Official sources checked August 29, 2026
Franklin County, Washington septic permits and requirements
Permitting authority
Benton-Franklin Health District — On-Site Sewage Program
Environmental Health / sewage systems: 509-460-4205. Pasco office: 412 W. Clark Street, Pasco, WA 99301.
Washington local-health-jurisdiction framework
Washington State Department of Health assigns property-level onsite sewage permitting and management to local health jurisdictions. County or district rules and procedures can be more specific than the statewide minimums.
Local health district permits systems under 3,500 gallons per day
Benton-Franklin Health District states that it is responsible for permitting onsite septic systems with design flows below 3,500 gallons per day and for overseeing design, installation, and inspection.
Permit forms and local standards
The Health District publishes onsite-sewage applications and local construction/design standards in addition to Washington State Department of Health rules. Applicants should use the current district forms rather than assuming another Washington county’s process applies.
Final inspection before backfill
After installation and before backfill, the owner or installer must request a Health District final inspection. Once the system passes, the district states it is approved and ready for use.
Official sources
- Washington State Department of Health — Onsite Sewage Systems
- Benton-Franklin Health District — On-Site Sewage
- Benton-Franklin Health District — Applications, Lists and Forms
- Benton-Franklin Health District — Sewage System Inspection
- Benton-Franklin Health District — Rules and Regulations
SepticScope summarizes public-agency information for planning purposes. The permitting agency's current instructions control if they differ from this guide.