Your using raised bed which should be fine. I wouldn't recommend digging into the soil. Is this garden just for your family?

No soil should be added to a septic field. Doing so decreases the normal function of the field. Very expensive to fix, worse yet to replace.

The usual suggestion for plantings on septic fields are shallow rooted plants such as wild flowers and/or grass.

No tilling.

No digging.

Sorry but I am with Jean, it has never been recommended - raised bed or not. You would just be asking for trouble with both the garden and the function of the field.

There are some previous discussions on this question if you want to review them. Just search 'septic' in the box at the bottom of the page.

Dave

bebe - If you really want to do this, I will give you my recommendations. First of all, like Dave and Jean said - the main thing is to not disturb the ground where the field lines are located. But.....there's nothing wrong with setting something on top of it, as long as it can't damage or alter the septic field. You say you would like to have a raised bed on top of the ground? That's easy. How big of a box are you talking about? I have one on top of mine, but also realize that if the field lines ever have to be unclogged, the box will have to be shoved out of the way by the backhoe doing the digging. This will of course destroy the box.....If it is a fairly small garden you're talking about, simply put down a 6" layer of gravel on the ground, then set your empty raised bed box on top of that...Staple some professional grade landscaping fabric in the bottom, then fill with soil. Let me know if I can help you further....

EG

Your advice is much appreciated. I'm going to skip the septic field - sounds too risky. There's another location that I didn't think of before because it's full of weeds, bushes and brush. I'll clear that area now in preparation for next spring. Thanks for your help.

what risk?

there is a link on our site to someone who suggests that growing over a septic field is quiet fine, i have seen very many posts on the subject and very many people are growing on leach fields.

why leave all that good nutrient to be sucked up by grass? doesn't make sense does it?

also can't understand why a necessary layer of medium can't be spread to provide a planting base for the seedlings? grow things that produce above ground so there is no need to dig to harvest. my dad had a hole dug below the leach field that filled up with excess fluid he would bucket that to the vege' patch (we all lived healthily).

use mulch the same as you would in any garden. hype stops lots of good ideas.

len

Here is a link that might be useful: len's garden page

It was said "there's nothing wrong with setting something on top of it, as long as it can't damage or alter the septic field."

Yes, there is.

A septic field won't function optimally unless left as is. The extra soil on top of the field decreases function.

Here's what just one university blurb says aabout sesptic fields.
http://extension.umd.edu/environment/Water/files/septic.html

Lots more can be found with a search on google-dot-com or your fav search engine.

Here is a link that might be useful: septic details

Len - perhaps you had just a grey water leach field. Some do garden over grey water fields.

But while many wouldn't want all the phosphates etc. that end up in grey water fields in their food, even more wouldn't care to have all the contaminants from a full septic leach field in their produce.

This, aside from the issue of affecting the functioning of the field.

hype stops lots of good ideas

Research also stops lots of bad ideas and even more of the old-time, once-considered-safe, past practices. ;)

Dave

unbelievable......that's all I have to say.

EG

I've got no experience with septic fields. Shame they can't be used to grow gardens. What a good idea that would be. Glad I don't have to worry about that.