| Company | Location | Certifications | License # |
|---|---|---|---|
| 1st Class Grading Inc | Westminster, SC | Installer (Tier 2) | 37-367-37213 |
| Action Septic Tank Service | Walhalla, SC | Installer (Tier 2) | 37-367-37078 |
| Action Septic Tank Service | Walhalla, SC | Pumper | 37-368-37002 |
| Adventure Jays Outdoor Rentals | Westminster, SC | Installer (Tier 2) | OSWWI0298 |
| Air Masonry | Walhalla, SC | Installer (Tier 2) | OSWWI0127 |
| All Hot Water Llc | Seneca, SC | Installer (Tier 2) | OSWWI0438 |
| Amity Builders Inc | Seneca, SC | Installer (Tier 2) | 37-367-37219 |
| Apex Landworks | Seneca, SC | Installer (Tier 2) | OSWWI0512 |
| B&D Grading & Landscaping | Westminster, SC | Installer (Tier 2) | 37-367-37059 |
| B&M Tree Company, Inc | West Union, SC | Installer (Tier 2) | OSWWI0800 |
| Baumgarner Builders | Seneca, SC | Installer (Tier 2) | 04-367-04231 |
| Belchers Earth Shaping | Westminster, SC | Installer (Tier 2) | 37-367-37270 |
| Burton Grading | Salem, SC | Installer (Tier 2) | 37-367-37204 |
| Butts Construction | Westminster, SC | Installer (Tier 2) | 37-367-37190 |
| C Jones Inc | Westminster, SC | Installer (Tier 2) | 04-367-04232 |
| Carolina Clay Grading Llc | West Union, SC | Installer (Tier 2) | 37-367-37278 |
| Carolina Mountain Grading | West Union, SC | Installer (Tier 2) | 37-367-37229 |
| Cirts | Westminster, SC | Installer (Tier 2) | OSWWI0831 |
| Cornerstone Masonry Inc | Walhalla, SC | Installer (Tier 2) | 37-367-37253 |
| Cox Excavating Llc | West Union, SC | Installer (Tier 2) | OSWWI0153 |
| Crystal Sewer & Water | Seneca, SC | Installer (Tier 2) | 37-367-37254 |
| D & C Grading | Walhalla, SC | Installer (Tier 2) | 37-367-37239 |
| Darrin Nichols | Seneca, SC | Installer (Tier 2) | 37-367-37242 |
| Dba Duvall Builders & Grading | Seneca, SC | Installer (Tier 2) | 37-367-37089 |
| Dwr Plumbing | Walhalla, SC | Installer (Tier 2) | 37-367-37212 |
| Earthworks Of Oconee, Inc | Westminster, SC | Installer (Tier 2) | 37-367-37240 |
| Frick Plumbing | Salem, SC | Installer (Tier 2) | 37-367-37164 |
| Golden Corner Trucking Llc | Westminster, SC | Installer (Tier 2) | 37-367-37251 |
| Goss Excavating And Grading Llc | West Union, SC | Installer (Tier 2) | OSWWI0033 |
| Grants Drain Care | Westminster, SC | Installer (Tier 2) | 37-367-37248 |
| Greenstone Construction Llc | Seneca, SC | Installer (Tier 2) | 37-367-37201 |
| Greenstone Construction Llc | Seneca, SC | Installer (Tier 2) | 37-367-37280 |
| Greenstone Construction, Llc | Seneca, SC | Pumper | 37-368-37016 |
| Griffin Waste | Seneca, SC | Pumper | OSWWP0102 |
| Harris Farms & Construction | Fair Play, SC | Installer (Tier 2) | 37-367-37077 |
| Hendricks Grading Llc | Seneca, SC | Installer (Tier 2) | OSWWI0366 |
| Holbrooks Grading & Land. Inc. | Seneca, SC | Installer (Tier 2) | 37-367-37216 |
| Iseli Brothers | West Union, SC | Installer (Tier 2) | 37-367-37141 |
| J&J Farms & Construction | Westminster, SC | Installer (Tier 2) | OSWWI0173 |
| James R Moore Sr | Seneca, SC | Installer (Tier 2) | 37-367-37267 |
| Jetton Hauling & Grading | Walhalla, SC | Installer (Tier 2) | 37-367-37158 |
| Joseph Kelly | Salem, SC | Installer (Tier 2) | OSWWI0053 |
| Keen Care, Llc | Walhalla, SC | Installer (Tier 2) | OSWWI0280 |
| Keith Moore | Mountain Rest, SC | Installer (Tier 2) | OSWWI0478 |
| King & Son Masonry Constructio | Westminster, SC | Installer (Tier 2) | 37-367-37269 |
| Legacy Property Solutions | Westminster, SC | Installer (Tier 2) | OSWWI0792 |
| Major Contracting Services Inc | Seneca, SC | Pumper | OSWWP0063 |
| Matt Kanagy Construction Inc. | Seneca, SC | Installer (Tier 2) | OSWWI0647 |
| Mcalister Masonry | Townville, SC | Installer (Tier 2) | 37-367-37227 |
| Medlin Grading | Tamassee, SC | Installer (Tier 2) | 37-367-37238 |
| Nathan Haley | Westminster, SC | Installer (Tier 2) | 37-367-37237 |
| Outdoor Restorations | Seneca, SC | Installer (Tier 2) | OSWWI0275 |
| Painter Constructions Llc | Seneca, SC | Installer (Tier 2) | 37-367-37271 |
| Palmetto State Site Solutions | Westminster, SC | Installer (Tier 2) | 37-367-37265 |
| Palmetto Upstate Services Llc | Seneca, SC | Installer (Tier 2) | 37-367-37262 |
| Philllips Construction & Gradi | Seneca, SC | Installer (Tier 2) | 37-367-37259 |
| Randy Cobb Grading | Salem, SC | Installer (Tier 2) | 37-367-37268 |
| Rochester'S Plumbing & Backflow Services | Westminster, SC | Installer (Tier 2) | OSWWI0047 |
| Rocksteady Excavations &Land Services, Llc | Mountain Rest, SC | Installer (Tier 2) | OSWWI0340 |
| Sass | Mountain Rest, SC | Installer (Tier 2) | OSWWI0283 |
| Seb Grading & Landscaping Llc | Westminster, SC | Installer (Tier 2) | 37-367-37215 |
| Seven Rivers Ranch | Salem, SC | Installer (Tier 2) | OSWWI0699 |
| Simpson And Sons Grading | Westminster, SC | Installer (Tier 2) | OSWWI0331 |
| Sloan Installations, Llc | West Union, SC | Installer (Tier 1) | OSWWI0288 |
| Stamp Creek Grading | Salem, SC | Installer (Tier 2) | 37-367-37274 |
| Standup Septic Solutions | Westminster, SC | Installer (Tier 2) | OSWWI0194 |
| Standup Septic Solutions Llc | Westminster, SC | Pumper | OSWWP0073 |
| Steven Wholey | West Union, SC | Installer (Tier 2) | OSWWI0134 |
| Stream Works Llc | Mountain Rest, SC | Installer (Tier 2) | OSWWI0163 |
| Sword'S Grading | Seneca, SC | Installer (Tier 2) | 37-367-37154 |
| Talley Builders Inc | Seneca, SC | Installer (Tier 2) | 37-367-37064 |
| The Chandler Group Inc. | Seneca, SC | Installer (Tier 2) | 37-367-37232 |
| Timberstone | Mountain Rest, SC | Installer (Tier 1) | OSWWI0468 |
| Tm Landscape Solutions | Seneca, SC | Installer (Tier 2) | OSWWI0715 |
| Tom Weber | Westminster, SC | Installer (Tier 2) | 37-367-37279 |
| Tracy Lanning Construction | Westminster, SC | Installer (Tier 2) | 37-367-37121 |
| Troy'S Excavation & Clearing Llc | Westminster, SC | Installer (Tier 2) | OSWWI0825 |
| Woody & Son Construction | Walhalla, SC | Installer (Tier 2) | 37-367-37109 |
78 companies in the SCDES on-site wastewater (OSWW) contractor registry are based in Oconee County as of 2026-07-23. Companies based elsewhere in South Carolina also commonly serve the county.
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