Swan Island Dahlia Farm at Dahlia Festival

Septic Smart Information

Home Owners

Follow these important guidelines:

Know where all of your septic system components are located. This is a crucial first step in proper septic system maintenance. Schedule an “Existing System Evaluation” with a certified Onsite Wastewater Inspector if you do not know where the septic tank, distribution lines, and drainfield are located. Visit the Department of Oregon website for a list of Certified Onsite Wastewater Inspectors.

Check for sludge and scum levels in your septic tank. When the bottom of the scum layer is within 6 inches of the bottom of the outlet tee, or the top of the sludge layer is within 12 inches of the bottom of the outlet tee, your tank needs to be pumped. You can measure this yourself, or you can hire a certified Onsite Wastewater Inspector to check it for you. Have regular septic system inspections completed by a certified Onsite Wastewater Inspector.

Typical gravity-fed systems should be inspected at least every three years. Alternative treatment technology systems (ATTs) and sand filter systems should be inspected every year**.

**Owners of ATT and sand filter systems, installed after Jan. 1, 2014, must maintain a Service Contract with a certified maintenance provider. The maintenance provider must inspect the system at least once every year and submit a report and required fees to the DEQ.

Home Buyers

Ask these questions before you buy:

  • Is the system currently working? — The best way to find out is to have a certified Onsite Maintenance Provider do an Existing System Evaluation. Visit the Department of Oregon website for a list of Certified Onsite Wastewater Inspectors.
  • Are there maintenance, pumping, or repair records? — Checking maintenance records will help you to identify if potentially costly repairs may be needed.
  • If the existing system fails, how will you repair it and what will it cost? — Repairs or replacement can be expensive. Plan ahead for system expenses!
  • Where is the existing system located? — Planting, building, or driving on the drainfield will ruin the system! There should also be a reserve area for a replacement system. Do not build or pave over the reserve area either!
  • Is there a septic system permit on file with the DEQ or local County agency? — If no permit is on file, the system may have been installed without a permit or be very old. You could be held responsible if the system fails or causes a public health risk.
  • Will the existing system support any changes to the home? — You may need a larger system if you make additions to the home. Ask before you build!
Septic System
  1. Septic Tank — The septic tank is a watertight container buried in the ground. It is designed to collect all of the sewage that comes from your home. For example, every time you flush a toilet, or do a load of laundry, you are sending sewage to your septic tank. When sewage enters the septic tank, the solids sink to the bottom of the tank (sludge) and oils float to the top of the tank (scum). All of the liquid between the sludge and scum layers is called wastewater. Once the tank is full, wastewater flows from the septic tank to the drainfield.
  2. Drainfield — The drainfield, also called leach field, typically consists of a series of trenches that sit below the ground. These trenches are filled with a porous material and covered with soil. Wastewater from the septic tank flows into the trenches. Microbes then purify the wastewater, as it moves down through the soil profile below the trenches.

Microbes are responsible for treating your waste!

The microbes are doing their job, but what can you do to keep your system working properly? Follow these guidelines for Operation and Maintenance of your septic system.

  1. Operation — The first step in keeping your septic system working is to make sure that you and your family are using it properly. Of course, never flush materials that are hard to decompose down your drains. For example, cigarette butts, hair, and food scraps are not septic friendly!
  2. Maintenance — Your septic system will need periodic maintenance even when you and a healthy microbial population are doing the job properly. Having periodic septic system inspections can help to save you thousands of dollars in expensive repairs or even system replacement!

Visit the Department of Oregon website and the Environmental Protection Agency website to learn more about being septic smart.

Why You Should Care About Your Septic System
  • Protect Your Investment — It is typically much cheaper to properly maintain a working septic system than it is to repair or replace a failing septic system.
  • Protect Community Health — Septic system owners, their neighbors, and the surrounding community run the risk of coming into contact with harmful bacterial and viral pathogens when septic systems are not properly maintained.
  • Protect Drinking Water — Septic systems that are not working properly can contaminate groundwater sources. More than 70% of all Oregonians are at least partially dependent on groundwater for their drinking water supplies!
  • Protect Environment — Septic systems that are not working properly can contaminate surface waters, which disrupts natural systems and impairs aquatic and riparian life.
Septic System Do’s & Dont’s
  • Do conserve water
  • Do substitute for bleach and ammonia cleaners
  • Do plant grass on drainfield
  • Do know the location of all system components
  • Do perform periodic septic system maintenance and inspections
  • Don't overload system
  • Don't flush medicines and hazardous materials down drain
  • Don't plant deep-rooted plants near tank or drainfield
  • Don't park, drive on, or allow animals access to drainfield
  • Don't wait until there is a problem before inspecting your septic system

Don’t Flush Household Hazardous Waste! Visit the Household Hazardous Waste website for the drop-off location nearest to you! Or call (800) 732-9253.