Island County Septic Design

Process for Septic System Permitting for a new Single Family Residence

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Site Registration

Mitchell Septic provides an on-site investigation of soil types and depth and documentation of site characteristics and constraints, determining septic system options allowed under Island County Health Department ICC Chapter 8.07D.  The goal of the evaluation is to locate the deepest usable soils on-site as this generally results in the lowest system installation cost.

Soil log holes are reviewed with Island County Health Department staff on-site (County fee prepaid).

The Site Registration is required prior to and is the basis for a design.  

The Site Registration has no expiration date.

Septic Design

Mitchell Septic generates a septic system design which is submitted to the Island 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 three years.


You can request bids and select a Licensed Installer from the Island County list.

The Designer of Record is not normally involved with Inspections or As-builts in Island County.  This is normally completed by the Installer.