Septic System Construction
Septic System Sizing
A licensed septic designer or professional engineer is needed to design and determine the size of your system.
The number of bedrooms in your home can impact the size of your system. The Snohomish County Health Department’s Code outlines the policy on bedrooms. Potential bedrooms are considered bedrooms regardless of the placement of closets, windows and doors, or the width or location within the structure.
For more information, you can review the Interpretation of Bedroom and Daily Flow Determination Policy.
Rooms that are considered potential bedrooms include, but are not limited to:
- Bonus rooms
- Hobby, sewing and exercise rooms
- Offices and studies
- Unfinished rooms
The Snohomish County Health Department typically does not count rooms such as living rooms, family rooms, dining rooms, storage areas, closets, and utility rooms as potential bedrooms.
If your system is commercial, you need to discuss with a septic system designer how your system should be sized.