Boulder Vermicomposting

Interview: Vermicomposting Dog and Cat Waste

September 25th, 2008

I recently interviewed Tracy, a classmate of mine.  She’s kept worms for a number of years, but the most interesting thing she has done, from my perspective, is vermicomposted dog and cat waste, both hair and fecal matter.

However, she has much to say about all things vermi, from selling worms to making worm bins.  Currently, she’s getting back into wormkeeping, and her next venture is “to compost dog waste at the dog ranch” at which she currently works.  (Only small edits for obvious typos were made.)

Dan: You used worms to vermicompost dog and cat hair.  Anything else (dog feces, etc)?

Tracy: I did vermicompost dog feces, at the time I had a 180 lb Rottweiler and a 80 lb Pittbull living at the house. (Large waste producing doggies!) I had a separate container (made of pallets about 4ft by 4ft),  I combined this with old soil and yard debris, it took quite a while for this to break down and I really only spread it around the grasses or large non food trees.

Dan: How long did you do this for?

Tracy: 3 years total at this location.

Dan: What safety measures did you take, if any?

Tracy: It is important to maintain an optimum temperature–especially if you are dealing with feces. The ideal temperature for composting with dog waste is about 145F, this will kill off any pathogens that may cause adverse bacteria.  The sun hit this containment a little more, and the manure itself heats up really rapidly. I stirred this when the temperature rose, about once a week or two. I kept this one bin away from the household bin. The household bin was usually kept at 60F to 80F degrees. Of course in the colder months–which was mild in Oregon–the worms will slow down.

Dan: How did you hot compost and vermicompost feces at the same time?  I thought hot temps killed worms.

Tracy: I think what I did was let the sawdust and dog feces get a head start in one bin, let it heat up, and then move it on down the bin row. I was using a thermometer just sticking it the middle. Again I was just starting and using trial and error.  When I started combining the worms, it would have been after I combined the partially broken down feces with yard debris and soil. The worms don’t tolerate excessive high temperatures, but it really only gets that hot in the very center, and that was initially when you start with a lot. They did have enough room to move away from the hottest spot. Some people have had their piles catch fire due to the heat, I never experienced that.

(I just want to mention that people have had very mixed reviews with the dog feces compost and it is important to note temperatures. The household worm bin is a fantastic idea. But I would not want to give the incorrect information when dealing with possible spread of bacteria when dealing with animal waste. So this is what worked for me to rid myself of dog waste and avoid putting this into a landfill. It is important to be careful and keep it away from food growing sources.)

Dan: What did you do with the worm castings?

Tracy: I harvested worm castings about every 2-3 months. I did make tea out of the casting, just by adding water, letting sit and pouring over my gardens. At this time I did not filter or use aeration to make my tea.  To harvest, I would pile up my compost in pyramid shaped piles on a work bench, let them sit for a few hours and then all the worms would travel to the base of the pile and I would scrape off the top, I believe there are more efficient ways to harvest. In my fresh garden beds I would apply this directly. I also would transfer this compost to a large bin that had soil in it. I would continue to mix this and use it for potting and had a ready made blend for new gardens.

Dan: In making the tea, what was the ratio of water to vermicompost–any references or did you just wing it?

Tracy: I was definitely winging it. I used 5 gallon buckets, put about 1/4 of compost and filled with water. Sometimes I would dilute it further. Now there are better references online for an accurate formula.

Dan: What kind of worms did you use? (Eisenia foetida?)

Tracy: Yes I used the good old red worm wigglers

Dan: What volumes were you dealing with?

Tracy: I started out with 1000 red worms, I had the main bin that was about 4ft and 4ft and at the time I was living in a household of four. We were vegetarian and had a lot of veggie and fruit scraps. The worms can eat about their own weight in food a day, I probably was feeding them 2lbs a day, more at times. Of course the worms quickly multiplied so I was removing some and expanding bin by bin to avoid over population. Moving them to the bins that held yard debris, the dog waste, the ready made soil; other spaces where for example a bunch of blackberry bushes had been cut back and piled.  I even sold a few to fisherman, sorry worms! At the time more people were interested in purchasing the tea from the farmers market and gardening store more than they wanted to have their own worm bin and do the work–which it really is no work at all! Now when I think of it I should have been selling the tea instead of the worms!

Dan: How did you find the fishermen to sell the worms to?

Tracy: Neighborhood, coffee shop and bar conversations! I am not sure what kind of fish and if they were catching any fish at all!

Dan: How long did the materials take to break down?

Tracy: Like I stated previously I think I was harvesting the castings about every 2 months during the warmer months. Some things were really quick to break down–a few weeks for green scraps or peelings. Some things took longer–a whole corn cob, citrus peels. I did it more often on a smaller scale, but if I wanted to get a lot of compost I would wait a little longer.

Dan: What did you use for bedding?

Tracy: I used A LOT of shredded newspaper, leaves, eggshells, coffee grounds, shredded cardboard, sweepings from the kitchen floor–pet hair, junk mail. Nothing with a lot of dyes like the glossy adds from the paper.

Dan: With the junk mail, what happened to the plastic envelope windows?  Did you end up fishing those out of the bins?

Tracy: I would always tear those out. I made sure to always shred any paper product going into the bin. Nothing went in as a whole envelope or a whole newspaper.

Dan: Any tips for someone who wants to do this themselves?

Tracy: The biggest thing is the moisture content. The bedding should feel like a wrung out sponge. They do need moisture but there should not be standing liquid in the bed. This will eliminate any smell coming out of it–you should be able to keep a small unit in your home with no odor. This will also keep out flies, etc. Having a good balance of coffee grounds and egg shells will balance the ph of the compost. Don’t over do the citrus, it is not their favorite food. Don’t use meatscraps or dairy.  Don’t use new materials to build a bin, you can use so many things you already have. I am about to change an old bathtub into a new bin!

Dan: What did you build the boxes out of?

Tracy: The boxes were made of pallets that I had. I just screwed them together with a drill. The main worm bin was made of a rubbermaid container with holes drilled all the way around it for oxygen to circulate. This was inside the pallet frame with four straw bales lined around the bin, to ensure warmth for the wormies. The worm bin had a lid on it and then the pallet closed around the straw bales to keep out animals. Four other pallet bins were lined up next to this along my fence for expansion.

Tracy: The bins were outside. I did have a mini bin–a five gallon bucket with a handful of worms I kept in my back room during the really rainy and cold months. I would just transfer that to the main bin on a nice day.

My gardens in Oregon were the best they have ever been in my life, using all those worm castings. Also the recycling program was really great in Oregon, so every week for a household of 4-5, two dogs, and a cat, I only had a small plastic grocery bag of garbage every week. Things are a little more challenging here at 9200ft, having to deal with colder weather and taking in all of my own garbage and recycling is one more step, but I am striving to again have zero to little waste.

Just talking about this makes me really excited to continue my vermicompost. I have been living in a tent or small cabin the years before I moved to Colorado, so it has been a few years. I guess I should have experimented with campicomposting!

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