Tainted urban lot, raise the grade or raise some beds.

My lot is tainted from where the burned out pre 1970 house that sat on it was demolished and pushed into what had been the basement.
Rather than spend money on soil tests I have resolved to make soil from scratch.
This could mean raised beds or it could mean covering the lot in woodchips.
I believe I could get two feet of wood chips in place, for the cost of transportation alone.
I would then plant into the wood chips with pockets of imported soil.
Or I could just go with raised beds. Which would be better?

Personally I'd build raised beds then cover the rest of the area in wood chips.

hau, William,

I take it the tainting you speak of is lead paint, asbestos, tars, and all the other nasties that were used in normal house construction up until the 1980's.

The first thing to decide, for me at any rate, would be whether or not to remediate the soil currently making up the lot.
Mycorrhizal remediation is always a possibility, especially when you do not have knowledge of exactly what has tainted the lot.

If you cover the whole lot with woodchips you would have a great base for introduction of mycorrhizal fungi which will clean up a lot of contaminants.
If you build raised beds from the start, you can still introduce the fungi for cleanup. In this case you would have all the benefits of the fungi at work from the get go.
Importing soil for the raised beds is a fast way to get useable, safe soil, if you know for a fact that what you bring in is contaminant free.

Most folks are most interested in quick results, if you are in that group then definitely go with building the raised beds and soil importing/amendment.

Soil testing is always the best method of knowing exactly what you are dealing with. It is possible that you have fewer contaminants than you think you have.
This also goes the other way, where you find out you have more of them than you though. Either way, you would have a better ability to make a proper plan of attack.

Thank you both for your responses.
I have considered soil testing but the it seems complicated and expensive.
The large amount of rubble in the soil also discourages trying to make the soil work.
I am planting fruit/seed/nuts directly in the soil as my reading indicates toxins are deposited in the roots and greenery of plants, not the fruit,etc..

Concerning the raised beds would a one foot base of wood chips at the bottom be good? I am thinking it will provide height and aeration to the beds. Nitrogen loss should be minimal,as the chips will not be mixed in. The beds at my actual house are made from years of oak leaves and green "wastes ", and are very rich.

soil testing is usually not expensive if done by county extension service. here it is 15 dollars per sample.

I like the idea of a deep base of woodchips.
Drainage will be super because of that and any soils that work down into the woodchips won't upset the system.
wood starts out sucking some N but end up giving it all back plus the N that was bound up in the wood in the first place.
I wouldn't worry about the rubble, I have a huge rubble pile left from the scrape off of the PO's burnt down mobile home. It grows lots of native plants quite well.
One must remember that even fruits get their nutrients through the plants roots.

If you don't test the soil, you have no real idea of what (if any) toxins are lurking.
Example, Our land had a brand new double wide set up on it in 2007, the same year it burned down and everything was scraped into one huge rubble pile. Concrete blocks, bricks, burnt tar paper, plastics, and everything else is in this pile.
The soil where the house stood was sampled and I then tested it. Only trace amounts of any contaminants is in that area. I then did two tests of the rubble pile, much higher concentrations were found in those samples.
If you have the same sort of situation, I would be fine with planting where the house used to be but not on or close to the rubble pile.
Since your rubble pile is in the pit formed by the old basement, just put down cardboard then build raised beds there. By using that deep woodchip base you talked of, you should not have any problems with toxic residues.

I have a similar problem (I think) and was considering posting a new thread but this is close enough.
I'm in my first year at my new house, and the soil is just horrible. The google street view of the house from a couple years ago shows NOTHING not even weeds growing. I don't know if the real estate people sprayed all the time or what but the soil is just awful. And on top of that the city sprayed herbicide around the edges this year; killed some of my spelt, most of my strawberries, some sunflowers, etc.
I got some weeds in the backyard, and some mulch from when they grew and died. The soil is salty as hell, and I keep digging up chunks of asphalt here and there.
I'm trying to get it looking nice as it's in a public location and use it as a showish garden, but I can barely even get grass to grow.
I put in two raised beds and place plants some stuff in the ground just to see what will grow. I'm thinking I'll try to accumulate yard waste from around town and spread it as a mulch. If I can get wood chips I'll put them wherever there is bare soil.
I'm considering tilling the old soil and mixing compost with it to fix the structure and then covering with thick mulch.
For the quick results I'm doing the raised beds, and the longer term project is the whole yard. I've heard the best things about composted wood chips, after a couple years just plain chips you can grow in. I'd dump urine around them too to speed things up and get some npk etc with the carbon.

Thomas, lay out a grid pattern and take soil samples, labeling each jar, use pints for the initial samples instead of quarts.
Now you can decide if you want to combine samples or get each one tested. I recommend that you combine blocks of 4 parts of your grid into one sample.
These get taken to you county extension service. In your situation you need to find out what contamination is present so this soil test is pretty important.

The other option I like (if you don't want to get the soil tests) is to till, since the ground appears to be pretty dead and compacted this is a viable option.
I would try to get some square bales of straw (not hay) to incorporate along with compost. Once you have that done, you can lasagna mulch the area.

With you finding asphalt hunks, I really would want to know what the soil is like before spending a lot of money in wrong direction remediation.

Your current plan is very sound too.
Perhaps you will need some sort of barrier to impede the city spraying.