Not Familiar With How a Septic System Works?

 Wondering what you should do when you purchase a home that is not connected to public sewer?

If you are working with REALTOR, he/she should be aware of the laws regarding septic tank disclosures and make sure your offer/contract addresses the septic system.

Purchasing a Home With a Septic Tank

In the Tennessee area, septic systems are based on number of bedrooms, not bathrooms.  The tank holds the solid waste and the liquids drain from the tank out into the field lines(filled with gravel and also underground) The number of field lines determines the number of bedrooms that the system can handle. One field line per bedroom.  The bedroom measurement is used rather than bathrooms as it is a measure of how many people can typically live in the house and thereby create waste via bathrooms, laundry, dishwasher, sinks, etc. Septic tanks are usually 1000 gallons in size.  You should ask to see the Septic Permit which will include a drawing of the septic system on the property and location of the field lines and the duplicate area(in case the first system should ever fail).  It is important to know the location as you may NOT build on top of, or too close to this septic system.  That would include pools, garages, barns or any other outdoor structure you are thinking of building in the future.  Also, you should not drive any heavy equipment on top of those lines while doing any type of construction as it can crush those lines and create septic issues in the future.  Again, it is important to know exactly where your septic system is.  

 When a septic system is first installed, there was a ground percolation test done to determine the absorption rate of the soil. Some homes are restricted to lesser bedrooms because of it, but most of the time, it is purely the number of bedrooms designed into the blueprints of the home.  More field lines means more construction costs, so many builders or homeowners will only install what they need at that time.  It is in later years, that a homeowner builds on, or finishes out an additional bedroom that this becomes an issue in regards to advertising a home for sale. 

Every Day Usage

For ever day usage, It is usually not a problem to use a room or a loft space as a 3rd or 4th bedroom for instance, as these systems can normally handle the waste within reason. It is a matter of advertising.  So, a 2 bedroom system cannot be advertised for sale as a 3 bedroom home. When purchasing your new home, your REALTOR will request the seller and seller's agent to produce the Tennessee Subsurface Sewage Disposal System Permit Disclosure.  This document will state how many bedrooms the original septic system was designed for and the permit should be attached.  There are cases in older homes where the septic records can not be found at the County Environmental office.  In this case, the number of bedrooms approved is unknown and can be advertised accordingly.

Another thing to watch for is an older home that is still on septic but paying for city sewer.  This happens when a municipality installs sewer lines on the street where the homes are already built and using septic systems.  The homeowner is not always required to hook up to the sewer line but that city municipality may charge them for sewer anyway.  Do not assume that because the listing says sewer, that it actually has been connected, especially on older homes.  This is where the due diligence aspect comes in to play.  Make sure you do your homework.

Septic Tank Inspection

During your home inspection time period, you should also consider an inspection of the septic system.  This can be done by a septic company.  To inspect the tank, the inspector will dig with a shovel to locate the access lid, which will be slightly underground   Then, open the hatch, empty tank into disposal truck if necessary and inspect the system.  These tanks are usually not too far underground for this very reason.  Septic tanks also require clean outs in the 3-5 year range depending on usage. You can also request a dye inspection to ensure the field lines are working properly.

Finally, don't be scared of the septic system.  These systems last for a long time when treated correctly.  Being kind to your system by not putting food, grease, or non-biodegradable paper down the drain will make for a long lasting system.  When purchasing an existing home with a septic, it is important to have the seller pump the tank or provide proof that it has been done recently. 

Additionally, you as a buyer may pay a fee to the Tennessee Department of Environment and Conservation, Division of Ground Water Protection, for a septic inspection letter.  This means that an onsite inspection will be done of the system but does not mean that they open up the tank.  The purpose is to evaluate the system at ground level and to make sure there is no standing water or sewage visible and that there are no obstructions or buildings that could compromise the system.  This Department also requires at least several weeks notice, to do this inspection, so make sure you allow enough time within your contract to accomplish this.  This inspection is not required to be done, and is strictly up to the buyer. If you should decide to have this additional inspection, please ask your REALTOR for assistance in getting it scheduled.  

Another good idea is to add a sewage rider to your homeowner's insurance policy.  It is a very inexpensive yearly cost, usually less than $50.  This will take care of any damage in your home caused by a sewer backup.  In fact, I recommend this for everyone, not just septic owners.

Tennessee Consumer Protection Act Regarding Septic Systems

For additional information on Subsurface Sewage Disposal Systems(septic) laws in the State of Tennessee, please see the Tennessee Consumer Protection Act, section 41, updated 2018, regarding septic systems, septic permits, advertising homes for sale with septic systems, etc.

Feel free to contact me for any additional questions or help in purchasing or selling your home or farm.

If you do not yet have a Realtor, please view my award winning post on Best Reason to Use a Realtor and give me a call to discuss your real estate needs.


kim blanton 20 years in real estate

Posted by Kim Blanton on


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I like that you said that you can have the septic system of the house that you're buying inspected during a home inspection to make sure that it's in good condition. My husband and I are planning to buy a house that has a septic system installed in it. We don't want to end up spending more for a house that has a septic system that needs to be repaired, so we'll do all your tips.

Posted by Sharon W Smith on Wednesday, November 21st, 2018 at 6:04pm

Purchasing a home that already has a septic system is great deal. Having a maintenance on your septic is a great plus.

Posted by Sally Bower on Tuesday, April 2nd, 2019 at 3:16pm

Thank you so much for this information, it will helps me a lot.

Keep it up.

Posted by Mike Saga on Tuesday, May 5th, 2020 at 1:37am

I want to get my first house before the end of this year. Thanks for explaining that I will want to consider not being scared of getting a house with a septic system. That is good for me to get an expert to test the system of the house I want to purchase.

Posted by penelope smith on Monday, October 26th, 2020 at 11:44pm

I like how you mentioned finding out how many bedrooms the septic system was designed for. My wife and I are looking for a house and I might want to look for one that has a septic system. Seems like a smart idea to find the right documentation for the original septic system for houses.

Posted by Taylor Hansen on Thursday, January 21st, 2021 at 1:03pm

Thanks for sharing this article. I love it.

Posted by Mortgage Broker Australia on Sunday, October 2nd, 2022 at 9:38pm

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