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Routine maintenance can lengthen the life of your septic system. Contact a certified On-site System Maintainer to inspect and monitor your system with the frequency that your septic system needs:

  • Gravity systems: Every three years
  • Pressure Distribution systems: Annually
  • Proprietary system such as an aerobic treatment unit (ATU), membrane bioreactor (MBR), drip irrigation, and other products: Annually, or more often if required by the manufacturer
  • Mound or sand filter systems: Annually

Learn more about inspecting your system.

How often you pump depends on the amount of water use in your household or business. As a rule of thumb, the more people who use your septic system, the greater your water flow. This means your septic tank will fill up faster and will require more frequent pumping.

Learn more about pumping your septic tank.

A lid that is open or not screwed shut is a safety hazard! People can fall into tanks that are not secured. Make sure tank access lids are not cracked or deteriorated to prevent a safety hazard from happening.

Using less water may increase the life of your septic system. Using too much water is a frequent factor in failed systems. Learn more easy-to-do tips for saving water in different parts of your house on the Washington Sea Grant Program's website.

This additional water may prevent the drainfield from working properly.

Grass is the best cover for your septic tank and drainfield. Other plants with shallow root systems can also be used for landscaping.

See suggested landscaping options.

Have "risers" installed to make septic tank pumping and monitoring visits easier, cheaper, and less time-consuming. A "riser" also makes pumping and monitoring cause less mess and disruption in your yard.

Contact a certified Installer, Pumper, or On-site System Maintainer to install risers.


Garbage disposals add solids and grease that can build-up quickly and clog your drainfield. If you absolutely must use one, limit your use as much as possible.

Do not flush cleaning wipes, baby wipes, facial tissue, personal care products, or paper towels. Even wipes that are labeled flushable or septic safe belong in the trash can. Download these flyers to learn more:

Chemicals destroy bacteria in your system that are necessary to break down solids.

  • Call the Public Health Hazardous Waste Line at 206-296-4692 to ask about chemical disposal.
  • Long-term use of medications, such as antibiotics, may also destroy important bacteria in your septic tank and drainfield. Visit the Secure Medicine Return site for saafe disposal of unwanted medications.

In addition, keep patios, carports, decks, storage sheds, sports courts, landscaping plastic, and grazing animals off the drainfield and drainfield reserve areas. This will prevent soils from being packed down and pipes from breaking.

These products may be harmful by adding extra solids to the system that can clog your drainfield. The chemicals can also pollute groundwater and surface water. If you feel you must use additives, be sure to use only those that have received written approval from the Washington State Department of Health. It is unlawful to use any non-approved additive.

Large volumes of water can 'drown' your drainfield, and chlorine can destroy important bacteria in your septic tank and drainfield. Drain hot tubs away from the system, especially the drainfield. For disposal options, call King County's Water and Land Resources Division at 206-477-4800 or email them at