| 1 | Mount Water Well Drilling | 689 | 2,412 | 3,547 |
| 2 | Keen Well And Pump | 648 | 2,190 | 10,231 |
| 3 | Beinhower Bros Drilling Co. | 191 | 1,990 | 3,766 |
| 4 | Bapst Inc. | 191 | 432 | 5,348 |
| 5 | Hurley's Water Well Drilling | 157 | 413 | 802 |
| 6 | K & B Well Drilling Co. | 139 | 225 | 1,837 |
| 7 | Central Soft Water | 138 | 138 | 1,489 |
| 8 | Warthman Drilling Inc. | 111 | 159 | 4,411 |
| 9 | Cantrell Well Drilling | 50 | 69 | 477 |
| 10 | Steve Nethers Drilling | 44 | 132 | 151 |
| 11 | Jamison Well Drilling Inc. | 37 | 63 | 11,219 |
| 12 | Smith's Well Drilling LLC | 31 | 74 | 1,966 |
| 13 | B Mowrey Drilling LLC | 27 | 31 | 89 |
| 14 | A & H Bevard Water Well Service | 21 | 26 | 44 |
| 15 | Seismic Drilling Co. Inc. | 12 | 20 | 5,783 |
| 16 | Moody's OF Dayton Inc. | 12 | 15 | 361 |
| 17 | Stage Inc. (Dba R C Barry) | 11 | 61 | 1,117 |
| 18 | Nethers Tom Drilling Co. | 8 | 101 | 108 |
| 19 | J E Wright Well Drilling | 8 | 36 | 1,126 |
| 20 | Jackson Well Services Inc. | 6 | 6 | 93 |
| 21 | Blair Drilling & Pump Serv LLC | 5 | 15 | 593 |
| 22 | Underhill Well & Pump Co. LLC | 4 | 7 | 519 |
| 23 | Eaton Well Drilling Inc. | 4 | 6 | 1,309 |
| 24 | Gard's Water Well Drilling | 3 | 17 | 160 |
| 25 | Yoder Drilling & Geothermal | 2 | 2 | 1,353 |
| 26 | Triple J Drilling (Newark) | 1 | 19 | 27 |
| 27 | National Water Services (Lanc) | 1 | 7 | 91 |
| 28 | Bushong Drilling | 1 | 5 | 852 |
| 29 | Flinner Drilling Inc. | 1 | 3 | 8,459 |
| 30 | Layne Christensen Co. | 1 | 2 | 33 |
| 31 | J Miller & Sons Drilling | 1 | 1 | 1,124 |
| 32 | Stewart (James) | 1 | 1 | 36 |
| 33 | R C Barry Company | — | 600 | 3,818 |
| 34 | Vollmuth (Raymond A) | — | 517 | 946 |
| 35 | Leindecker Well Drilling | — | 508 | 796 |
| 36 | Snedden (E J) Well Drilling | — | 425 | 456 |
| 37 | Pataskala Well Drilling | — | 322 | 362 |
| 38 | Danny's Water Well Drilling | — | 317 | 379 |
| 39 | S & N Berea Drilling Co. | — | 296 | 331 |
| 40 | Dan Allen Well Drilling | — | 287 | 493 |
| 41 | Robert Davis Well Drilling | — | 278 | 377 |
| 42 | Parks Well Drilling | — | 274 | 283 |
| 43 | Keen Drilling | — | 267 | 436 |
| 44 | Garrabrant Well Drilling | — | 247 | 279 |
| 45 | Applegate (Glenn C) | — | 207 | 235 |
| 46 | Plummer & Sons | — | 194 | 3,365 |
| 47 | Charles Allen Water Well Drilling | — | 190 | 235 |
| 48 | Barry (R C) | — | 182 | 1,392 |
| 49 | Markle Drilling | — | 174 | 199 |
| 50 | Larry Bevard Water Well Drilling | — | 171 | 187 |
| 51 | Lupher Drilling | — | 170 | 295 |
| 52 | Arthur E Plummer & Son | — | 158 | 560 |
| 53 | Wilson (Vance) Well Drilling | — | 158 | 181 |
| 54 | Sprowls Drilling Co. | — | 143 | 1,348 |
| 55 | J & O Drilling | — | 124 | 399 |
| 56 | Hoover Well Drilling | — | 121 | 173 |
| 57 | Parks & Mcbride | — | 119 | 120 |
| 58 | H & D Drilling Company | — | 110 | 118 |
| 59 | Doug Frost Drilling | — | 105 | 118 |
| 60 | Professional Water Well Systems | — | 104 | 624 |
| 61 | Plummer-Mcdannald Drilling | — | 87 | 1,333 |
| 62 | Jackson & Sons Drilling & Pump Co. | — | 86 | 3,154 |
| 63 | Applegate (G D) | — | 83 | 88 |
| 64 | Gates Well Drilling | — | 79 | 496 |
| 65 | H & A Water Well Drlg & Pump Svc | — | 79 | 106 |
| 66 | Water Systems Inc. | — | 73 | 196 |
| 67 | Wheeler (Ray) | — | 72 | 254 |
| 68 | Wilson (Jim) Well Drilling | — | 68 | 1,464 |
| 69 | Gibbons Drilling | — | 66 | 69 |
| 70 | Dingess (Jay) Well Drilling | — | 65 | 87 |
| 71 | Snedden (Robert) Well Drilling | — | 58 | 62 |
| 72 | Cave Well Drilling | — | 57 | 204 |
| 73 | Wheeler Drilling Co. | — | 57 | 122 |
| 74 | Phillips Water Well Drilling | — | 53 | 90 |
| 75 | Frost Drilling | — | 51 | 386 |
| 76 | Bebout (R C) | — | 51 | 116 |
| 77 | Blauser (Grover C) | — | 49 | 247 |
| 78 | Jobes & Jobes Drilling | — | 49 | 64 |
| 79 | C & H Water Well Drilling Co. | — | 48 | 55 |
| 80 | Filkill Water Well Drilling | — | 46 | 318 |
| 81 | James R Moran Drilling Co. | — | 46 | 82 |
| 82 | Lothes Drilling Inc. | — | 44 | 44 |
| 83 | L & M Drilling | — | 43 | 240 |
| 84 | Denman Water Well Drilling | — | 43 | 49 |
| 85 | Ashcraft Drilling | — | 40 | 42 |
| 86 | Chas Hoover Well Drilling | — | 39 | 180 |
| 87 | Hoover Water Systems | — | 39 | 143 |
| 88 | Bevard (Larry) Well Drilling | — | 38 | 43 |
| 89 | Bevard (Carl) Well Drilling | — | 36 | 40 |
| 90 | Brown Drilling | — | 34 | 152 |
| 91 | Shoemaker Drilling Inc. | — | 34 | 46 |
| 92 | Daley Drilling Co. | — | 34 | 35 |
| 93 | Scheideggers Pump Service | — | 31 | 76 |
| 94 | G M Baker & Son | — | 30 | 259 |
| 95 | Mullins Well Drilling | — | 30 | 60 |
| 96 | Keaton Drilling | — | 30 | 39 |
| 97 | Swingle (Donald) Well Drilling | — | 29 | 364 |
| 98 | Kautz Well Drilling | — | 29 | 251 |
| 99 | Moran (John T) | — | 27 | 53 |
| 100 | Helser & Sons Water Well Drilling | — | 26 | 121 |
| 101 | Hunter Drilling Co. | — | 26 | 75 |
| 102 | Snook Well Drilling Company | — | 25 | 30 |
| 103 | Short Drilling | — | 24 | 1,580 |
| 104 | Ryan (A F) | — | 23 | 653 |
| 105 | Davis Drilling | — | 21 | 415 |
| 106 | B & B Well Drilling | — | 20 | 134 |
| 107 | Anderson Water Well Drilling | — | 20 | 92 |
| 108 | Timberlake (S B) | — | 20 | 37 |
| 109 | Snedden (Frank) & Sons | — | 20 | 34 |
| 110 | Varner (Lloyd) | — | 20 | 33 |
| 111 | Gobel Well Drilling | — | 17 | 1,184 |
| 112 | Edmonds Water Well Drilling | — | 17 | 308 |
| 113 | Ulery Service & Repair | — | 17 | 197 |
| 114 | May (H J) | — | 16 | 338 |
| 115 | Harley (V J) And Son | — | 16 | 236 |
| 116 | Mike's Water Well Drilling | — | 15 | 175 |
| 117 | Silver Fleet Drilling | — | 15 | 61 |
| 118 | Dingess (Mansfield) Well Drilling | — | 15 | 35 |
| 119 | Price Drilling | — | 14 | 184 |
| 120 | Pickerington Well Drilling | — | 14 | 51 |
| 121 | Belton Water Well Drilling | — | 13 | 264 |
| 122 | Kerr Corporation | — | 12 | 404 |
| 123 | Wolfe's Drilling Co. | — | 12 | 323 |
| 124 | Riser Frank Drilling | — | 12 | 42 |
| 125 | Dean's Drilling | — | 11 | 1,010 |
| 126 | J R Wells Water Well Drilling | — | 11 | 520 |
| 127 | Stewart Well Drilling | — | 11 | 177 |
| 128 | New Rome Pump Service | — | 10 | 682 |
| 129 | Sarbaugh Drilling | — | 10 | 475 |
| 130 | Aqua Drilling Inc. | — | 10 | 430 |
| 131 | Layne Ohio (Layne Christensen) | — | 10 | 346 |
| 132 | Earl Davis Well Drilling | — | 10 | 289 |
| 133 | Burch Well Drilling | — | 10 | 143 |
| 134 | Sprowls Drilling Co. (Groveport) | — | 10 | 84 |
| 135 | Agua Well Drilling Inc. | — | 9 | 449 |
| 136 | Ramsey Drilling | — | 8 | 614 |
| 137 | Flick's Drilling Inc. | — | 8 | 355 |
| 138 | Pinkerton (Carl) & Son | — | 8 | 112 |
| 139 | Allen Water Well Drilling | — | 8 | 96 |
| 140 | Quinter Well Drilling LLC | — | 7 | 12,078 |
| 141 | Plummer Brothers | — | 7 | 863 |
| 142 | B E Wright Drilling | — | 7 | 260 |
| 143 | Morgan Well Drilling | — | 7 | 147 |
| 144 | Melick (W O) | — | 7 | 124 |
| 145 | Swingle (Robert) | — | 7 | 37 |
| 146 | Griffith Drilling Co. | — | 6 | 854 |
| 147 | Frazier Drilling | — | 6 | 376 |
| 148 | Suburban Drilling Co. | — | 6 | 246 |
| 149 | Williams Drilling Co. | — | 5 | 65 |
| 150 | Mullet Drilling Company Inc. | — | 5 | 2,605 |
| 151 | Union County Drilling | — | 5 | 663 |
| 152 | Alliance Water Well Inc. | — | 5 | 458 |
| 153 | Harpest (Ron) Well Drilling | — | 5 | 377 |
| 154 | Goodwin (R H) | — | 5 | 164 |
| 155 | Marsh II Drilling | — | 5 | 133 |
| 156 | Davis (J C) | — | 5 | 73 |
| 157 | Bob's Well Drilling Service | — | 5 | 58 |
| 158 | Hellwig (H M) & Sons | — | 5 | 48 |
| 159 | Ryan Well Drilling | — | 5 | 46 |
| 160 | Tedrow Water Well Drilling | — | 4 | 577 |
| 161 | Wright (Merle) Well Drilling | — | 4 | 1,044 |
| 162 | Short Brothers | — | 4 | 374 |
| 163 | Casey's Well Drilling | — | 4 | 312 |
| 164 | Peacock Well Drilling | — | 4 | 265 |
| 165 | Benedict Well Drilling | — | 4 | 58 |
| 166 | Mcgee Drilling | — | 4 | 56 |
| 167 | Cameron (Berlin A) | — | 4 | 47 |
| 168 | R & C Drilling Co. | — | 4 | 34 |
| 169 | Kniceley Well Drilling | — | 3 | 3,389 |
| 170 | Ohio Drilling Company | — | 3 | 409 |
| 171 | Thomas Well Drilling | — | 3 | 1,244 |
| 172 | Paul W Wright Drilling | — | 3 | 1,236 |
| 173 | Bauer Well Drilling | — | 3 | 393 |
| 174 | Wright Well Drilling | — | 3 | 366 |
| 175 | Snoddy Well Drilling | — | 3 | 207 |
| 176 | Lancaster Well Service | — | 3 | 179 |
| 177 | Carroll's Well & Pump Service | — | 3 | 127 |
| 178 | Watson Drilling | — | 3 | 88 |
| 179 | Davis Water Systems | — | 3 | 80 |
| 180 | Water Well Drilling & Supply Co. | — | 3 | 56 |
| 181 | Riser (H E) | — | 3 | 56 |
| 182 | Moran's Water Well Service | — | 3 | 42 |
| 183 | Glen T Speedy Drilling | — | 3 | 32 |
| 184 | Duncan Drilling Co. | — | 2 | 1,395 |
| 185 | Mason Well Drilling | — | 2 | 908 |
| 186 | Speedy Drilling Co. | — | 2 | 2,142 |
| 187 | Harpest Well Drilling | — | 2 | 781 |
| 188 | Had Inc. | — | 2 | 783 |
| 189 | Eaton Well & Pump | — | 2 | 3,329 |
| 190 | Ruby (Stan) Well Drilling | — | 2 | 750 |
| 191 | Fyffe (T J) | — | 2 | 747 |
| 192 | Smith Drilling Contractors | — | 2 | 609 |
| 193 | Kerr & Maxwell | — | 2 | 605 |
| 194 | Leyden Management | — | 2 | 525 |
| 195 | Underhill Water Well Drilling | — | 2 | 451 |
| 196 | Complete Well Service | — | 2 | 362 |
| 197 | Vickroy Well Drilling | — | 2 | 260 |
| 198 | A & A Well Drilling | — | 2 | 237 |
| 199 | Asher (A J) | — | 2 | 207 |
| 200 | Jordan (Emmett M) | — | 2 | 204 |
| 201 | Stebelton (Everett) | — | 2 | 181 |
| 202 | Dixie Drilling | — | 2 | 121 |
| 203 | Fouts Drilling | — | 2 | 61 |
| 204 | Cap Drilling | — | 2 | 36 |
| 205 | Hamm (Everett G) | — | 2 | 33 |
| 206 | Justice Drilling Co. | — | 2 | 31 |
| 207 | Hamilton & Sons Well Drilling | — | 1 | 3,862 |
| 208 | Persing Water Well Drilling | — | 1 | 1,373 |
| 209 | Automatic Septic & Well | — | 1 | 1,160 |
| 210 | Cooper Water Well Drilling | — | 1 | 2,153 |
| 211 | Havens & Sons Drilling | — | 1 | 516 |
| 212 | Mock Well Drilling | — | 1 | 1,220 |
| 213 | Sever Water Well Drilling | — | 1 | 4,250 |
| 214 | Bell Well Drilling Inc. | — | 1 | 2,095 |
| 215 | White Well Drilling | — | 1 | 1,710 |
| 216 | Wes Britenstine Well Drilling | — | 1 | 786 |
| 217 | Buckeye Valley Well Drilling | — | 1 | 721 |
| 218 | Burchett (William H) | — | 1 | 712 |
| 219 | Dewitt Drilling Co. | — | 1 | 600 |
| 220 | Fisher (Fred B) | — | 1 | 545 |
| 221 | Parker Well Drilling | — | 1 | 339 |
| 222 | Phillips Well Drilling | — | 1 | 338 |
| 223 | Shamrock Drilling | — | 1 | 315 |
| 224 | Bushong (Charles Burton) | — | 1 | 295 |
| 225 | Poole's Water Well Drilling | — | 1 | 293 |
| 226 | Schneider Well Drilling Inc. | — | 1 | 253 |
| 227 | Messenger (Carl) | — | 1 | 248 |
| 228 | Bohn Bros Well Drilling | — | 1 | 221 |
| 229 | Garnes Water Wells | — | 1 | 213 |
| 230 | Crist Well Service | — | 1 | 200 |
| 231 | Moats Drilling Co. | — | 1 | 196 |
| 232 | Hines Drilling | — | 1 | 175 |
| 233 | Carl Lemon Well Drilling | — | 1 | 163 |
| 234 | Hickman (Charles W) | — | 1 | 157 |
| 235 | Thomas (Grant) | — | 1 | 153 |
| 236 | Wilson Plbg Htg & Cooling | — | 1 | 145 |
| 237 | Haines Well Drilling | — | 1 | 127 |
| 238 | Roberts (Edward) Well Drilling | — | 1 | 108 |
| 239 | Edwards (Clyde) | — | 1 | 105 |
| 240 | Scott A Welch Water Well Drilling | — | 1 | 85 |
| 241 | Dunbar-Stark-Layne Drilling | — | 1 | 83 |
| 242 | Ricketts & Co. | — | 1 | 83 |
| 243 | Tincher (Hugh) Well Drilling | — | 1 | 83 |
| 244 | L & L Well Drilling | — | 1 | 81 |
| 245 | Spung's Well Drilling | — | 1 | 80 |
| 246 | M & M Contractors | — | 1 | 79 |
| 247 | Porter (M J & M S) | — | 1 | 69 |
| 248 | Hayes (Fred M) | — | 1 | 62 |
| 249 | Lehman & Lynn | — | 1 | 59 |
| 250 | Underhill (James) | — | 1 | 58 |
| 251 | Bill's Bit Service | — | 1 | 47 |
| 252 | Gillum Water Well Drilling | — | 1 | 46 |
| 253 | Massey Drilling Inc. | — | 1 | 43 |
| 254 | Dutro (M L) | — | 1 | 43 |
| 255 | Berry (Robert) Well Drilling | — | 1 | 39 |
| 256 | Hill & Son | — | 1 | 37 |
| 257 | Bischoff Drilling | — | 1 | 37 |
| 258 | Dailey (Larry S) | — | 1 | 33 |
| 259 | Snider Drilling Co. | — | 1 | 31 |
| 260 | Adams Drilling | — | 1 | 30 |
| 261 | M & S Drilling | — | 1 | 29 |
| 262 | Aqua Spring Well Drilling | — | 1 | 28 |
| 263 | Plummer (Walter) | — | 1 | 27 |
| 264 | Sand Run Drilling Co. | — | 1 | 25 |
| 265 | Mckee Well Drilling | — | 1 | 25 |