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.

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.

If you take 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 is in good working order and keeps working for years to come. 

Learn more about your septic system now
Septic care is up to you:

Get to know your system

As a homeowner, you're responsible for the care and maintenance of your septic system. LakeWise suggests you start here:

  • Download a map of you 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 your system map to locate the tank, drainfield and 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.
If it's in your septic
system, it's in your lake

Help LakeWise keep its 11 targeted lakes clean. Register at to attend a FREE LakeWise Septic Care workshop and learn the simple steps you can take to keep your septic system and lake healthy.

Calculate this

A routine septic inspection might cost a couple of hundred dollars, but a new septic system will cost thousands of dollars to design and install.
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 and haven't been damaged. 
  • Pump your tank when recommended by your inspector.  To save money, ask for an inspection and a pump out only if needed.
  • More advanced septic systems (e.g. sand filters, mounds, ATUs) require annual inspections under the Washington Administrative Code
  • Clean the tank outlet 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 to see what your inspection report should include.

Don't trash your septic system:

It's up to you to make your septic system last

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, feminine hygiene products, condoms 
  • Old medicines
  • Chemical bases and solids and caustic drain cleaners
  • Automotive anti-freeze and other auto fluids
  • Oil-based paints and solvents
  • Latex paint brush and roller cleanup waste should be minimized.

Keep your septic system healthy:

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.
  • 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 or drainfield. 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.
  • Don't drain a hot tub near the septic tank or drainfield.

More septic resources:

Click on the photos 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