Whatcom County Septic Design

Process for Septic System Permitting for a new Single Family Residence

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Site Evaluation

Mitchell Septic performs an on-site investigation of soil types and depth and documentation of site characteristics and constraints, determining septic system options under Whatcom County Health Department WCC Chapter 24.05.  

The goal of the evaluation is to locate the deepest usable soils on-site as this will generally correspond to the lowest system installation cost.

Septic Design

Involves staking out the drain field, generating a septic system design, and submitting it to the Whatcom County Health Department for review and approval.

An approved design is required to support a building permit.

Once approved, the design is valid for three years.


You request bids and select a Licensed Installer.

The Designer of Record is not normally involved with Inspections or As-builts in Whatcom County unless there are significant changes during installation.