Garden over septic drainfield??

Discussion in 'Gardening & Plant Propagation' started by gohammergo, Jul 1, 2006.

  1. gohammergo

    gohammergo Active Member

    Dec 18, 2005
    Is it a problem to have a garden in the soil above a septic drainfield? We didn't realize it at the time, but we put our new garden in right where the drainfield is. The garden is doing great, but I'm wodering if having the soil exposed will cause problems to the field? I am not worried about the garden itself, just the drainfield. It seems to me that I heard years ago that it was not advisable. Does anyone have personal experience with this? Thanks in advance for any help. Best of days, John
  2. IowaLez

    IowaLez Glowing in The Sun Supporter

    Mar 6, 2006
    Since 12/14 in Osceola, IA. Before that 6 yrs in f
    I'm not an expert, just a home gardener. Our veggie garden is over our leachfield in our backyard. Has been so for 10 years. We've used drip irrigation and overhead sprinklers. Our field leaches just fine, even when we water the garden heavily. From what I've heard, you don't want to plant trees or plants with invasive roots over the field. They can choke it and cause it to fail. But I think a lot of it has to do with your soil type and the size of your leachfield. I don't think simple vegetables are a problem.

  3. Fla Gal

    Fla Gal Bunny Poo Monger Supporter

    Jul 14, 2003
    Central Florida
    It's my understanding that a drainfield is where a septic tank spills it's waste to and is absorbed by the soil and a leachfield (that I know as a leachbed) is where gray water is sent to and it's absorbed by the soil.

    Are the terms drainfield and leachfield being used in the same context, as in, the field where septic waste goes?
  4. pickapeppa

    pickapeppa Well-Known Member

    Jan 1, 2005
    I always wondered if any septic actually went out into the leachfield and if it did, how often. Our tank is so big it only needs emptied every three years, and then is never completely full. But then, I may not understand fully the workings of the septic system. I could only see it actually needing drained if we had a sudden outpouring of rain with possible flooding.
  5. suitcase_sally

    suitcase_sally Well-Known Member Supporter

    Mar 20, 2006
    Michigan's Thumb
    The "stuff" in the septic doesn't end up in the leach bed unless you don't maintain the tank. The "stuff" settles to the bottom of the tank and is digested by bacteria in the tank. If you don't maintane the tank it could end up in the leach bed, plugging it up and causing major surgery to fix - as in a new leach bed.

    The only problem with using the bed as a garden spot would be if you were to hit one of the tiles when you rototill the bed. I believe the tiles are supposed to be a certain depth so that the water can evaporate thru the soil. Seems like that depth is 18" which shouldn't cause a problem when rototilling.
    Vegetable Gardens and Drainage Fields
    Sometimes the ideal place to put a vegetable garden seems to be over the leach field, raising the question of bacterial and viral contamination from the effluent. Soils vary a great deal in their ability to filter viruses and bacteria. Clay soils work best, eliminating bacteria within a few inches of the drain trenches, but sandy soils may allow bacterial movement for several feet. A properly operating system will not contaminate the soil with disease-causing organisms, but it is very difficult to determine if a field is operating just as it should. If at all possible, use your septic drain field for ornamentals and plant your vegetables elsewhere. If you must plant vegetables, take the following precautions. Do not plant root crops over drain lines. Leafy vegetables could be contaminated by rain splashing soil onto the plant, so either mulch them to eliminate splashing or don't grow them. Fruiting crops are probably safe; train any vining ones such as cucumbers or tomatoes onto a support so that the fruit is off the ground. Thoroughly wash any produce from the garden before eating it. Do not construct raised beds over the field; they might inhibit evaporation of moisture.

    A good site: