| 1 | American Construction And Supply Inc. | 144 | 179 | 1,685 |
| 2 | Earth Flow Drilling Company | 93 | 708 | 2,192 |
| 3 | Gregg Drilling & Testing Inc. | 65 | 271 | 4,828 |
| 4 | National E W P Inc. | 60 | 97 | 431 |
| 5 | Maggiora Bros Drilling Inc. | 56 | 190 | 4,674 |
| 6 | Cascade Drilling L P | 49 | 52 | 2,827 |
| 7 | Pitcher Drilling Co. | 48 | 198 | 1,232 |
| 8 | Gregg Drilling LLC | 36 | 36 | 558 |
| 9 | Guardino Well Drilling Inc. | 29 | 54 | 1,736 |
| 10 | Corrpro Companies Inc. | 28 | 28 | 737 |
| 11 | Directed Technologies Drilling Inc. | 25 | 25 | 29 |
| 12 | Pitcher Services LLC | 23 | 23 | 114 |
| 13 | Exploration Geoservices Inc. | 19 | 69 | 956 |
| 14 | Wilkinson Enterprises Inc. | 18 | 374 | 445 |
| 15 | V T S Drilling LLC | 12 | 18 | 92 |
| 16 | Landino Drilling Co. | 10 | 21 | 151 |
| 17 | Weeks Drilling And Pump Co. | 7 | 14 | 14,789 |
| 18 | A B C Liovin Drilling Inc. | 6 | 6 | 1,281 |
| 19 | Cascade Drilling LP | 3 | 3 | 826 |
| 20 | Gregory Drilling Incorporated | 3 | 3 | 143 |
| 21 | Bertram Drilling Inc. | 2 | 80 | 1,171 |
| 22 | Roscoe Moss Company | 2 | 45 | 130 |
| 23 | Roadrunner Drilling & Pump Company Inc. | 2 | 33 | 205 |
| 24 | T S A Drilling Inc. Dba Penecore Drilling | 2 | 9 | 577 |
| 25 | Pacific Coast Well Drilling Inc. | 2 | 2 | 337 |
| 26 | Curtis Drilling Co. | 2 | 2 | 42 |
| 27 | Western Well Drilling Co. Ltd | 1 | 18 | 842 |
| 28 | Pacific Coast Well & Pump Inc. | 1 | 5 | 182 |
| 29 | Farwest Corrosion Control Company | 1 | 2 | 2,649 |
| 30 | Canepa And Sons Inc. | 1 | 1 | 3,173 |
| 31 | Wildrose Drilling LLC | 1 | 1 | 102 |
| 32 | Geocentric Drilling Inc. | 1 | 1 | 81 |
| 33 | Trinity Drilling Inc. | 1 | 1 | 36 |
| 34 | Digges & Son | — | 414 | 421 |
| 35 | Digges & Son Water Well Drilling | — | 248 | 250 |
| 36 | Mel Meyer | — | 126 | 101,127 |
| 37 | Coastside Drilling & Pump Company | — | 105 | 131 |
| 38 | H A M Drilling Inc. | — | 102 | 273 |
| 39 | Moss Roscoe Company | — | 82 | 1,220 |
| 40 | Woodward Drilling Company Inc. | — | 79 | 1,542 |
| 41 | Robert Garcia Well & Pump Co. | — | 78 | 192 |
| 42 | Aqua Science Engineers Inc. | — | 75 | 131 |
| 43 | Montalvo Well & Pump Co. | — | 56 | 113 |
| 44 | West Hazmat Drilling Corp | — | 46 | 1,702 |
| 45 | Resonantsonic International Inc. | — | 36 | 397 |
| 46 | Layne Christensen Company | — | 28 | 2,362 |
| 47 | W D C Exploration & Wells | — | 28 | 2,421 |
| 48 | Signal Drilling Company | — | 26 | 8,301 |
| 49 | Cache Creek Drilling | — | 26 | 247 |
| 50 | Vironex, Inc. | — | 24 | 649 |
| 51 | Robert Garcia Well Drilling & Pump Co. | — | 21 | 46 |
| 52 | Case Pacific Company | — | 20 | 55 |
| 53 | Hew Drilling Co. | — | 20 | 38 |
| 54 | California Well Drilling & Pump Co. | — | 20 | 37 |
| 55 | Bayland Drillers | — | 19 | 317 |
| 56 | C & N Pump & Well Co. | — | 18 | 697 |
| 57 | Cascade Drilling Inc. - California | — | 17 | 3,167 |
| 58 | Rea Construction | — | 15 | 46 |
| 59 | Water-Tech Well Drilling | — | 14 | 665 |
| 60 | Ase Drilling Inc. | — | 12 | 82 |
| 61 | Precision Sampling Inc. | — | 11 | 234 |
| 62 | William L Myers | — | 10 | 66 |
| 63 | Kvilhaug Drilling & Pump Inc. | — | 9 | 327 |
| 64 | Guardino Pump & Well | — | 9 | 482 |
| 65 | Golden Empire Drilling | — | 7 | 168 |
| 66 | Dyna Drill International Inc. | — | 7 | 115 |
| 67 | Martell Water Systems Inc. | — | 5 | 1,094 |
| 68 | D B Drilling Co. | — | 5 | 973 |
| 69 | Landino Construction And Well Drilling | — | 5 | 703 |
| 70 | Mitchell Drilling Environmental Corp | — | 5 | 199 |
| 71 | Trinity Source Group Inc. | — | 5 | 67 |
| 72 | R E S N A | — | 5 | 37 |
| 73 | Johnson Drilling Co. | — | 4 | 11,865 |
| 74 | Environmental Control Associates | — | 4 | 277 |
| 75 | Dodson Contracting Co. | — | 4 | 113 |
| 76 | Xxx Soils Exploration SV | — | 4 | 48 |
| 77 | Seebeck M E | — | 3 | 567 |
| 78 | Freedom General Repair & Pump Shop | — | 3 | 690 |
| 79 | Spectrum Exploration Inc. | — | 3 | 307 |
| 80 | Roman Well Drilling | — | 3 | 242 |
| 81 | Zim Industries Inc. Dba Bakersfield Well & Pump Co. | — | 2 | 1,716 |
| 82 | Bc2 Environmental LLC | — | 2 | 416 |
| 83 | Frank's Well Driling | — | 2 | 740 |
| 84 | Kenneth Roman | — | 2 | 320 |
| 85 | Fisch Bros Pump Service | — | 2 | 620 |
| 86 | Multi Water Systems | — | 2 | 269 |
| 87 | Pioneer Pump And Well Co. | — | 2 | 195 |
| 88 | Scott Xxx PC Exploration Inc. | — | 2 | 154 |
| 89 | Tide Tool & Engr. Co. | — | 2 | 128 |
| 90 | Cornerstone Pump & Well Inc. | — | 2 | 90 |
| 91 | Enprobe Environental Direct Push & Drilling Services | — | 2 | 76 |
| 92 | Nero Ostenberg | — | 2 | 55 |
| 93 | Les Petersen Drilling & Pump Inc. | — | 1 | 4,096 |
| 94 | Briski Well Drilling Co. | — | 1 | 2,747 |
| 95 | Eaton Drilling Co. LLC | — | 1 | 3,793 |
| 96 | DE LA Grange & Sons Inc. | — | 1 | 263 |
| 97 | Chappell Pump & Supply Inc. | — | 1 | 927 |
| 98 | Yosemite Falls Well Drilling | — | 1 | 464 |
| 99 | Malcolm Drilling Company Inc. | — | 1 | 63 |
| 100 | All Well Abandonment | — | 1 | 607 |
| 101 | Rauch Drilling Company Inc. | — | 1 | 520 |
| 102 | V & W Drilling | — | 1 | 310 |
| 103 | R F Keyt | — | 1 | 299 |
| 104 | West Coast Drilling | — | 1 | 288 |
| 105 | Hudson R Barrow | — | 1 | 262 |
| 106 | DE Lucchi Well & Pump, Inc. | — | 1 | 157 |
| 107 | V F Bassett | — | 1 | 101 |
| 108 | Environmental Investigation Services, Inc. | — | 1 | 100 |
| 109 | R P Seay | — | 1 | 86 |
| 110 | M S Seebeck & Son | — | 1 | 75 |
| 111 | Stang Hydronics Inc. | — | 1 | 56 |
| 112 | R Barrick For Great Sierra | — | 1 | 55 |
| 113 | J Lippi & Son | — | 1 | 47 |
| 114 | William Porter Well Drilling | — | 1 | 46 |
| 115 | Louis A Wood Co. | — | 1 | 38 |
| 116 | Cofferdam Unwatering Corporation | — | 1 | 32 |