From: hart0037@student.tc.umn.edu ()
Subject: Re: Social inhibitions to environmental change
Organization: University of Minnesota
Date: Sun, 13 Dec 1992 19:05:12 GMT

In article <1992Dec13.052233.15840@pasteur.Berkeley.EDU> 
radzy@ICSI.Berkeley.EDU (T. O. Radzykewycz) writes:

>radzy@ICSI.Berkeley.EDU (T. O. Radzykewycz) writes: 
>>  <snip>
>>
>>Does *anyone* know of *any* city that does a single-stage
>>processing on their sewage and then sells the resulting sludge
>>to local farmers?  Or even double-stage processing?
>
>hart0037@student.tc.umn.edu () writes:
>> Columbus, Ohio had a program that was in existence in the mid 80's
>> where they took sewage and used it to produce very fertile soil.  It took a
>>  <snip> 
>>       I hope I'm wrong, but I think they were having a hard time
>> making it an economically feasible program...probably b/c of the amount of
>> processing involved to get rid of any pathogens and also b/c of public
>> relations in getting people to *buy* the product.  It's kind of like how
>> you can gross out a lot of people who eat meat by telling them they're
>> consuming muscle tissue.  If you mention to some people what fertilizer
>> is,  it sets off all kinds of reactions!
>
>Those public reactions are what we have to change if we're to:
>1.  Stop pollution of the rivers and oceans.
>2.  Reduce waste of a potentially valuable resource.
>3.  Break the cycle of using petrolium-based, non-renewable fertilizers
>	to make up for the loss of productivity in the soil.

     Exactly!  I don't think the average U.S. city-dweller really
understands where food comes from and where wastes go.  And why would
they?  So many people spend so much of their lives surrounded by concrete.
It isn't necessary for someone to know how produce is grown--we just go to
our local supermarket where it magically appears for our consumption. 
Human waste magically disappears down the toilet and we don't give it much
thought because somebody else takes care of treating it.  Day-to-day
survival for your average person doesn't depend on understanding these
things, so we're not transmitting such information to the general public....
    All of what I've said may have already been hashed over here--I
disappeared for awhile and couldn't read up on everything!

>
>But what about the pathogens?  I *know* that working with sewage is
>a dangerous business, but can it really be less bad to dump it in
>the river or ocean rather than dumping it on farmland?

    It might be bad in both situations, though.  Sewage can carry some
nasty stuff like Hepatitis B.  

 >
>I doubt it would be feasible, but I wonder about the idea of having
>pipelines to pump the sewage sludge from the cities to the country.
>If part of the processing cost is to reduce the water in the sewage,
>then perhaps it would be cheaper to leave it wet, and pump the water
>back to farms as well?  (OK, it would be expensive water, but it might
>be cheaper to pump the water than to remove it.)

    This is a neat idea, actually.  If there were a way to get rid of
pathogens and heavy metals, etc. and leave it wet and pump it to farms,
then not only would you be fertilizing, you'd be irrigating as well!
I can see how the economic problems could be difficult, though.

>I'm really thinking of something like taking the existing post-processed
>sewage, and putting it on cropland.  If there aren't nasty things that
>can't be put on cropland, then the cost of using this fertilizer would
>be no more than the cost of transportation.  If there *ARE* nasty things
>in it, then why are we allowing them to be pumped into the ocean?

  I realize your last question is probably rhetorical, but I've spent some
time living and researching in the Caribbean.  What we are doing to our
oceans is absolutely disgusting.  For a long time the attitude has been
that oceans are big and can absorb all of the junk we put into them.  Not
so.  I have been swimming at places in the Caribbean and suddenly realized
the water smelled like sewage.  Granted, it was local sewage, but the U.S.
also dumps.  There are harbors in the US that are dangerous to dredge b/c
dredging kicks up toxic sediments--of course those aren't just from sewage.
 We are all familiar with what happens when we organically enrich fresh
water...one of the reasons the Caribbean reef systems work the way they do
is b/c the water is nutrient poor.  We are changing that.
   When I lived in Nassau, Bahamas, there were 1,000 cases of food
poisoning in one month b/c people were eating raw conch that was stored in
wells in the harbor next to a sewage plant that dumped into the harbor. 
The conch picked up a virus from the sewage....so there is potential for
danger in mixing human sewage with human food.  The problems are
probably different when one is talking about using sewage as fertilizer,
though, so  I think I've kind of drifted off the subject!
  
     --Amy

>
>Bear Blessings!
>
>		-- radzy
>