Septic Systems


Here's the problem

Septic systems are designed to keep harmful sewage pathogens in the ground, protecting your family, pets and visitors. However, if not properly maintained, septic systems can lead to untreated sewage leaking into your yard and surface and groundwater, which can:

  • Carry harmful pathogens that spread disease.
  • Impact drinking water wells
  • Leach pollution and bacteria into nearby lakes or streams, including phosphorus that promotes algae growth

With an estimated 78,000 homeowners who rely on septic systems in Snohomish County, these problems can add up. 

Protect Your Investment and Your Lake - Be LakeWise

The good news is that you can make a difference by taking a few simple steps to ensure your septic system runs properly  for years to come. The LakeWise Clear Choices for septic care to have your property LakeWise certified are to:

  • Attend a FREE septic system care workshop
  • Have inspections by licensed provider at least every three years (frequency determined by system type)

Learn more below about the steps you can take to care for your system and identify problems early so they can be fixed before it becomes a hassle. 

Step 1. Look Up Your Septic System Type and Records

You can find the type of your septic system and its location by finding your system's "As-Built Drawing" on the Snohomish County Health Department website in their Online RME database.

  • Learn how to look up your septic system As-Built by watching this video or viewing this instruction sheet
  • Once you find your As-Built, carefully review the drawings and records to find your system type and components.
  • In the table at the bottom of the page, find your system type and download the guide(s) for your system.

Step 2. Practice Proper Septic System Care and Maintenance

Inspect Your System Regularly 

Septic systems require regular inspections or checkups from a septic care professional. They will make sure your system is working as intended and if pumping is required. 

Simple gravity systems are required to be inspected at least every three years. All other systems have advanced features (e.g. pumps, pressurized systems, sand filters etc.) require annual inspection (more if the Health Department requires it per your system documentation). 

Household Practices & Drainfield Care

Learn more about ways to care for your system such as what to avoid putting down the drain and how to protect your drainfield in the resources below. 

Septic BMP handout
Easy ways to keep your system running
Septic Sense booklet image
Septic Sense - An overview of septic system care 
Landscape Handout
Landscaping On and Around Your Septic System

Financial Help 

The Snohomish Health Department's Savvy Septic Program is your one-stop-shop for septic system financing options, incentives, and education to help you maintain a healthy septic system. Visit to learn more about: 

  • Workshops - learn how to care for your system at a free online class
  • Rebates for septic inspections & risers
  • Grants for maintenance or repairs (qualifying low-income homeowners)

Step 3. Attend An Upcoming Septic Care Workshop

Visit the Snohomish Health Department's Savvy Septic Program to view upcoming workshop dates, register for workshops or sign up to receive notice of upcoming workshops in their quarterly newsletter for septic system homeowners. 

Care Guides by Septic System Type

In the table below, find your system type and download the corresponding guides.

System Type / Component Corresponding Guide & Example Inspection Report
GravityGravity System Guide 
Gravity Inspection Report 
Pump Chamber & Alarm Pump Chamber & Alarm Guide 
Low-Pressure Distribution (LPD)LPD System Guide 
LPD Inspection Reports
Drip DispersalDrip System Guide 
Drip Inspection Report 
MoundMound System Guide
Mound Inspection Report 
Sand FilterSand Filter Guide 
Sand Filter Inspection Report
Sand-Lined Bed (SLB)Sand-Lined Trench Systems
Sand Filter Inspection Report
Aerobic Treatment Unit (ATU)ATU Guide
ATU Inspection Report 
Proprietary SystemFind and strictly follow the manufacturer’s operation and maintenance manual 
Example Proprietary Inspection Report