Septic companies in Flagstaff, AZ

What the ground in Flagstaff is like

The USDA soil survey rates mapped ground in Flagstaff for septic drain-field suitability across roughly 66 square miles. About 97% 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 Flagstaff, the leading limit is depth to bedrock: rock sits close enough to the surface that there is not enough soil column above it for a conventional field to sit in. Effluent needs that depth to disperse; when bedrock comes up, the workable layer runs out. The survey flags that limit on about 71% of the rated ground here.

The limiting features the survey records most often here:

• Depth to bedrock71.3%
• Slow water movement45.2%
• Large stones23.7%
• Seepage, bottom layer17.0%

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 · 96.8% Very limited · Depth to bedrock · 35 map units · 66.05 sq mi · read 2026-08-30