| 1 | Cascade Drilling L P | 178 | 290 | 2,827 |
| 2 | D & D Drilling Inc. Dba Valley Drilling Co. | 81 | 438 | 1,282 |
| 3 | Scotty's Well Drilling | 77 | 140 | 140 |
| 4 | Goodell Well & Pump Service | 68 | 179 | 342 |
| 5 | Jensen Kelin Drilling | 56 | 56 | 94 |
| 6 | Hedman Drilling | 44 | 118 | 126 |
| 7 | T S A Drilling Inc. Dba Penecore Drilling | 42 | 150 | 577 |
| 8 | All Well Abandonment | 39 | 263 | 607 |
| 9 | Cascade Drilling LP | 32 | 60 | 826 |
| 10 | Fox Loomis Incorporated | 27 | 66 | 225 |
| 11 | Ken Gross Pump Service | 24 | 377 | 507 |
| 12 | American Construction And Supply Inc. | 22 | 100 | 1,685 |
| 13 | Phifer Well Service | 22 | 22 | 37 |
| 14 | Blaine's Well Drilling | 18 | 18 | 55 |
| 15 | Eaton Drilling Co. LLC | 16 | 203 | 3,793 |
| 16 | Gregg Drilling & Testing Inc. | 15 | 173 | 4,828 |
| 17 | Gregory Drilling Incorporated | 15 | 15 | 143 |
| 18 | A B C Liovin Drilling Inc. | 14 | 15 | 1,281 |
| 19 | Roadrunner Drilling & Pump Company Inc. | 12 | 28 | 205 |
| 20 | Nor - Cal Pump & Well Drilling Inc. | 12 | 12 | 248 |
| 21 | Masellis Drilling Inc. | 10 | 14 | 6,081 |
| 22 | Modern Technology Resources Inc. | 8 | 8 | 44 |
| 23 | Zim Industries Inc. Dba Bakersfield Well & Pump Co. | 7 | 38 | 1,716 |
| 24 | Gregg Drilling LLC | 7 | 7 | 558 |
| 25 | Well Industries Inc. | 7 | 7 | 558 |
| 26 | Stonehouse Well Drilling | 7 | 7 | 157 |
| 27 | Robert Allen Nix Well Drilling | 6 | 367 | 373 |
| 28 | Woodward Drilling Company Inc. | 6 | 289 | 1,542 |
| 29 | National E W P Inc. | 6 | 50 | 431 |
| 30 | Seebeck M E | 5 | 215 | 567 |
| 31 | A & A Gross Drilling | 5 | 148 | 816 |
| 32 | Gulf Shore Construction Services Inc. | 5 | 10 | 28 |
| 33 | H & B Drilling And Sons LLC | 5 | 5 | 414 |
| 34 | Pacific Coast Well Drilling Inc. | 5 | 5 | 337 |
| 35 | Canepa And Sons Inc. | 4 | 16 | 3,173 |
| 36 | Castle Well Drilling Inc. | 4 | 4 | 294 |
| 37 | Layne Christensen Company | 3 | 61 | 2,362 |
| 38 | Pitcher Drilling Co. | 3 | 16 | 1,232 |
| 39 | Hennings Bros Drilling Co. Inc. | 3 | 13 | 6,823 |
| 40 | Environmental Control Associates | 3 | 4 | 277 |
| 41 | Farwest Corrosion Control Company | 3 | 3 | 2,649 |
| 42 | Waters Backhoe & Dozer Service | 3 | 3 | 110 |
| 43 | Maggiora Bros Drilling Inc. | 2 | 30 | 4,674 |
| 44 | Sullivan Drilling Inc. | 2 | 4 | 1,387 |
| 45 | J & H Drilling Co. Inc. | 2 | 2 | 978 |
| 46 | Parks Water Resources | 2 | 2 | 385 |
| 47 | Geocentric Drilling Inc. | 2 | 2 | 81 |
| 48 | Pitcher Services LLC | 2 | 2 | 114 |
| 49 | Norton Drilling | 1 | 292 | 596 |
| 50 | Purviance Drillers Inc. | 1 | 43 | 663 |
| 51 | Gary C Tanko Well Drilling Inc. | 1 | 22 | 12,022 |
| 52 | Martell Water Systems Inc. | 1 | 10 | 1,094 |
| 53 | Confluence Environmental Inc. | 1 | 5 | 65 |
| 54 | Hunt Drilling Company Inc. | 1 | 3 | 1,213 |
| 55 | Briski Well Drilling Co. | 1 | 2 | 2,747 |
| 56 | Guardino Well Drilling Inc. | 1 | 1 | 1,736 |
| 57 | Living Water Well Drilling | 1 | 1 | 441 |
| 58 | Huckfeldt Well Drilling Inc. | 1 | 1 | 1,881 |
| 59 | R & M Water Well Drilling & Pumps Inc. | 1 | 1 | 91 |
| 60 | Mid State Pump And Drilling | 1 | 1 | 74 |
| 61 | Diamond Well Drilling Company Inc. | 1 | 1 | 1,150 |
| 62 | Points West Drilling | 1 | 1 | 78 |
| 63 | M & M Well Drilling | 1 | 1 | 74 |
| 64 | Directed Technologies Drilling Inc. | 1 | 1 | 29 |
| 65 | D Hedman & Co. | — | 1,269 | 1,305 |
| 66 | Mel Meyer | — | 703 | 101,127 |
| 67 | Woods Well Drilling | — | 673 | 755 |
| 68 | Preston Well Drilling | — | 559 | 698 |
| 69 | Bertram Drilling Inc. | — | 475 | 1,171 |
| 70 | W D C Exploration & Wells | — | 336 | 2,421 |
| 71 | Cascade Drilling Inc. - California | — | 255 | 3,167 |
| 72 | Water Well Drilling Cont | — | 178 | 263 |
| 73 | R D Norris & Son | — | 174 | 237 |
| 74 | Baker Lester A Wells & Pumps | — | 163 | 191 |
| 75 | Allen's Drilling & Pump Service | — | 127 | 134 |
| 76 | Kile's Well Drilling | — | 126 | 943 |
| 77 | V & W Drilling | — | 122 | 310 |
| 78 | Beylik Drilling & Pump Service | — | 117 | 1,267 |
| 79 | V J Mcgrew | — | 110 | 147 |
| 80 | Harrison & Son's | — | 92 | 187 |
| 81 | W L Kirchgater | — | 87 | 98 |
| 82 | Signal Drilling Company | — | 86 | 8,301 |
| 83 | Mitchell Drilling Environmental Corp | — | 83 | 199 |
| 84 | West Hazmat Drilling Corp | — | 82 | 1,702 |
| 85 | Wayne Drilling Co. | — | 79 | 1,113 |
| 86 | Taber Drilling | — | 76 | 87 |
| 87 | Dyna Drill International Inc. | — | 68 | 115 |
| 88 | Anderson & Seebeck | — | 65 | 178 |
| 89 | Wayne Environmental Drilling Company Inc. | — | 63 | 664 |
| 90 | Pacific Gas And Electric Company | — | 62 | 264 |
| 91 | Western Well Drilling Co. Ltd | — | 56 | 842 |
| 92 | Jeffrey L Gross | — | 52 | 103 |
| 93 | Day, Sloan | — | 52 | 52 |
| 94 | G Gakin Well Drilling | — | 51 | 147 |
| 95 | Island Drilling | — | 50 | 221 |
| 96 | Jensen Drilling Company | — | 49 | 186 |
| 97 | Baliel Drilling | — | 44 | 44 |
| 98 | Myers Brothers Well Drilling Inc. | — | 40 | 2,865 |
| 99 | Vannucci Technologies | — | 40 | 66 |
| 100 | Turner Explorations Inc. | — | 39 | 200 |
| 101 | Precision Sampling Inc. | — | 38 | 234 |
| 102 | D & S Well Drilling | — | 38 | 84 |
| 103 | Alberts Pump & Well Service | — | 37 | 37 |
| 104 | Wahl & Wood Drilling | — | 36 | 58 |
| 105 | Jdk Drilling Inc. | — | 36 | 36 |
| 106 | Geo S Bandy | — | 34 | 36 |
| 107 | A A A Pump And Well Drilling | — | 33 | 33 |
| 108 | Resonantsonic International Inc. | — | 29 | 397 |
| 109 | Whiting Well Drilling | — | 28 | 30 |
| 110 | Heer Nar S | — | 26 | 245 |
| 111 | Humboldt Drilling & Pump Co. | — | 25 | 131 |
| 112 | Johnson Drilling Co. | — | 24 | 11,865 |
| 113 | Diamond Core Drilling Inc. | — | 24 | 480 |
| 114 | M S Seebeck & Son | — | 24 | 75 |
| 115 | Vironex, Inc. | — | 22 | 649 |
| 116 | Spectrum Exploration Inc. | — | 21 | 307 |
| 117 | Precision Drilling Co. | — | 21 | 71 |
| 118 | Geo W Taylor Well Drlg Service | — | 20 | 58 |
| 119 | Trc Solutions Inc. | — | 19 | 137 |
| 120 | Shoup Burton C Well Drilling And Pumps | — | 19 | 79 |
| 121 | R Barrick For Great Sierra | — | 19 | 55 |
| 122 | Westex | — | 19 | 40 |
| 123 | Frank P Conley | — | 17 | 218 |
| 124 | Taber Consultants | — | 17 | 30 |
| 125 | Calwater Drilling Company Inc. | — | 15 | 5,421 |
| 126 | Scott Xxx PC Exploration Inc. | — | 15 | 154 |
| 127 | Rea Construction | — | 15 | 46 |
| 128 | George Stamp | — | 15 | 44 |
| 129 | Testamerica Drilling Corp | — | 13 | 378 |
| 130 | Weeks Drilling And Pump Co. | — | 12 | 14,789 |
| 131 | Kvilhaug Drilling & Pump Inc. | — | 12 | 327 |
| 132 | Bfr Associates | — | 12 | 5,621 |
| 133 | Dejesus Pump & Well Drilling Inc. | — | 12 | 1,157 |
| 134 | S A Andresen All Terrain Exploration | — | 12 | 468 |
| 135 | Cofferdam Unwatering Corporation | — | 12 | 32 |
| 136 | M R Peck & Sons | — | 11 | 125 |
| 137 | Big Valley Drilling & Exploration Co. | — | 11 | 32 |
| 138 | Bc2 Environmental LLC | — | 10 | 416 |
| 139 | Jeffrey David Harra | — | 10 | 109 |
| 140 | Xxx Soils Exploration SV | — | 10 | 48 |
| 141 | B & F Drilling | — | 10 | 35 |
| 142 | Robert Dawson Drilling & Pumps | — | 9 | 1,415 |
| 143 | Universal Pump & Supply Inc. | — | 9 | 43 |
| 144 | Viking Drillers Inc. | — | 8 | 83 |
| 145 | Groundwater Technology | — | 8 | 46 |
| 146 | Bradley & Sons Inc. | — | 7 | 3,627 |
| 147 | Aulman And Aulman Drilling Con | — | 7 | 1,251 |
| 148 | Enprobe Environental Direct Push & Drilling Services | — | 7 | 76 |
| 149 | Corder Drilling | — | 7 | 31 |
| 150 | North State Well & Pump | — | 7 | 30 |
| 151 | Pacific Coast Drilling | — | 6 | 262 |
| 152 | Thayer Well Drilling | — | 6 | 125 |
| 153 | Gibson Well Drilling | — | 6 | 115 |
| 154 | Bsk Associates | — | 6 | 37 |
| 155 | Hydro Resources - West Inc. | — | 5 | 97 |
| 156 | Welltest Inc. | — | 5 | 52 |
| 157 | S D Drilling Inc. | — | 5 | 31 |
| 158 | Aaa Pump | — | 5 | 28 |
| 159 | Beymer Well Service | — | 4 | 2,921 |
| 160 | Lang Pump & Well Company | — | 4 | 60 |
| 161 | Fisch Brothers Drilling, Inc. | — | 3 | 6,393 |
| 162 | Triangle Well Drilling | — | 3 | 2,894 |
| 163 | Exploration Geoservices Inc. | — | 3 | 956 |
| 164 | Panero Well Drilling Inc. | — | 3 | 921 |
| 165 | Williams Well Drilling | — | 3 | 376 |
| 166 | Cornerstone Pump & Well Inc. | — | 3 | 90 |
| 167 | Alva E Morgan | — | 3 | 45 |
| 168 | Cache Creek Drilling | — | 2 | 247 |
| 169 | C & N Pump & Well Co. | — | 2 | 697 |
| 170 | Wasco Drilling Company, Inc. | — | 2 | 554 |
| 171 | Robert Garcia Well & Pump Co. | — | 2 | 192 |
| 172 | Jim's Pump & Drilling | — | 2 | 157 |
| 173 | Koenig Enterprises | — | 2 | 83 |
| 174 | L & L Well Drilling | — | 2 | 76 |
| 175 | Everett E. Mcbride Dba | — | 2 | 57 |
| 176 | Stang Hydronics Inc. | — | 2 | 56 |
| 177 | Dan's Water Well & Pump Service Inc. | — | 2 | 37 |
| 178 | Geoloop Drilling/Tom Moreland | — | 2 | 32 |
| 179 | Nor-Cal Pump & Well Service | — | 2 | 26 |
| 180 | Butte Pump Service | — | 2 | 26 |
| 181 | Peters Drilling And Pump Service | — | 1 | 11,563 |
| 182 | Fisch Drilling And Pump Inc. | — | 1 | 663 |
| 183 | Fredrick Mark Pump & Supply Co. | — | 1 | 295 |
| 184 | Superior Well Service | — | 1 | 327 |
| 185 | Valley Pump & Motor Works Inc. | — | 1 | 181 |
| 186 | DE LA Grange & Sons Inc. | — | 1 | 263 |
| 187 | Martin Pump & Supply Inc. | — | 1 | 2,524 |
| 188 | Boart Longyear Company | — | 1 | 172 |
| 189 | Randall N Wallis | — | 1 | 531 |
| 190 | Vaca Drilling Co. /Del Crew JR | — | 1 | 2,745 |
| 191 | Myers Reverse, Inc. | — | 1 | 2,389 |
| 192 | Moss Roscoe Company | — | 1 | 1,220 |
| 193 | Myers Brothers Inc. | — | 1 | 796 |
| 194 | Seanaco Inc. | — | 1 | 327 |
| 195 | Clark Well Inc. | — | 1 | 273 |
| 196 | Winter Abajian Well Drilling | — | 1 | 203 |
| 197 | Agri-Cal Pump & Supply | — | 1 | 105 |
| 198 | Radulovich Well Drilling | — | 1 | 67 |
| 199 | Graham & Son Drilling Co. | — | 1 | 66 |
| 200 | All American Water Supply OF California Inc. | — | 1 | 40 |
| 201 | Louis A Wood Co. | — | 1 | 38 |
| 202 | Levy Matthews & Son | — | 1 | 35 |
| 203 | Mclaren Environmental Engineering | — | 1 | 30 |