| Company | Location | Certifications | License # |
|---|---|---|---|
| Capex Oilfield Services Inc | Williston, ND | Pumper (Class II) | NDSP07406 |
| JTH Portables LLC | Tioga, ND | Pumper (Class I) | NDSP007281 |
| MonDak Portables LLC | Williston, ND | Pumper (Class I) | NDSP007303 |
| Nova Oilfield Services, Inc. | Williston, ND | Pumper (Class I) | NDSP007292 |
| Seidel Septic LLC | Williston, ND | Pumper (Class II) | NDSP07400 |
| Stallion Infrastructure - Williston | Williston, ND | Pumper (Class I) | NDSP007342 |
| Vac-U-Jet Septic and Sump Service Inc. | Missoula, ND | Pumper (Class I) | NDSP007369 |
7 companies in the North Dakota DEQ licensed septic system installers and sanitary pumpers are based in Williams County as of 2026-07-23. Companies based elsewhere in North Dakota also commonly serve the county.
Tell us what you need — we'll connect you with state-certified companies serving your area. No obligation.