Putting on my enviromental litigation paralegal hat ( it has large mouse ears that glow in the dark ;) ) I'd say that any municipality that did not execute a due diligence soil test of any potential public park or garden site would be negligent to the taxpayers - in fact, possibly opening themselves up to all kind of litigation exposure, let's say, if a toddler picked up too much lead.
Soil testing is also great for the folks in a garden to see what nutrients the soil needs in order to make intelligent organic amendments.
That said - some cities are kind of lax about this, expecially if the garden is not, or close to a superfund site, or have a reasonable expectation to be loaded with heavy metals. And the lease that the gardeners get is an "as is." lease, leaving the GARDENERS with a great deal of legal exposure.
Not good. But gardeners can do anything they put their minds to. In the North East, we love the University of Massachussets Amherst Soil Lab - http://www.umass.edu/plsoils/soiltest.html - because it is superior and much cheaper than many states in the region....go figure. Now I don't know what your CA extension service charges for soil testing, but hopefully it will be within reason. And with the right amendments and your lovely CA climate, you should be growing a great dea.
Lookit - you would hate going into a garden space and finding out that it was the back yard for a radium clock face plant, or worse , would you? I mean, you wouldnt' want anyone or anyone's kid getting sick from lack of knowing what's in your dirt,right?
Most good gardens soil test themselves every few years to check the PH, and any other reasons. It's always prudent to test your soil, anyway.
Clinton Community Garden
Subj: [cg] Soils test required for City owned Community Gardens?
Date: 7/26/04 7:46:01 PM Eastern Daylight Time
Sent from the Internet
Wondering if other Cities parks and rec. dept are doing soils testing on potential community garden sites ;or are they just developing them without looking into the soil? This has come up in Sacramento by the parks and Rec deptâ. it could slow or stop projects due to lack of city funds to address their concern. testing or remediation of the sites can be budget killers.
Lots of feed back needed on this