Portland / Vancouver Metro - The Dalles - Hermiston OR & Tri Cities WA


Gravity Fed Septic System in Portland OR and Vancouver WA and The DallesA gravity system is a traditional type of septic system used by many homeowners that uses natural forces rather than complicated technology.

What is a Gravity System?

A gravity system, also called a gravity fed system, is a conventional type of septic system. As its name implies, it uses gravity to send effluent out and into the soil instead of a pump. Gravity systems consist of three main components:

  • The septic tank
  • Drainfield
  • The soil beneath the drainfield

How Does a Gravity Fed System Work?
Water and sewage from plumbing fixtures and appliances like sinks and toilets are carried to the septic tank all by gravity and through a series of pipes.
The sewage and wastewater flow into the septic tank where they settle and separate into three layers: the scum layer, the effluent layer, and the sludge layer. (These layers are important as a traditional gravity fed system is built to only extract the middle, watery effluent layer.)
The effluent flows through an outlet into a distribution box or drop box where it is equally distributed to the drainfield pipes.
The drainfield to be treated by the soil. The scum and sludge layers are naturally treated by the good bacteria in the septic tank and should be pumped out regularly by a septic system technician when necessary.

Advantages of a Gravity Septic System

  • Gravity fed septic systems are affordable.
  • Since they rely on gravity and not technology, they are easy to service.

Disadvantages of a Gravity Septic System

  • Gravity fed septic systems require a good slope so that effluent will flow naturally without the use of a pump.
  • At least 3 feet of sufficient soil beneath the drainfield is required.
  • Earthquakes and vehicles can cause the soil in the drainfield to shift, affecting the wastewater flow.

If you’re interested in a gravity system for your property, Speedy Septic can help! Our highly-skilled technicians will inspect your property and determine if it is sufficient for a gravity system then install it for you. We are licensed, bonded, and insured, so contact Speedy Septic today!

Back to Types of Septic Systems

Gravity System in Portland OR and Vancouver WA

Also Serving Customers In These Regions

Portland Vancouver Metro
Portland OR | Gresham OR | Troutdale OR | Sandy OR | Cascade Locks OR | Clackamas OR | Happy Valley OR | Oregon City OR | Canby OR | Molalla OR | Beaverton OR | Hillsboro OR | St Helens OR | Scappoose OR
The Dalles
The Dalles OR | Hood River OR | White Salmon WA | Bingen WA | Parkdale OR | Mosier OR | Biggs Junction OR | Dufur OR
Mid-Columbia
Hermiston OR | Arlington OR | Boardman OR | Umatilla OR | Irrigon OR | Pendleton OR | Tri-Cities WA | Kennewick WA | Richland WA | West Richland WA | Pasco WA