Cities and towns (requirements may differ)
Butte Creek Canyon
*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: