Composting 2.0
From Green Garage Detroit
This is a project undertaken by the Green Garage community leadership to update the current composting systems used at the Green Garage.
Importance
Why is composting important?
- diversion from landfills
- energy in hauling
- healthier ecosystem (i.e. soils) around building
Compostables
- Browns
- Paper towels
- Coffee cups
- Greens
- Coffee grounds and tea leaves
- Lunch scraps; fruits, vegetables, etc.
- landscape plant cuttings
Volume
- Est. 5 lbs/week food scraps | ?/week paper products | Measurement in cubic yards?
- Results of study, week of 8/31:
- 7.5 lbs paper products (6.5 lbs paper towels (est. 350 towels) & 1 lb cups & other products)
- 20 lbs food scraps
Composting Google Worksheet
Current System
- Food scraps/coffee grounds/tea leaves collected daily, stored in tote bin outside
- Paper towels collected daily / paper cups collected weekly, stored together in plastic bags outside
- 1x/month, food scraps & paper towels incorporated into backyard pile
- Compost added to gardens in winter and spring
Current Issues
- Volume of paper towels (Matt)
- Volume of Green waste (Matt)
- Winter? (Tom)
- Waste in backyard issues (Matt)
- Ants, fruit flies (Matt)
- Length of time to compost?
- Mix of brown and greens by weight or volume? (Tom)
- Great technical article on the right C:N mix (carbon:nitrogen)
Sustainability 3D Goals
- Environmental
- Community
- Economic
Composting 101
- Mix 2-Brown / 1-Green
Research
- Composting Barrels
- Dual Tumbler .. next generation product
- Mother Earth Article on Selecting Best Composting Bin/Tumbler
- Stationary bin (requires turning) holds 10-15 cubic yards
- Tumbler (designed to make turning easier) holds 5-12 cubic feet
- Affect of cold weather on composting performance
- How much longer does it take? Is it good to cover it to keep in the warmth? Any techniques?
- Winter Composting ideas
- Length of time to compost
- Compost pail and bag
- CalRecycle Composting Resource Page...outstanding
- Urban Worm Composting Resource Center...excellent
- Large Composting Barrel
- How much can worms eat?
- Some suggest that a good guideline is 1/2 worm weight per day. In your case, since 1000 worms on average weigh somewhere around 1 lb, an estimate of 1/2 lb of waste per day – or 3.5 lb of waste per week might not be a bad guess. I’m a little hesitant to even mention that, but hopefully you will take that recommendation with a grain of salt, based on what I’ve said above.
- 5 pounds per day = 10,000 worms
- 25 lbs/wk divided by 3.5 lbs/wk/1,000 worms = 7,000 worms
- Need 1 lb worms (1,000 worms) per 1 sf of tray.
Design
- Worm Composting (DEC-MAR)
- In basement (temp needs to be above 50F)
- Use bin system
- Need bins to handle 25 lbs of Green per week
- Need 7,000 worms .... start with 3,000 worms?
- they can grow in number and then separate
- Composted material carried up to pile in backyard during winter (need bin?)
- Do weekly
- Use small pail so it is not heavy
- Don't know how much paper towel is needed...some is needed for bedding
- Bin Composting (APR-NOV)
- Use composting barrels
- Need to hold 40 cu ft
- Also have vertical square bin to hold near-finished or finished compost that isn't placed yet.
- Use composting barrels
- Shredder
- Buy a commercial shredder
- Use to:
- shred paper towels
- shred business paper from Bus in Res
- Compost Pail
- Consider new pail for top lid to prevent fruit flies
