Septic permits & rules in Warren County: The Warren County Health Department reviews plans for proposed septic system installations, physically inspects installations, and responds to complaints about malfunctioning systems. Homeowners can also look up existing records through the county's searchable online Septic System and Private Well database. Details: Warren County Health Department.
| Company | Location | Certifications | License # |
|---|---|---|---|
| Ofallon Sewer Service | — | Installer (Level Basic) | 39147 |
1 company in the Missouri DHSS registered OWTS installer list is based in Warren County as of 2026-07-23. Companies based elsewhere in Missouri also commonly serve the county.
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