Septic companies in Walla Walla, WA

What the ground in Walla Walla is like

The USDA soil survey rates mapped ground in Walla Walla for septic drain-field suitability across roughly 14 square miles. About 73% of the rated ground is classed "Very limited", meaning the soil has one or more features unfavorable for a conventional drain field, and the limits generally cannot be overcome without major soil reclamation, special design or expensive installation.

In Walla Walla, the leading limit is flooding: parts of the mapped ground sit in areas that inundate from time to time. A drain field under water cannot treat or disperse effluent, and floodwater can lift untreated waste into the open. The survey flags that limit on about 60% of the rated ground here.

The limiting features the survey records most often here:

• Flooding60.0%
• Depth to saturated zone59.9%
• Seepage, bottom layer50.0%
• Slow water movement49.9%

This is survey data for mapped areas, not a substitute for a site evaluation on your own lot. Conditions on a single parcel can differ from the map.

USDA NRCS SSURGO, ENG Septic Tank Absorption Fields · 73.4% Very limited · Flooding · 24 map units · 14.07 sq mi · read 2026-08-30