Does every house have a septic tank?

Having a way to deal with wastewater is a pretty fundamental requirement for any home buyer. As such, you may be wondering if all houses have septic tanks to manage waste. In truth, only about one quarter of homes in the U.S. have septic tanks, according to the US Census Bureau. 

Septic tanks are most common in New England, where about half of homes are on septic, and least common in California, where just 10% of homes are on septic. The primary alternative to septic is connection to public sewer lines.

What is a septic tank?

A septic tank is a watertight container that collects and treats wastewater received from your home. Most septic tanks are installed underground, at a minimum of five feet away from the house, with a drain field located even further away.

Tanks are made from concrete, fiberglass, or polyethylene and are designed to hold wastewater for up to three days. It works by separating wastewater into three layers: solids that sink to the bottom, sludge that floats to the top, and water in the middle. Water is discharged into the drain field to be treated naturally by the soil, creating an organic way to break down waste.

What’s the difference between sewer and septic?

The most common alternative to septic tanks are public sewer systems, which connect to your home’s plumbing to carry wastewater away. Then, it’s treated at a facility and clean water is put back into the water cycle.

Public sewer systems are often more convenient than septic tanks because you don’t have to deal with the maintenance of a tank. They’re also usually more expensive to install if your house wasn’t already connected to a public system.

In many areas where houses are close to one another, septic systems aren’t allowed, making public sewer your only option.

How do you know if a house has a septic tank?

It’s very unlikely that someone would sell you a house without disclosing that it has a septic tank. That information would be included on the MLS listing and among the basic information shared with you by an agent, if you’re working with one. But if you’ve moved into a new house and realize you still don’t know if your house has a septic tank, here are some ways you can find out.

Get a property inspection

The easiest way to figure out if your home has a septic tank is to hire a home inspector. They’ll have both the knowledge of the area to understand if septic tanks are common, and the physical know-how to identify where it’s located.

Check the property records

Your property records on file with the municipal government are filled with valuable information about your home. These will dictate how wastewater is treated on your property and will likely show you exactly where you can find the septic tank, if it exists.

Look for the lid

If your septic tank is above ground, it will be pretty easy to find. But one underground also has a pretty obvious tell: It has a lid. Take a walk in the backyard and look for a concrete or plastic lid that is flush with the ground. If the backyard is overgrown, you could go out with a metal detector or magnet as there’s a chance the lid has a metal handle.

Another good clue is new grass growth. Since septic tanks tend to actively fertilize the ground, greener grass is a good indicator that the drain field lies below and the tank itself is nearby.

Consider your home’s features

There are a few factors that make a home more likely to have a septic tank. Older homes in rural areas are more likely to have a septic tank than newer ones in suburban areas. But some homes in suburban areas may still be hooked to a septic tank even if there’s a public sewer system in place.

Another good indicator is your type of home. If you live in an apartment, condo, or other multi-family home, it’s very likely that you’re connected to the public sewer. Most septic tanks aren’t equipped to handle the waste for multiple housing units.

4 things to know before buying a house with a septic tank

A septic tank isn’t as low maintenance as a connection to the public sewer system. As such, there are a few things you’ll need to keep in mind.

Learn the local laws

Different areas have different regulations around septic systems. Some state and local health departments require a septic tank inspection before transferring the title, which can hold up a home sale. Different municipalities may have specific regulations around inspection, maintenance, and replacement. It’s your responsibility to know how to stay compliant.

Regular inspections and maintenance

Public sewer connections should be inspected from time to time, too, but septic tanks need more regular inspection and maintenance. You should get a septic tank inspection every three years to check for pipe integrity, proper ventilation, and proper drainage.

More importantly, if you’re buying a house with a septic tank, ask to see its inspection history. These reports will show any previous system issues, from leaks or clogs to tree roots blocking pipes.

In addition to the inspection schedule, you also need to have the sludge pumped out of the septic tank and disposed of every few years. Depending on the size of the tank, this could cost $300 to $600 each time.

More caution about what goes down the drain

You may have seen a sign above a toilet that says something to the effect of “flush toilet paper ONLY.” Sometimes that’s due to old pipes connecting to the public sewer, but usually it’s because if you put something down the drain that doesn’t belong in your septic system, it’s not leaving your property.

Grease and oil, hair, dental floss, hygienic products, paint, paper towels — all the things that people put down the toilet from time to time — can cause significant damage to a sewage system. They can cause clogs and prevent drainage, which may put undue stress on the septic tank or force sewage to flow back into your home. Toilet paper and flushable wipes are designed to break down in the system; other items are not.

When septic tanks burst or have significant problems, it can be a real disaster for homeowners. Leaks or ruptured pipes can flood the drain field and turn your backyard into a sewage-sopping mess that will be extremely expensive (not to mention smelly and disgusting) to clean up.

Learn your system

Finally, if you’re buying a house with a septic tank, make sure you familiarize yourself with the system. Knowing the specs of the septic tank, like the size and age, will help you know how frequently it needs to be drained and how soon it may need replacing. (Septic tanks typically last 20 to 40 years.)

Knowing your system will also help you detect a potential problem before it becomes a real one. Unusual odors, strange plumbing sounds, slow drainage, and backflow are all clear indicators that something’s not right with your septic tank.

Pros and cons of septic tanks

We know that not all houses have septic tanks, but if you have one or are thinking about buying a house with a septic tank, let’s cover the pros and cons.

Pros

• Septic tanks can save you money in the long run since you’re not paying sewer costs to the city or property taxes for public sewer maintenance.
• Properly maintained septic tanks are more environmentally friendly and can improve the quality of groundwater in your area.
• Septic tanks can last for up to 40 years before being replaced, about twice as long as the typical lifespan of a pipe connecting to a public sewer.
• Can be more reliable than public sewer systems since they don’t require electricity to function.

Cons

• Septic tank maintenance requires greater attention and responsibility since it’s on your property and it’s up to you to schedule inspections and maintenance.
• Poorly maintained septic systems can contaminate groundwater, which is a bigger problem if you’re using well water on the same property.
• A burst septic tank can cause an enormous, costly mess.
• Eventually, a septic tank must be replaced on your own dime.
• You’ll have to be very careful about what you put down the drain.