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. Since septic systems are often out of sight and out of mind, many people may have systems that pose a threat to their health and could pollute nearby lakes or streams. That's why it's so important to have your septic system regularly inspected.

Register for a FREE Septic Care Workshop

  1. Learn how to keep your septic system running properly for years to come. Plus attend and receive up to $200 in rebates for your next septic system inspection and/or septic riser installation - learn more about rebates.

    Check back for Nov 2016 Dates
The solution: Be LakeWise for your septic system
Protect your family and your lake 

The good news is that you can make a difference by taking a few simple steps to ensure your septic system keeps running 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.

By taking these simple steps you can ensure you have the know-how to care for your system, identify and fix problems early, and ensure your system lasts for years to come.  
New in 2014- 2015.  Earn $200 in septic care rebates* 
Septic maintenance can be expensive.  Attend a septic care workshop in 2015-2016 and receive $100 rebate towards your next professional septic inspection and/or up to $100 rebate towards installing a septic system riser ($50 each). 

LakeWise septic rebates are limited to select lake areas but additional rebates are available through the County's Savvy Septic program. Select areas include: Crabapple, Echo, Flowing, Howard, Ketchum, Ki, Loma, Lost, Panther, Shoecraft, and Sunday

If it's in your septic
system, it's in your lake

Septic System Care is up to you - learn how to care for your system
Step 1:  Get to know your system: 

As a homeowner, you're responsible for the care and maintenance of your septic system. Here is how you can learn about your system:   
  • Download a map of your septic system and drainfield (called an “As-Built” from the Snohomish Health District). Go to and follow links under "Septics" to find wastewater information and the link to your property's as-built records. Use the drop-down windows to search by parcel number, address or owner name.
  • Use your system map to locate the tank and drainfield, and whether you have a designated drainfield reserve area on your property.
  • Learn more about your specific system by finding out the type (e.g. gravity, sand filter, mound) on your as-built and reading more about it in our resources.

Find your septic tank, drainfield, and reserve area

Calculate this

A routine septic inspection might cost a couple of hundred dollars and help you catch a problem early.  Replacing your septic system can be much more expensive and be a headahce.
Step 2:  Maintain your septic system:

Schedule routine inspections at least every three years

Routine inspection of your septic system is a smart investment. By catching a problem early you can avoid costly repairs and keep your system running efficiently for years to come.

  • Schedule routine inspections from a certified septic provider at least every three years. Your provider will look at the tank, drainfield and any other system components to make sure they are working properly.
  • Pump your tank when recommended by your inspector after they assess your system.  To save money, when you request service ask for a system inspection and ask for a pump-out only if it's needed.
  • More advanced septic systems (e.g. sand filters, mounds, ATUs, etc. ) require annual inspections under the Washington Administrative Code.
  • Clean the septic tank outlet filter screen yearly (if you have one).

Let's get pumped:

A pumper can be an inspector -- but not always

Find the right provider to inspect or pump your system. Depending on the provider's license and your septic system, some can pump tanks, some can inspect entire systems and some can do both. 

  • Find the list of licensed septic service providers on the Snohomish Health District’s website. Contractors certified as a monitoring & maintenance specialist can inspect all systems. Gravity septic systems without pumps can also be inspected by certified pumpers.
  • Contact at least three qualified providers to obtain the best service and pricing. Use the “Choosing a Septic System Provider” to see what to ask. Also check out some example inspection reports (see left) to see what your inspection report should include.
  • Check out an example inspection report to see what inspectors should look for when they check your septic system. The reports below are actual inspection reports filed online with the Snohomish Health District - just select your system type to view:


  • Gravity
  • Gravity with pump
  • Sand Filter (SF)
  • Drip
  • Low Pressure Distribution (LPD)
  • Aerobic Treatment Unit (ATU)
  • Mound
  • SF with LPD


Step 3:  Keep your septic system healthy 

It's up to you to make your septic system last - Don't trash your septic system

Your septic system is designed to safely process wastewater and the two things your body makes every day. Keep it simple and don't flush or pour any of this other stuff down the drain:

  • Undigested food and food scraps, grease, oils, fats and paper towels
  • Pet waste and kitty litter
  • Hair, dental floss, bath tissues, baby wipes and "personal" wipes, feminine hygiene products and condoms 
  • Old medicines
  • Chemical bases and solids and caustic drain cleaners
  • Automotive fluids such as anti-freeze, oils, brake fluid and degreasers
  • Oil-based paints and solvents
  • Latex paint brush and roller cleanup waste should be minimized

 Do's and don'ts for your septic tank, drainfield and reserve area

It's up to you to protect your septic tank, drainfield and reserve area. Here's how:

  • Do call a septic service provider if you smell foul odors or find wet spots or leaking sewage near the septic tank or drainfield.
  • Do keep deep-rooted plants away from the septic tank, pipes and drainfield. Roots are drawn to the moisture and nutrients and will grow into pipes and underground components.
  • Do keep your drainfield and reserve area clear any structures, pavement, livestock, irrigation, sprinklers and stormwater infiltration systems.
  • Do plant grass or keep existing native vegetation over your drainfield. These are the best covers.
  • Do use water in your house wisely: Fix leaks, use water-saving fixtures, space dishwashing and laundry loads throughout the week.
  • Don't plant a vegetable garden over or near the drainfield.
  • Don't cover your drainfield with plastic sheeting, bark, gravel or other fill.
  • Don't drive across or park over your septic tank, drainfield or reserve area. You'll compact the soil, which hampers its ability to filter water back into the ground.
  • Don't direct any surface water drainage toward the septic system, drainfield or reserve area.
  • Don't drain a hot tub near the septic tank or drainfield.

Septic resources:

Click on the images in the slide show for links to septic system publications and guidelines from the Washington Department of Health, the U.S. Environmental Protection Agency and Washington Sea Grant.

  • Proper Landscaping On and Around Your Septic System
  • Septic Sense, Scents, Cents: 3 Supreme Insights to the Fearless Flush
  • Understanding and Caring For Your Mound System
  • Understanding and Caring For Your Pressure Distribution System
  • Understanding and Caring For Your Sand Filter System
  • Understanding and Caring For Your Septic Tank System