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Skagit County Septic Design

Process for Septic System Permitting for a new Single Family Residence

Site Evaluation

Mitchell Septic provides an on-site investigation of soil types and depth, and documentation of site characteristics and constraints. This determines septic system options allowed under Skagit Count Health Department SCC Chapter 12.05.  

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

Soil log details can be submitted to Skagit County as a precursor to a design and can be used in the future as the basis for a design.  This application is called a "site/soil evaluation" and it has no expiration date.

Septic Design

Mitchell Septic generates a septic system design which is then submitted it to the Skagit County Health Department for their review and approval.

An approved design is required to support a building permit.

Once approved, the design is valid for five years.

Proprietary alternative systems require an "Operation-Maintenance & Monitoring requirement for proprietary on-site sewage systems" document signed, notarized and recorded at the Skagit County Auditor's Office.


Request bids and select Licensed Installer for the Skagit County list.

Designer of Record will generally perform a final inspection and create an as-built on any system that has a pump.