How Big Is A Septic Tank?

How Big Is A Septic Tank?

If you’re new to homeownership, you may be new to the idea of the septic tank.  Tucked away underground, this wastewater management system is often overlooked or forgotten about despite its essential service.  Septic tanks are a necessary feature of any home that’s built outside the boundaries of an urban sewage system.  If you’re considering installing a septic tank, or have bought a home with one already installed, your first question might be “How big is a septic tank?”

The Size and Length of Ground Septic Tanks

Unfortunately, the answer isn’t that straightforward.  Generally, septic tanks vary in size depending on several factors.  The biggest factor is the expected wastewater output of the household; a home with more bedrooms would therefore have a larger septic tank to accommodate the residents of those rooms.  Additional factors such as local regulations and environmental conditions play a part in deciding the size of a septic tank system.  Some locales have specific laws regarding the size of septic tanks.  Here in Washington state, all septic tanks are required to be at least 900 gallons in capacity.  In April of 2025, the law will be changed to require a full 1,000 gallon tank for all homes with up to four bedrooms; homes with more than four bedrooms must have an additional 250 gallons per extra bedroom.  Most homes, even outside of Washington state, have septic tanks of between 1,000 and 2,000-gallon capacities.

Given these volume capacity needs, one can imagine that such tanks are quite large.  Depending on the model and capacity, they range in size somewhat.  Most septic tank sizes are largest by length, though your specific septic tank size may be different depending on the model and year of installation.  A common thousand-gallon model lists dimensions of around 100 inches in length (8.3ft), 60 inches wide (5ft), and 60 inches high (5ft).  Models with greater volume capacities are usually longer, making them approximately the size of a sedan or compact car.

Home Septic Tank and Septic System Maintenance

If your home has a septic tank, it’s important to remember that these tanks are not entirely self-regulating.  While the tanks do process and eliminate some of the waste volume over time, the amount of waste added often outpaces the rate of waste processing and decomposition. For this reason, it is important to get your septic tank pumped regularly.  The general recommendation is to have the system emptied every three to five years; if a septic tank is not emptied regularly, it may overflow, causing sewage to back up into household drains.  Ground septic systems are designed to release filtered waste water into a drainage field (your yard) for natural processing in the soil; if the tank overflows, the drainage field may flood with sewage.  For obvious reasons, it’s important to avoid this outcome, so be sure to track the service history of your residential septic system.

If your home has a septic tank that may be due for an emptying, contact our team at Upfront Septic to schedule services.  Don’t wait until there’s sewage flooding in your house.. Get your septic tank pumped!  Our professional team will handle all the dirty work so you can be assured that our services have everything taken care of.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top