| 1 | Wallis Water Systems | 212 | 676 | 688 |
| 2 | Bar - H Well Drilling Inc. | 197 | 197 | 197 |
| 3 | North American Drilling Company | 185 | 498 | 692 |
| 4 | Eagle Well Drilling & Pump Service | 173 | 536 | 542 |
| 5 | Chambers D P Drilling | 160 | 443 | 488 |
| 6 | Solomon Well Drilling & Pump Service Inc. | 146 | 194 | 194 |
| 7 | Farwest Corrosion Control Company | 92 | 231 | 2,649 |
| 8 | J & H Drilling Co. Inc. | 79 | 104 | 978 |
| 9 | Cascade Drilling LP | 76 | 78 | 826 |
| 10 | Daugherty Pump & Drilling | 72 | 111 | 122 |
| 11 | Water Well Service Inc. | 68 | 96 | 145 |
| 12 | Chambers Choice Drilling | 65 | 68 | 73 |
| 13 | Harich Enterprises Company Inc. | 54 | 598 | 612 |
| 14 | J & O Well Drilling | 52 | 92 | 159 |
| 15 | Cascade Drilling L P | 49 | 98 | 2,827 |
| 16 | Randall N Wallis | 47 | 516 | 531 |
| 17 | L O Lynch Quality Wells & Pumps Inc. | 44 | 132 | 3,373 |
| 18 | Donald C Vickery Well Drilling | 35 | 138 | 150 |
| 19 | Heritage Well Service | 35 | 35 | 528 |
| 20 | Well Tec Services Inc. | 33 | 58 | 126 |
| 21 | Yellow Jacket Drilling Services LLC | 32 | 35 | 291 |
| 22 | Layne Christensen Company | 25 | 331 | 2,362 |
| 23 | A B C Liovin Drilling Inc. | 15 | 21 | 1,281 |
| 24 | Bc2 Environmental LLC | 15 | 20 | 416 |
| 25 | American Construction And Supply Inc. | 13 | 25 | 1,685 |
| 26 | Beks Acquisition Inc. | 12 | 12 | 465 |
| 27 | Best Drilling And Pump Inc. | 11 | 38 | 248 |
| 28 | Lucerne Valley Pump Service | 11 | 26 | 26 |
| 29 | Southern California Well Service LLC | 11 | 11 | 50 |
| 30 | Southwest Pump & Drilling Inc. | 9 | 53 | 290 |
| 31 | Gregg Drilling LLC | 9 | 9 | 558 |
| 32 | Sebastian Valente | 9 | 9 | 66 |
| 33 | Crum Sam Water Well Drilling Inc. | 7 | 266 | 591 |
| 34 | A Z C A Drilling & Pump Inc. | 5 | 11 | 171 |
| 35 | Corrpro Companies Inc. | 5 | 7 | 737 |
| 36 | Fain Drilling & Pump Co. Inc. | 4 | 22 | 3,029 |
| 37 | Gregory Drilling Incorporated | 4 | 4 | 143 |
| 38 | Abundant Water Wells | 4 | 4 | 173 |
| 39 | M & M Well Drilling | 4 | 4 | 74 |
| 40 | Bryant Pump & Drilling Company | 3 | 19 | 1,000 |
| 41 | National Corrosion | 3 | 3 | 28 |
| 42 | Gregg Drilling & Testing Inc. | 2 | 38 | 4,828 |
| 43 | Dechenne Water Well Drilling Inc. | 2 | 30 | 1,204 |
| 44 | Arthur & Orum Well Drilling Inc. | 2 | 22 | 3,219 |
| 45 | Lundigan Drilling | 2 | 4 | 179 |
| 46 | Nor - Cal Pump & Well Drilling Inc. | 2 | 3 | 248 |
| 47 | National E W P Inc. | 2 | 3 | 431 |
| 48 | Howard Pump Inc. A California Corporation | 1 | 1,400 | 1,650 |
| 49 | Fundin Well Drilling | 1 | 334 | 394 |
| 50 | Jack Jones Wells & Pumps | 1 | 223 | 1,145 |
| 51 | Arsenal Well Drilling Inc. | 1 | 1 | 234 |
| 52 | Matthew Davis Enterprises Inc. | 1 | 1 | 40 |
| 53 | Garrison Brothers Well Service | 1 | 1 | 46 |
| 54 | Gibson Well Drilling | 1 | 1 | 115 |
| 55 | Fugro Usa Land Inc. | 1 | 1 | 36 |
| 56 | Mel Meyer | — | 2,123 | 101,127 |
| 57 | MC Dougall's Well Drilling Inc. | — | 1,336 | 1,345 |
| 58 | Independent Well Drilling Inc. | — | 612 | 615 |
| 59 | Dane Pike Wells And Pump | — | 320 | 323 |
| 60 | Mccalla Brothers | — | 247 | 578 |
| 61 | V L Allen | — | 227 | 227 |
| 62 | Eagle Drilling | — | 205 | 205 |
| 63 | Arrowhead Group | — | 200 | 244 |
| 64 | Barstow Pump & Drilling | — | 197 | 197 |
| 65 | Van Norman Well Drilling | — | 193 | 194 |
| 66 | Clifford Suffdy | — | 188 | 198 |
| 67 | Warren Opie Wallis | — | 161 | 161 |
| 68 | HI-Desert Drillers | — | 157 | 158 |
| 69 | Chapman Pump & Drilling Company | — | 143 | 145 |
| 70 | Cascade Drilling Inc. - California | — | 136 | 3,167 |
| 71 | Beylik Drilling & Pump Service | — | 135 | 1,267 |
| 72 | Kirkland Well Service | — | 131 | 184 |
| 73 | Ephraim Harris | — | 126 | 127 |
| 74 | Aqua-Tek | — | 111 | 117 |
| 75 | Harich Construction | — | 109 | 122 |
| 76 | Moss Roscoe Company | — | 103 | 1,220 |
| 77 | Coe Machine Works | — | 100 | 110 |
| 78 | Leroy Tyler | — | 97 | 100 |
| 79 | David Engel | — | 95 | 98 |
| 80 | Howard H. Ley | — | 92 | 92 |
| 81 | Howard Pump Company | — | 86 | 106 |
| 82 | Valley Well Drilling LP | — | 83 | 410 |
| 83 | Garcia Well Drilling | — | 77 | 77 |
| 84 | West Hazmat Drilling Corp | — | 70 | 1,702 |
| 85 | Santa Rosa Drilling Co. | — | 70 | 77 |
| 86 | Zim Industries Inc. Dba Bakersfield Well & Pump Co. | — | 68 | 1,716 |
| 87 | W D C Exploration & Wells | — | 68 | 2,421 |
| 88 | F Lahorgue | — | 68 | 87 |
| 89 | Mcdougall's Well Drilling | — | 67 | 67 |
| 90 | SO Cal Pump And Well Drilling | — | 65 | 158 |
| 91 | Scoggin Drilling Company | — | 65 | 67 |
| 92 | Meridian Drilling & Well Supply | — | 64 | 74 |
| 93 | Woodward Drilling Company Inc. | — | 63 | 1,542 |
| 94 | S & S Water Well Drilling | — | 61 | 143 |
| 95 | H-F Drilling, Inc. | — | 60 | 618 |
| 96 | Ron Engeldinger Well | — | 58 | 616 |
| 97 | Rottman Drilling Co. | — | 57 | 1,331 |
| 98 | R H Forney | — | 57 | 88 |
| 99 | H & L Drilling Company | — | 56 | 56 |
| 100 | American Drilling | — | 54 | 970 |
| 101 | Errin A Smith Drilling | — | 52 | 54 |
| 102 | Desert Oasis Drilling | — | 50 | 50 |
| 103 | Pierson Drilling | — | 48 | 59 |
| 104 | Hall Construction Company | — | 47 | 49 |
| 105 | J. R. Greenlee | — | 47 | 47 |
| 106 | Herzog & Associates | — | 45 | 45 |
| 107 | Dell D Beck | — | 44 | 60 |
| 108 | Murrieta Water Well Drilling Company | — | 42 | 80 |
| 109 | Suffdy Earl Ramey | — | 40 | 40 |
| 110 | Furlong Well Drilling | — | 39 | 39 |
| 111 | Solomon Excavation Inc. | — | 34 | 34 |
| 112 | Layne Environmental Services Inc. | — | 33 | 104 |
| 113 | Mogle Brothers | — | 33 | 57 |
| 114 | Mogle Drilling & Pump Company | — | 33 | 53 |
| 115 | Water Well Supply | — | 31 | 533 |
| 116 | Patrick O Fortney & Son | — | 31 | 46 |
| 117 | Cliff Steele & Van Norman | — | 31 | 31 |
| 118 | Scoggin Drilling & Dev Co. | — | 28 | 30 |
| 119 | C. Cruse Drilling | — | 27 | 301 |
| 120 | Errol A Smith Drilling | — | 27 | 37 |
| 121 | F M Van Norman | — | 27 | 27 |
| 122 | Webb Drilling Company | — | 27 | 27 |
| 123 | Hiram G Smith | — | 26 | 46 |
| 124 | W L Watkins | — | 26 | 29 |
| 125 | Testamerica Drilling Corp | — | 25 | 378 |
| 126 | T. Carmack | — | 25 | 69 |
| 127 | Barber-Bridge Drilling Corp Ltd | — | 25 | 64 |
| 128 | Roche Well And Pump Company | — | 24 | 54 |
| 129 | C Johnson Well Drilling & Pump | — | 24 | 25 |
| 130 | Dyna Drill International Inc. | — | 21 | 115 |
| 131 | Datum Exploration Inc. | — | 20 | 223 |
| 132 | Coachella Valley Pump & Supply | — | 19 | 660 |
| 133 | Evans Bros | — | 18 | 107 |
| 134 | Teredon Company | — | 18 | 48 |
| 135 | Active Drilling & Pump Supply | — | 17 | 276 |
| 136 | Layne-Western Co. Inc. | — | 17 | 255 |
| 137 | Beylik Drilling Inc. | — | 17 | 174 |
| 138 | Chino Valley Water Well Supply Inc. | — | 17 | 77 |
| 139 | Trunnell Wells & Pumps | — | 16 | 384 |
| 140 | Great Basin Drilling | — | 16 | 51 |
| 141 | Carmack & Stephenson | — | 16 | 37 |
| 142 | Roscoe Moss Company | — | 15 | 130 |
| 143 | Clearwater Drilling | — | 14 | 351 |
| 144 | Patrick O Fortney | — | 14 | 57 |
| 145 | Melton Drilling Co. | — | 14 | 46 |
| 146 | Shipps For Water Well Drilling | — | 14 | 33 |
| 147 | C C Scott | — | 13 | 75 |
| 148 | Peerless Welding & Machine Shop | — | 13 | 63 |
| 149 | Boart Longyear Company | — | 12 | 172 |
| 150 | Tri-County Drilling Inc. | — | 12 | 227 |
| 151 | Charles Nyberg Well Drilling | — | 12 | 55 |
| 152 | Garrison Bros | — | 12 | 27 |
| 153 | S A Andresen All Terrain Exploration | — | 10 | 468 |
| 154 | JC Drilling | — | 10 | 110 |
| 155 | Shipps For Water Well | — | 9 | 54 |
| 156 | Modern Drilling | — | 8 | 29 |
| 157 | Johnson Drilling Co. | — | 7 | 11,865 |
| 158 | Kirschenman's Well Drilling | — | 7 | 1,159 |
| 159 | Mann Brothers | — | 7 | 326 |
| 160 | Ralph E Anderson | — | 7 | 171 |
| 161 | R Glick & Sons Water Wells | — | 7 | 109 |
| 162 | Pioneer Drilling Inc. | — | 7 | 61 |
| 163 | Cruse Drilling Co. | — | 6 | 341 |
| 164 | D P Well Drilling | — | 6 | 60 |
| 165 | Stang Hydronics Inc. | — | 6 | 56 |
| 166 | J C Water Well Drilling | — | 6 | 52 |
| 167 | Farm Pump And Irrigation Company Inc. | — | 5 | 451 |
| 168 | Westervelt Well Drilling | — | 5 | 122 |
| 169 | Desert Water Drilling Company | — | 5 | 279 |
| 170 | John H Correll | — | 5 | 158 |
| 171 | Agri-Cal Pump & Supply | — | 5 | 105 |
| 172 | Everett E. Mcbride Dba | — | 5 | 57 |
| 173 | Paul Neville | — | 5 | 51 |
| 174 | John H. And Jack A. Correll | — | 5 | 32 |
| 175 | Staal, Gardner, & Dunne, Inc. | — | 5 | 31 |
| 176 | Rex Anderson Corp | — | 4 | 1,493 |
| 177 | Starr Drilling And Pump Co. | — | 4 | 875 |
| 178 | Burt Drilling Co. | — | 4 | 438 |
| 179 | S/G Testing Laboratories Inc. | — | 4 | 187 |
| 180 | M R Peck & Sons | — | 4 | 125 |
| 181 | Tex Bassham Drilling | — | 4 | 107 |
| 182 | A & R Drilling | — | 4 | 60 |
| 183 | Melvin A Mcfadden | — | 4 | 51 |
| 184 | Trihydro Corporation | — | 4 | 46 |
| 185 | Cofferdam Unwatering Corporation | — | 4 | 32 |
| 186 | Multi Water Systems | — | 3 | 269 |
| 187 | Southern Sierra Drilling | — | 3 | 92 |
| 188 | Interstate Soils Sampling Inc. | — | 3 | 75 |
| 189 | Andy Noblin | — | 3 | 39 |
| 190 | Environmental West Drilling | — | 3 | 38 |
| 191 | Collum Drilling Company | — | 3 | 37 |
| 192 | Mcgann | — | 3 | 34 |
| 193 | Keeler Drlg Co. | — | 3 | 30 |
| 194 | Stehly Brothers Drilling Inc. | — | 2 | 2,191 |
| 195 | Consolidated Testing Laboratories Inc. | — | 2 | 1,405 |
| 196 | Myers Brothers Well Drilling Inc. | — | 2 | 2,865 |
| 197 | Krazan & Associates | — | 2 | 30 |
| 198 | Maranatha Drilling And Pump Service | — | 2 | 307 |
| 199 | Myers Reverse, Inc. | — | 2 | 2,389 |
| 200 | Acme Drilling Company | — | 2 | 1,439 |
| 201 | Aqua Drilling | — | 2 | 923 |
| 202 | Myers Brothers Inc. | — | 2 | 796 |
| 203 | Jim Mcclain Wells | — | 2 | 768 |
| 204 | Midway Drilling & Pump Company | — | 2 | 753 |
| 205 | Butler Drilling Company | — | 2 | 714 |
| 206 | Knapp & Graham Inc. | — | 2 | 596 |
| 207 | Batson Drilling Service | — | 2 | 436 |
| 208 | James E Wright, JR | — | 2 | 328 |
| 209 | Mccalla Bros Pump And Drilling Co. | — | 2 | 229 |
| 210 | Rainbow Drilling | — | 2 | 207 |
| 211 | Benny DI Prima | — | 2 | 205 |
| 212 | Turner Explorations Inc. | — | 2 | 200 |
| 213 | Don Redfeairn Drilling Co. | — | 2 | 186 |
| 214 | Corrosion Technology Inc. | — | 2 | 169 |
| 215 | Steve's Pumps & Well Drilling Inc. | — | 2 | 162 |
| 216 | Barnes Core Drlg | — | 2 | 86 |
| 217 | Ase Drilling Inc. | — | 2 | 82 |
| 218 | Clark Well Drilling Co. | — | 2 | 63 |
| 219 | Anderson G C Drilling & Pump | — | 2 | 53 |
| 220 | Hacker's Pump Service | — | 2 | 51 |
| 221 | Vics Well Drilling Inc. | — | 1 | 337 |
| 222 | Pacific Coast Well Drilling Inc. | — | 1 | 337 |
| 223 | Palm Springs Pump Inc. | — | 1 | 115 |
| 224 | Sargent Drilling | — | 1 | 442 |
| 225 | Whitten Pumps Inc. | — | 1 | 874 |
| 226 | Frank Scully/Morrison Drilling Inc. | — | 1 | 582 |
| 227 | Manos Jim Drilling & Pump | — | 1 | 542 |
| 228 | Boetsch Well Drilling And Pump Service | — | 1 | 522 |
| 229 | M A Bryant Drilling | — | 1 | 311 |
| 230 | Spectrum Exploration Inc. | — | 1 | 307 |
| 231 | Pacific Gas And Electric Company | — | 1 | 264 |
| 232 | Lynch L O Well Drilling And Supply | — | 1 | 213 |
| 233 | Curtis Hole Drilling Company | — | 1 | 187 |
| 234 | Clark Albert M | — | 1 | 181 |
| 235 | Alexander Dean Water Well Drilling | — | 1 | 145 |
| 236 | L Van Winkle | — | 1 | 115 |
| 237 | Xxx | — | 1 | 113 |
| 238 | Haddon Drilling | — | 1 | 105 |
| 239 | Warden Drilling Co. | — | 1 | 102 |
| 240 | O Hardcastle | — | 1 | 98 |
| 241 | Graves & Graves Drilling | — | 1 | 72 |
| 242 | Precision Drilling Co. | — | 1 | 71 |
| 243 | Moore Twining Associates Inc. | — | 1 | 46 |
| 244 | Saunders Brothers | — | 1 | 44 |
| 245 | Keener Exploration Drilling Co. | — | 1 | 37 |
| 246 | M & W Pumps Inc. | — | 1 | 35 |
| 247 | U S Geological Survey | — | 1 | 30 |
| 248 | Daniel F Anderson | — | 1 | 30 |
| 249 | Morris A Balderman | — | 1 | 29 |
| 250 | William W Tarbutton | — | 1 | 28 |