Sand filter Septic System Cost in Washington
Estimated 2026 installed range: $10,200 – $20,500
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Open the cost calculatorWhy Washington prices differ
Statewide cost drivers here are hard ground, terrain and remote access. Locally, wet soils and strict local health rules drive design costs. That is why a sand filter system in Washington can land well above or below the national range of $8,000–$16,000.
All system types in Washington
| System | Low | High |
|---|---|---|
| Conventional | $4,500 | $10,200 |
| Chamber | $6,400 | $14,100 |
| Aerobic / ATU | $10,200 | $23,000 |
| Mound | $12,800 | $28,200 |
| Sand filter | $10,200 | $20,500 |
What sand filter systems are for
A sand filter treats effluent before it reaches the drain field, which helps on poor soil. It adds cost and requires scheduled maintenance.
Related pages
All septic costs in Washington · Sand filter system overview