Soil testing for anything more than basic nutrient content, like for toxins or heavy metals, is not going to be free. You can contact your local extension office for how to prepare a soil sample, where to send it for testing and what you should have it tested for. The more extensive the list of contaminates you are testing for, the more expensive the test.

Compost is one of the best soil amendments you can use to improve drainage and reduce soil compaction. It also has considerable bioremediation properties that are very effective in correcting toxin contaminated soils. Look to see if your area offers commercially prepared bulk compost from recycled yard waste - many urban areas and larger municipalities do. It is typically of good quality, relatively inexpensive if purchased in bulk and you will need quite a lot :-)

But the effects of adding compost - even in quantity - are not immediate. If poor drainage and compaction are serious issues, dig wide but very shallow planting holes and plant the fruit trees high then mulch to the top of the rootball with the compost or whathaveyou, creating little mini berms or mounds. The tree roots will work their way into the compacted soil, loosening it up gradually and the shallowly dished planting hole and high planting level will circumvent drainage problems.

Vegetables are another matter, You can do a similar mounded planting - an unstructured raised bed if you will - or it may be better to grow them in containers for at least this season or until you get a better handle on soil quality and drainage.

What that soil does need is lots of organic matter, compost, shredded leaves, any vegetative waste you can get to put into that soil. This soil was abused for many years so it will take some time to get it repaired, it is not going to happen in a couple of years. If petroleum products were spilled onto the soil it may take much longer, but as GardenGal has stated testing will not be free unless you can convince your states Environmental Protection people that this site is a hazard to the community.
For this site I would consider containers and raised beds.

Wow, you have a lot of work ahead of you! The two things I can think of that will help is adding organic matter and planting cereal rye. If you have dug down that far I would mix 50% aged compost and 50% native soil back into the holes where you're going to be planting. Sowing cereal rye will help as it's roots go down VERY far and when you harvest it the material makes a great addition to a compost pile. Also did you find any worms in the soil when you were digging? If so how many?

You may not want to grow fruit trees or vegetables there. Years ago(50s-60s) there was an article in the Organic Gardening magazine or Mother Earth News about a fellow that made maple syrup from the trees on his property. He ended up in the hospital and nearly died. It turns out that the property was an old covered landfill planted with the maple trees and when he reduced the maple sap 50:1 to make the syrup he concentrated the toxins. Do you have a well, if so I would have it tested also?


John

I would start with something easy. I would cover the area with a thin layer of compost, a thin layer of flour or corn meal, and a heavy layer of mulch. Thin layer would be a scattered dusting and the heavy layer would 3 inches. Then I would put a soaker hose on it for a full week at a time, moving the hose 18 inches away from the first place every week. The hose does not need to be on very hard, a trickle at the faucet is plenty. The idea is to allow the soil to grow the compost bacteria and fungi it needs under the mulch using the protein from the flour or corn meal and moisture from the hose. At the end of three full week-long cycles over the entire area (that could take all summer depending on your area) you should have a very soft soil.

Before you get your soil tested, please check with the Texas Plant and Soils Lab and see what their cost would be. They use a test process much more like what the plants use when they extract minerals from the soil. You may have lead in your soil but that lead may be tied up in other compounds and completely unavailable to the plants. TPSL will tell you the difference. And their testing is not usually more expensive for "other" testing because their normal testing covers much more ground than the normal testing at other labs. You could get the same test from another lab but they are not familiar with the techniques, chemicals, or how to interpret the results. The other labs would have to charge you more because of these factors plus they would have to order the testing chemicals in a small batch whereas the TPSL buys in bulk. They are the only lab I am aware of that uses these techniques.

Here is a link that might be useful: Texas Plant and Soil Lab

I would have it tested before I spent any money on it. Check with the Ca. Board of Health and the Ca. EPA I'm sure they could recomend a Lab. or do it themselves. They may also have funds available to clean it up if it is contaminated as a public service.


John

Don't go looking for official declarations and cleanups. You may be asking for condemnation of property and for vacating the premise if the ground is seriously contaminated. Ask the neighbors what went on with the property. In the meantime...

We are just speculating because you haven't come back with any additional information. You might as well be living in virtual reality as far as our advice serves your needs.

Yeah, it's been a while since I checked this, I'm sorry. Thanks for all of your follows ups.

As far as worms go, I did find some worms in it, but only one or two. The soil was VERY tightly compacted. I also did a drainage test on the hole I dug and it took a VERY long time for it to drain, so the drainage is shite, too. I through some compost into it and mixed in some of the native soil that I had chopped and broke up. It's going to be a lenthy process. I'll try planting some of that rye grass, too. Thanks again for all of your help. Any additional info or advice will not go unappreciated.

Here's what I would do, but it's going to be costly.

I would dig out the top 12 inches of dirt and dump it, being in 6 inches of new dirt and mix in compost to that to get it back to the level you need.

It's a quick fix, but like I said, it might cost you.

What you really need to do to make any food safe will be neither quick, cheap nor easy.

There's no way you can get away from testing the soil. Call your local Cooperative Extension Service/Master Gardener and tell them what you've got and what you want to do, and ask them if they know what labs tests for soil contaminants. If they don't know, call the EPA (Environmental Protection Agency). This is a common problem-- somebody does it.

When you contact the lab, be very specific about what you're trying to do: grow food. This is very different than wanting to plant grass.

I think the main contaminants you're facing are petroleum hydrocarbons, antifreeze, and possibly lead.

Once you get your soil test results in hand, call your Master Gardener again and ask if there are plants that can absorb these materials. I know the plants exist that will absorb some contaminants from the soil. Then the plants are cut down and taken to a landfill (not used for mulch, as they're contaminated). Ask how many times you might have to sow these plants before the levels might be low enough for it to be worth testing the soil again. At least you live in CA, where you have a long, if not continuous, growing season.

I understand that compost microbes can eat materials like oil, but I don't know the details.

If your friend doesn't want to go through all this, the other alternative, as discussed above, is to get some heavy equipment and remove the top foot or two of contaminated soil, and replace it with fresh. Not cheap.

Your friend might be better off looking for a piece of clean land to borrow for growing food. I would look for a nearby homeowner who has a double lot, that they have to keep mowing to keep the weeds down. It is likely far more clean (if it wasn't a dump site) and pretty heavy with organic matter. Ask if a deal could be made where the homeowner provides the land and the water (very important), and your friend keeps the weeds down and provides the vegetables, which would be shared.

And if the piece of land is large enough, maybe you could start a community garden.

Sue

Here is a link that might be useful: Alameda County Master Gardener Program

This is someone's back yard, not a big lot, I suspect. If the edible landscaping is to feed just a family and friends, starting small and doing it right is more important than some massive and expensive project.

I have installed edible landscapes for enthusiastic clients only to see the enthusiasm wane sooner or later as family life and other matters change their focuses.