How Often Should You Get a Septic Inspection in Washington State?

01/05/2026

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If your home uses a septic system, regular inspections are essential for preventing costly repairs and keeping your system running properly. In Washington State, inspection frequency depends on the type of system you have.

Septic Inspection Guidelines in Washington:

• With conventional septic systems an inspection is recommended every 3 years
• With Alternative septic systems an inspection is required every year (or more often, depending on the system)

Alternative systems include aerobic units, sand filters, mound systems, and any system with pumps or mechanical components. These require closer monitoring under Washington State and county regulations.

When You Should Inspect Sooner

Schedule an inspection right away if you notice:

• Slow drains or frequent clogs
• Sewage odors inside or outside the home
• Wet or unusually green areas near the drainfield
• Gurgling plumbing sounds
• Sewage backups

You’ll also need an inspection if you’re selling your home, as many Washington counties require one before or during a real estate transaction.

Inspections vs. Pumping

An inspection checks the health of your system, while pumping removes buildup. Most septic tanks should be pumped every 3 to 5 years, depending on household size and usage. An inspection helps determine the right timing.

The Bottom Line

• Conventional systems: inspect every 3 years
• Alternative systems: inspect annually
• Selling your home: inspection recommended or required
• Warning signs present: inspect immediately

Need a Septic Inspection in Washington State?

Staying on schedule helps protect your home, your investment, and the environment. Contact LaVergne Plumbing & Heating to schedule your inspection today.

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