I need a perc test! — 24 Comments

    • I am not sure what you are asking, but if your property is not served by a public/private sewer system, then yes, you will need a septic system. You may or may not need a perc test, this will be determined by the local Environmental Health Department. Their decision will be based on soil conditions and proposed building size.

      Before you decide where you want the house, you need to talk with Environmental Health. I would hate to hear that your builder put the foundation in the only place a drainfield could go and thereby making the lot unbuildable.

    • Unfortunately, I no longer do perc tests. I recommend you contact a local soil scientist and speak with him or her to determine if you need to have a perc test done and what they charge. It is something that can vary widely so you may want to call around.

    • Perc tests are essentially forever. I do believe there may be an “expiration” date, but if so, it is a LONG time. Now, that implies that there have not been any alterations to the land since the map and perc test were done. Any topographic or planimetric changes, whether by God or man affect the results and therefore may require a new test. This is likely at the discretion of your local environmental health department.

    • It may be possible, but it will depend on if there is any un-mapped, usable land in your lot. If they mapped all of the land capable of sustaining a septic system, then I am afraid that the only way you can get it approved for more bedrooms is to gain more land, either fee-simple or via easement, or to have an engineer design you a system to accommodate your desire for a larger home.

    • I could, but it wouldn’t do any good unless you just happen to be in the counties I work in. Your best bet is to contact your local environmental health department and find out who works in the area.

  1. i have a little over 5 acres of land and want to split it with my brother he wants it to have a big garden does it have to perk to divide my land

    • In Tennessee, if you go below 5 acres for every parcel you are dealing with, it constitutes a subdivision. You must provide adequate sanitary sewer disposal for all parcels. It doesn’t matter that he doesn’t intend on building on it, someone may want to eventually and you would have created an unbuildable lot – and a potential lawsuit for doing just that.

  2. Hello, I inherited land with not house in Tehachapi California . I live abroad and cannot sell the land because it won’t pass the Perc test.
    How can I find a local person to prepare the land for perc testing for a reasonable fee?
    I have no way to travel to the States to do this. Can just anyone turn the land and prepare it for Perc or does it have to be a contractor or engineer which are very costly?
    Thank you in advance for helping me solve this great problem.

    • If I am understanding you, you have a tract of land that has failed perc testing? If that is the case, and you have exhausted all potential septic sites, then there is nothing a “normal” person can do. As far as I know, you cannot alter the land to make it more suitable for subsurface disposal and if you did, it would have to sit, untouched, for a very long time (7-20 years).

      The only solution I can tell you is to contact a local civil engineer and see if they have some options for alternative onsite sewer disposal systems. There are several options I have seen used here in Tennessee: artificial wetlands, low pressure pipes, enhanced filtration, etc. They are costly and they would need to be specifically designed for the site and the house that would be built. Perhaps a letter of “intent” and a quote might be enough for your Realtor to sell the land, at a reduced rate to other lands in the same area (that support conventional septic systems).

  3. Hi, Timothy,
    I’m buying a farm in Maury county, Tennessee and asked the seller to perform a perc test.
    The results are 75min per inch. What’s the next step if I want a perc permit? All I have is a sketch from the soil consultant.

  4. Hi, I have a piece of land in Rutherford County, a Readyville address, that has a site marked at 75 MPI on an expired septic permit dated 2005 (says it was good for 3 years). On the attached map, there is only one site on the property. Someone told me that you have to have a secondary backup site now to build a home. I’m wondering what the actual rule is on that. Thanks!

    • If the permit is expired, you will need to get a new one. This doesn’t mean new testing, only paying the appropriate fees and what not. Of course, this assumes there has been no change to the property.
      As for redundancy, yes. Typically, you are required to have enough land for both a primary system AND a secondary system in the event that the primary fails. You don’t have to build it, but the land must be there for it.
      A 2005 permit should have included any need for this redundancy. There are instances where this isn’t required, but they are few and far between.

  5. I own 87 acres in Maury County that has a 2-bed cabin (living in it) while we locate a site for a bigger home. A high-intensity soils test was done in 2008, and seller stipulated that site was permitted for two 5 bed homes. Something doesn’t match up. I have tried calling the soils scientist but no response. The document is a hand-drawn page with notes am [?] is “legal”. The one house site on it says 60mpi We are so confused as to where to go next and what has to be started over. Going to try to find the county environmental department, no listing on county website! We have a survey with full GPS coordinates and just recently had important corners flagged. Help!

    • If I am to understand you, you have a high-intensity soil map (hand drawn) from some soil scientist. He/she mapped out a site to support 2 5-bedroom structures (according to the seller).
      Your next step is to reach out the environmental health department that can be found at the Health Department (
      They should be able to make sense out of the soil map and guide you in your endeavor.

  6. We live in Rutherford County. We currently have a 3 Bedroom home, but would like to add 2 more bedrooms. We had someone come out and find another perk site for 2 more beds, but it is on the side of the house that we now want to put the addition. Part of the addition would be directly over a portion of the perk site. My husband keeps telling me that we can’t build on top of the perk site, but this does not make sense to me. Can you please tell me if this is true, and if so, what options do we have if we want to build in that spot? We live on 12 acres.

    • I hate to go against nature, but your husband is correct. You cannot build on top of a septic system. They work by both allowing the water to absorb into the ground and to wick through the ground cover on the surface. Even if the water all went down, building on top of a drain field would compress the ground too much to allow it to function properly. If it didn’t, the resulting soft ground would not be suitable for construction.

      I am going to go out on a limb here and assume that the person who decided where to map had no idea that was where you wanted to expand. I would assume they mapped the area that would cost you the least to expand your septic system into. If you are dead set on building your addition in that place, you will need to have someone come back out and identify a different area. It will likely cost for another trip. Someone should have made sure where the house addition was going before the map was made. Not sure who dropped the ball on that – I am NOT going to point fingers.

  7. We actually were originally going to build on the other side of the house, but changed plans after he came and found the perk site, so it’s not really his fault. Thank you so much for the info. It really helps!

  8. I bought a house in Wilson County on 12 acres. We wanted to build a new home on the lower section of our property and sale our current house. I found the soil map and was curious if TrC2 soil could possibly perc for a 3 BR house or would it be a waste of time and money, requiring multiple test sites?

Leave a Reply

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