Septic companies in Philadelphia, PA

What the ground in Philadelphia is like

The USDA soil survey rates mapped ground in Philadelphia for septic drain-field suitability across roughly 134 square miles. About 71% of the rated ground is classed "Somewhat limited", the survey records restrictions that design and sizing can often work around.

In Philadelphia, 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 75% of the rated ground here.

The limiting features the survey records most often here:

• Depth to bedrock75.3%
• Seepage, bottom layer19.5%
• Slope17.1%
• Slow water movement10.4%

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 · 71.4% Somewhat limited · Depth to bedrock · 92 map units · 134.33 sq mi · read 2026-08-30