Septic Tank prices in Washington

The median delivered septic tank in Washington costs $1,822 (October 2026); most sell between $1,789 and $1,943.

Delivered prices listed by distributors on landplan.io, in US dollars. The median is the middle price; the typical range runs from the 25th to the 75th percentile. A figure is published only when enough listings from enough distributors back it. Open the interactive price index.