You can have the soil tested to see if that chemical spill is now an issue. It may be cheaper in the long run: many are surprised to find that lots, but not all, chemicals have a fairly short life in the environment. (Hot composting is a good way to break many down).

If you do remove it- I would have just standard screened loam brought in and mix with compost or build a lasagna bed on top.

maybe after 30 years that chemical (whatever it was?) has well and truely leeched away? do any plants that grow there show any signs of any porblems related to chemical contamination? or as has been suggest get a soil test done might not be cheap but?

all things beinbg equal i'd just add composted or compostable material on top and go from there, a good product for the job would be spent mushroom compost and cover it with a good cover of mulch hay.

len

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

Buying soil seems wasteful. Go to the soil, compost, and mulch forum and read about lasagna gardens. Just get free stuff and layer it in the place you want to make new soil. Possible layers: leaves, grass clippings, wood chips, old produce, corn husks, used coffee grounds, animal manure. Usually one puts down a layer of cardboard or newspaper on the bottom to smother anything, but if you are digging two feet of soil out I suppose you could skip that step.

I get old produce from a local stand. Ask at a grocery where you shop or a farmer's market, and watch stores for when corn is on sale. Usually there is a large garbage can next to the corn and people put husks in there. Ask if you can take that bag home. Starbucks and other coffee shops will give you their used grounds. Anybody with animals is usually only to happy to let you take all the manure home you want. Etc. Ask on freecycle and craigslist for organic material. Easy enough to make soil and this way the result is FABULOUS.

Marcia