Toxic Sewage Sludge in Your Food?

Discussion in 'Soils, Fertilizers and Composting' started by bob 2, Dec 18, 2009.

  1. bob 2

    bob 2 Active Member

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    Quote from a recent artcle by Michael Mack, the chief executive of Syngenta:
    It makes sense to me at least that if we don't know what is going into that toilet we should not be complacent about feeding it to our food plants.

    It seems a rather slippery slope .

    Bob
     
    Last edited by a moderator: Dec 20, 2009
  2. GreenElephant

    GreenElephant Active Member

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    Slippery slope, yes if you cover it with sludge. The problem with sewer sludge is not the organic component, but the traces of heavy metals, medicines, etc that linger therein. That said, I know it's been peddled to farmers as a free or super cheap soil ammendment for croplands.

    I wouldn't use it for edibles but I'd use it for ornamentals any time.
     
  3. Ron B

    Ron B Esteemed Contributor 10 Years

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    A requirement being that future land use does not conflict with metals etc. being present from when the sludge was applied.
     
  4. GreenElephant

    GreenElephant Active Member

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    Right Ron.
     
  5. Millet

    Millet Well-Known Member 10 Years

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    It has to go somewhere. If you don't agree with applying the sludge to farm fields, then do you have a better solution to get rid of it? Here in Colorado sludge that is applied to farm fields is NOT FREE. The farmer (mostly winter wheat farms) pay a nominal fee to have it applied on his property. I can tell you that it is in high demand by local farmers. - Millet
     
  6. bob 2

    bob 2 Active Member

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    Millet, should sludge be tested for harmful chemicals before it is applied or just tossed on the fields as a random act of blind faith?
    I don't see where anyone was recommending that it not be used but rather that it be safe.

    Right now the jury is out on that one as we have no data.

    Regards
    Bob
     
    Last edited: Dec 25, 2009
  7. 2annbrow

    2annbrow Active Member

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    It's unfortunate that many sellers seem to have a caveat emptor attitude (let the buyer beware) about products. A local woodmill in Oregon was giving away at one point a lot of sawdust which turned out to be contaminated with some kind of poison. Many folks found that they lost entire gardens due to using this sawdust as mulch. I think they would agree that "test before using" is a good idea; I don't believe that it ever occurred to them that it might be toxic - and ten years ago, it might not even have occurred to the folks at the mill. Who knows?
     
  8. Ron B

    Ron B Esteemed Contributor 10 Years

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    If any of that sludge contains heavy metals contaminating acres of land used for food production with it is a bad thing. With sawdust a likely problem is contamination with wood preservatives such as arsenic.

    http://www.puyallup.wsu.edu/~linda chalker-scott/Horticultural Myths_files/Myths/CCA wood.pdf

    The only plant that grows noticeably in the arsenic contamination at the Tacoma smelter site is field horsetail - a carboniferous age relict that used to be exposed to frequent volcanoes.
     
  9. monkeydog

    monkeydog Active Member

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    Several years ago I worked for 9 months at the local sewage treatment plant, putting in a new treatment system. The old system had the sludge going to the landfill and the new system has the treated waste trucked away as fertilizer.

    Officials always claimed that the sludge was perfectly safe and could in fact be eaten or drank with no ill effects! Of course, no plant official would actually consume any of it to prove their point!

    Anyways... what's interesting is that a lot of this new sludge is now used to fertilize farms in the next valley over. For years I fished in the river that meanders through this valley, a nice un-polluted stream with no industry in the surrounding watershed, just farmland. About 3 years have passed now since the new fertilizer started being used in this valley, and now there are signs posted up and down this river warning that only so many ounces of catfish should be consumed per year.

    Since there is no industry in the water shed and the signs appeared shortly after introduction of the fertilizer, I can't help but believe that it is run-off from this sludge applied to the fields that is polluting the stream. I don't know really what the answer is to what to do with this stuff, but yeah, more research and testing would be definately be in order as I believe the effects to be far reaching.
     

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