| Company | Location | Certifications | License # |
|---|---|---|---|
| Allen'S Septic Tank Services | Williston, SC | Pumper | OSWWP0170 |
| Felica Renee Washington | Blackville, SC | Installer (Tier 2) | 06-367-06034 |
| Lrb Site Prep & Hauling, Llc | Blackville, SC | Installer (Tier 2) | 06-367-06033 |
| Mlto Inc | Barnwell, SC | Installer (Tier 2) | 02-367-02048 |
| Owens Septic Tanks & Construction, Llc | Blackville, SC | Installer (Tier 2) | 06-367-06037 |
| Quality Septic Service | Barnwell, SC | Pumper | 02-368-02047 |
| R&R Llc | Barnwell, SC | Installer (Tier 2) | OSWWI0161 |
| Sargent'S Septic And Lot Clearing | Barnwell, SC | Installer (Tier 2) | OSWWI0271 |
| Still'S Backhoe Service | Barnwell, SC | Installer (Tier 2) | OSWWI0055 |
| Superior Hardscapes & Excavation Llc | Barnwell, SC | Installer (Tier 2) | OSWWI0644 |
| Troyer Excavating Llc | Blackville, SC | Installer (Tier 2) | 06-367-06036 |
| Wade'S Repair Service Inc | Barnwell, SC | Installer (Tier 2) | 06-367-06035 |
| Wade'S Repair Service Inc | Barnwell, SC | Pumper | 06-368-06008 |
| Walls Lawncare And Landsacping | Williston, SC | Installer (Tier 2) | OSWWI0508 |
| William Debruhl | Barnwell, SC | Installer (Tier 2) | OSWWI0381 |
15 companies in the SCDES on-site wastewater (OSWW) contractor registry are based in Barnwell County as of 2026-07-23. Companies based elsewhere in South Carolina also commonly serve the county.
Tell us what you need — we'll connect you with state-certified companies serving your area. No obligation.