Can I grow a vegetable garden over my septic tank?

reply to post by Morningglory

It seems the big problem with planting food crops over a leach field are that the sewage may seep up and physically get on the part you eat. Not that the sewage gets absorbed by the roots and then transferred to the all the cells in the plant.

The following link is a very informative one that goes over the whys and why nots to plant a garden over the leach field including the possibility of damage to the pipes in the leach field themselves.

www.unce.unr.edu...

One of the greatest concerns when planting a
garden over a leach field is the potential for
contamination of soil and produce by disease causing
pathogens, such as viruses and bacteria.
Never plant root crops over the leach field.
Pathogens can be expected to travel short
distances through the soil, especially in sandy soils.
Root crops, such as carrots and potatoes, that grow
in the soil are the most likely to pick up
contamination from the area above or downhill from
the leach field. It is not possible to determine if a
crop has been contaminated by its appearance.

Over all, the paper says "No you shouldn't, but IF YOU DO..." which leads me to believe that with reasonable precautions you should be ok.

Hope this helps.

Originally posted by nixie_nox
reply to post by Morningglory

 

No afraid not. You can be the healthiest people on the planet but there is still e.coli in a septic system. In fact, if the grass is growing really well there, there may be some leaking going on.

There is always leaking going on in a leach field. I am not being sarcastic at all, I am a plumber by trade, and I am just pointing out something that perhaps you arent aware of. Thats what a leach field does, it disposes of the excess moisture from the septic tank by leaking (leaching) it into the soil.

www.co.el-dorado.ca.us...

WASTEWATER DISPOSAL BY SOIL ABSORPTION
Effluent from the septic tank flows by gravity or is pumped to a leach field for disposal. The wastewater effluent is absorbed by soil particles and moves both horizontally and vertically through the soil pores. The dissolved organic material in the effluent is removed by bacteria which live in the top ten feet of the soil. As the effluent moves through the soil, the temperature and chemical characteristics of the wastewater change and create an unfavorable habitat for most bacteria and viruses. Therefore, as the septic tank effluent moves through the soil, organic material and microorganisms are removed. The wastewater generally percolates downward through soil and eventually enters a groundwater aquifer. A portion of the wastewater moves upwards by capillary action and is removed at the ground surface by evaporation and transpiration of plants.

From a plumbing standpoint, shrubs and greenery may NOT be the best thing to plant over a leach field. You really do not want aggressive root systems infiltrating your pipes. Vegetables with normal shallow roots should be fine, but as the article I posted earlier says, you dont want plants that place the edible portions in or on the ground where they can be contaminated.