Can I install a septic system myself?

Most areas require licensed designers or installers and inspections. Check with the Spokane County health department before planning any work yourself.

What is a mound system?

A mound system raises the drain field above the natural soil using sand and fill. It is used where the soil is too shallow, too wet or too slow draining for a conventional field.

Can a replacement system go in the same place?

Sometimes. It depends on the condition of the soil in the old field and local rules. Many replacements use a new area of the yard.

Is SepticTank.com the installer?

No. SepticTank.com connects you with an independent local septic company that serves Spokane. That company designs, installs and prices the system.

Septic System Installation in Spokane, WA

Whether you are building a new home in Spokane or replacing a system that has reached the end of its life, septic installation is a project that starts with the soil. The right system depends on your lot, your soil and the size of your household.

Request a call and a local septic company that installs systems in Spokane and Airway Heights, Millwood, Spokane Valley will explain the process from site evaluation to final inspection.

From soil test to final inspection

A soil evaluation decides almost everything else. It tells the designer what type of system and how large a field the lot needs. Once plans are approved, installation itself often takes a few days to a couple of weeks, depending on the system and the site.

Conventional and alternative systems

A conventional system is the simplest and usually the least expensive to maintain. Alternative systems add pumps, controls or treatment steps so they can work in difficult soil. Around Spokane, the soil on your specific lot is what decides which category you fall into.

Permits and approvals

New and replacement systems almost always need a permit. Expect a soil evaluation, a design that meets local code, plan review and at least one inspection during installation. the Spokane County health department or your state agency sets the requirements, and many installers handle the application for you.

Why installation prices vary

Installation price depends on the system type the soil allows, the size of the house, the distance from the house to the field, how easy the site is to reach with equipment, and design and permit fees. Engineered systems such as mounds and aerobic units cost more to build and maintain.

Caring for a new septic system

Keep a copy of the design and as-built drawing, schedule your first pumping as recommended, and keep vehicles and structures off the tank and field. Plant only grass over the dispersal area and direct roof and yard runoff away from it. Systems with pumps or treatment units need regular service to stay under warranty.

Questions for a septic installer

Ask who will do the soil test and design, whether they pull the permit, and which system types they recommend for your lot and why. Ask how long the project will take, what warranty they give, and whether the quote includes restoring the yard. Ask for references from recent jobs near Spokane.

Planning a timeline in Spokane

A realistic plan starts with the soil evaluation and design, then the permit review, then installation and inspection. Soil testing can depend on weather, and review times vary by county. Building the septic schedule into a home build or replacement plan early helps avoid delays, especially when the old system has already failed.

Mistakes to avoid on a Spokane installation

The most expensive mistakes happen before the digging starts. Skipping the soil evaluation, choosing a system on price alone, or placing the drain field where future driveways, pools or additions will go all lead to trouble later. Undersizing the tank for the number of bedrooms is another common one. Ask your Spokane installer to walk you through the site plan and explain why each part sits where it does.

Before the digging starts in Spokane

Installing a septic system in Spokane touches the whole yard, so plan access for the excavator and the tank delivery. Mark wells, water lines and property corners first. Ask the installer how they will restore the lawn afterward. A clear plan now avoids moving a driveway, a shed or a fence later.

What Spokane's soil means for a new system

The USDA soil survey rates most mapped soils near Spokane as very limited for septic absorption fields. New systems here often need a mound, pressure distribution or another engineered design, which your soil test will confirm. Spokane averages about 22 inches of precipitation a year, which your designer will factor into where the system goes. About 3 months below freezing mean pipes and components must sit deep enough or be insulated, and installation is usually easiest outside winter.

Local conditions in Spokane that affect septic installation

Among the mapped soils within about two miles of central Spokane, the USDA soil survey rates 99% as very limited for septic absorption fields, 1% as somewhat limited and 0% as not limited. The most common drainage class is 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.

Spokane averages about 22 inches of precipitation a year, and December is usually the wettest month. Average temperatures stay below freezing for about 3 months a year, with December averaging 27°F, so tank lids and shallow lines benefit from a layer of snow or mulch rather than being cleared bare.

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.

What the soil around Spokane means for septic installation

By drainage class, the USDA soil survey maps the land around Spokane as 63% well drained, 30% somewhat excessively drained, 6% poorly drained, 1% very poorly drained. Most of the soil here drains reasonably well, so a conventional trench field is often possible where the lot allows, but the soil test still decides.

Source: USDA NRCS Soil Survey (SSURGO), Soil Data Access

Septic companies near Spokane

These are the septic companies in our directory closest to Spokane, with straight-line distance. Call any of them directly, or send one request and we will pass it to the best match.

Spokane Septic Systems, Spokane, WA, 5.3 mi
Sunshine Septic Service, Spokane Valley, WA, 8.0 mi
Lilac City Septic, Spokane Valley, WA, 13.4 mi
Cheney Septic Service Inc, Cheney, WA, 13.5 mi
Elk Chattaroy Septic Service, Elk, WA, 22.7 mi
Bub's Septic Pumping, Deer Park, WA, 25.4 mi

Septic Installation in nearby towns

We also cover septic installation in these towns near Spokane:

Airway Heights, 6.9 mi
Millwood, 7.2 mi
Spokane Valley, 9.3 mi
Medical Lake, 13.6 mi
Cheney, 14 mi
Liberty Lake, 15.3 mi

About Spokane, WA

Spokane is in Spokane County, Washington. About 229,447 people live there, across 68.8 square miles of land (about 3,337 per square mile).

Septic Installation questions in Spokane

Can I install a septic system myself?: Most areas require licensed designers or installers and inspections. Check with the Spokane County health department before planning any work yourself.
What is a mound system?: A mound system raises the drain field above the natural soil using sand and fill. It is used where the soil is too shallow, too wet or too slow draining for a conventional field.
Can a replacement system go in the same place?: Sometimes. It depends on the condition of the soil in the old field and local rules. Many replacements use a new area of the yard.
Is SepticTank.com the installer?: No. SepticTank.com connects you with an independent local septic company that serves Spokane. That company designs, installs and prices the system.