All septic systems require a permit for new installations, repairs and replacements, house or building remodels or expansions, subdivisions, boundary line adjustments and rezones. Click below for more information about each permit:

• New septic design and installation
• Septic repair and replacement
• House or building remodels or expansions
• Subdivisions, Boundary line adjustments and rezones

NOTE: A septic system is also referred to as an "on-site sewage system" or OSS in official documents, forms and applications.

Wastewater Applications (PDF):

• Application for Appeal, King County Sewage Review Committee
• Application for Final Subdivision
• Application for Health Department Approval of Building Permit
• Application for Winter Water Table Review (WWTR)
• Application to Change Designer of Record
• Pre-Application for Review of Subdivision

Wastewater Forms (PDF):

• Instructions to order your As-built Drawing
• Buyer's Declaration of Receipt of Copy of Notice of On-Site Sewage System Operation and Maintenance Requirements
• Drainfield Easement Form (example only)
• Declaration of Covenant: Detached Structure Restriction (example only)
• Declaration of Covenant: Bedroom Restriction (example only)
• "Notice on Title" Generic Form: Notice of On-site Sewage System Operation and Maintenance Requirements (OSSM)
• Nonconforming Notice on Title: Notice of On-Site Sewage System Operation and Maintenance Requirements
• Explanation of OSSM - Generic Form
• On-site Sewage System/Sewage Tank Service Report
• Report of Wastewater Tank Abandonment

Miscellaneous Forms:

• Approved Wastewater Tanks for OSS (PDF)
• Property Owner Notification Letter

OSS Homeowner's Manual: Gravity System
OSS Homeowner's Manual: Mound System
OSS Homeowner's Manual: Pressure Distribution System
OSS Homeowner's Manual: Sand Filter System
OSS Homeowner's Manual: Sand Filter / Mound System

NOTE: A septic system is also referred to as an "on-site sewage system" or OSS in official documents, forms and applications.

• King County Board of Health Codes
  See BOH Code Titles 12 and 13 as it pertains to wastewater issues.
  
  
• Washington State Board of Health Codes & Publications
  Washington Administrative Code (WAC)
  Use the WAC search engine to look for:
  • Chapter 246-272 – On-site Sewage Systems
  • Chapter 246-273 – On-site Sewage System Additives
    
    
• Washington State Department of Health's Wastewater Management Publications
  Includes information regarding:
  • Recommended Standards and Guidance (RS&G's) for Performance, Application, Design, and Operation and Maintenance (Alternative On-Site Wastewater Systems)
  • List of Approved Systems and Products
  • Link to Rule Development Committee homepage