Civil-Environmental Engineering

Butte County

Cities and towns (requirements may differ)


Oroville
Paradise


Chico
Gridley

Unincorporated communities
 

Bangor
Berry Creek
Butte Creek Canyon
Butte Meadows
Butte Valley
Cherokee
Clipper Mills
Cohasset
Concow
Durham
Forbestown
Forest Ranch
Hamilton

Honcut
Kelly Ridge
Magalia
Nord
Oroville East
Palermo
Rackerby
Richvale
Robinson Mill
South Oroville
Stirling City
Thermalito
Yankee Hill

*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.
 

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 (including the 'Counties frequently require the following'.)

 

  • Vertical Separation: 36"

  • Trench Sidewall-to-Sidewall Separation: 6'

  • Maximum Trench Length:  100 ft

  • Bottom Width: 12" to 48"

  • Trench Depth: 6" to 18" - Shallow Trenches - Soil cap to extend 5ft                                          uphill and 10 ft on downhill and sides                                    18" to 36"  - Standard Trench ​                                                                   36" to 48" - Deep Trench - Filled to within 24" of top                                           with approved sand; trench separation                                            must be equal to twice the depth (10' max)

  • ​Minimum of 2" of gravel over drain lateral, and 6" under.

  • Maximum drop of 1" in 100' for drain lateral.

  • Field sizes should be based on 240 gpd for 2 bdrm, 360 gpd for 3 bdrm, and 60 gpd for each additional bdrm over 3. 

  • ​Dispersion beds wider than 4' must have area increased by 50%.

  • Minimum septic tank capacity is 1500 gal., plus 200 gal. for each additional bdrm over 4.

​​

 

Butte County Setback Requirements

For a graphical representation of Butte County setback requirements:

 

Links to Butte County Website

For County home page:

For County's On-site Waste Water Manual: