permaculture

["Lawrence F. London, Jr." <lflj@bellsouth.net>]

-------- Original Message --------
Subject: [SANET-MG] biosolids in compost
Date: Fri, 28 Jun 2013 06:48:42 -0700
From: Edna Weigel <eweigel@CABLEONE.NET>
Reply-To: Sustainable Agriculture Network Discussion Group 
<SANET-MG@LISTS.IFAS.UFL.EDU>, Edna Weigel <eweigel@CABLEONE.NET>
To: SANET-MG@LISTS.IFAS.UFL.EDU

A nearby municipal composting facility has switched from using horse
manure/bedding as their primary source of nitrogen supplemented by bottled
"nitrogen" (which I assume was really ammonia) and now use biosolids from
the adjacent sewage treatment plant. This is a well-run hot composting
operation far, far surpassing anything I can do in my back yard. I'm
favorably impressed with their controls to make sure they kill pathogens,
not only from the biosolids but also plant pathogens from the (primarily
landscape) green waste they are composting. I have been promised test
results that will cover heavy metals and pathogens. As a retired analytical
chemist, I feel competent to evaluate those test results when I get them
although I don't have a feel for what levels are acceptable in food-growing
soil. I realize the USDA organic standards prohibit use of biosolids and
believe the reasoning behind the prohibition has been concern about heavy
metal contamination. There are no major industries contributing to this
sewage so I don't anticipate seeing much in the way of heavy metals.

The facility supervisor admits that their finished compost used to be very
deficient in nitrogen but reports it now contains much more nitrogen
although he doesn't consider it a fertilizer as such. I'll be interested in
the test results for nitrate and ammonium.

Several gardeners have expressed concern about possible pharmaceutical
contamination from the sewage. The state doesn't require tests for
pharmaceuticals but I've obtained reports of a couple of studies done on
recycled water from another municipality in another part of the state (also
primarily domestic sewage without major industrial contribution). They did
find pharmaceutical contamination in the recycled water. I need to study
these reports more but I'm out of my element when it comes to
pharmaceuticals. I wonder if the risk wouldn't be just as high with horse
manure as it is with domestic sewage.

There is still a concern about possible herbicide contamination. The
composting facility does not "now" receive landscape waste from any golf
courses but I've recently heard multiple vague warnings about gardeners
buying straw for mulch (or for "straw bale" gardens) and finding it kills
their broad-leaf plants. I forget the name of the class of herbicides that
was discussed at length on SANET that kill beans at the ppb level and
survives hot composting, but the latest I remember was that Dow Chemical 
was
trying to get approval to market this stuff to homeowners. Does anyone on
the list have knowledge of the prevalence of these herbicides in domestic
green waste?

I'm hoping to write about my conclusions in a local newspaper but won't
write about it until I've decided whether or not to put the compost on my
own garden. I make use of all my own green waste but, in the arid
environment of southeastern Arizona, I am short of water for growing 
organic
matter to compost and like being able to purchase compost by the pickup 
load
from this facility.

Can anyone on the list help with one or more of these questions?

1) What are reasonable limits for the various heavy metals in food garden
soil? ("None" is not an acceptable answer because theoretically at least 
one
atom of every natural element can be found anywhere.)

2) Should we be concerned about pharmaceuticals in biosolids used for
composting?

2a) Would pharmaceutical contamination be more concentrated in treated
sewage effluent or in the biosolids removed from the sewage?

2b) If the compost does have pharmaceutical contamination, what would be 
the
effect on plants and people eating the plants?

3) What is the prevalence of herbicides that survive hot composting in
domestic green waste?

3a) Did Dow get their approval to market these herbicides to homeowners?

I'll appreciate any help with any of these questions.

Regards,

Edna


-------- Original Message --------
Subject: Re: [SANET-MG] biosolids in compost
Date: Fri, 28 Jun 2013 16:28:15 -0400
From: Frank L Teuton III <fteuton@VIDEOTRON.CA>
Reply-To: Sustainable Agriculture Network Discussion Group 
<SANET-MG@LISTS.IFAS.UFL.EDU>,              Frank L Teuton III 
<fteuton@VIDEOTRON.CA>
To: SANET-MG@LISTS.IFAS.UFL.EDU

Hi Edna,

As I recall from my time on various compost lists, the issues include heavy
metals, pharmaceuticals, and industrial wastes, summarized best I 
believe at
the Cornell site:

http://cwmi.css.cornell.edu/sewagesludge.htm

Composting helps with some of the chemicals which can be broken down, but
leaves others, and of course, does not eliminate heavy metals. For lack 
of a
better term, I would say, absent really rigorous testing, that using
biosolids compost in your food growing is more than a bit of a crap
shoot....;-)

Frank Teuton....follows Deuteronomy 23:13 whilst camping in non-fragile
ecosystems


-------- Original Message --------
Subject: Re: [SANET-MG] biosolids in compost
Date: Fri, 28 Jun 2013 23:51:13 -0700
From: Alia Tsang <alia@DIETRICK.ORG>
Reply-To: Sustainable Agriculture Network Discussion Group 
<SANET-MG@LISTS.IFAS.UFL.EDU>, Alia Tsang <alia@DIETRICK.ORG>
To: SANET-MG@LISTS.IFAS.UFL.EDU

One of my main concerns with biosolids is the antibiotics (prescription, as
well as the ubiquitous triclosan) and how they affect the soil microbial
community. A lab at UC Davis has been working a bit with biosolids and has
found Cipro in I think every batch they tested. I can't remember the
details, I heard about it probably a year ago. I don't know if any of the
results have been published yet. Here's the grad student who's looking at
that issue:

http://scowlab.lawr.ucdavis.edu/people/profile-pages/carolyn-anderson

She might be able to direct you to more information.

Alia