Skip to content

Septic service in Seattle, WA

Homes in Seattle that are not on city sewer depend on a septic tank and drain field that need regular care. Whether you need routine pumping, a repair, an inspection for a home sale or a new system, a local septic company that works in Seattle and across King County can help.

Seattle has about 755,078 residents across 84.0 square miles. The same crews typically serve Medina, Clyde Hill, Yarrow Point and other nearby communities.

Get septic help in Seattle, WA

By submitting this request you agree that SepticTank.com and the local septic company it matches you with may contact you by phone, text or email about your request. Message frequency varies. Message and data rates may apply. Reply STOP to opt out, HELP for help.

Septic basics for Seattle homeowners

Most septic trouble starts with a tank that went too long between pumpings or a drain field that gets more water than it can absorb. A regular pumping schedule, a working outlet filter and a few household habits prevent most of it. Only toilet paper should be flushed. Fix running toilets and leaky faucets quickly, since a steady trickle adds up to a lot of water in the drain field.

Signs your system needs attention

Septic problems tend to show up gradually. Listen for gurgling pipes, watch for slow drains in more than one fixture, and check the yard for standing water or a sewer smell after heavy water use. If an alarm sounds on a pump or aerobic system, cut back on water and call for service rather than silencing it and waiting.

Questions Seattle homeowners should ask first

Before hiring in Seattle, ask three things. Are you licensed and insured for septic work in King County? Will you inspect the baffles and filter when you pump? Can you show me what you found? Clear answers tell you more than a low quote does.

New construction and septic in Seattle

Building on a lot without sewer near Seattle starts with a soil evaluation and a permit from King County. The soil test decides what kind of system the lot can support and how large the drain field must be. Some lots need a mound or another engineered system. Get this done before finalizing house plans.

Local conditions in Seattle

Among the mapped soils within about two miles of central Seattle, the USDA soil survey rates 100% as very limited for septic absorption fields, 0% as somewhat limited and 0% as not limited. The most common drainage class is moderately well drained. Soils like these often call for careful system design, such as a larger drain field, a mound or another engineered system, and a site evaluation before any new installation or replacement.

Seattle averages about 48 inches of precipitation a year, and November is usually the wettest month. December is the coldest month at about 39°F on average, so freezing is rarely the main concern here. Heavy rain and saturated ground are the bigger factors for drain fields.

Sources: USDA NRCS Soil Survey (SSURGO), Soil Data Access; NASA POWER long-term climatology. Soil ratings describe mapped soil types near the city center and do not replace a site evaluation of your property.

Septic services in Seattle

Common septic questions in Seattle

How often should a septic tank in Seattle be pumped?
Most households pump every three to five years. Tank size, the number of people in the home and whether you use a garbage disposal all change that. A local company can check your tank and set a schedule.
Who handles septic permits for Seattle?
Septic permits and inspection rules are usually set at the county or state level. Check with the King County health department or permitting office, or ask the septic company to pull permits for you.
What are signs of septic trouble?
Slow drains in several fixtures, gurgling pipes, sewage odors, wet or unusually green grass over the drain field, and backups in the lowest drains are the common warning signs.
Does SepticTank.com do the work?
No. SepticTank.com connects you with an independent local septic company that serves Seattle and nearby communities.

Own a septic company in Seattle? This city is available to one company. Every request from this page goes to you.

See availability