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

[frank]

David, thanks for your reply.
My comments below:


>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
>"fudg
>

>e" monitoring results, but monitoring equipment for temperature may be
>improperly maintained or calibrated leading to reduced accuracy of
>temperature measurements.  
>  
>
 From a true lab person! In the best of conditions (a lab) we know the 
problems that can occur and the need for accurate standards. No one 
trust us either. We are required to dot all the iii's and cross all the 
ttt's.  I would like to see the biosolids/wood chips composting changed 
to  introducing biosolids  in small amounts to every yard waste-manure 
composting operations. But before doing this, IMO, there is a need for 
better control and monitoring of temperature and mixing.

> 
>
>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.  
>
>  
>
I believe the temperature reading should be taken at the center of the 
pile or as an average directly at after mixing (perhaps attached to the 
mixer).  We know (and want) the pile to be cooler on the outside. If the 
center is hot there is likely a large enough percentage of the pile that 
is hot, and when mixed the number of times required, will reduce the 
pathogens to an acceptable risk (not kill them all off but reduce 
them).  What we want to make sure is that the center is not cool and 
anaerobic resulting in temperatures not killing the pathogens.

I think we could learn a LOT about composting by taking these 
temperature reading along the pile.

> 
>
>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.  
>
Biosolids are so different than manures because they result from a large 
pool of water, then collected and anaerobic digested and the water again 
squeezed out. This process must move 99.9999% of the water soluble 
components to the outflow. If we find a contaminate in the biosolids i 
think it important to look for the source and enforce removal because if 
its in the biosolids there must have been a lot more released into the 
waterways. Also; the constituents you mention are all organic. What 
better method is out there to degrade these organics than a cycling of 
anaerobic/aerobic/hot and cold composting (short of burning)? We have 
the best method!

>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.  
> 
>  
>
I agree but lets not limit this to biosolids products. Hormones and 
pharmaceuticals used in raising cattle, herbicides in lawns are just as 
bad. The few samples that have failed the 503 metals were found in yard 
waste composts, not biosolids compost. That is why I think it is time to 
mix all the feedstock to optimize conditions and do the best job we can.

>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.  
>
>  
>
These are likely site specific problems that should be aimed at the 
problem site and not used to criticize the entire program. But it does 
indicate better monitoring (like QC in the lab) is needed to prevent 
these from occurring.

> 
>
>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.    
> 
>  
>
I agree we need to optimize the process to degrade pathogens and organic 
contaminants. Research for better ways should be on-going forever.
But if a section of pile is found to not be up to temperature we need to 
start over by mixing with new material to have it on  'record' that it 
passed.  We should not just add time.  Also; if it has been shown in 
studies that the time - temperature is enough lets not require a longer 
time.  That may not be possible for some composts mixes and not desired 
for products used in teas, berms or disease suppression. Lets just do 
the job and not require anything more.


>Personally, I would never want use of sewage that has composted for only a
>few days in my yard. 
>
No one would!

>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).  
>
There is no 'pathogen' testing. We only test for the indicator, fecal 
coliform. There may not be test methods developed for testing pathogens 
in the matrix of compost, and even if there was it would cost a lot for 
all the tests, detection limits required would not be possible and we 
may not know all the pathogens - they may not have been discovered yet. 
We can only count on temperatures and time that has been shown to kill 
pure batches of  know pathogens in the lab and try to reproduce that 
environment in the field. We know there will still be some left, but 
there is always some in the environment. We just need to get the 
concentration below the risk level. No need to reduce the pathogens in 
compost to below what is found in receiving soil from birds, dogs, cats, 
deer, etc. 

>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.    
> 
>  
>
 From what I see the system is not really working very well as it is 
now. Biosolids are not handled in a manor, nor marketed for long term 
acceptance from the public. We need to change that for the long road ahead.

David - Thank - you for the reply.




Frank

>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
>
> 
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> 
>
> 
>
>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
>
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-- 
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