Hi all- The UMass service is oriented toward commercial agriculture, so they don't normally test for pesticides or volatiles (like gasoline or dry cleaning fluid or solvents) that cause lots of problems on urban sites. My sense is that that's where the costs come in (see their online brochure). They also recommend only testing the root zone of the crops you intend to grow and basing your sampling on visible differences in soils on a site. Contamination often runs deeper than 6 inches, particularly if the source is liquid/leachable or if the soil has been seriously disturbed during demolition or grading. Here in Hartford on a vacant lot, you can sometimes make assumptions about where a frame house stood and therefore where likely lead contamination would be found (from paint chipping off the structure), but there may be no visible indicators, and who knows where soil may have been pushed during demolition. You may find a dark, smelly patch near the rear of a property where resident "shade tree mechanics" dumped motor oil and other automotive products. Sometimes we find a pile of coal ash buried near what was once the back door of a house or used for fill when a new concrete walkway was poured. Here in New England, "civilization" has been around for over 350 years, so you really can't make assumptions about historic uses of a property. A property near the historic city center may have had half a dozen different uses, none of which have left any visible trace.
Lots of questions: 1. What is safe? The ppm discussion is interesting, but it's not obvious how deeply soil must be clean for it to "count." EPA standards don't really apply to gardening use. Is gardening more like farming or a home, or what? 2. What constitutes adequate screening? Contamination can be highly localized (in 3 dimensions). We had one site with a hot spot of around 8,000 ppm lead near the back door of what had once been a paint store. We could have missed it entirely, and sometimes I wish we had. We need a rough screening process that will give us a sense of whether we need to go "deeper." I envision some research on urban lands that would come up with results like, for instance, "if you do one 6-inch deep sample for every ?? square feet and any sample has lead levels above ?? parts per million or the aggregate is above ?? parts per million, then chances are ??% that some part of the site has lead levels above the EPA residential standard." 3. What is adequate remediation? Replacement of surface soil? Removal of all contaminants? Raised beds and covering of soil in pathways? Dilution? Phytoremediation (using plants to reduce contamination in their root zone)? Running for cover and pretending you never knew anything about it? Fact is, we've pretty much dirtied up the place and now we have to figure out what to do about it. I don't have the time or expertise to follow the science, but my sense is that we're pretty far from figuring this out. The brownfields folks have some ideas about how to handle industrial sites that are slated for development, but it's really expensive and it leads to "disposal" of huge amounts of pretty good soil with some pretty bad stuff in it. Someday soon we need to get a whole crowd together to talk about this. We need chemists, soil scientists, public health people, politicians, gardeners, neighborhood activists, planners, and maybe some poets. Somehow they all need to sit at the same table and talk about what the standards should be, how to reach them, how to pay for it, how to avoid destroying communities in the process, etc. I keep suggesting this to academic and government types, but so far nobody has jumped on it. End of sermon. We're in the soil business and we have a long way to go. Good luck to us all. Jack -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Honigman, Adam Sent: Wednesday, October 02, 2002 4:58 PM To: 'Bill Maynard' Cc: '[EMAIL PROTECTED]' Subject: RE: [cg] soils testing on urban lots Bill, $700 seems a trifle too dear... Here is the website for the Soil and Plant Tissue Testing Laboratory at theUniversity of Massachussets - Amherst. They do a great US $ 8.00 soil test (per sample) which includes all heavy metals. They also do a very complex test for every nutrient known to man for $12 a sample. Garden coordinators from all over the midwest and northeastern US use them for price, speed and accuracy. If you have something particularly tricky, I'm sure that they do it, and for less that $700 a sample. http://www.umass.edu/plsoils/soiltest/ -----Original Message----- From: Bill Maynard [mailto:[EMAIL PROTECTED] Sent: Wednesday, October 02, 2002 4:39 PM To: '[EMAIL PROTECTED]' Subject: [cg] soils testing on urban lots What you don't know ...might hurt you.... As our 30 year old Mandella com garden site in sacramento has recently found out: "some areas with higher than acceptable levels of Lead, DDT, and PAH'S(polyaromatic Hydrocarbons left from the incomplete burning of gas, coal, etc) were found." The levels of lead that sacramento county deems acceptable is under 200 parts per million (some professionals say 80 is the highest lead should be)... this site had 500 to 1300 parts per million....plus other toxins the site had older homes from the 1860's on it before it was torn down back in the 1960's the garden started in the 1970's....apparently no testing was done.... As I understand it...the complete palette of soil tests (lead, heavy metals, PCB's, PAH's, etc, etc) costs $700 per sample (many sites would require 12 or more samples.... Question 1: are there any places that will do all these tests for free or low cost for us community gardeners? Question 2: How many urban gardens have had their soil tested for lead and other toxins? and what levels did they find? this will be a big issue in the sacramento area and will be the first HIGH hurdle for each new com garden in the area. (we have approx 6 CG's proposed in various stages in the long approval process) In the mean time.... Each garden should ask itself: was the lot built on before? Answer: Your local USDA office will have old aerial photos of your area back to the 1930's and other photos taken every 10 years or so to the present... Article was in oct 2 issue of the sacramento bee http://www.sacbee.com/content/news/story/4631378p-5649671c.html ---------------------------------------------This email and any files transmitted with it are confidential and are intended solely for the use of the individual or entity to whom they are addressed. This communication represents the originator's personal views and opinions, which do not necessarily reflect those of Wood-Rodgers, Inc.. If you are not the original recipient or the person responsible for delivering the email to the intended recipient, be advised that you have received this email in error, and that any use, dissemination, forwarding, printing, or copying of this email is strictly prohibited. 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