Making black gold

Humboldt State University food waste feeds worm farm

Every two and a half weeks when school is in session, HSU sends about 18,000 pounds of food waste to a local worm farmer for composting.

According to HSU’s Facilities Management website, CSU sustainability policy calls for HSU to reduce its solid waste disposal rate by 80 percent by 2020.

The Facilities Management website also states that HSU employs two different compost operations. An off campus vermi-composting operation (vermi – relating to worms), and an on campus operation run by the Waste-Reduction and Resource Awareness Program.

Food Waste to the Worms

Megan Tolbert is the Grounds, Recycling & Waste Coordinator at HSU. Tolbert said sending food waste to the worms starts with having the food waste placed in specially labeled compost receptacles in or near dining areas around campus. Student assistants and recycling staff collect food waste from events and from these receptacles and empty into the BioBin.

The BioBin is a 20 yard capacity food waste holding receptacle located near the J dining hall. Once the BioBin is close to capacity a truck loads the receptacle and delivers to a worm farm in Humboldt County.

The worm farms are operated by a small, local business, the Local Worm Guy. Lloyd and Stacey Barker operate several worm farms throughout Humboldt County.

Tolbert said that while school is in session BioBin loads are being delivered to Local Worm Guy farms about every two and a half weeks.

Between worm deliveries, according to Tolbert, student assistants and recycling staff maintain conditions of food waste being stored in the BioBin. The goal is to create optimal compost conditions once the food waste reaches the worm farm. Excess liquids are removed, and the food waste is mixed and layered.

Tolbert said that extra carbon sources are regularly added to the BioBin. Having a proper carbon to nitrogen ratio is important for organisms breaking down the organic matter. Sometimes this extra carbon comes from pizza boxes from campus events since pizza boxes cannot be recycled because of pizza grease saturation.

Contamination or trash is regularly removed from the BioBin. Trash is accidentally thrown into compost receptacles around dining areas which ultimately makes its way into the BioBin.

“We’re controlling contamination better,” Tolbert said. “We must not feed the worms trash.”

Not all contamination can be removed from the Biobin. Lloyd Barker said that once trash lands on the worm farm it has to be removed by hand and none of it can be recycled.

“We really appreciate whenever the students and dining staff are able to keep their CRV’s and trash out of the compost bin, it saves me and Stacey a lot of time and energy,” Barker said.

A Lumberjack article published nearly one year ago, reported that compost deliveries to the worm farmer had ceased and that all food waste in the BioBin would be sent to the landfill.

Tolbert said that it was true that HSU’s annual contract with the worm farmer had ended last year but deliveries have never stopped. Temporary purchase orders have been used in lieu of a contract.

Katie Koscielak works as a Sustainability Analyst for HSU and said that it’s rare when food waste from the BioBin is sent to a landfill. Koscielak said that it has only happened twice in the past two years.

Tolbert said that BioBin loads are only sent to landfill when weather won’t permit deliveries to the worm farm. During heavy periods of rain a fully loaded BioBin delivery truck has gotten stuck in soft soil while trying to access the farm.

HSU truck with loaded BioBin delivers a load to one of the worm farms operated by Local Worm Guy, Calif. Video from HSU Sustainability Facilities Management.

The HSU sustainability facilities management team said that because of the high volume flow of food waste on campus a rare delivery of a BioBin load to the landfill, determined by weather conditions, is necessary.

Earthtub

Earthtub is an on campus compost receptacle managed by WRRAP. According to WRRAP’s website Earthtub diverts approximately 500 pounds of food waste from the landfill per week.

Diana Orozco is an environmental science and management student who manages compost conditions for Earthtub. Orozco said that Earthtub can hold about three cubic yards of food waste. Unlike the BioBin where worms are eventually used to break down food waste Earthtub uses microbial decomposition.

According to Orozco mobile compost waste buckets are distributed and picked up once a week by operators to 42 locations across campus. Various departments across campus voluntarily opted in to use compost buckets.

Similarly to the BioBin carbon is added to the Earthtub to optimize ratios that favor the decomposition process. Orozco said that the decomposition process takes about three weeks.

After decomposition, compost from Earthtub is available for free for students and staff to use for their gardens. CCAT also uses it in their gardens on campus.

“When you take good care of it you get black gold,” Tolbert said.