Cities and towns (requirements may differ)
Summary of Specific Requirements For Gravity Systems
for Single Family Dwellings*
The following is in addition to the items listed on the FAQ page for Gravity System Requirements.
Vertical Separation to Water Table: 8', or 4' if parcel over 1 ac.
Trench Sidewall-to-Sidewall Separation: 8'
Trench Length: 10' to 125'
Bottom Width: 18" to 36"
Depth of Earth Coverage Over Lines: 36" max.
Usable Material Below Trench Bottom: 12" min.
Minimum of 2" of gravel over drain lateral, and 12" under.
Maximum drop of 4" in 100' for drain lateral.
Trench Bottom: 150 sf min.
*The information on this page is a summary for quick reference only and may not represent the latest standards. For complete and up-to-date information, see each counties official website.
Shasta County Setback Requirements
For a graphical representation of Shasta County setback requirements:
Links to Shasta County Website
For County home page:
For County's rules for
on-site sewage disposal:
Manual, Chapter 5)