How Septic Systems Work: A Complete Guide

How septic systems work

Do you ever wonder where the waste goes after you flush your toilet? If you’re not hooked up to a government-maintained sewer, chances are you have a septic system. You can thank a buried tank and drainfield in your backyard for making daily tasks like dishes, laundry, and using the toilet possible.

Understanding how your septic system works is crucial to avoiding waste management mishaps, and follow proper care. Here’s what you need to know.

How a septic tank works

Your septic tank is a large container made of concrete, polyethylene, or fiberglass. This is where all the wastewater from your plumbing fixtures drain. Heavy solids settle in the bottom, where bacteria turn them into sludge and gases, while lighter solids like grease and fats rise to the top.

septic tank

Some septic tanks have a single compartment, while others have two compartments. Dual compartment septic tanks are better at settling solids than single compartment septic tanks. The second compartment provides an additional treatment area to help break down the waste, leaving a lower chance of sewage spilling into the drainfield before it has fully decomposed.

Most septic systems constructed before 1975 in the Puget Sound region have single compartment tanks. Septic systems that were built after 1975 tend to have double compartment tanks.

How a septic system drainfield works

The drainfield in your septic system is a covered area for absorbing partially treated wastewater, usually beneath the ground in your yard. This is where liquid from the septic tank flows for final treatment.

Organisms in the soil of your drainfield treat the wastewater, naturally removing harmful bacteria and viruses. Once the wastewater is safely filtered, the soil disperses the wastewater into groundwater.

Drainfields are usually quite shallow, which is why you shouldn’t plant anything other than grass and shallow-rooted plants over a drainfield.

garden having a septic system malfunction

Preventing and repairing a septic system malfunction

You should never flush toxic materials, detergents, grease, or other difficult-to-treat substances down your drain. An overloaded drainfield can flood, and no one wants to deal with toilet backups or sewage rising to the ground.

If you have a septic system, make sure to avoid putting extra pressure on the ground covering the drainfield and septic tank. That means you shouldn’t have driveways, patios, decks, storage sheds, sports courts, landscaping plastic, or even grazing animals over your drainfield.

We suggest covering drainfields with grass or other shallow-rooted plants. Consider planting a wildflower garden to keep your yard beautiful without risking a septic system malfunction. As a bonus, wildflowers are easy to regrow if you ever need to dig up the drainage field.

In most cases, a septic tank is buried between 4 inches and 4 feet underground in the owner’s backyard. Septic service professionals usually do minor repairs with video cameras and other specialized tools to avoid damaging the owner’s yard.

Worker pumping out a home septic tank

If your septic tank needs replacement, it may impossible to avoid digging up your garden. This is just another reason why you should get regular inspections and maintenance done on your septic tank. You want to fix any problems before they become serious enough to require digging up your property!

How often does my septic tank need maintenance?

Your septic tank maintenance needs depends on the type of sewer system you have and the number of people using the system.

A family of 4 using a typical gravity-fed drain system without a garbage disposal should have their septic tank inspected every three years. If you have a larger family, a more complex septic system, or a garbage disposal, you should get your septic tank inspected annually. We’ve outlined additional factors that may influence the frequency of septic pumping on our blog.

Ace Acme will inspect your septic system using state-of-the-art equipment with minimal harm to the surrounding environment. If you need an inspection or a repair, we’ll save you time and money by doing it right the first time. As a family-owned and operated business serving Snohomish, Skagit, Island, and North King Counties, we care about our customers and their pets!