Caring for your Septic System

Most homes in rural areas are serviced by a septic system rather than sewer. Septic systems are small, on-site wastewater treatment systems. They have an indefinite lifespan if they are properly maintained and cared for, and they don't require extensive up-keep. Maintaining your septic system is an ongoing process, like changing the oil in your car's engine. This prevents problems from occurring at a very inconvenient moment, such as when you have a house full of company! We have all heard stories about septic tank systems that have worked well for many years without any maintenance or care. Unfortunately, these are the exception (or more likely, the problems haven't surfaced yet!). Most septic tank systems require proper care if they are to work well for a long time. Unless you have a large family, an abnormally high water usage, or use a garbage disposal, pumping every three years should be adequate.


How Your Septic System Works

Septic tanks range in size from 750 to 1500 gallons for most homes. All of the drains in the house including the sinks, showers, toilets and laundry lead to the septic tank. From here, the liquid effluent exits the tank and flows to the drainfield (or is pumped to the drainfield via a pump tank). The most common drainfield consists of a series of trenches containing perforated pipe surrounded by gravel, and covered with dirt. The effluent entering the drainfield is absorbed and treated by the soil.

It is normal for a septic tank to maintain a liquid level of 6-8" from the top of the tank, even if it was recently pumped. When waste enters the tank, some will float to the top, forming a scum layer. Paper products and lighter substances remain here until bacteria decomposes them. The liquid effluent remains in the center portion of the tank. The material that the bacteria decomposes eventually sinks to the bottom of the tank, forming a sludge layer. It is ideal to pump out the sludge before it can reach the drainfield where expensive damage can occur.


Dos and Don'ts

Proper care includes:

  • Knowing where your tank(s) and drainfield are located
  • Pumping your septic tank every three to five years
  • Practicing water conservation
  • Diverting runoff away from your drainfield
  • Not constructing anything over your drainfield
  • Not parking or driving cars over your drainfield
  • Being careful what you flush into your septic tank
  • Inspecting your system every year
  • Don't put additives into your septic system
  • Use all cleaning products sparingly (especially bleach)
  • Repair leaking faucets and toilets quickly

The naturally occurring micro-organisms that grow in your system generate their own enzymes that are sufficient for breaking down and digesting nutrients in the wastewater.

Commercial septic tank additives do not eliminate the need for periodic pumping and may actually be harmful. Regular and proper maintenance is all that is needed to prolong the life of a system.

Everything that goes down any drain in the house ends up in the septic tank. Therefore, it is vital that you flush only biodegradable materials down your toilet. The only paper product that should be flushed down the toilet is toilet paper! Even if a non-toilet paper product states that it is safe for septic, it should not be flushed. Collect cooking oils, fats, and grease in a container and dispose of it with your trash. Compost food scraps, or dispose with your trash. Food byproducts accelerate the need for septic pumping and increase maintenance.

Use your washing machine in moderation; one load per day is better than four or five loads in one day, as this puts a strain on the drainfield. If replacing the washer, consider a front-loading machine (they use less than half the water).

The roots of trees and shrubbery are a common source of trouble. They may enter the lines and cause extensive (and expensive) damage.

Don't flush dangerous and damaging substances into your septic system:

  • Flammable or toxic products
  • Pesticides
  • Paint or paint thinner
  • Excessive amounts of bath or body oils
  • Cigarette butts
  • Feminine products
  • Condoms
  • Cooking grease
  • Medicines

The important operation and maintenance steps itemized above can significantly extend the life of your septic tank system. These steps are not difficult. If you do them regularly, you can avoid the expense and inconvenience of repairing a system that has broken down prematurely.


Common Signs of Septic System Trouble

  • Effluent surfacing from the ground, or soft spots in the drainfield
  • Slow flushing toilets, or sewage backup in the house
  • Septic odors inside the house
  • Sewage flowing back into the shower or bathtub drains
  • Bubbling sounds coming from the toilet

Note: some of these warnings are also signs of a blockage in the line.



Serving the septic pumping needs of Bellevue, Issaquah, Kirkland, Newcastle, Mercer Island, Redmond, Sammamish, Bothell, Woodinville, Duvall, Carnation, Fall City, North Bend, Snoqualmie, and the greater eastside for almost 40 years.