| 1 | Parks Water Resources | 91 | 106 | 385 |
| 2 | Gregg Drilling & Testing Inc. | 81 | 230 | 4,828 |
| 3 | Cascade Drilling L P | 59 | 59 | 2,827 |
| 4 | Sullivan Drilling Inc. | 38 | 85 | 1,387 |
| 5 | Kvilhaug Drilling & Pump Inc. | 35 | 46 | 327 |
| 6 | Eaton Drilling Co. LLC | 33 | 513 | 3,793 |
| 7 | Cascade Drilling LP | 27 | 40 | 826 |
| 8 | Martell Water Systems Inc. | 14 | 25 | 1,094 |
| 9 | Pacific Coast Well & Pump Inc. | 14 | 22 | 182 |
| 10 | Huckfeldt Well Drilling Inc. | 13 | 74 | 1,881 |
| 11 | Bill Pulliam | 12 | 52 | 1,299 |
| 12 | Weeks Drilling And Pump Co. | 10 | 24 | 14,789 |
| 13 | Nor - Cal Pump & Well Drilling Inc. | 10 | 12 | 248 |
| 14 | Canepa And Sons Inc. | 10 | 10 | 3,173 |
| 15 | Gregg Drilling LLC | 9 | 9 | 558 |
| 16 | American Construction And Supply Inc. | 8 | 24 | 1,685 |
| 17 | Wildrose Drilling LLC | 8 | 8 | 102 |
| 18 | Corrpro Companies Inc. | 7 | 7 | 737 |
| 19 | Pulliam Well Exploration Inc. | 6 | 49 | 234 |
| 20 | Gregory Drilling Incorporated | 6 | 6 | 143 |
| 21 | Stonehouse Well Drilling | 5 | 6 | 157 |
| 22 | Cache Creek Drilling | 4 | 12 | 247 |
| 23 | Roadrunner Drilling & Pump Company Inc. | 4 | 6 | 205 |
| 24 | Jensen Kelin Drilling | 4 | 4 | 94 |
| 25 | Woodward Drilling Company Inc. | 3 | 40 | 1,542 |
| 26 | Zim Industries Inc. Dba Bakersfield Well & Pump Co. | 3 | 5 | 1,716 |
| 27 | Farwest Corrosion Control Company | 3 | 3 | 2,649 |
| 28 | Maggiora Bros Drilling Inc. | 2 | 10 | 4,674 |
| 29 | A & A Gross Drilling | 2 | 8 | 816 |
| 30 | Vannucci Technologies | 2 | 7 | 66 |
| 31 | Well Industries Inc. | 2 | 6 | 558 |
| 32 | Bertram Drilling Inc. | 2 | 2 | 1,171 |
| 33 | Modern Technology Resources Inc. | 1 | 12 | 44 |
| 34 | Island Drilling | 1 | 8 | 221 |
| 35 | Pacific Gas And Electric Company | 1 | 5 | 264 |
| 36 | Valley Pump & Motor Works Inc. | 1 | 3 | 181 |
| 37 | A B C Liovin Drilling Inc. | 1 | 2 | 1,281 |
| 38 | Bess D Pump & Well Elect | 1 | 2 | 359 |
| 39 | Hennings Bros Drilling Co. Inc. | 1 | 1 | 6,823 |
| 40 | Geocentric Drilling Inc. | 1 | 1 | 81 |
| 41 | Pitcher Services LLC | 1 | 1 | 114 |
| 42 | Diversified Drilling | 1 | 1 | 82 |
| 43 | Allison Sierra | 1 | 1 | 127 |
| 44 | Vaca Drilling Co. /Del Crew JR | — | 2,342 | 2,745 |
| 45 | H O Krossa | — | 594 | 681 |
| 46 | Aulman And Aulman Drilling Con | — | 289 | 1,251 |
| 47 | Doshier-Gregson Inc. | — | 283 | 1,156 |
| 48 | Layne Christensen Company | — | 154 | 2,362 |
| 49 | Vaca Drilling Co. | — | 147 | 176 |
| 50 | Signal Drilling Company | — | 95 | 8,301 |
| 51 | Williams Well Drilling | — | 83 | 376 |
| 52 | Clark & Sons | — | 69 | 76 |
| 53 | W D C Exploration & Wells | — | 50 | 2,421 |
| 54 | Cascade Drilling Inc. - California | — | 46 | 3,167 |
| 55 | Mel Meyer | — | 38 | 101,127 |
| 56 | Pitcher Drilling Co. | — | 31 | 1,232 |
| 57 | Western Well Drilling Co. Ltd | — | 31 | 842 |
| 58 | Spectrum Exploration Inc. | — | 29 | 307 |
| 59 | Seebeck M E | — | 28 | 567 |
| 60 | J W Evans & Sons | — | 26 | 44 |
| 61 | Ronald L Clark Clark Water Svc | — | 21 | 43 |
| 62 | Resonantsonic International Inc. | — | 19 | 397 |
| 63 | Pacific Coast Drilling | — | 16 | 262 |
| 64 | Beymer Well Service | — | 14 | 2,921 |
| 65 | Anderson & Seebeck | — | 14 | 178 |
| 66 | Baker Scott | — | 13 | 33 |
| 67 | H A M Drilling Inc. | — | 12 | 273 |
| 68 | Myers Brothers Well Drilling Inc. | — | 10 | 2,865 |
| 69 | West Hazmat Drilling Corp | — | 8 | 1,702 |
| 70 | MC Lean & Williams Inc. | — | 6 | 830 |
| 71 | National E W P Inc. | — | 6 | 431 |
| 72 | Bfr Associates | — | 6 | 5,621 |
| 73 | Dejesus Pump & Well Drilling Inc. | — | 6 | 1,157 |
| 74 | Cooper Drilling Co. | — | 6 | 315 |
| 75 | R D Norris & Son | — | 6 | 237 |
| 76 | A R S Fracturing And Drilling Service | — | 6 | 86 |
| 77 | D & D Drilling Inc. Dba Valley Drilling Co. | — | 5 | 1,282 |
| 78 | Vironex, Inc. | — | 5 | 649 |
| 79 | Water Well Drilling Cont | — | 5 | 263 |
| 80 | M S Seebeck & Son | — | 5 | 75 |
| 81 | Xxx Soils Exploration SV | — | 5 | 48 |
| 82 | Boart Longyear Company | — | 4 | 172 |
| 83 | Scott Xxx PC Exploration Inc. | — | 4 | 154 |
| 84 | Humboldt Drilling & Pump Co. | — | 4 | 131 |
| 85 | Calwater Drilling Company Inc. | — | 3 | 5,421 |
| 86 | All Well Abandonment | — | 3 | 607 |
| 87 | Doshier-Gregson Well Drilling Service | — | 3 | 167 |
| 88 | E E Luhdorff | — | 3 | 155 |
| 89 | Aulman & Aulman | — | 3 | 145 |
| 90 | Jeffrey David Harra | — | 3 | 109 |
| 91 | Clear Heart Drilling Inc. | — | 2 | 694 |
| 92 | D Hedman & Co. | — | 2 | 1,305 |
| 93 | Beylik Drilling & Pump Service | — | 2 | 1,267 |
| 94 | Moss Roscoe Company | — | 2 | 1,220 |
| 95 | Doshier And Gregson Drilling Inc. | — | 2 | 489 |
| 96 | V & W Drilling | — | 2 | 310 |
| 97 | Heer Nar S | — | 2 | 245 |
| 98 | Turner Explorations Inc. | — | 2 | 200 |
| 99 | Baker Lester A Wells & Pumps | — | 2 | 191 |
| 100 | Graham & Son Drilling Co. | — | 2 | 66 |
| 101 | Rea Construction | — | 2 | 46 |
| 102 | Geoloop Drilling/Tom Moreland | — | 2 | 32 |
| 103 | Johnson Drilling Co. | — | 1 | 11,865 |
| 104 | Wilkinson Enterprises Inc. | — | 1 | 445 |
| 105 | Drilling Services Inc. | — | 1 | 63 |
| 106 | Crislip Drilling Company | — | 1 | 1,174 |
| 107 | Wayne Drilling Co. | — | 1 | 1,113 |
| 108 | Kile's Well Drilling | — | 1 | 943 |
| 109 | C & N Pump & Well Co. | — | 1 | 697 |
| 110 | Water-Tech Well Drilling | — | 1 | 665 |
| 111 | S A Andresen All Terrain Exploration | — | 1 | 468 |
| 112 | Seanaco Inc. | — | 1 | 327 |
| 113 | J Field Drilling Co. | — | 1 | 275 |
| 114 | Layne-Western Co. Inc. | — | 1 | 255 |
| 115 | Frank P Conley | — | 1 | 218 |
| 116 | V J Mcgrew | — | 1 | 147 |
| 117 | Coastside Drilling & Pump Company | — | 1 | 131 |
| 118 | Cowart Well Drilling | — | 1 | 131 |
| 119 | Jeffrey L Gross | — | 1 | 103 |
| 120 | V F Bassett | — | 1 | 101 |
| 121 | Hydro Resources - West Inc. | — | 1 | 97 |
| 122 | D & S Well Drilling | — | 1 | 84 |
| 123 | Oberto's Plumbing & Well Drilling | — | 1 | 78 |
| 124 | M & M Well Drilling | — | 1 | 74 |
| 125 | All American Water Supply OF California Inc. | — | 1 | 40 |
| 126 | B & F Drilling | — | 1 | 35 |