Boulder Vermicomposting

Report from the Rocky Mountain Compost School

April 18th, 2009

I just returned from the third annual Rocky Mountain Compost School, four days of classes about compost in Fort Collins.  It was quite interesting, though definitely not aimed at home vermicomposters, home composters, or  vermicomposters in general (I think the North Carolina Vermiculture conference would be a better be for vermis).  The focus was on industrial composting, and all the intricacies therein.

I’m not complaining–there was a ton to learn and the conference was never billed as a home vermicomposting conference.  Most of the attendees (there were about 20) were from Colorado and Wyoming municipalities that were composting or were thinking of composting.  There was an attendee from the EPA, some environmental consulting companies, someone from Waste Not Recycling, two farmers, and me.

Among other things, I realized that instead of sending my worm castings to a soil lab to find out their chemical content, I should have sent it to a compost lab.  One of the speakers, Will Brinton, runs Woods End, which does compost testing among other things.  He mentioned that there were only seven labs capable of analyzing compost in the United States.  (Europe has ~200, and compost running out of their ears, apparently.)

Large scale vermicomposting of biosolids, municipal waste, and yard waste doesn’t appear to be happening locally.  If you are composting more than 100 cubic yards of waste yearly, the Colorado Department of Public Health and Environment regulates you, heavily .  Wyoming doesn’t have any such regulations, and Illinois has some of them.  Apparently, the EPA 503 rules, which deal with biosolids (humanure), are the starting point for many regulators, but each state then layers on their own regulations.

The class spent some time talking about compost tea.  Again, this was specific to compost, and not to vermicompost, but I was amazed to learn that the main research focus of compost tea has been on increasing plant resistance to pathogens, *not* on increasing nutrient delivery to plants.  Also, the common practice of adding sugars to compost tea during the brewing process actually increases the viability of E. coli (if any E. coli is present in the compost).  And the bubblers that are often sold are overkill–simply stirring the compost tea three times a day with an oar is enough aeration.

Some of the other interesting talks including what it took to make compost that was certified as organic, experiences with composting dead animals, how applying compost to Colorado soil affected pH and organic matter, and the various standards and lack of standards in the compost market.  There was also some hands on exercises and demonstrations: the class made and monitored a compost pile, measured the water content of compost, saw how to use the Solvita compost testing kit, and used a spreadsheet to build a compost recipe.

The class also toured two different municipal composting facilities (Cheyenne, WY and Boulder, CO).  It was great to have a chance to ask questions of people on the ground, doing real industrial composting.  Another interesting tidbit was the US Composting Council was started as a way to deal with the public relations problem of disposable diapers.

A highlight, for me, was visiting John Anderson’s worm farm but I’m hoping to get another post up with some pictures from that visit, so I won’t go over about that.

Compost making seems like a relatively young science.  Brinton mentioned several times that there was a large amount of disagreement in many aspects of compost, including what it actually is, how the process works, and how to characterize it in terms of quality.  There are few nationwide standards, and any group can put out their own standard (as a group of Colorado composters did a while back).  The class was fascinating, and there’s a ton of work being done.

My overall takeaways from this course:

• finding a market for compost is the most difficult part of the process, but there are markets out there
• large scale composting is real and happening
• large scale vermicomposting is not prevalent, at least not around here
• compost nutrient value and process depends highly on the purity of ingredients
• there’s no ‘one way’ to make compost–how you make it depends on your end use

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