I need a perc test! — 42 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.

      • I have a customer that lives on a 3.5 acre lot and has a home currently on the property. They want to sell to a developer, but would this be feasable with no more land than 3.5 acres that already has a house on it.

        • There are too many factors to be able to accurately answer that question. Depending on the zoning and the availability of public water and sewer, one might be able to put as many as 12 houses on that land or maybe only the one. Again, too many variables to know.

  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?

  9. I bought 3.7 acres in Houston County, TN and there are multiple perc sites that were done. Do you know where I can find the information regarding the results of these percs?

    • If they were filed, they would be with the County Environmental Health Department. If they weren’t filed, they will either be with the person that ordered them or with the soil scientist/surveyor/engineer/architect that performed them. If it is the latter, I have no idea how to sort that out, sorry.

  10. So I have an interesting situation. We bought our home in Davidson county and discovered during the septic inspection that the original perc test was done in 1991 and restricted the home to a two bedroom max. Yet, a three bedroom home was built. And eventually, the basement was finished out with another bedroom and bathroom added. Fast forward to today and we are updating our septic tanks and wondering if we should get a perc test done and find out if the land with our leech field has changed over the years. Could a new perc test support the additional bedrooms after so many years have passed? I’m not sure what the original owners were thinking.

    • Honestly, this is definitely a question for your local health department. If your system isn’t failing, they shouln’d be too up in arms about it. You may need to have your land remapped by a soil scientist to find a suitable area to expand the field lines. The Environmental Health Department for your county is about your only option (short of a civil engineer and lots of money).

  11. It is my understanding that if a soils scientist has said that on 4 acres of land he was able to locate only one two bedroom site that another area would also be needed to act as an alternative or secondary area before a person could build a home on that property.

    • Yes, that is basically true. However, it isn’t necessarily that only a 1-bedroom can go on that 4 acres, just that the area that was mapped would only support that. There are lots of reasons that the entire lot may not have been perced. You would need to clarify with that soil scientist (or check the soil map). Worse case scenario, you can contract with a civil engineer and see if an alternate system would be feasible (both physically and economically).

    • As I recall, a perc test is “permanent,” at least in Tennessee. Here, a perc test represents a 50′ square (2500 ft²) (see here). This means, in theory, that the area represented by a failed perc test is no longer usable for subsurface disposal. I would like to think that if an effective persuasive argument was provided, that a new perc test might be allowed.

  12. My situation is that my wife has taken care of her grandparents for the last 10 yrs and we all moved to TN. Her grandparents bought a home on 11 acres in Wilson county Lebanon TN and planned on us getting half the land and putting a home there so my wife can continue to take care of them. The problem is that we had a perc test done and the gentleman said that it cannot perc for it is suppose to be 2ft soil and only has 1 ft of soil. My question is is there any other way or anything else that can be done to get a house out there? Thank you.

    • If your soil scientist has stated that there is not adequate soil on 11 acres for 2 houses, then your next recourse would be to contact a civil engineer and discuss alternate sewage disposal options. There are several options, like recirculating sand filtration systems, constructed wetlands, and others. All of them will need to be designed by a licensed engineer and approved by the Department of Environmental Health.

  13. I live in Wilson county,is there a limit to how far away I can build my house from the perc site of my property if I still plan to put my septic system on the perc location?

    • I don’t know that I have ever had this issue. As far as I know, you can pump your effluent as far as you want. We have worked with on-site sewer systems that were essentially communal drain fields. They collected the effluent from all of a subdivision and use a central drain field. The issue you may run into is pipe and pump sizing. Too small or large of pipe or an undersized/oversized pump can cause other issues. For this, you may want to talk to an engineer or an expert at a plumbing supply store. Most manufacturers can size your pump and pipe for you, given the correct information (rise/fall, run, usage, etc).

    • To my best recollection, a perc test is “permanent.” Essentially, if the land has not been modified since the test, then the passing results stand. The same goes for failing. Submitting a failing perc test to the health department makes a 50-foot square, centered on the hole, non-usable for sub-surface disposal. You cannot retest a failing hole. However, you can move over a few feet, dig a new hole, and test that hole. Also, if you are in a dry season, you are more likely to get desired results versus a wet, saturated season.

      To answer your question, if you have not submitted the holes to the Environmental Health Department, try all you want. If you have, you basically have to abandon that square and try another area.

  14. My house was built in 2004, it used to be farm land, I’m having issues with my septic tank, the next door neighbors land is slopped towards my property and the water run off is flooding my yard. the soil is red clay and i do not believe it is perking properly. I purchased the property 2 years ago and have had this issue since, but it was not disclosed that there was septic issues in the sale, is there any way that the builders could have slipped by or not done the correct perk test for the type of soil I have? If so what type of actions can I take to resolve this issue seeing as it is preexisting from the builder/previous owner.

    • “is there any way that the builders could have slipped by or not done the correct perk test for the type of soil I have?” Absolutely they could have slipped by. Was that the case? Who knows or would ever know. However, the builder cannot do the perc test. It has to be done by a soil scientist or surveyor. They may not have installed the system properly, but they are usually inspected by the health department. It is possible that they didn’t install enough line for your size house (it happened on mine). It is also likely that runoff from the neighbor is infiltrating your drain field and saturating it.

      Talk to the local environmental health department and find out what they recommend. One thing you can do is install something (an interceptor ditch or berm) to prevent the runoff from getting to the drain field. This may alleviate the problem. In the end, it will come to the health department to make a determination.

      As for lack of disclosure, that is a legal issue and you would need to speak to an attorney on that matter.

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