Home-sale septic inspections in Whatcom County, Washington
Whatcom County: Yes, starting in 2027. The owner must have a third-party inspector check the system when the property changes hands. Whatcom County Code § 24.05.280, Operation, Monitoring and Maintenance · checked 2026-09-23
Does Whatcom County require a septic inspection before a sale?
Yes, starting in 2027. The owner must have a third-party inspector check the system when the property changes hands.
Applies to a sale or other transfer of the property.
The county health officer may waive this if the system already passed its regular check. State law sets this same rule statewide.
Whatcom County Code § 24.05.280, Operation, Monitoring and Maintenance · checked 2026-09-23
Who may inspect a septic system in Whatcom County?
The county inspects a new or repaired system before workers cover it. A county-approved worker checks a system already in use.
Whatcom County Code § 24.05.260, Inspection · checked 2026-09-23
Sources
Each figure on this page has a government source and a checked-on date.
- Whatcom County — On-Site Sewage
- Whatcom County Health and Community Services — Septic Forms & Applications
- Whatcom County — OSS Annual Fee
- Whatcom County Code § 24.05.380, Licensing
- Whatcom County Health and Community Services — On-Site Sewage System Permit Process
- Washington Administrative Code § 246-272A-0232, Design Requirements — Septic Tank Sizing
- Washington Administrative Code § 246-272A-0210, Location, Table IV
- USDA NRCS Soil Data Access (SSURGO)
- Whatcom County — 2025-2026 Unified Fee Schedule
Verify before you act. Septic rules are set locally and they change. Check anything here before you spend money on it. Call the Whatcom County Health and Community Services, On-Site Sewage (OSS) Program, on 360-778-6000.