| 1 | Sensenig & Weaver Well Drilling Inc. | 1,165 | 2,878 | 18,480 |
| 2 | C S Garber & Sons Inc. | 547 | 3,531 | 18,484 |
| 3 | Petersheim Brothers H20,LLC | 325 | 2,047 | 8,096 |
| 4 | Phares Fry Well Drilling & Pump Svc Inc. | 286 | 2,396 | 5,909 |
| 5 | Eichelbergers Inc. | 229 | 851 | 37,074 |
| 6 | Odyssey Environmental Services, Inc. | 208 | 269 | 7,584 |
| 7 | Myers Brothers Drilling Contr.,Inc. | 172 | 700 | 33,477 |
| 8 | R H Odenheimer Co. | 86 | 286 | 5,276 |
| 9 | Ameridrill, Inc. | 79 | 162 | 5,442 |
| 10 | Mayer's Well Drilling | 29 | 97 | 2,948 |
| 11 | Parratt-Wolff Inc. | 25 | 39 | 3,500 |
| 12 | Kocher's Water Pumps & Tanks Inc. | 21 | 33 | 2,402 |
| 13 | Environmental Probing Investigations Inc. | 21 | 26 | 1,212 |
| 14 | Todd Mayer's Well Drilling | 18 | 185 | 5,307 |
| 15 | Talon Drilling Company | 18 | 42 | 1,966 |
| 16 | George Leib Well Drilling Inc. | 17 | 24 | 908 |
| 17 | Allied Well Drilling | 13 | 40 | 2,213 |
| 18 | Mountain Research LLC | 12 | 12 | 1,243 |
| 19 | Accell Inc. | 10 | 10 | 116 |
| 20 | Active Environmental Technologies, Inc. | 8 | 8 | 206 |
| 21 | Negley's Well Drilling, LLC | 6 | 7 | 9,098 |
| 22 | East Coast Drilling, Inc. | 6 | 6 | 1,106 |
| 23 | Thomas Keyes, Inc. | 5 | 17 | 5,253 |
| 24 | Morrison Excavating Morrison Excavating Inc. | 4 | 11 | 1,160 |
| 25 | H & M Well Drilling Inc. | 3 | 305 | 696 |
| 26 | Duane Moyer Well Drilling | 3 | 24 | 11,486 |
| 27 | Shiffer Drilling, Inc. | 3 | 11 | 904 |
| 28 | Chris Cook - C W Cook, Inc. | 3 | 6 | 274 |
| 29 | Funks Drilling Inc. | 3 | 6 | 2,469 |
| 30 | Werner & Sons Well Drilling LLC | 2 | 3 | 1,396 |
| 31 | Bellview Pump, LLC | 1 | 67 | 1,025 |
| 32 | Summit Drilling LLC | 1 | 1 | 1,492 |
| 33 | AC Schultes Inc. | 1 | 1 | 115 |
| 34 | Phares Fry Well Drilling | — | 2,063 | 3,694 |
| 35 | Kohl Bros., Inc. | — | 658 | 2,398 |
| 36 | Lenhart-Stitzel Well Drilling | — | 385 | 772 |
| 37 | Robert D Grant | — | 331 | 1,090 |
| 38 | B. L. Myers Bros OF MD,LLC | — | 222 | 12,524 |
| 39 | Arnold Drilling LLC | — | 182 | 266 |
| 40 | R And R Garber Inc. | — | 168 | 732 |
| 41 | Richard H Stanley | — | 162 | 200 |
| 42 | Snyder Well Drilling Inc. | — | 157 | 1,464 |
| 43 | Mays Well Drilling | — | 131 | 374 |
| 44 | Reith Bros. Inc. | — | 112 | 1,435 |
| 45 | Kerr Bros | — | 85 | 121 |
| 46 | Louis Heintz Well Drilling Inc. | — | 75 | 689 |
| 47 | Douglas K Reigner | — | 69 | 396 |
| 48 | Fisher's Well Drilling | — | 68 | 551 |
| 49 | Morris Bailey | — | 63 | 64 |
| 50 | James Bucci | — | 58 | 81 |
| 51 | Gill Enterprises Inc. | — | 54 | 449 |
| 52 | Robert H Bailey | — | 54 | 57 |
| 53 | Groundwater Technology | — | 45 | 75 |
| 54 | Michael Kuszyk | — | 35 | 652 |
| 55 | Leidos | — | 34 | 338 |
| 56 | Lininger Drilling & Pumps | — | 33 | 773 |
| 57 | Thomas E Bailey | — | 26 | 39 |
| 58 | Wonsidler Well Drilling Inc. | — | 25 | 2,891 |
| 59 | Water Well Drillers Licensing--Topo Geo | — | 17 | 732 |
| 60 | Miller Pump Service Inc. | — | 14 | 2,893 |
| 61 | Geo-Environmental Drilling Co. Inc. | — | 13 | 3,228 |
| 62 | Handex Consulting & Remediation, LLC | — | 13 | 575 |
| 63 | Advanced Drilling Inc. | — | 10 | 248 |
| 64 | B L Myers Bros Inc. | — | 7 | 1,232 |
| 65 | Rufus A Light | — | 7 | 174 |
| 66 | Empire Soils Investigations Inc. | — | 7 | 82 |
| 67 | Keller Industrial, Inc. | — | 7 | 56 |
| 68 | Lutz Environmental Co., Inc. | — | 6 | 431 |
| 69 | Bassett Environmental Associates, Inc. | — | 5 | 73 |
| 70 | Layne Christensen Company | — | 5 | 44 |
| 71 | Charles Lauman And Son Inc. | — | 4 | 338 |
| 72 | Aaa Quality Wells & Pumps Inc. | — | 4 | 265 |
| 73 | IT Environmental Inc. | — | 4 | 131 |
| 74 | Floyd R Sensenig | — | 4 | 78 |
| 75 | Kuser Well Drilling | — | 3 | 648 |
| 76 | Tristate Env. Mgmt. Svcs. Inc. | — | 3 | 199 |
| 77 | Alexander Macphee--Cvm Industries | — | 3 | 495 |
| 78 | Logan Bollinger | — | 3 | 795 |
| 79 | Martin Schafer Jr. Inc. Well Drilling | — | 3 | 593 |
| 80 | Arthur Reinheimer Layne Christensen Company | — | 3 | 225 |
| 81 | Chasity Jones | — | 3 | 214 |
| 82 | Raab Well Drilling, Inc. | — | 2 | 2,909 |
| 83 | Edward Powell Pump & Well Drilling Inc. | — | 2 | 4,204 |
| 84 | Terra Testing, Inc. | — | 2 | 4,532 |
| 85 | Michael Kavlunas Total Quality Drilling, LLC | — | 2 | 49 |
| 86 | Michael Barlow Well Drilling Service | — | 2 | 81 |
| 87 | Bucks County Well Drilling, Inc. | — | 2 | 3,006 |
| 88 | John Thran | — | 2 | 2,266 |
| 89 | C E Sunday & Son Water Well Drilling | — | 2 | 1,452 |
| 90 | Ron Mitchell Well Drilling | — | 2 | 422 |
| 91 | David Lyman/Samuel Stothoff Co., Inc. | — | 2 | 149 |
| 92 | H20 Well Drilling T/A | — | 2 | 126 |
| 93 | Clayton S Grimm JR | — | 2 | 84 |
| 94 | William Stothoff Co. Inc. | — | 2 | 70 |
| 95 | Rulon And Cook Inc. | — | 2 | 68 |
| 96 | Midway Drillers | — | 2 | 41 |
| 97 | Environmental Services & Engineering | — | 2 | 27 |
| 98 | Alexander's | — | 1 | 3,447 |
| 99 | Knight Well Drilling Inc. | — | 1 | 9,484 |
| 100 | William W. Reichart, Inc. | — | 1 | 3,242 |
| 101 | G S Fleese Drillin | — | 1 | 248 |
| 102 | Bell Bros Well Drl & Water Sys Solns | — | 1 | 2,190 |
| 103 | K.l. Madron Well Drilling, LLC | — | 1 | 5,980 |
| 104 | Harrisburg's Kohl Bros Inc. | — | 1 | 2,819 |
| 105 | George R. Brookover Well Drlg | — | 1 | 1,754 |
| 106 | Pyle Well Drilling LLC | — | 1 | 1,575 |
| 107 | Ralph Neeb Well Drilling | — | 1 | 542 |
| 108 | Bernard Swogger Drilling | — | 1 | 429 |
| 109 | Roger Leeds Well Drilling | — | 1 | 298 |
| 110 | Frontz Drilling Inc. | — | 1 | 199 |
| 111 | H.w. Kocher Well Drilling Inc. | — | 1 | 172 |
| 112 | Bonnie J Myers | — | 1 | 134 |
| 113 | Alfred G Gurley | — | 1 | 115 |
| 114 | C & I Enterprises | — | 1 | 105 |
| 115 | Mcmichael And Son | — | 1 | 83 |
| 116 | Don Armstrong Well Drilling, LLC | — | 1 | 49 |
| 117 | MB Drilling LLC | — | 1 | 35 |