[USCC] Vol 29, #9--Regulation by various agencies

[dschelli]

Frank,

I agree to a certain extent that more intensive monitoring of the biosolids
composting process would improve current regulatory compliance. Many
problems with current regulatory monitoring system result from reliance on
the honor system for self monitoring of biosolids composting processes.  The
data presented to regulatory offices may be flawed either by design or
unintentionally.  I do not insinuate that "all" composting operations would
"fudge" monitoring results, but monitoring equipment for temperature may be
improperly maintained or calibrated leading to reduced accuracy of
temperature measurements.  

 

Temperatures are rarely taken at different depths in composting materials
even though we know there will be differences.  Because windrows are three
dimensional, there are not only horizontal sections of the composting
windrows or piles that are often cooler than necessary, but also vertical
stratification of temperature differentials, and stratification of
temperatures with depth in the material.  I don't really know if improved
monitoring instrumentation would help or hinder the process of biosolids
composting monitoring unless it was fool-proof and did not allow tampering
with results, and if certified personnel calibrated instruments regularly.
Intensive monitoring as proposed would probably do more to show the
inadequacy of time/temperature composting process for biosolids than to
improve the composting process.  

 

Whereas I am pro-sewage use as a feedstock in composting, I do not really
approve of the current regulatory treatment and monitoring program.  It does
not (as some opponents to biosolids use point out) account for many chemical
contaminants that may be found in biosolids. I realize that many
contaminants are destroyed over time in soils where biosolids are applied,
but composted biosolids are often used more in residential settings.
Chemical contaminants that could be found in sewage might include
pharmaceuticals, paints, cleaners, paint thinners, pesticides, herbicides,
oils, etc., many of which are hazardous if not toxic in nature.  Some may
also be recalcitrant in nature, requiring more exposure to the harsh
conditions and enzyme activity of microbiological activity during composting
than just three to fifteen days.  More aggressive testing for chemical
contaminants, in addition to the current regulated metals, might not be a
bad idea for any biosolids products to be land applied.  

 

Some literature exposes a fault in the current regulatory composting process
because pathogens have been observed in finished products, at the point of
sale, above regulatory limits.  Whether due to growth of pathogens after
composting or to inadequate process control, high pathogen counts after the
process is complete shows that the current regulatory monitoring and testing
program is inadequate(This evidence also suggests that testing at the point
of sale has proven to provide better results for consumer safety).  Changes
in the current regulatory framework for composting and monitoring of the
process would seem to be in order; process management that would provide
more flexibility to compost producers but would accomplish the same goals
and provide a more stable and mature end product would seem to be a better
option.  

 

We know that most anaerobic bacteria, pathogens included, can be killed by
sufficient exposure to air as well as to temperatures above 126°F (the
temperature at which proteins begin to become denatured).  You point out
that the current regulations require biosolids compost producers to
re-process materials that do not meet the regulatory 131°F temperature
regimen during the prescribed time.  I submit that reprocessing would not be
necessary if the composting process was extended, even at temperatures
between 126 and 131.  Assuming adequate biologically available nutrient
resources exist after 15 days, why not compost for longer durations (30
days) with scheduled turning twice weekly in windrows to reduce the
probability of pathogen survival, and to increase exposure of chemical
contaminants to enzyme activity?  Because aeration is also important in the
pathogen reduction and the overall composting process, monitoring pore space
oxygen in the composting materials may also provide evidence of composting
adequacy.    

 

Personally, I would never want use of sewage that has composted for only a
few days in my yard. I think it may be time for regulatory reforms rather
than to try to doctor the current monitoring programs (pathogen testing at
the end of the composting process).  What may be intended as a way to help
improve the current system may actually not help compost producers who use
biosolids as a feedstock, and may bring about regulatory change anyway.    

 

Dave Schellinger

Alternatives. L.L.C.

 

-----Original Message-----
From: compost-bounces at composter.com [mailto:compost-bounces at composter.com]
On Behalf Of frank
Sent: Wednesday, July 26, 2006 12:27 PM
To: US Composting Council Compost Discussion List
Subject: Re: [USCC] Vol 29, #9--Regulation by various agencies

 

U.S. COMPOSTING COUNCIL 15th ANNUAL CONFERENCE AND TRADESHOW

Wyndham Orlando Resort | Orlando, FL | January 21-24, 2007

The National forum for those involved in the development and expansion of
the composting and organics recycling industry

CONFERENCE PROGRAM, REGISTRATION FORMS, WORKSHOP AGENDAS,

EXHIBITOR INFORMATION AND SPONSORSHIP OPPORTUNITIES ARE AVAILABLE AT THE
USCC WEBSITE: www.compostingcouncil.org OR CALL THE USCC AT 631-737-4931 

 

 

Rufus, David and others,

I am wondering your thoughts on the following:

 

Because the killing of pathogens in a typical compost operation is based 

on Temperature & Time I am thinking it would be better if we replaced 

testing for fecal coliform with a more intensive temperature monitoring 

system.  For the past two years at the USCC conference there has been a 

growing number of vendors that  are marketing new systems that 

continuously monitor the temperature and send the readings to the war 

room. I look forward to seeing what they present at the USCC conference 

in January. I would prefer to see equipment that runs down the windrow 

taking readings along the way and monitor using GPS tracking than a few 

probes that must be inserted and removed, but maybe that will come 

later.  Having many, many readings all along the row that are 

automatically recorded would show 1) sections of a pile that are cool 

and could be removed before harvest and used as a microbe seed for a new 

row 2) proof of readings and 3) proof of time of composting.  Soon as 

the required temperatures and times were met Pathogen Reduction has been 

achieved and nothing more needs be done. If we still want fecal coliform 

to confirm complete mixing that should be done at 'end of the time', not 

at 'point of sale'.

 

As it is now we seem to rely more on fecal coliform at point of sale to 

determine if pathogen reduction has been met. That is a few random 

temperature readings, a calender and one fecal coliform reading from a 

mixture of windrows at the end. Before we can add small amount of 

biosolids to every windrow at every compost facility, as I hope we will 

be doing in the near future, it must be -proved- that pathogen kill has 

been met. I think the above is needed for this proof.

 

Thanks

Frank

 

 

 

 

 

-- 

Frank Shields

Soil Control Lab

42 Hangar way

Watsonville, CA  95076

(831) 724-5422 tel

(831) 724-3188 fax

frank at compostlab.com

www.compostlab.com

 

 

 

_______________________________________________

Compost maillist  -  Compost at composter.com

 

 

Ongoing Sponsors of the USCC Discussion list are:

 

Food Industry Environmental Network (FIEN), a regulatory and policy e-mail
alert service for environmental, food and agricultural industry
professionals.

Contact Jack Cooper 301/384-8287 JLC at fien.com --- www.fien.com

 

Renewable Carbon Management, LLC with the containerized, in-vessel NaturTech
Composting System www.composter.com rcm at composter.com

 

(c) Copyright 2006 United States  - All rights reserved

Opinions expressed are represent only the poster and are not necessarily the
opinion or policy of any organization.

 

Non-members of USCC are encouraged to join the Council through our website
at: http://www.compostingcouncil.org/membership.cfm     For discussion list
policies and information regarding subscribing, unsubscribing, digest or
other options, go to:http://mailman.cloudnet.com/mailman/listinfo/compost

 

For additional help in unsubscribing or to report bugs and problems, send a
message to the List Manager, Jim McNelly, at compost-owner at composter.com