Septic companies in Mount Vernon, WA

What the ground in Mount Vernon is like

The USDA soil survey rates mapped ground in Mount Vernon for septic drain-field suitability across roughly 12 square miles. About 89% 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 Mount Vernon, the leading limit is depth to the saturated zone: the water table sits so close to the surface that a drain field has little dry soil left underneath it. Effluent needs unsaturated ground to treat and disperse; when that column is thin, the field has nowhere safe to go. The survey flags that limit on about 79% of the rated ground here.

The limiting features the survey records most often here:

• Depth to saturated zone79.1%
• Slow water movement60.3%
• Slope20.5%
• Seepage, bottom layer14.4%

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 · 88.8% Very limited · Depth to saturated zone · 39 map units · 12.3 sq mi · read 2026-08-30