 | 78 | 2,363 |
| 9 | Farwest Corrosion Control Company | 11 | 67 | 2,667 |
| 10 | Bc2 Environmental LLC | 10 | 17 | 435 |
| 11 | Sar Construction | 10 | 12 | 47 |
| 12 | Rottman Drilling Co. | 8 | 142 | 1,331 |
| 13 | Zim Industries Inc. Dba Bakersfield Well & Pump Co. | 8 | 32 | 1,721 |
| 14 | Best Drilling And Pump Inc. | 8 | 20 | 248 |
| 15 | Abundant Water Wells | 6 | 11 | 173 |
| 16 | Vics Well Drilling Inc. | 6 | 7 | 337 |
| 17 | Ike's Pump & Drilling Inc. | 5 | 224 | 300 |
| 18 | Drill Hog | 5 | 5 | 75 |
| 19 | Cascade Drilling L P | 4 | 146 | 2,827 |
| 20 | D C A Drilling And Construction Inc. | 4 | 10 | 69 |
| 21 | All American Drilling Inc. | 4 | 4 | 145 |
| 22 | S/G Testing Laboratories Inc. | 3 | 14 | 187 |
| 23 | A B C Liovin Drilling Inc. | 3 | 3 | 1,282 |
| 24 | South Valley Pump & Drilling | 3 | 3 | 69 |
| 25 | Corrpro Companies Inc. | 2 | 3 | 737 |
| 26 | Cascade Drilling LP | 2 | 2 | 830 |
| 27 | Maggiora Bros Drilling Inc. | 2 | 2 | 4,676 |
| 28 | Mel Meyer | 1 | 1,824 | 101,127 |
| 29 | Boetsch Well Drilling And Pump Service | 1 | 30 | 522 |
| 30 | Parks Water Resources | 1 | 1 | 391 |
| 31 | Consolidated Testing Laboratories Inc. | 1 | 1 | 1,406 |
| 32 | Wildrose Drilling LLC | 1 | 1 | 102 |
| 33 | Nor - Cal Pump & Well Drilling Inc. | 1 | 1 | 250 |
| 34 | Southwest Pump & Drilling Inc. | 1 | 1 | 292 |
| 35 | National E W P Inc. | 1 | 1 | 431 |
| 36 | Jensen Drilling Company | 1 | 1 | 186 |
| 37 | Midway Drilling & Pump Company | — | 611 | 753 |
| 38 | George Chamberlain | — | 203 | 256 |
| 39 | Leonard A Anderson Company | — | 202 | 203 |
| 40 | F H Dengley | — | 165 | 167 |
| 41 | Midwest Water Well Contracting Inc. | — | 99 | 147 |
| 42 | Cascade Drilling Inc. - California | — | 91 | 3,167 |
| 43 | Valley Well Drilling LP | — | 84 | 421 |
| 44 | Council Harold Drilling Co. | — | 84 | 154 |
| 45 | Midway Drilling Xxx | — | 79 | 100 |
| 46 | Council Harold Drilling & Pump Service | — | 70 | 91 |
| 47 | Barbour Corporation | — | 69 | 88 |
| 48 | Cruse Drilling Co. | — | 58 | 341 |
| 49 | Gilbert Drilling | — | 57 | 107 |
| 50 | C W Drilling | — | 52 | 55 |
| 51 | Graves & Graves Drilling | — | 48 | 72 |
| 52 | Gene Dyke | — | 47 | 51 |
| 53 | Arrowhead Water Well Drilling | — | 35 | 36 |
| 54 | Beylik Drilling & Pump Service | — | 32 | 1,267 |
| 55 | Dales Drilling | — | 31 | 46 |
| 56 | Floyd V Wells | — | 30 | 1,771 |
| 57 | Moss Roscoe Company | — | 26 | 1,220 |
| 58 | Harry Crinklaw | — | 26 | 26 |
| 59 | Staal, Gardner, & Dunne, Inc. | — | 25 | 31 |
| 60 | Tom Seay | — | 21 | 67 |
| 61 | Environmental West Drilling | — | 19 | 38 |
| 62 | R Cruse Drilling And Well Service | — | 19 | 25 |
| 63 | Paul Neville | — | 17 | 51 |
| 64 | H-F Drilling, Inc. | — | 16 | 618 |
| 65 | West Hazmat Drilling Corp | — | 15 | 1,702 |
| 66 | Gregg Drilling & Testing Inc. | — | 14 | 4,828 |
| 67 | C. Cruse Drilling | — | 14 | 301 |
| 68 | Don Redfeairn Drilling Co. | — | 14 | 186 |
| 69 | Batson Drilling Service | — | 12 | 436 |
| 70 | Filipponi-Thompson Drilling Inc. | — | 11 | 2,135 |
| 71 | Johnson Drilling Co. | — | 11 | 11,872 |
| 72 | Pipe Dreams Inc. | — | 10 | 52 |
| 73 | Miller Drilling Co. | — | 9 | 1,778 |
| 74 | Rainbow Drilling | — | 8 | 207 |
| 75 | Bakersfield Pump Co. | — | 7 | 303 |
| 76 | Hugh M Harris Drilling Company | — | 7 | 105 |
| 77 | Old Creek Drilling | — | 7 | 94 |
| 78 | Foothill Drilling | — | 7 | 26 |
| 79 | American Construction And Supply Inc. | — | 6 | 1,697 |
| 80 | Pacific Coast Well & Pump Inc. | — | 6 | 183 |
| 81 | Jack Jones Wells & Pumps | — | 6 | 1,145 |
| 82 | Redfeairn R L Drilling | — | 6 | 195 |
| 83 | Roscoe Moss Company | — | 6 | 130 |
| 84 | L E Tomson | — | 6 | 35 |
| 85 | Howard Pump Inc. A California Corporation | — | 5 | 1,650 |
| 86 | Testamerica Drilling Corp | — | 5 | 378 |
| 87 | Pacific Geoscience Inc. | — | 5 | 84 |
| 88 | Interstate Soils Sampling Inc. | — | 5 | 75 |
| 89 | Peaker Paul | — | 5 | 36 |
| 90 | Taylor Drilling And Pump Inc. | — | 4 | 342 |
| 91 | Enloe Well Drilling | — | 4 | 279 |
| 92 | Sargent Drilling | — | 4 | 442 |
| 93 | Starr Drilling And Pump Co. | — | 4 | 875 |
| 94 | Datum Exploration Inc. | — | 4 | 223 |
| 95 | Corrosion Technology Inc. | — | 4 | 169 |
| 96 | Pipeline Industries-Drill Line Division | — | 4 | 84 |
| 97 | Ray Parnell Drilling Contractor | — | 4 | 79 |
| 98 | S I Guardino | — | 4 | 43 |
| 99 | J & H Drilling Co. Inc. | — | 3 | 994 |
| 100 | Yellow Jacket Drilling Services LLC | — | 3 | 296 |
| 101 | Boart Longyear Company | — | 3 | 172 |
| 102 | D W Slocum Water Well Drilling | — | 3 | 217 |
| 103 | Rottman Dick Water Well Drilling | — | 3 | 211 |
| 104 | Beylik Drilling Inc. | — | 3 | 174 |
| 105 | Xxx | — | 3 | 113 |
| 106 | Layne Environmental Services Inc. | — | 3 | 104 |
| 107 | Hydro Resources - West Inc. | — | 3 | 97 |
| 108 | Southern Deep Well Drilling Co. | — | 3 | 69 |
| 109 | Melvin A Mcfadden | — | 3 | 51 |
| 110 | Bradley & Sons Inc. | — | 2 | 3,631 |
| 111 | Eaton Drilling Co. LLC | — | 2 | 3,792 |
| 112 | Water Well Service Inc. | — | 2 | 146 |
| 113 | W D C Exploration & Wells | — | 2 | 2,421 |
| 114 | Alexander Brothers | — | 2 | 903 |
| 115 | Whitten Pumps Inc. | — | 2 | 874 |
| 116 | Western Well Drilling Co. Ltd | — | 2 | 842 |
| 117 | Trudell Drilling Co. | — | 2 | 707 |
| 118 | Water Well Supply | — | 2 | 533 |
| 119 | Mann Brothers | — | 2 | 326 |
| 120 | M A Bryant Drilling | — | 2 | 311 |
| 121 | Filipponi & Thompson Drilling Company | — | 2 | 303 |
| 122 | SO Cal Pump And Well Drilling | — | 2 | 158 |
| 123 | Robertson Bros | — | 2 | 68 |
| 124 | Pioneer Drilling Inc. | — | 2 | 61 |
| 125 | Stang Hydronics Inc. | — | 2 | 56 |
| 126 | Mclaren Environmental Engineering | — | 2 | 30 |
| 127 | Canepa And Sons Inc. | — | 1 | 3,178 |
| 128 | Camp S A Pump Company | — | 1 | 498 |
| 129 | Martell Water Systems Inc. | — | 1 | 1,094 |
| 130 | Bryant Pump & Drilling Company | — | 1 | 1,000 |
| 131 | Bertram Drilling Inc. | — | 1 | 1,171 |
| 132 | Hearn Drilling Co. | — | 1 | 492 |
| 133 | Myers Brothers Inc. | — | 1 | 796 |
| 134 | D. W. Slooum | — | 1 | 688 |
| 135 | Mccalla Brothers | — | 1 | 578 |
| 136 | Wasco Drilling Company, Inc. | — | 1 | 554 |
| 137 | S A Andresen All Terrain Exploration | — | 1 | 468 |
| 138 | Layne-Western Co. Inc. | — | 1 | 255 |
| 139 | Island Drilling | — | 1 | 221 |
| 140 | Coe Machine Works | — | 1 | 110 |
| 141 | Clark F Wells Corp | — | 1 | 83 |
| 142 | Barber-Bridge Drilling Corp Ltd | — | 1 | 64 |
| 143 | Mogle Brothers | — | 1 | 57 |
| 144 | Melton Drilling Co. | — | 1 | 46 |
| 145 | Shipps For Water Well Drilling | — | 1 | 33 |
| 146 | Keeler Drlg Co. | — | 1 | 30 |
| 147 | U S Geological Survey | — | 1 | 30 |
| 148 | Don's Drilling Company | — | 1 | 28 |