| Company | Location | Certifications | License # |
|---|---|---|---|
| Agec | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 02735-OSP |
| Amelia Strand | Cedar City, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 03661-OSP |
| Applied Geotechnical Engineering Consultant | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 04539-OSP |
| Ash Creek Special Service District | Hurricane, UT | Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 04669-OSP |
| Ash Creek SSD | Hurricane, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 03201-OSP |
| Bradley Johnson | La Verkin, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 04472-OSP |
| Brown Consulting Engineers | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 03701-OSP |
| Canaan Peaks Engineering | Hildale, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 00351-OSP |
| Dale Johnson | Hurricane, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 03046-OSP |
| David Morgan | Pintura, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 04400-OSP |
| Environmental Scientist | Leeds, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 00027-OSP |
| Geotechnical and Environmental Services, INC. | Hurricane, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 04445-OSP |
| Geotechnical Testing Services, Inc. | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 03287-OSP |
| Great Basin Engineering Inc. | Ogden, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 00435-OSP |
| Gts | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 03086-OSP |
| J Brad Barto Construction | Plain City, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 02310-OSP |
| J. Paul Wright | Central, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 02520-OSP |
| Jackson Excavation | Bicknell, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 02430-OSP |
| Jackson Excavation / Bull Head Sand & Gravel | Bicknell, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 02926-OSP |
| Jackson Excavation, Inc. | Bicknell, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 02928-OSP |
| Justin Hudspeth | Hurricane, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 04215-OSP |
| Krystyl Parker | Washington, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 04197-OSP |
| Landmark Testing & Engineering | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 03401-OSP |
| Nelson Septic Solutions | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 02941-OSP |
| Pratt Engineering, P.C. | Hurricane, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 00269-OSP |
| Pro Construction & Landscaping | Torrey, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 02455-OSP |
| Rosenberg Associates | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 00233-OSP |
| Rosenberg Associates | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 03636-OSP |
| Southwest UT Public Health Dept. | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 04329-OSP |
| Southwest Utah Health Department | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 04655-OSP |
| Southwest Utah Public Health Dept. | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 00442-OSP |
| Southwest Utah Public Health Dept. | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 02050-OSP |
| Southwest Utah Public Health Dept. | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2) | 02630-OSP |
| Southwest Utah Public Health Dept. | St. George, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 03351-OSP |
| Western States Enterprises | Washington, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 04170-OSP |
| Western View Construction | Ogden, UT | Onsite Wastewater Professional (Level 1)Onsite Wastewater Professional (Level 2)Onsite Wastewater Professional (Level 3) | 04663-OSP |
36 companies in the Utah DEQ certified onsite wastewater system professionals list are based in Washington County as of 2026-07-23. Companies based elsewhere in Utah also commonly serve the county.
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