Annette Ding
Co-News Editor
Last Saturday at noon, the A.S. Department of Public Worms (DPW) and the Santa Barbara County Resource Recovery & Waste Management Division (RRWMD) hosted their annual composting workshop outside the Isla Vista Co-op.
Open to the public, the workshop was lead by Country Compost Specialist and UCSB alumni Sam Dickinson, DPW Outreach Student Coordinator Rachel Dice, and DPW Worm Wrangler Margot Mason, as part of a wider effort to reach UCSB’s goal to achieve Zero Waste by 2020. This mission also aligns with the state of California’s commitment to composting and recycling 75 percent of its solid waste by 2020.
Why compost?
According to the RRWMD, organics comprise 37 percent of Santa Barbara’s wastestream. Of that 37 percent, Dickinson estimates 20 percent to be food waste, all of which ends up buried in landfills.
“A lot of people think that there’s some magical machine that’s pulling out all the good stuff that shouldn’t be thrown in the trash, that’s not happening,” said Dickinson.
When food scraps are buried in landfills, everything gets pressed down, pushing out the oxygen.
According to Dickinson, “A landfill is an anaerobic environment — that means without oxygen. When you have organics in an anaerobic environment that removes oxygen, there’s this special kind of bacteria that starts making methane gas … This doesn’t happen in backyard composting as there is oxygen present.”
Methane gas is 25 times more potent than carbon dioxide in terms of global climate change. Referencing Santa Barbara’s Tajiguas landfill as an example, Dickinson stated, “All the methane that is escaping out of the landfill is equivalent to 20,000 cars on the road every single year … And there are landfills everywhere.”
While Santa Barbara County does have numerous industrial composting facilities, the city itself does not have one near it. Thus, its truckloads of heavy food scraps are driven 45 miles away to the Agromin facilities in Oxnard and UCSB’s are sent to San Maria-based Engel & Gray, about 67 miles away. “How sustainable does that sound?” asked Dickinson.
On the bright side, Dickinson announced that an industrial composting facility is currently under construction at Taijguas landfill and will be operational by 2021.
In the meantime, composting at home, or on-site composting, is a relatively easy and effective way for local residents and UCSB students to divert food waste away from landfills or long gas-guzzling truck drives. When it comes to on-site composting there are two options: aerobic composting or vermicomposting.
Aerobic Compositng
Aerobic composting, also known as hot composting, is the more space intensive of the two options. Aerobic means requiring the presence of oxygen. Thus, aerobic composting systems need outdoor space, ideally a yard, to accommodate a large pile or bin, which should be about three by three feet large, according to Dickinson.
The circulation of oxygen is crucial in creating prime living conditions for what the RRWD has termed the “FBI”: fungi, bacteria, and invertebrates. These microbes are what will break down the food scraps and yard waste into compost.
Next on the ingredient list are your food scraps and yard waste, or in other terms, nitrogen and carbon. The RRWD recommends putting two parts nitrogen to three parts carbon in compost piles or bins, which will promote microbe growth and cultivate an ideal warm temperature.
The carbon — cardboard, yard waste, paper products — has the added benefit of acting as a filter, which is why it should be covering the nitrogen materials. A common issue with compost piles is the odor when things start to break down, usually a good indicator of insufficient carbon.
When adding new material to the compost, “turnover and fluff the pile” in order to add more oxygen. This can be done with a shovel or pitchfork. Water may be added as well to keep the pile moist specifically “as moist as a wrung out sponge,” noted Dickinson.
Summing it all up, Dickinson concluded, “food scraps with yard waste, keeping it moist, and turning it. In about three months you’ll get compost. It’s really that simple.”
For those who may be put off by the potential for odors and pests that comes with outdoor piles and regular bins, Dickinson suggested purchasing the Earth Machine, a $45 compost bin that would allow users to practice aerobic composting in a simpler and contained way.
Vermicomposting
Another odorless option is vermicomposting, or worm composting. This type of composting uses worms instead of microbes to consume organic waste and needs little space, a popular choice for apartment residents.
Compared to aerobic composting, vermicomposting produces richer soil amendments in the form of worm castings or “worm poop.” “By far the best quality compost you’ll ever get” said Dickinson.
It’s important to note that vermicomposting doesn’t use just any kind of worms. The DPW website states that Red Wiggler worms or Einsenia fetida, are “considered the standard for vermicomposting because they can tolerate a wider range of conditions while still being extremely productive.” Unlike most worms, Red Wigglers don’t burrow into the soil but instead prefer wiggling around in organic materials.
To set up, beginners will need, two four by four wood block, a drill with a one-eighth inch drill bit, and two 10-gallon Rubbermaid storage bins, which must be opaque. Even though Red Wigglers are surface worms, they still don’t tolerate sunlight. For every square foot of bin space, there should be one pound or 1,000 worms, which means two pounds of worms for a 10-gallon bin.
The bins are to be stacked, with the four by four wood blocks placed in between to keep them separated. Using the drill, drill holes three inches apart on all four sides along the top of the bin stacked on top, 8-10 holes in the bottom of the same bin, and 20-30 holes in one of the lids. The holes in the lid and the bottom will allow for ventilation and drainage of the leachate (liquid byproduct released in the composting process).
For a carbon source, shredded newspaper is ideal as it is easier for the worms to break down and absorbs moisture better than cardboard, straw, or dried leaves, though they can still be added to the mix, including untreated paper towels and tissue paper. The shredded newspaper should be enough “to fill your bin about two-thirds full when dry and fluffed up.”
According to the RRWD’s composting guide, the shreddings should be soaked then rung out till damp. Alternatively, the DPW’s online guide suggests letting the newspaper and food waste sit for a day or two so moisture from the food can spread, then adding water if its still not damp enough. In addition to newspaper, add a handful or two of soil to the mixture.
In terms of sources of nitrogen or organic material, vermicomposting is similar to aerobic composting (carbons should still be covering nitrogens) but with a few restrictions due to the more delicate constitution of the worms. Egg shells, coffee grounds, and most fruits and vegetable scraps are still appropriate.
However, “No citrus, because it’s too strong for them, like onions” stated Dice, “the general rule of thumb is that if you couldn’t put it on your eye, if it would irritate your eye, you can’t feed it to the worms.” Dice also noted that garlic and hot peppers are best left out of the worm bins.
Furthermore, according to the DPW vermicomposting guide, “Some people feed their worms bread, rice, or beans, but be aware that these items may ferment or mold heavily in your bin and may disturb the worms in large quantities. Meat, dairy, and oils should be kept out of the bin as they will cause odors and attract pests.”
When introducing the worms to their new home spread them “evenly and lightly over the damp bedding material,” but do not rush to feed them as they are in shock. Both Dickinson and Dice recommended waiting about a week for the worms to adjust, and to begin feeding in small amounts.
Where the food is placed in the bin should be alternated weekly to avoid accumulation and thereby rotting food. Overfeeding can also result in rotting food, which lowers oxygen levels and potentially kill the worms.
In terms of frequency of feeding, Dice recommended to “wait for the food to break down a little … a good rule of thumb is every week and week and a half you feed them and add a little bit more newspaper.”
Worms bins should be kept in a shady area. While Red Wiggler worms can tolerate a temperature range of 55-85 degrees, an ideal range of 65-77 degrees will promote heartier consumption.
After four to six months, your worm castings will be ready for harvest. A week leading up to the harvest, Dickison suggested placing food scraps in one side of the bin, tricking the worms to migrate and clearing the area for you to collect their worm castings without having to sort through a tangle of wiggling worms.
For those that are interested in vermicomposting and purchasing their own Red Wigglers, DPW does not sell them but both they and RRWD have local sources that they recommend listed on their websites.