[USCC] Gypsum

[Matthew Cotton]

Ginny -

Here in California a few composters accept drywall from construction  
and demolition projects. What I have seen is that most, if not all of  
this is stockpiled separately, crushed, screened, and sold separately  
as an amendment (primarily to farmers who use it to condition the  
soil). A very small portion may be added to finished compost as part  
of a blended material, but I am not aware of anyone "composting" the  
wallboard itself.  I don't believe that composting would have much  
effect on the gypsum, though I've heard some folks speculate that the  
gypsum added to an active compost pile might reduce odors (something  
about odor molecules adsorbing to the many surfaces of the ground  
gypsum), but I don't know anyone adding gypsum for that reason.

Once the wallboard is crushed and screened there is a remaining  
fraction of mostly paper which previously sandwiched the gypsum. A  
few composters I know compost this paper, but in my opinion this is  
more of a way to use the by product of the gypsum "recycling" process.

Matthew Cotton
Integrated Waste Management Consulting, LLC
19375 Lake City Road
Nevada City, CA  95959
(530) 265-4560
Fax (530) 265-4547
matt at mattcotton.com
www.mattcotton.com




On Nov 10, 2008, at 10:54 AM, uscc-ginny at att.net wrote:

> To All:
>
> I have a grant proposal that is proposing a beneficial reuse of  
> wall board, by mixing the ground gypsum product with compostable  
> materials. I have been asked by the project team reviewing the  
> grant proposal if any has done this? If so, has anyone tested the  
> final product?
>
> I have heard inklings of projects like this, but do not know of  
> anyone who has actually done this. Any info any of you might have  
> would be greatly appreciated.
>
> You can e-mail me, or call at 651-215-0284.
>
> Ginny
> Minnesota Pollution Control Agency
> _______________________________________
> Join us at the US Composting Council's 17th Annual Conference &  
> Trade Show
> January 26-29th, 2009 at the Westin Galleria in Houston, TX.
> The National forum for those involved in the development and  
> expansion of the composting and organics recycling industry.
> Conference Highlights, Registration forms, Exhibitor information  
> and Sponsorship Opportunities available at the USCC website:  
> www.compostingcouncil.org or call the USCC at 631.737.4931
> ______________________________________________________________________ 
> ________
> Compost maillist - compost at mailman.cloudnet.com
> http://mailman.cloudnet.com/mailman/listinfo/compost
> _______________________________________
> This list is a service provided by the US Composting Council (USCC).
> (c) Copyright 2004 United States Composting Council - All rights  
> reserved
>
> Opinions expressed do not necessarily represent the USCC, the  
> Foundation, or the Board of Directors.
>
> Non-members of USCC are encouraged to join the Council through its  
> website at: http://www.compostingcouncil.org/membership.cfm
>
> Members posting CC copies to the list and other addresses may have  
> their posting privileges suspended. 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 unsubcribing or to report bugs and problems,  
> send a message to the List Manager at  
> compostlistmanager at compostingcouncil.org